Autism#Burnout

Before the DSM-5 (2013) and ICD-11/ICD-11 CDDR (2019/2024){{sfn|ICD-11}}{{Cite web |url=https://www.who.int/publications/i/item/9789240077263 |title=Clinical descriptions and diagnostic requirements for ICD-11 mental, behavioural and neurodevelopmental disorders (CDDR) |website=www.who.int |access-date=2025-01-23}} diagnostic manuals were adopted, autism was found under the diagnostic category pervasive developmental disorder. The previous system relied on a set of closely related and overlapping diagnoses such as Asperger syndrome and the syndrome formerly known as Kanner syndrome. This created unclear boundaries between the terms, so for the DSM-5 and ICD-11, a spectrum approach was taken. The new system is also more restrictive, meaning fewer people qualify for diagnosis.{{Cite journal |last=Sturmey |first=Peter |last2=Dalfern |first2=Samantha |date=2014-12-01 |title=The Effects of DSM5 Autism Diagnostic Criteria on Number of Individuals Diagnosed with Autism Spectrum Disorders: A Systematic Review |url=https://link.springer.com/article/10.1007/s40489-014-0016-7 |journal=Review Journal of Autism and Developmental Disorders |language=en |volume=1 |issue=4 |pages=249–252 |doi=10.1007/s40489-014-0016-7 |issn=2195-7185}}

The DSM-5 and ICD-11 use different categorization tools to define this spectrum. DSM-5 uses a "level" system, which specifies the level of support needed by the person. In this system, level 1 is the mildest form and level 3 the most severe.{{cite web |url=https://www.cdc.gov/ncbddd/autism/hcp-dsm.html |title=Diagnostic Criteria | Autism Spectrum Disorder (ASD) | NCBDDD | CDC |date=2 November 2022 |access-date=21 February 2021 |archive-date=16 August 2019 |archive-url=https://web.archive.org/web/20190816080840/https://www.cdc.gov/ncbddd/autism/hcp-dsm.html |url-status=live}} In contrast, the ICD-11 system uses two separate specifiers, intellectual impairment and language impairment,{{cite web |url=https://icd.who.int/browse11/l-m/en#/http://id.who.int/icd/entity/437815624 |title=ICD-11 for Mortality and Morbidity Statistics |access-date=6 April 2022 |archive-date=1 August 2018 |archive-url=https://archive.today/20180801205234/https://icd.who.int/browse11/l-m/en%23/http://id.who.int/icd/entity/294762853#/http://id.who.int/icd/entity/437815624 |url-status=live}} as these are seen as the most crucial factors.

Autism is currently defined as a highly variable neurodevelopmental disorder{{cite journal |vauthors=Geschwind DH |title=Autism: many genes, common pathways? |journal=Cell |volume=135 |issue=3 |pages=391–395 |date=October 2008 |pmid=18984147 |pmc=2756410 |doi=10.1016/j.cell.2008.10.016}} that is generally thought to cover a broad and deep spectrum, manifesting very differently from one person to another. Some have high support needs, may be nonspeaking, and experience developmental delays; this is more likely with other co-existing diagnoses. Others have relatively low support needs; they may have more typical speech-language and intellectual skills but atypical social/conversation skills, narrowly focused interests, and wordy, pedantic communication.{{cite journal |vauthors=Happé F |year=1999 |title=Understanding assets and deficits in autism: why success is more interesting than failure |url=http://www.thepsychologist.org.uk/archive/archive_home.cfm/volumeID_12-editionID_46-ArticleID_133-getfile_getPDF/thepsychologist/psy_11_99_p540-547_happe.pdf |journal=Psychologist |volume=12 |issue=11 |pages=540–547 |archive-url=https://web.archive.org/web/20120517162434/http://www.thepsychologist.org.uk/archive/archive_home.cfm/volumeID_12-editionID_46-ArticleID_133-getfile_getPDF/thepsychologist/psy_11_99_p540-547_happe.pdf |archive-date=17 May 2012}} They may still require significant support in some areas of their lives. The spectrum model should not be understood as a continuum running from mild to severe, but instead means that autism can present very differently in each person,{{cite journal |vauthors=Wing L |title=The autistic spectrum |language=English |journal=The Lancet |volume=350 |issue=9093 |pages=1761–1766 |date=December 1997 |pmid=9413479 |doi=10.1016/S0140-6736(97)09218-0 |s2cid=7165992}} with support needs depending on context and changing over time.{{cite web |title=Diagnostic criteria – a guide for all audiences |url=https://www.autism.org.uk/advice-and-guidance/topics/diagnosis/diagnostic-criteria/all-audiences |access-date=1 December 2022 |website=National Autistic Society |language=en |archive-date=21 September 2023 |archive-url=https://web.archive.org/web/20230921010739/https://www.autism.org.uk/advice-and-guidance/topics/diagnosis/diagnostic-criteria/all-audiences |url-status=live}}

While the DSM and ICD greatly influence each other, there are also differences. The ICD and the DSM change over time, and there has been collaborative work toward a convergence of the two since 1980 (when DSM-III was published and ICD-9 was current), including efforts to better integrate findings from biological research and a move towards simpler classification systems, while diagnosis continues to rely primarily on behavioral criteria.{{cite news |date=2009 |title=ICD vs. DSM |volume=40 |page=63 |newspaper=APA Monitor |publisher=American Psychological Association |number=9 |url=https://www.apa.org/monitor/2009/10/icd-dsm |access-date=22 October 2021 |archive-date=29 December 2022 |archive-url=https://web.archive.org/web/20221229093045/https://www.apa.org/monitor/2009/10/icd-dsm |url-status=live}}{{cite journal |vauthors=Mezzich JE |date=2002 |title=International surveys on the use of ICD-10 and related diagnostic systems |journal=Psychopathology |volume=35 |issue=2–3 |pages=72–75 |doi=10.1159/000065122 |pmid=12145487 |s2cid=35857872}}{{cite journal |vauthors=Goldberg D |date=January 2010 |title=The classification of mental disorder: a simpler system for DSM–V and ICD–11 |journal=Advances in Psychiatric Treatment |volume=16 |pages=14–19 |doi=10.1192/apt.bp.109.007120 |doi-access=free |number=1}}

As of 2023, empirical and theoretical research highlights how established autism criteria may be ineffective descriptors of autism as a whole, encouraging alternative research approaches, such as going back to autism prototypes, exploring new causal models of autism, or developing transdiagnostic endophenotypes.{{cite journal |last1=Waterhouse |first1=Lynn |last2=Mottron |first2=Laurent |title=Editorial: Is autism a biological entity? |journal=Frontiers in Psychiatry |volume=14 |date=2 May 2023 |doi=10.3389/fpsyt.2023.1180981 |pmid=37200904 |pmc=10185896 |doi-access=free}} There are proposed alternatives to the current disorder-focused spectrum model that deconstruct autism into separate phenomena: (1) a non-pathological spectrum of behavioral traits in the population,{{cite journal |last1=Sarovic |first1=Darko |date=16 November 2021 |title=A Unifying Theory for Autism: The Pathogenetic Triad as a Theoretical Framework |journal=Frontiers in Psychiatry |volume=12 |doi=10.3389/fpsyt.2021.767075 |pmid=34867553 |pmc=8637925 |doi-access=free}}{{cite journal |last1=Chawner |first1=Samuel |date=2 September 2022 |title=Autism: A model of neurodevelopmental diversity informed by genomics |journal=Frontiers in Psychiatry |volume=13 |doi=10.3389/fpsyt.2022.981691 |pmid=36117659 |pmc=9479184 |doi-access=free}} (2) the effect of rare genetic mutations and environmental factors potentially leading to neurodevelopmental and psychological conditions, and (3) individual cognitive ability's role in compensating for neurodivergence.

The World Health Organization's International Classification of Diseases (11th revision), ICD-11, was released in June 2018 and came into full effect as of January 2022.{{cite web |url=https://www.who.int/news/item/18-06-2018-who-releases-new-international-classification-of-diseases-(icd-11) |title=WHO releases new International Classification of Diseases (ICD 11) |website=World Health Organization |type=Press Release |access-date=29 October 2021 |archive-date=25 December 2021 |archive-url=https://web.archive.org/web/20211225230744/https://www.who.int/news/item/18-06-2018-who-releases-new-international-classification-of-diseases-(icd-11) |url-status=live}}{{cite report |vauthors=Pickett D, Anderson RN |title=Status on ICD-11: The WHO Launch |url=https://ncvhs.hhs.gov/wp-content/uploads/2018/08/ICD-11_WHO-v_7-17-2018.pdf |date=18 July 2018 |publisher=CDC/NCHS |access-date=22 October 2021 |archive-date=15 March 2023 |archive-url=https://web.archive.org/web/20230315022814/https://ncvhs.hhs.gov/wp-content/uploads/2018/08/ICD-11_WHO-v_7-17-2018.pdf |url-status=live}} It describes autism spectrum disorder (ASD) as follows:{{sfn|ICD-11}}

{{Blockquote|text=Autism spectrum disorder is characterised by persistent deficits in the ability to initiate and to sustain reciprocal social interaction and social communication, and by a range of restricted, repetitive, and inflexible patterns of behaviour, interests or activities that are clearly atypical or excessive for the individual's age and sociocultural context. The onset of the disorder occurs during the developmental period, typically in early childhood, but symptoms may not become fully manifest until later, when social demands exceed limited capacities. Deficits are sufficiently severe to cause impairment in personal, family, social, educational, occupational or other important areas of functioning and are usually a pervasive feature of the individual's functioning observable in all settings, although they may vary according to social, educational, or other context. Individuals along the spectrum exhibit a full range of intellectual functioning and language abilities.|title=ICD-11|source=chapter 6, section A02}}

ICD-11 was produced by professionals from 55 countries out of the 90 involved and is the most widely used reference worldwide.

The American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR), released in 2022, is the current version of the DSM. It is the predominant mental health diagnostic system used in the United States and Canada, and is often used in Anglophone countries.

Its fifth edition, DSM-5, released in May 2013, was the first to define ASD as a single diagnosis,{{cite Q|Q3064664}} which is still the case in the DSM-5-TR.{{sfn|DSM-5-TR}} ASD encompasses previous diagnoses, including the four traditional diagnoses of autism—classic autism, Asperger syndrome, childhood disintegrative disorder, and pervasive developmental disorder not otherwise specified (PDD-NOS)—and the range of diagnoses that included the word "autism".{{sfn|DSM-5-TR|loc="Autism spectrum disorder encompasses disorders previously referred to as early infantile autism, childhood autism, Kanner's autism, high-functioning autism, atypical autism, pervasive developmental disorder not otherwise specified, childhood disintegrative disorder, and Asperger's disorder"}} Rather than distinguishing among these diagnoses, the DSM-5 and DSM-5-TR adopt a dimensional approach with one diagnostic category for disorders that fall under the autism spectrum umbrella. Within that category, the DSM-5 and the DSM include a framework that differentiates each person by dimensions of symptom severity, as well as by associated features (i.e., the presence of other conditions or factors that likely contribute to the symptoms, other neurodevelopmental or mental conditions, intellectual disability, or language impairment).{{sfn|DSM-5-TR}} The symptom domains are (a) social communication and (b) restricted, repetitive behaviors, and there is the option of specifying a separate severity—the negative effect of the symptoms on the person—for each domain, rather than just overall severity.{{sfn|DSM-5-TR|loc="It may be helpful to note level of support needed for each of the two core psychopathological domains in Table 2 (e.g., 'requiring very substantial support for deficits in social communication and requiring substantial support for restricted, repetitive behaviors')"}} Before the DSM-5, the DSM separated social deficits and communication deficits into two domains.{{cite journal |vauthors=Kulage KM, Smaldone AM, Cohn EG |title=How will DSM-5 affect autism diagnosis? A systematic literature review and meta-analysis |journal=Journal of Autism and Developmental Disorders |volume=44 |issue=8 |pages=1918–1932 |date=August 2014 |pmid=24531932 |doi=10.1007/s10803-014-2065-2 |s2cid=18865395}} Further, the DSM-5 changed to an onset age in the early developmental period, with a note that symptoms may manifest later when social demands exceed capabilities, rather than the previous, more restricted three years of age.{{cite web |title=DSM-5 Diagnostic Criteria |url=https://iacc.hhs.gov/about-iacc/subcommittees/resources/dsm5-diagnostic-criteria.shtml#autism-spectrum-disorder |publisher=U.S. Department of Health & Human Services Interagency Autism Coordinating Committee |access-date=17 May 2017 |archive-date=11 February 2017 |archive-url=https://web.archive.org/web/20170211004905/https://iacc.hhs.gov/about-iacc/subcommittees/resources/dsm5-diagnostic-criteria.shtml#autism-spectrum-disorder |url-status=live}} These changes remain in the DSM-5-TR.{{sfn|DSM-5-TR}}

{{Expand section|date=April 2025}}

A person for whom there is reasonable expectation of autism can undergo assessment to determine whether a formal diagnosis of autism is appropriate to describe the difficulties they are experiencing. Assessment should take into account both the person's reported and directly observed behavior.{{cite journal |vauthors=Baird G, Cass H, Slonims V |date=August 2003 |title=Diagnosis of autism |journal=BMJ |volume=327 |issue=7413 |pages=488–493 |doi=10.1136/bmj.327.7413.488 |pmc=188387 |pmid=12946972}} There are no known biomarkers for autism that allow for a conclusive diagnosis.{{Cite journal |last1=Lord |first1=Catherine |author-link=Catherine Lord (psychologist) |last2=Charman |first2=Tony |last3=Havdahl |first3=Alexandra |last4=Carbone |first4=Paul |last5=Anagnostou |first5=Evdokia |last6=Boyd |first6=Brian |last7=Carr |first7=Themba |last8=de Vries |first8=Petrus J |last9=Dissanayake |first9=Cheryl |author-link9=Cheryl Dissanayake |last10=Divan |first10=Gauri |last11=Freitag |first11=Christine M |last12=Gotelli |first12=Marina M |last13=Kasari |first13=Connie |last14=Knapp |first14=Martin |last15=Mundy |first15=Peter |date=2022 |title=The Lancet Commission on the future of care and clinical research in autism |journal=The Lancet |language=en |volume=399 |issue=10321 |pages=271–334 |doi=10.1016/S0140-6736(21)01541-5 |pmid=34883054 |s2cid=244917920|hdl=11250/2975811 |hdl-access=free }} In most cases, diagnostic criteria are applied from the World Health Organization's ICD-10 or ICD-11, or the American Psychiatric Association's DSM-5. One commonly used assessment tool is the Autism Diagnostic Observation Schedule, which can be used at any age. In children, assessment tools such as these are used in combination with other information, such as parent and teacher reports.{{Cite web |title=Autism diagnostic observation schedule (ADOS) assessment |url=https://bedslutonchildrenshealth.nhs.uk/neurodiversity-support/neurodevelopmental-assessment-and-diagnosis-process/autism-diagnostic-observation-schedule-ados-assessment/ |access-date=2025-04-23 |website=bedslutonchildrenshealth.nhs.uk |language=en-GB}}

According to the DSM-5-TR (2022), to receive a diagnosis of autism spectrum disorder, one must present with "persistent deficits in social communication and social interaction" and "restricted, repetitive patterns of behavior, interests, or activities".{{Cite book |title=Diagnostic and statistical manual of mental disorders: DSM-5-TR |publisher=American Psychiatric Association Publishing |year=2022 |isbn=978-0-89042-575-6 |edition=Fifth edition, text revision. |location=Washington, DC |chapter=Section 2: Neurodevelopmental Disorders |type=Print}} These behaviors must begin in early childhood and affect one's ability to perform everyday tasks. Furthermore, the symptoms must not be fully explainable by intellectual disability or global developmental delay.

Autism is primarily characterized by differences and difficulties in social interaction and communication, alongside restricted or repetitive patterns of interests, activities, and behaviors (stimming), and in many cases distinctive reactions to sensory input. The specific presentation varies widely.{{cite web |url=https://www.canada.ca/en/public-health/services/diseases/autism-spectrum-disorder-asd/signs-symptoms-autism-spectrum-disorder-asd.html |title=What are the signs and symptoms of ASD? |website=Government of Canada |language=en |date=18 January 2016 |access-date=4 November 2021 |archive-date=1 June 2023 |archive-url=https://web.archive.org/web/20230601202634/https://www.canada.ca/en/public-health/services/diseases/autism-spectrum-disorder-asd/signs-symptoms-autism-spectrum-disorder-asd.html |url-status=live}}{{cite web |author= |date=25 March 2020 |title=What is Autism Spectrum Disorder? |url=https://www.cdc.gov/ncbddd/autism/facts.html |archive-url=https://web.archive.org/web/20230921231100/https://www.cdc.gov/ncbddd/autism/facts.html |archive-date=21 September 2023 |access-date=24 October 2021 |website=Centers for Disease Control and Prevention}} For many autistic people, characteristics first appear during infancy or childhood and continue lifelong.{{cite web |year=2007 |title=F84. Pervasive developmental disorders |url=http://apps.who.int/classifications/apps/icd/icd10online/?gf80.htm+f84 |archive-url=https://web.archive.org/web/20130421042448/http://apps.who.int/classifications/apps/icd/icd10online/?gf80.htm%20f84 |archive-date=21 April 2013 |access-date=10 October 2009 |website=ICD-10: International Statistical Classification of Diseases and Related Health Problems: Tenth Revision |publisher=World Health Organization}} Autistic people may be significantly disabled in some respects but average, or even superior, in others.{{cite book |vauthors=Loukusa S |title=Handbook of Pragmatic Language Disorders |veditors=Cummings L |date=2021 |publisher=Springer |location=Cham, Switzerland |isbn=978-3-030-74984-2 |pages=45–78 |doi=10.1007/978-3-030-74985-9_3 |chapter=Autism Spectrum Disorder |s2cid=239160368 |oclc=1269056169}}{{cite book |title=Biopsychology |vauthors=Pinel JP |publisher=Pearson |year=2011 |isbn=978-0-205-03099-6 |edition=8th |location=Boston, Massachusetts |page=235 |oclc=1085798897}}{{cite book |title=Autism Spectrum Disorders |date=2018 |publisher=American Psychiatric Association |chapter=Cognitive Assessment |doi=10.1176/appi.books.9781615371921 |isbn=978-1-61537-192-1 |veditors=Hollander E, Hagerman R, Fein D}}

Clinicians often consider assessment for autism when these types of characteristics are present, especially if they are associated with things such as: difficulties in obtaining or sustaining employment or education; difficulties in initiating or sustaining social relationships; involvement with mental health or learning disability services; or a history of neurodevelopmental conditions (including learning disabilities and ADHD) or mental health conditions{{citation |title=Autism spectrum disorder in adults: diagnosis and management |date=14 June 2021 |url=https://www.nice.org.uk/guidance/cg142 |access-date=24 October 2021 |archive-url=https://web.archive.org/web/20230902193040/https://www.nice.org.uk/guidance/cg142 |archive-date=2 September 2023 |url-status=live |publisher=NICE |id=CG142}}{{cite web |date=18 January 2016 |title=About autism spectrum disorder (ASD) |url=https://www.canada.ca/en/public-health/services/diseases/autism-spectrum-disorder-asd/about-autism-spectrum-disorder-asd.html |url-status=live |archive-url=https://web.archive.org/web/20230326225043/https://www.canada.ca/en/public-health/services/diseases/autism-spectrum-disorder-asd/about-autism-spectrum-disorder-asd.html |archive-date=26 March 2023 |access-date=4 November 2021 |website=Government of Canada |language=en}}

Common signs of autism within the social domain include little or no babbling as an infant{{Cite web |date=2025-02-12 |title=Autism: Signs and characteristics |url=https://www.canada.ca/en/public-health/services/diseases/autism-spectrum-disorder-asd/signs-characteristics.html |url-status=live |archive-url=https://web.archive.org/web/20250430193025/https://www.canada.ca/en/public-health/services/diseases/autism-spectrum-disorder-asd/signs-characteristics.html |archive-date=30 April 2025 |access-date=2025-04-30 |website=www.canada.ca}} as well as limited eye contact;{{Cite web |last=CDC |date=2024-07-19 |title=Signs and Symptoms of Autism Spectrum Disorder |url=https://www.cdc.gov/autism/signs-symptoms/?CDC_AAref_Val=https://www.cdc.gov/ncbddd/autism/signs.html |archive-url=https://web.archive.org/web/20250430193654/https://www.cdc.gov/autism/signs-symptoms/?CDC_AAref_Val=https://www.cdc.gov/ncbddd/autism/signs.html |archive-date=30 April 2025 |access-date=2025-04-30 |website=Autism Spectrum Disorder (ASD) |language=en-us}} language skills developed later (e.g., having a smaller vocabulary than peers or difficulty expressing themselves in words); and less interest in other children or caretakers, possibly with more interest in objects. Difficulty may also be apparent in reciprocal social interactions, such as in games like peek-a-boo or pat-a-cake, as well as in shared attention to objects of interest.

Repetition of words or phrases, including echolalia, as well as repetitive movements (stimming) are commonly found in autistic people. Rigid routines and aversion to change are also common signs, and autistic people often have a very specific area of interest. Other signs include playing with toys in ways that are considered limited or unusual (e.g., lining up toys) and distinctive reactions to smells, textures, sounds, tastes, or appearances.

According to the medical model, autistic people experience impairments in social communication and interaction. The current social criteria for autism diagnosis require people to have difficulties across three social domains: social-emotional reciprocity, nonverbal communication, and developing and sustaining relationships.{{sfn|DSM-5-TR}}

Historically, autistic children were said to be delayed in developing a theory of mind, and the empathizing–systemizing theory has argued that while autistic people have compassion (affective empathy) for others with similar autistic features, they have limited, though not necessarily absent, cognitive empathy.{{cite journal |last1=Baron-Cohen |first1=Simon |last2=Knickmeyer |first2=Rebecca C. |last3=Belmonte |first3=Matthew K. |author1-link=Simon Baron-Cohen |title=Sex differences in the brain: implications for explaining autism |journal=Science |volume=310 |issue=5749 |pages=819–823 |doi = 10.1126/science.1115455 |pmid=16272115 |date=4 November 2005 |bibcode=2005Sci...310..819B |s2cid=44330420 |url=http://docs.autismresearchcentre.com/papers/2005_BC_etal_Science.pdf |access-date=10 September 2023 |archive-date=17 May 2017 |archive-url=https://web.archive.org/web/20170517064851/http://docs.autismresearchcentre.com/papers/2005_BC_etal_Science.pdf |url-status=live}} This may present as social naïvety,{{cite book |vauthors=Klin A, Volkmar FR, Sparrow SS |date=2000 |chapter=Introduction |veditors=Klin A, Volkmar FR, Sparrow SS |title=Asperger syndrome |location=New York |publisher=Guilford Press |pages=1–24 |isbn=1-57230-534-7}} lower than average intuitive perception of the utility or meaning of body language, social reciprocity,{{cite journal |last=Gernsbacher |first=Morton Ann |date=6 August 2017 |title=Editorial Perspective: The use of person-first language in scholarly writing may accentuate stigma |journal=Journal of Child Psychology and Psychiatry |language=en |volume=58 |issue=7 |pages=859–861 |doi=10.1111/jcpp.12706 |pmc=5545113 |pmid=28621486}} or social expectations, including the habitus, social cues, and some aspects of sarcasm,{{cite web |title=DSM-5 Full Text Online |url=http://repository.poltekkes-kaltim.ac.id/657/1/Diagnostic%20and%20statistical%20manual%20of%20mental%20disorders%20_%20DSM-5%20(%20PDFDrive.com%20).pdf |url-status=live |access-date=10 January 2022 |website=Repository Poltekkes Kaltim |archive-url=https://archive.today/20220108082216/http://repository.poltekkes-kaltim.ac.id/657/1/Diagnostic%20and%20statistical%20manual%20of%20mental%20disorders%20_%20DSM-5%20(%20PDFDrive.com%20).pdf |archive-date=8 January 2022}} which to some degree may also be due to co-occurring alexithymia.{{cite book |vauthors=Hogeveen J, Grafman J |title=Disorders of Emotion in Neurologic Disease |chapter=Alexithymia |series=Handbook of Clinical Neurology |volume=183 |pages=47–62 |date=2021 |pmid=34389125 |pmc=8456171 |doi=10.1016/b978-0-12-822290-4.00004-9 |publisher=Elsevier |isbn=978-0-12-822290-4}} But recent research has increasingly questioned these findings,{{Cite journal |last1=Long |first1=Emily L. |last2=Catmur |first2=Caroline |last3=Bird |first3=Geoffrey |date=2025-01-09 |title=The theory of mind hypothesis of autism: A critical evaluation of the status quo. |url=https://psycnet.apa.org/fulltext/2025-63789-001.html |journal=Psychological Review |language=English |doi=10.1037/rev0000532 |pmid=39786849 |issn=1939-1471 |archive-url=http://web.archive.org/web/20250416051244/https://psycnet.apa.org/fulltext/2025-63789-001.html |archive-date=2025-04-16}} as the "double empathy problem" theory (2012) argues that there is a lack of mutual understanding and empathy between both non-autistic and autistic individuals.{{cite journal |last=Milton |first=Damian E. M. |date=October 2012 |title=On the ontological status of autism: the 'double empathy problem' |url=http://www.tandfonline.com/doi/abs/10.1080/09687599.2012.710008 |journal=Disability & Society |language=en |volume=27 |issue=6 |pages=883–887 |doi=10.1080/09687599.2012.710008 |issn=0968-7599 |s2cid=54047060 |access-date=22 November 2023 |archive-date=8 March 2023 |archive-url=https://web.archive.org/web/20230308062210/https://www.tandfonline.com/doi/abs/10.1080/09687599.2012.710008 |url-status=live }}{{cite journal |last1=Milton |first1=Damian |last2=Gurbuz |first2=Emine |last3=López |first3=Beatriz |date=November 2022 |title=The 'double empathy problem': Ten years on |url=http://journals.sagepub.com/doi/10.1177/13623613221129123 |journal=Autism |language=en |volume=26 |issue=8 |pages=1901–1903 |doi=10.1177/13623613221129123 |pmid=36263746 |s2cid=253020669 |issn=1362-3613 |access-date=25 February 2023 |archive-date=25 February 2023 |archive-url=https://web.archive.org/web/20230225135833/https://journals.sagepub.com/doi/10.1177/13623613221129123 |url-status=live}}{{cite journal |title=Double Empathy: Why Autistic People Are Often Misunderstood |year=2021 |language=en |doi=10.3389/frym.2021.554875|doi-access=free |last1=Crompton |first1=Catherine J. |last2=Debrabander |first2=Kilee |last3=Heasman |first3=Brett |last4=Milton |first4=Damian |last5=Sasson |first5=Noah J. |journal=Frontiers for Young Minds |volume=9|hdl=20.500.11820/94ee032a-6103-470a-bc06-08337dd6b512 |hdl-access=free }}{{cite journal |last1=Sasson |first1=Noah J. |last2=Faso |first2=Daniel J. |last3=Nugent |first3=Jack |last4=Lovell |first4=Sarah |last5=Kennedy |first5=Daniel P. |last6=Grossman |first6=Ruth B. |date=1 February 2017 |title=Neurotypical Peers are Less Willing to Interact with Those with Autism based on Thin Slice Judgments |journal=Scientific Reports |language=en |volume=7 |issue=1 |page=40700 |bibcode=2017NatSR...740700S |doi=10.1038/srep40700 |issn=2045-2322 |pmc=5286449 |pmid=28145411}}{{cite journal |vauthors=Hamilton AF |title=Goals, intentions and mental states: challenges for theories of autism |journal=Journal of Child Psychology and Psychiatry |volume=50 |issue=8 |pages=881–92 |year=2009 |pmid=19508497 |doi=10.1111/j.1469-7610.2009.02098.x |citeseerx=10.1.1.621.6275}}

File:Double empathy problem image.jpg

Thus there has been a recent shift to acknowledge that autistic people may simply respond and behave differently than non-autistic people. So far, research has identified two unconventional features by which autistic people create shared understanding (intersubjectivity): "a generous assumption of common ground that, when understood, led to rapid rapport, and, when not understood, resulted in potentially disruptive utterances; and a low demand for coordination that ameliorated many challenges associated with disruptive turns". Autistic interests, and thus conversational topics, seem to be largely driven by an intense interest in specific topics (monotropism).{{cite journal |first1=Rachel |last1=Grove |first2=Rosa A |last2=Hoekstra |first3=Marlies |last3=Wierda |first4=Sander |last4=Begeer |date=20 May 2020 |title=Special interests and subjective wellbeing in autistic adults |journal=Autism Research |language=en |volume=11 |issue=5 |pages=766–775 |doi=10.1002/aur.1931 |pmid=29427546 |hdl=1871.1/d5c70844-3d23-4e71-8c5d-82533196b003 |s2cid=205456773 |url=https://research.vu.nl/en/publications/d5c70844-3d23-4e71-8c5d-82533196b003 |hdl-access=free}}{{cite journal |first1=Dinah |last1=Murray |first2=Mike |last2=Lesser |first3=Wendy |last3=Lawson |date=May 2005 |title=Attention, monotropism and the diagnostic criteria for autism |journal=Autism Research |language=en |volume=9 |issue=2 |pages=139–156 |doi=10.1177/1362361305051398 |pmid=15857859 |s2cid=6476917 |doi-access=free}} A recent study found that autistic–autistic interactions are as effective in information transfer as interactions between non-autistics are, and that communication breaks down only between autistics and non-autistics.{{cite journal |last=Crompton |first=Catherine J |date=20 May 2020 |title=Autistic peer-to-peer information transfer is highly effective |journal=Autism |language=en |volume=24 |issue=7 |pages=1704–1712 |doi=10.1177/1362361320919286 |pmid=32431157 |pmc=7545656}}{{cite journal |last1=Heasman |first1=Brett |last2=Alex |first2=Gillespie |title=Neurodivergent intersubjectivity: Distinctive features of how autistic people create shared understanding |url=https://eprints.lse.ac.uk/90098/1/Heasman_Neurodivergent-intersubjectivity_Published.pdf |journal=Autism |date=2019 |language=en |volume=23 |issue=4 |pages=910–921 |doi=10.1177/1362361318785172 |pmid=30073872 |pmc=6512057 |access-date=22 November 2023 |archive-date=16 November 2023 |archive-url=https://web.archive.org/web/20231116225321/https://eprints.lse.ac.uk/90098/1/Heasman_Neurodivergent-intersubjectivity_Published.pdf |url-status=live }}

Autistic people display atypical nonverbal behaviors or show differences in nonverbal communication. They may make infrequent eye contact, even when called by name, or avoid it altogether. This may be due to the high amount of sensory input received when making eye contact.{{Cite journal |last1=Trevisan |first1=Dominic A. |last2=Roberts |first2=Nicole |last3=Lin |first3=Cathy |last4=Birmingham |first4=Elina |date=28 November 2017 |title=How do adults and teens with self-declared Autism Spectrum Disorder experience eye contact? A qualitative analysis of first-hand accounts |journal=PLOS ONE |language=en |volume=12 |issue=11 |pages=e0188446 |doi=10.1371/journal.pone.0188446 |doi-access=free |pmid=29182643 |pmc=5705114 |bibcode=2017PLoSO..1288446T |issn=1932-6203}} Autistic people often recognize fewer emotions and their meaning from others' facial expressions, and may not respond with facial expressions expected by their non-autistic peers.{{cite web |title=Autism: Overview |url=https://www.asha.org/Practice-Portal/Clinical-Topics/Autism/ |publisher=American Speech-Language-Hearing Association |access-date=17 December 2017 |archive-date=23 April 2019 |archive-url=https://web.archive.org/web/20190423134030/https://www.asha.org/Practice-Portal/Clinical-Topics/Autism/ |url-status=live}}{{cite web |date=18 August 2015 |title=Autism Spectrum Disorder: Communication Problems in Children |url=https://www.nidcd.nih.gov/health/autism-spectrum-disorder-communication-problems-children |access-date=17 December 2017 |website=NIDCD |archive-date=22 December 2017 |archive-url=https://web.archive.org/web/20171222090623/https://www.nidcd.nih.gov/health/autism-spectrum-disorder-communication-problems-children |url-status=live}} Temple Grandin, an autistic woman involved in autism activism, described her inability to understand neurotypicals' social communication as leaving her feeling "like an anthropologist on Mars".{{cite news |last1=Cohen |first1=David |last2=Grandin |first2=Temple |author2-link=Temple Grandin |title=Temple Grandin: 'I'm an anthropologist from Mars' |url=https://www.theguardian.com/education/2005/oct/25/highereducationprofile.academicexperts |access-date=6 July 2022 |work=The Guardian |issn=0261-3077 |eissn=1756-3224 |oclc=60623878 |location=Kings Place, London |publisher=Scott Trust |date=25 October 2005 |archive-url=https://web.archive.org/web/20131109145205/https://www.theguardian.com/education/2005/oct/25/highereducationprofile.academicexperts |archive-date=9 November 2013}} Autistic people struggle to understand the social context and subtext of neurotypical conversational or printed situations, and form different conclusions about the content.{{cite web |title=Social communication and language characteristics associated with high-functioning, verbal children and adults with autism spectrum disorder |url=https://www.iidc.indiana.edu/pages/Social-Communication-and-Language-Characteristics-Associated-with-High-Functioning-Verbal-Children-and-Adults-with-ASD |url-status=live |archive-url=https://web.archive.org/web/20181214181341/https://www.iidc.indiana.edu/pages/Social-Communication-and-Language-Characteristics-Associated-with-High-Functioning-Verbal-Children-and-Adults-with-ASD |archive-date=14 December 2018 |access-date=17 December 2017 |publisher=Indiana Resource Center for Autism |vauthors=Vicker B}} Autistic people may not control the volume of their voice in different social settings. At least half of autistic children have atypical prosody.{{cite journal |vauthors=Fusaroli R, Lambrechts A, Bang D, Bowler DM, Gaigg SB |date=March 2017 |title=Is voice a marker for Autism spectrum disorder? A systematic review and meta-analysis |url=https://pure.au.dk/ws/files/101709535/046565.full.pdf |journal=Autism Research |volume=10 |issue=3 |pages=384–407 |doi=10.1002/aur.1678 |pmid=27501063 |s2cid=13772771 |access-date=27 March 2020 |archive-date=20 March 2021 |archive-url=https://web.archive.org/web/20210320203509/https://pure.au.dk/ws/files/101709535/046565.full.pdf |url-status=live}}

What may look like self-involvement or indifference to non-autistic people stems from autistic differences in recognizing other people's personalities, perspectives, and interests.{{cite book |url=https://archive.org/details/understandingwor00laws_352 |title=Understanding and Working With the Spectrum of Autism: An Insider's View |vauthors=Lawson W |publisher=Jessica Kingsley Publishers |year=2001 |isbn=978-1-85302-971-4 |location=London UK, & Philadelphia PA |pages=[https://archive.org/details/understandingwor00laws_352/page/n33 33] |url-access=limited}} Most published research focuses on the interpersonal relationship difficulties between autistic people and their non-autistic counterparts and how to solve them through teaching neurotypical social skills, but newer research has also evaluated what autistic people want from friendships, such as a sense of belonging and benefits to mental health.{{cite journal |last1=Finke |first1=Erinn |date=16 May 2022 |title=The Kind of Friend I Think I Am: Perceptions of Autistic and Non‑autistic Young Adults |journal=Journal of Autism and Developmental Disorders |language=en |volume=53 |issue=8 |pages=3047–3064 |doi=10.1007/s10803-022-05573-4 |pmid=35570241 |s2cid=248812844 |url=https://www.researchgate.net/publication/360622541 |access-date=23 November 2023 |archive-date=6 March 2024 |archive-url=https://web.archive.org/web/20240306230604/https://www.researchgate.net/publication/360622541_The_Kind_of_Friend_I_Think_I_Am_Perceptions_of_Autistic_and_Non-autistic_Young_Adults |url-status=live }}{{cite journal |last1=O'Connor |first1=Rachel A G |first2=Neeltje |last2=van den Bedem |first3=Els M A |last3=Blijd-Hoogewys |first4=Lex |last4=Stockmann |first5=Carolien |last5=Rieffe |title=Friendship quality among autistic and non-autistic (pre-) adolescents: Protective or risk factor for mental health? |journal=Autism |date=22 January 2022 |language=en |volume=26 |issue=8 |pages=2041–2051 |doi=10.1177/13623613211073448 |pmid=35068188 |pmc=9597130}} Children on the autism spectrum are more frequently involved in bullying situations than their non-autistic peers, and predominantly experience bullying as victims rather than perpetrators or victim-perpetrators, especially after controlling for co-occurring psychopathology.{{cite journal |first1=Eeske |last1=van Roekel |first2=Ron H. J. |last2=Scholte |first3=Robert |last3=Didden |date=2010 |title=Bullying Among Adolescents With Autism Spectrum Disorders: Prevalence and Perception |journal=Journal of Autism and Developmental Disorders |volume=40 |issue=1 |pages=63–73 |doi=10.1016/j.pcl.2007.02.011 |pmid=17543905 |s2cid=13615727 |doi-access=free|pmc=2809311 }} Prioritizing dependability and intimacy in friendships during adolescence, coupled with lower friendship quantity and quality, often leads to increased loneliness in autistic people.{{cite journal |last1=O'Connor |first1=Rachel A G |first2=Neeltje |last2=van den Bedem |first3=Els M A |last3=Blijd-Hoogewys |first4=Lex |last4=Stockmann |first5=Carolien |last5=Rieffe |title=Sex differences in friendships and loneliness in autistic and non-autistic children across development |journal=Molecular Autism |date=November 2022 |language=en |volume=4 |issue=9 |page=9 |doi=10.1186/s13229-023-00542-9 |pmid=36829214 |pmc=9960478 |doi-access=free}} As they progress through life, autistic people observe and form models of social patterns, and develop coping mechanisms, some of which are referred to as "masking".{{cite journal |last1=Pearson |first1=Amy |last2=Rose |first2=Kieran |date=1 March 2021 |title=A Conceptual Analysis of Autistic Masking: Understanding the Narrative of Stigma and the Illusion of Choice |journal=Autism in Adulthood |volume=3 |issue=1 |pages=52–60 |doi=10.1089/aut.2020.0043 |issn=2573-9581 |pmc=8992880 |pmid=36601266}}{{cite journal |last1=Petrolini |first1=Valentina |last2=Rodríguez-Armendariz |first2=Ekaine |last3=Vicente |first3=Agustín |date=2023 |title=Autistic camouflaging across the spectrum |journal=New Ideas in Psychology |language=en |volume=68 |page=100992 |doi=10.1016/j.newideapsych.2022.100992 |hdl=10810/59712 |s2cid=253316582 |doi-access=free|hdl-access=free }}

File:Autistic-sweetiepie-boy-with-ducksinarow.jpg

The second core feature of autism is a pattern of restricted and repetitive behaviors, activities, and interests. To be diagnosed with autism under the DSM-5-TR, a person must have at least two of the following behaviors:{{sfn|DSM-5-TR}}{{cite journal |vauthors=Lord C, Elsabbagh M, Baird G, Veenstra-Vanderweele J |date=August 2018 |title=Autism spectrum disorder |journal=The Lancet |volume=392 |issue=10146 |pages=508–520 |doi=10.1016/S0140-6736(18)31129-2 |pmc=7398158 |pmid=30078460 |s2cid=51922565}}

File:James arranging brads.jpg on a cork coaster]]

• Repetitive behaviors: repetitive behaviors such as rocking, hand flapping, finger flicking, head banging, or repeating phrases or sounds.{{cite web |url=https://www.uptodate.com/contents/autism-spectrum-disorder-clinical-features |title=Autism spectrum disorder: Clinical features |vauthors=Augustyn M |website=UpToDate |access-date=22 March 2020 |archive-date=7 November 2022 |archive-url=https://web.archive.org/web/20221107065340/https://www.uptodate.com/contents/autism-spectrum-disorder-clinical-features |url-status=live}} These behaviors may occur constantly or only when the person is stressed, anxious, or upset. They are also known as stimming.
• Resistance to change: strict adherence to routines such as eating certain foods in a specific order or taking the same path to school every day. The person may become distressed if their routine changes or is disrupted.
• Restricted interests: intense interest in a particular activity, topic, or hobby, and devoting all one's attention to it. For example, young children might completely focus on things that spin and ignore everything else. Older children might try to learn everything about a single topic, such as the weather or sports, and perseverate or talk about it constantly.
• Sensory reactivity: an unusual reaction to certain sensory inputs, such as aversion to specific sounds or textures, fascination with lights or movements, or apparent indifference to pain or heat.{{sfn|DSM-5-TR|loc="Hyper- or hyporeactivity to sensory input or unusual interest in sensory aspects of the environment (e.g., apparent indifference to pain/temperature, adverse response to specific sounds or textures, excessive smelling or touching of objects, visual fascination with lights or movement)"}}

It is increasingly argued that these characteristics should be accepted, which is supported by their recognized functions, such as self-regulation.{{Cite journal |last1=Kapp |first1=Steven K |last2=Steward |first2=Robyn |last3=Crane |first3=Laura |last4=Elliott |first4=Daisy |last5=Elphick |first5=Chris |last6=Pellicano |first6=Elizabeth |last7=Russell |first7=Ginny |date=2019-10-01 |title='People should be allowed to do what they like': Autistic adults' views and experiences of stimming |journal=Autism |language=EN |volume=23 |issue=7 |pages=1782–1792 |doi=10.1177/1362361319829628 |issn=1362-3613 |pmc=6728747 |pmid=30818970}}{{Cite journal |last1=Lung |first1=Stephanie Lock Man |last2=Picard |first2=Ève |last3=Soulières |first3=Isabelle |last4=Bertone |first4=Armando |date=2024-09-01 |title=Identifying the functions of restricted and repetitive behaviours and interests in Autism: A scoping review. |url=https://www.sciencedirect.com/science/article/pii/S1750946724001338 |journal=Research in Autism Spectrum Disorders |volume=117 |page=102458 |doi=10.1016/j.rasd.2024.102458 |issn=1750-9467}} Focused interests can also offer significant personal fulfillment and foster the development of specialized knowledge.{{Cite book |last1=Henderson |first1=Donna A. |title=Is this autism? a guide for clinicians and everyone else |last2=Wayland |first2=Sarah C. |last3=White |first3=Jamell |date=2023 |publisher=Routledge, Taylor & Francis Group |isbn=978-1-003-24213-0 |location=New York |pages=134–149 |chapter=Intense or atypical interests}} A crucial distinction must be made between these features and those of obsessive-compulsive disorder, which can co-occur with autism and involves distressing compulsions or obsessions aimed at preventing feared negative events.{{Cite book |last1=Henderson |first1=Donna A. |title=Is this autism? a guide for clinicians and everyone else |last2=Wayland |first2=Sarah C. |last3=White |first3=Jamell |date=2023 |publisher=Routledge, Taylor & Francis Group |isbn=978-1-003-24213-0 |location=New York |pages=178–179}}

File:SpeechWatch - First wearable AAC speech device from Gus Communication Devices (2021).png for non-speaking or minimally speaking autistic people]]

Differences in verbal communication begin to be noticeable in childhood, as many autistic children develop language skills at an uneven pace. Verbal communication may be developed later or never (non-speaking autism), while reading ability may be present before school age (hyperlexia). Less joint attention seems to distinguish autistic from non-autistic infants.{{cite journal |vauthors=Johnson CP, Myers SM |date=November 2007 |title=Identification and evaluation of children with autism spectrum disorders |journal=Pediatrics |volume=120 |issue=5 |pages=1183–1215 |doi=10.1542/peds.2007-2361 |pmid=17967920 |doi-access=free}} Infants may show later onset of babbling, unusual gestures, lower responsiveness, and vocal patterns that are not synchronized with the caregiver. In their second and third years, autistic children may have less frequent and less diverse babbling, consonants, words, and word combinations, and their gestures may be less often integrated with words. Autistic children are less likely to make requests or share experiences and more likely to simply repeat others' words (echolalia).{{cite journal |vauthors=Tager-Flusberg H, Caronna E |date=June 2007 |title=Language disorders: autism and other pervasive developmental disorders |journal=Pediatric Clinics of North America |volume=54 |issue=3 |pages=469–81, vi |doi=10.1016/j.pcl.2007.02.011 |pmid=17543905 |s2cid=13615727}} The CDC estimated in 2015 that around 40% of autistic children do not speak at all.{{Update inline|date=April 2025|reason=Percentage is lower now}}{{cite web |url=https://www.cdc.gov/ncbddd/autism/signs.html |title=Signs & Symptoms: Autism Spectrum Disorder |date=26 February 2015 |author=National Center on Birth Defects and Developmental Disabilities |website=Centers for Disease Control and Prevention |archive-url=https://web.archive.org/web/20150310030922/https://www.cdc.gov/ncbddd/autism/signs.html |archive-date=10 March 2015}} (Also available in Spanish.) Autistic adults' verbal communication skills largely depend on when and how well speech is acquired during childhood.{{cite journal |first1=Vanessa H. |last1=Bal |first2=So-Hyun |last2=Kim |first3=Megan |last3=Fok |first4=Catherine |last4=Lord |date=12 August 2018 |title=Autism Spectrum Disorder symptoms from 2 to 19: Implications for diagnosing adolescents and young adults |journal=Autism Research |language=en |volume=12 |issue=1 |pages=89–99 |doi=10.1002/aur.2004 |pmc=6600818 |pmid=30101492}}

Self-injurious behavior (SIB) is approximately three times more likely in autistic people than non-autistic people.{{Cite journal |last1=Blanchard |first1=Ashley |last2=Chihuri |first2=Stanford |last3=DiGuiseppi |first3=Carolyn G. |last4=Li |first4=Guohua |date=2021-10-01 |title=Risk of Self-harm in Children and Adults With Autism Spectrum Disorder: A Systematic Review and Meta-analysis |journal=JAMA Network Open |volume=4 |issue=10 |pages=e2130272 |doi=10.1001/jamanetworkopen.2021.30272 |issn=2574-3805 |pmc=8527356 |pmid=34665237}} These behaviors encompass actions like head-banging, hand-biting, and skin-picking, and can lead to serious injury or, in rare cases, death.{{cite journal |vauthors=Minshawi NF, Hurwitz S, Fodstad JC, Biebl S, Morriss DH, McDougle CJ |date=April 2014 |title=The association between self-injurious behaviors and autism spectrum disorders |journal=Psychology Research and Behavior Management |volume=7 |pages=125–36 |doi=10.2147/PRBM.S44635 |pmc=3990505 |pmid=24748827 |doi-access=free}} Multiple theories explore the development and persistence of SIB within developmental conditions, including autism.{{cite journal |vauthors=Oliver C, Richards C |date=October 2015 |title=Practitioner Review: Self-injurious behaviour in children with developmental delay |url=http://pure-oai.bham.ac.uk/ws/files/26880648/Oliver_Richards_2015_Self_injurious_behaviour_children_dev._delay_JCPP.pdf |url-status=live |journal=Journal of Child Psychology and Psychiatry |type=Review |volume=56 |issue=10 |pages=1042–54 |doi=10.1111/jcpp.12425 |pmid=25916173 |s2cid=206034400 |archive-url=https://web.archive.org/web/20230812175509/http://pure-oai.bham.ac.uk/ws/files/26880648/Oliver_Richards_2015_Self_injurious_behaviour_children_dev._delay_JCPP.pdf |archive-date=12 August 2023 |access-date=25 August 2020}} Explanations include communication difficulties, leading individuals to use self-injury as a way to express needs, distress, or other messages to caregivers or others.{{Cite journal |last1=Minshawi |first1=Noha F. |last2=Hurwitz |first2=Sarah |last3=Fodstad |first3=Jill C. |last4=Biebl |first4=Sara |last5=Morriss |first5=Danielle H. |last6=McDougle |first6=Christopher J. |date=2014 |title=The association between self-injurious behaviors and autism spectrum disorders |journal=Psychology Research and Behavior Management |volume=7 |pages=125–136 |doi=10.2147/PRBM.S44635 |doi-access=free |issn=1179-1578 |pmc=3990505 |pmid=24748827}} Additionally, SIB may be linked to efforts to regulate sensory input{{Cite journal |last1=Summers |first1=Jane |last2=Shahrami |first2=Ali |last3=Cali |first3=Stefanie |last4=D'Mello |first4=Chantelle |last5=Kako |first5=Milena |last6=Palikucin-Reljin |first6=Andjelka |last7=Savage |first7=Melissa |last8=Shaw |first8=Olivia |last9=Lunsky |first9=Yona |date=2017-10-26 |title=Self-Injury in Autism Spectrum Disorder and Intellectual Disability: Exploring the Role of Reactivity to Pain and Sensory Input |journal=Brain Sciences |volume=7 |issue=11 |page=140 |doi=10.3390/brainsci7110140 |doi-access=free |issn=2076-3425 |pmc=5704147 |pmid=29072583}} or modulate pain perception, particularly for those experiencing chronic discomfort or medical conditions. Neurological factors are also under investigation, with anomalies in basal ganglia connectivity suggested as a potential biological predisposition in some autistic individuals.

Other risk factors for self-harm and also for suicidality include circumstances that could affect anyone, such as mental health problems (e.g., anxiety disorder) and social problems (e.g., unemployment and social isolation). In addition, there are autism-specific factors such as exhausting attempts to behave like a neurotypical person to avoid stigma and negative reactions of neurotypical society towards autistic people (masking).{{Cite journal |last1=Newell |first1=Victoria |last2=Phillips |first2=Lucy |last3=Jones |first3=Chris |last4=Townsend |first4=Ellen |last5=Richards |first5=Caroline |last6=Cassidy |first6=Sarah |date=2023-03-15 |title=A systematic review and meta-analysis of suicidality in autistic and possibly autistic people without co-occurring intellectual disability |journal=Molecular Autism |volume=14 |issue=1 |page=12 |doi=10.1186/s13229-023-00544-7 |issn=2040-2392 |pmc=10018918 |pmid=36922899 |doi-access=free}} Autistic people are also at significantly increased risk of victimization, including bullying, sexual assault, and other forms of criminal abuse.{{Cite journal |last1=Trundle |first1=Grace |last2=Jones |first2=Katy A. |last3=Ropar |first3=Danielle |last4=Egan |first4=Vincent |date=October 2023 |title=Prevalence of Victimisation in Autistic Individuals: A Systematic Review and Meta-Analysis |journal=Trauma, Violence & Abuse |volume=24 |issue=4 |pages=2282–2296 |doi=10.1177/15248380221093689 |issn=1552-8324 |pmc=10486169 |pmid=35524162}} Approximately 8 in 10 autistic people have a mental health problem in their lifetime, in comparison to 1 in 4 of the general population.{{cite web |date=14 March 2024 |title=Depression and autism |url=https://www.autistica.org.uk/what-is-autism/depression-and-autism |access-date=23 January 2025 |website=Autistica}}{{cite web |date=7 March 2024 |title=Suicide and autism |url=https://www.autistica.org.uk/what-is-autism/suicide-and-autism |archive-url=https://web.archive.org/web/20250308021617/https://www.autistica.org.uk/what-is-autism/suicide-and-autism |archive-date=8 March 2025 |access-date=23 January 2025 |website=Autistica}}{{cite journal |last1=Lever |first1=Anne |last2=Hilde |first2=Geurts |date=2016 |title=Psychiatric Co-occurring Symptoms and Disorders in Young, Middle-Aged, and Older Adults with Autism Spectrum Disorder |journal=Journal of Autism and Developmental Disorders |volume=46 |issue=6 |pages=1916–1930 |doi=10.1007/s10803-016-2722-8 |pmc=4860203 |pmid=26861713}} A 2019 meta-analysis found autistic people to be four times more likely to have depression than non-autistic people, with approximately 40% of autistic adults having depression.{{cite journal |last1=Hudson |first1=Chloe C |last2=Hall |first2=Layla |last3=Harkness |first3=Kate L |date=2019 |title=Prevalence of Depressive Disorders in Individuals with Autism Spectrum Disorder: a Meta-Analysis |journal=Journal of Abnormal Child Psychology |volume=47 |issue=1 |pages=165–175 |doi=10.1007/s10802-018-0402-1 |pmid=29497980}}

Rates of suicidality vary significantly depending upon what is being measured.{{Cite journal |last1=Newell |first1=Victoria |last2=Phillips |first2=Lucy |last3=Jones |first3=Chris |last4=Townsend |first4=Ellen |last5=Richards |first5=Caroline |last6=Cassidy |first6=Sarah |date=2023-03-15 |title=A systematic review and meta-analysis of suicidality in autistic and possibly autistic people without co-occurring intellectual disability |journal=Molecular Autism |volume=14 |issue=1 |page=12 |doi=10.1186/s13229-023-00544-7 |issn=2040-2392 |pmc=10018918 |pmid=36922899 |doi-access=free}} This is partly because questionnaires developed for neurotypical subjects are not always valid for autistic people. As of 2023, the Suicidal Behaviours Questionnaire–Autism Spectrum Conditions (SBQ-ASC) is the only test validated for autistic people. According to some estimates, about a quarter of autistic youth{{Cite journal |last1=O'Halloran |first1=L. |last2=Coey |first2=P. |last3=Wilson |first3=C. |date=April 2022 |title=Suicidality in autistic youth: A systematic review and meta-analysis |journal=Clinical Psychology Review |volume=93 |page=102144 |doi=10.1016/j.cpr.2022.102144 |issn=1873-7811 |pmid=35290800|doi-access=free}} and a third of all autistic people{{Cite journal |last1=Huntjens |first1=Anne |last2=Landlust |first2=Annemiek |last3=Wissenburg |first3=Sophie |last4=van der Gaag |first4=Mark |date=March 2024 |title=The Prevalence of Suicidal Behavior in Autism Spectrum Disorder |journal=Crisis |volume=45 |issue=2 |pages=144–153 |doi=10.1027/0227-5910/a000922 |issn=2151-2396 |pmid=37668055|hdl=1871.1/2e96e0d9-7230-421a-bb77-834a9c4ae2bb |url=https://pure.rug.nl/ws/files/877687272/retrieve_1_.pdf |hdl-access=free }} have experienced suicidal ideation at some point. Autistic people are about three times as likely as non-autistic people to make a suicide attempt.{{Cite journal |last1=Blanchard |first1=Ashley |last2=Chihuri |first2=Stanford |last3=DiGuiseppi |first3=Carolyn G. |last4=Li |first4=Guohua |date=2021-10-01 |title=Risk of Self-harm in Children and Adults With Autism Spectrum Disorder: A Systematic Review and Meta-analysis |journal=JAMA Network Open |volume=4 |issue=10 |pages=e2130272 |doi=10.1001/jamanetworkopen.2021.30272 |issn=2574-3805 |pmc=8527356 |pmid=34665237}}{{Cite journal |last1=Santomauro |first1=Damian F. |last2=Hedley |first2=Darren |last3=Sahin |first3=Ensu |last4=Brugha |first4=Traolach S. |last5=Naghavi |first5=Mohsen |last6=Vos |first6=Theo |last7=Whiteford |first7=Harvey A. |last8=Ferrari |first8=Alize J. |last9=Stokes |first9=Mark A. |date=November 2024 |title=The global burden of suicide mortality among people on the autism spectrum: A systematic review, meta-analysis, and extension of estimates from the Global Burden of Disease Study 2021 |journal=Psychiatry Research |volume=341 |page=116150 |pmid=39197224 |doi=10.1016/j.psychres.2024.116150 |issn=1872-7123}} Almost 10% of autistic youth and 15% to 25% of autistic adults have attempted suicide. Rates of suicide attempts and suicidal ideation are the same for people formally diagnosed with autism and people who have typical intelligence and are believed to be autistic but have not been diagnosed. A study found the suicide rate for verbal autistics to be nine times that of the general population.{{Cite journal |last1=Kirby |first1=Anne V. |last2=Bakian |first2=Amanda V. |last3=Zhang |first3=Yue |last4=Bilder |first4=Deborah A. |last5=Keeshin |first5=Brooks R. |last6=Coon |first6=Hilary |date=2019 |title=A 20-year study of suicide death in a statewide autism population |journal=Autism Research: Official Journal of the International Society for Autism Research |volume=12 |issue=4 |pages=658–666 |doi=10.1002/aur.2076 |issn=1939-3806 |pmc=6457664 |pmid=30663277}} The suicide risk is lower among cisgender autistic males and autistic people with intellectual disabilities.

{{Main|Autistic burnout|Autistic meltdown}}

Autistic people identify a subset of burnout that interacts uniquely with characteristics and experiences of autism. This burnout is termed autistic burnout. It is a prolonged state of exhaustion that results in reduced social and occupational skill capacity and quality of life.{{Cite journal |title=Confirming the nature of autistic burnout |first1=Samuel RC |last1=Arnold |first2=Julianne M |last2=Higgins |first3=Janelle |last3=Weise |first4=Aishani |last4=Desai |first5=Elizabeth |last5=Pellicano |first6=Julian N |last6=Trollor |date=10 October 2023 |journal=Autism |volume=27 |issue=7 |pages=1906–1918 |doi=10.1177/13623613221147410 |pmid=36637293 |url=https://discovery.ucl.ac.uk/id/eprint/10163509/}} Academic and clinical research has begun on the ways in which autistic burnout is experienced.{{Cite journal |title="Having All of Your Internal Resources Exhausted Beyond Measure and Being Left with No Clean-Up Crew": Defining Autistic Burnout |first1=Dora M. |last1=Raymaker |first2=Alan R. |last2=Teo |first3=Nicole A. |last3=Steckler |first4=Brandy |last4=Lentz |first5=Mirah |last5=Scharer |first6=Austin |last6=Delos Santos |first7=Steven K. |last7=Kapp |first8=Morrigan |last8=Hunter |first9=Andee |last9=Joyce |first10=Christina |last10=Nicolaidis |date=1 June 2020 |journal=Autism in Adulthood: Challenges and Management |volume=2 |issue=2 |pages=132–143 |doi=10.1089/aut.2019.0079 |pmid=32851204 |pmc=7313636}}

Autistic people have said that autistic burnout can occur repeatedly, have cognitive and physical effects, be misunderstood by medical professionals, and adversely affect life goals in extended cases. But autistic burnout is often cited by autistic people as a catalyst for autism diagnosis or improved self-care and well-being strategies. In particular, autistic people have anecdotally identified patterns of factors that lead to burnout.{{cite web |url=https://www.autismparentingmagazine.com/burnout-autism-prevention-causes/ |title=Autistic Burnout: Causes and Prevention Tips |date=13 September 2022 |archive-url=https://web.archive.org/web/20250323111605/https://www.autismparentingmagazine.com/burnout-autism-prevention-causes/ |archive-date=23 March 2025}} Autistic people can also derive support from community members by sharing mitigating and coping strategies.{{Cite journal |title=What Is Autistic Burnout? A Thematic Analysis of Posts on Two Online Platforms |first1=Jane |last1=Mantzalas |first2=Amanda L. |last2=Richdale |first3=Achini |last3=Adikari |first4=Jennifer |last4=Lowe |first5=Cheryl |last5=Dissanayake |date=1 March 2022 |journal=Autism in Adulthood |volume=4 |issue=1 |pages=52–65 |doi=10.1089/aut.2021.0021 |pmid=36605565 |pmc=8992925}} This is a reason that community psychology is used to study autistic communities.{{Cite thesis |degree=PhD |last=Botha |first=M |title=Autistic community connectedness as a buffer against the effects of minority stress |publisher=University of Surrey |access-date=2024-11-27 |date=2020 |url=https://openresearch.surrey.ac.uk/esploro/outputs/doctoral/99512577202346 |archive-url=https://web.archive.org/web/20250318055113/https://openresearch.surrey.ac.uk/esploro/outputs/doctoral/99512577202346 |archive-date=18 March 2025}}

Autistic inertia is described by autistic people as difficulty in transitioning between activities or states.{{Cite journal |last1=Buckle |first1=Karen Leneh |last2=Leadbitter |first2=Kathy |last3=Poliakoff |first3=Ellen |last4=Gowen |first4=Emma |date=2021 |title="No Way Out Except From External Intervention": First-Hand Accounts of Autistic Inertia |journal=Frontiers in Psychology |volume=12 |page=631596 |doi=10.3389/fpsyg.2021.631596 |doi-access=free |issn=1664-1078 |pmc=8314008 |pmid=34326790}}{{Cite journal |last1=Rapaport |first1=Hannah |last2=Clapham |first2=Hayley |last3=Adams |first3=Jon |last4=Lawson |first4=Wenn |last5=Porayska-Pomsta |first5=Kaśka |last6=Pellicano |first6=Elizabeth |date=2024-05-01 |title='I live in extremes': A qualitative investigation of Autistic adults' experiences of inertial rest and motion |journal=Autism |language=EN |volume=28 |issue=5 |pages=1305–1315 |doi=10.1177/13623613231198916 |issn=1362-3613 |pmc=11067417 |pmid=37776056}} This can manifest both in starting (initiation difficulties) and finishing (persistence or difficulties in switching) tasks or actions. Those affected often report an inner sluggishness or inertia, even when they want to start or finish an action. Therefore, it is different from laziness or lack of motivation.

A meltdown may arise if an autistic person has to process too much information, resulting in anxiety and overwhelm.{{cite web|access-date=2025-01-22 |language=en |title=Understanding autistic meltdowns and shutdowns {{!}} Autism Space |url=https://www.leicspart.nhs.uk/autism-space/health-and-lifestyle/meltdowns-and-shutdowns/ |website=Leicestershire Partnership NHS Trust}} Triggers may be sensory or social, and include unpredictability, unmet basic needs, or emotional situations, and often accumulate.{{Cite journal |last=Belek |first=Ben |date=2019-01-02 |title=Articulating Sensory Sensitivity: From Bodies with Autism to Autistic Bodies |url=https://www.tandfonline.com/doi/full/10.1080/01459740.2018.1460750 |journal=Medical Anthropology |volume=38 |issue=1 |pages=30–43 |doi=10.1080/01459740.2018.1460750 |issn=0145-9740 |pmid=29727204}} A meltdown can be expressed audibly (e.g., screaming or crying) or physically.{{Cite journal |last1=Phung |first1=Jasmine |last2=Penner |first2=Melanie |last3=Pirlot |first3=Clémentine |last4=Welch |first4=Christie |date=2021-11-03 |title=What I Wish You Knew: Insights on Burnout, Inertia, Meltdown, and Shutdown From Autistic Youth |journal=Frontiers in Psychology |language=English |volume=12 |doi=10.3389/fpsyg.2021.741421 |doi-access=free |pmid=34803822 |pmc=8595127 |issn=1664-1078}} These are not intentional actions and are thus not tantrums; the autistic person cannot express themself in any other way. The person often shows signs of distress beforehand, such as pacing, asking repetitive questions, trembling, or sweating. A shutdown is similar, but inward, and the autistic person is often unable to speak or withdraws completely. Meltdown or shutdown can be prevented by eliminating the distressing factors. They can be ameliorated by avoiding further questions or pressure, showing the person that one is there to help, and allowing the person to calm down by leaving the situation or breathing slowly.

Autistic people may exhibit traits or characteristics that are not part of the formal diagnostic criteria but can nonetheless affect their personal well-being or family dynamics.{{cite journal |display-authors=6 |vauthors=Filipek PA, Accardo PJ, Baranek GT, Cook EH, Dawson G, Gordon B, Gravel JS, Johnson CP, Kallen RJ, Levy SE, Minshew NJ, Ozonoff S, Prizant BM, Rapin I, Rogers SJ, Stone WL, Teplin S, Tuchman RF, Volkmar FR |date=December 1999 |title=The screening and diagnosis of autistic spectrum disorders |journal=Journal of Autism and Developmental Disorders |volume=29 |issue=6 |pages=439–484 |doi=10.1023/A:1021943802493 |pmid=10638459 |s2cid=145113684}} This paper represents a consensus of representatives from nine professional and four parent organizations in the US.

• Some autistic people show unusual or notable abilities, ranging from splinter skills (such as the memorization of trivia) to rare talents in mathematics, music, or artistic reproduction, which in exceptional cases are considered a part of the savant syndrome.{{cite journal |vauthors=Treffert DA |date=May 2009 |title=The savant syndrome: an extraordinary condition. A synopsis: past, present, future |journal=Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences |volume=364 |issue=1522 |pages=1351–1357 |doi=10.1098/rstb.2008.0326 |pmc=2677584 |pmid=19528017}}{{cite journal |vauthors=Zhang Y, Han VZ |date=April 2018 |title=[Neurobiological mechanisms of autistic savant and acquired savant] |trans-title=Neurobiological mechanisms of autistic savant and acquired savant |journal=Sheng Li Xue Bao |language=zh |volume=70 |issue=2 |pages=201–210 |pmid=29691585}}{{cite journal |vauthors=Hughes JE, Ward J, Gruffydd E, Baron-Cohen S, Smith P, Allison C, Simner J |date=October 2018 |title=Savant syndrome has a distinct psychological profile in autism |journal=Molecular Autism |volume=9 |page=53 |doi=10.1186/s13229-018-0237-1 |pmc=6186137 |pmid=30344992 |doi-access=free}} One study describes how some autistic people show superior skills in perception and attention relative to the general population.{{cite journal |vauthors=Plaisted Grant K, Davis G |date=May 2009 |title=Perception and apperception in autism: rejecting the inverse assumption |journal=Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences |volume=364 |issue=1522 |pages=1393–1398 |doi=10.1098/rstb.2009.0001 |pmc=2677593 |pmid=19528022}}
• More generally, autistic people tend to show a "spiky skills profile", with strong abilities in some areas contrasting with much weaker abilities in others.{{cite journal |vauthors=Happé F, Frith U |date=August 1996 |title=The neuropsychology of autism |journal=Brain |publisher=Oxford University Press |volume=119 |issue=4 |pages=1377–1400 |doi=10.1093/brain/119.4.1377 |pmid=8813299 |doi-access=free}}
• An estimated 60–80% of autistic people have motor signs that include poor muscle tone, poor motor planning, and toe walking;{{cite journal |author-link=Daniel Geschwind |vauthors=Geschwind DH |year=2009 |title=Advances in autism |journal=Annual Review of Medicine |volume=60 |pages=367–380 |doi=10.1146/annurev.med.60.053107.121225 |pmc=3645857 |pmid=19630577}}{{cite journal |vauthors=Gargot T, Archambault D, Chetouani M, Cohen D, Johal W, Anzalone SM |date=10 January 2022 |title=Automatic Assessment of Motor Impairments in Autism Spectrum Disorders: A Systematic Review |journal=Cognitive Computation |volume=14 |issue=2 |pages=624–659 |doi=10.1007/s12559-021-09940-8 |issn=1866-9964 |s2cid=248326222 |url=https://hal.archives-ouvertes.fr/hal-03520967/file/review_article__for_Cognitive_computations__with_proper_model_.pdf |access-date=14 July 2022 |archive-date=15 December 2022 |archive-url=https://web.archive.org/web/20221215184813/https://hal.archives-ouvertes.fr/hal-03520967/file/review_article__for_Cognitive_computations__with_proper_model_.pdf |url-status=live}} difficulties in motor coordination are pervasive across the autism spectrum.{{cite journal |vauthors=Fournier KA, Hass CJ, Naik SK, Lodha N, Cauraugh JH |date=October 2010 |title=Motor coordination in autism spectrum disorders: a synthesis and meta-analysis |journal=Journal of Autism and Developmental Disorders |volume=40 |issue=10 |pages=1227–1240 |doi=10.1007/s10803-010-0981-3 |pmid=20195737 |s2cid=3469612}}{{cite journal |last1=Wang |first1=Leah A. L. |last2=Petrulla |first2=Victoria |last3=Zampella |first3=Casey J. |last4=Waller |first4=Rebecca |last5=Schultz |first5=Robert T. |date=2022 |title=Gross motor impairment and its relation to social skills in autism spectrum disorder: A systematic review and two meta-analyses. |journal=Psychological Bulletin |language=en |volume=148 |issue=3–4 |pages=273–300 |doi=10.1037/bul0000358 |issn=1939-1455 |pmc=9894569 |pmid=35511567}}
• Pathological demand avoidance can occur. People with this set of autistic characteristics are more likely to refuse to do what is asked or expected of them, even to activities they enjoy.{{Citation needed|date=March 2025}}
• Unusual or atypical eating behavior occurs in about three-quarters of children on the autism spectrum, to the extent that it was formerly a diagnostic indicator. Selectivity is the most common characteristic, although eating rituals and food refusal also occur.{{cite journal |vauthors=Dominick KC, Davis NO, Lainhart J, Tager-Flusberg H, Folstein S |year=2007 |title=Atypical behaviors in children with autism and children with a history of language impairment |journal=Research in Developmental Disabilities |publisher=Elsevier |eissn=1873-3379 |issn=0891-4222 |volume=28 |issue=2 |pages=145–162 |doi=10.1016/j.ridd.2006.02.003 |pmid=16581226}}

In his 2015 book NeuroTribes, Steve Silberman highlights the emergence of online communities centered around autistic people, such as Autism Network International—founded by Jim Sinclair—and Wrong Planet.{{Cite book |last1=Silberman |first1=Steve |title=NeuroTribes: the legacy of autism and the future of neurodiversity |last2=Sacks |first2=Oliver W. |date=2016 |publisher=Avery, an imprint of Penguin Random House |isbn=978-0-399-18561-8 |location=New York |pages=439–455}} Silberman writes that these digital spaces offer a "natural home" for autistic people to communicate through written language. A 2022 systematic review of 21 studies found that most studies reported moderate correlations between autism, problematic internet use, and gaming disorder.{{cite journal |last1=Murray |first1=Alayna |last2=Koronczai |first2=Beatrix |last3=Király |first3=Orsolya |last4=Griffiths |first4=Mark D. |last5=Mannion |first5=Arlene |last6=Leader |first6=Geraldine |last7=Demetrovics |first7=Zsolt |year=2021 |title=Autism, Problematic Internet Use and Gaming Disorder: A Systematic Review |journal=Review Journal of Autism and Developmental Disorders |publisher=Springer |volume=9 |pages=120–140 |doi=10.1007/s40489-021-00243-0 |hdl-access=free |hdl=10379/16762}}

Families who care for an autistic child face greater stress for varying reasons.{{cite book |url={{Google books|4yzqAgAAQBAJ|page=301|plainurl=yes}} |title=Handbook of Autism and Pervasive Developmental Disorders: Volume Two: Assessment, Interventions, and Policy |publisher=John Wiley & Sons |year=2014 |isbn=978-1-118-28220-5 |veditors=Volkmar FR, Paul R, Pelphrey KA, Rogers SJ |edition=4th |volume=2 |location=Hoboken, New Jersey |page=301 |lccn=2013034363 |oclc=946133861 |access-date=1 March 2019}}{{cite journal |vauthors=Aguiar MC, de Pondé MP |date=March 2019 |title=Parenting a child with autism |journal=Jornal Brasileiro de Psiquiatria |language=en |volume=68 |issue=1 |pages=42–47 |doi=10.1590/0047-2085000000223 |issn=0047-2085 |s2cid=165119472 |doi-access=free}} Parents may struggle to understand their child and to find appropriate care options. They can take a negative view of autism, and may struggle emotionally.{{cite news |date=29 April 2015 |title=An Alternative-Medicine Believer's Journey Back to Science |newspaper=WIRED |url=https://www.wired.com/2015/04/alternative-medicine-believers-journey-back-science/ |access-date=13 February 2017 |vauthors=Levinovitz A}} Affiliate stigma also decreases quality of life, where negative attitudes towards the autistic child are extended to those close to the child.{{Cite journal |last=Ye |first=Yifan |last2=Deng |first2=Tao |last3=Chen |first3=Miaoying |last4=Huang |first4=Baoqin |last5=Ji |first5=Yan |last6=Feng |first6=Yongshen |last7=Liu |first7=Shaofei |last8=Zhang |first8=Tao |last9=Zhang |first9=Lifeng |date=2024-04-01 |title=Relationship between affiliate stigma and family quality of life among parents of children with autism spectrum disorders: The mediating role of parenting self-efficacy |url=https://www.sciencedirect.com/science/article/abs/pii/S0883941724000116 |journal=Archives of Psychiatric Nursing |volume=49 |pages=23–31 |doi=10.1016/j.apnu.2024.01.011 |issn=0883-9417}} About 85% of autistic people need support with independent living in adulthood.{{cite journal |vauthors=Karst JS, Van Hecke AV |date=September 2012 |title=Parent and family impact of autism spectrum disorders: a review and proposed model for intervention evaluation |journal=Clinical Child and Family Psychology Review |volume=15 |issue=3 |pages=247–77 |doi=10.1007/s10567-012-0119-6 |pmid=22869324 |s2cid=19170894}} Family members who are themselves autistic are often better able to understand the autistic child.{{Cite journal |last=Crane |first=Laura |last2=Lui |first2=Lok Man |last3=Davies |first3=Jade |last4=Pellicano |first4=Elizabeth |date=2021-05-01 |title=Autistic parents’ views and experiences of talking about autism with their autistic children |url=https://journals.sagepub.com/doi/10.1177/1362361320981317 |journal=Autism |language=EN |volume=25 |issue=4 |pages=1161–1167 |doi=10.1177/1362361320981317 |issn=1362-3613 |pmc=8111227 |pmid=33397133}}{{Cite journal |last=Crompton |first=Catherine J |last2=Hallett |first2=Sonny |last3=Ropar |first3=Danielle |last4=Flynn |first4=Emma |last5=Fletcher-Watson |first5=Sue |date=2020-08-01 |title=‘I never realised everybody felt as happy as I do when I am around autistic people’: A thematic analysis of autistic adults’ relationships with autistic and neurotypical friends and family |url=https://journals.sagepub.com/doi/10.1177/1362361320908976 |journal=Autism |language=EN |volume=24 |issue=6 |pages=1438–1448 |doi=10.1177/1362361320908976 |issn=1362-3613 |pmc=7376620 |pmid=32148068}}

{{Main|Conditions comorbid to autism}}

File:Overlapping clinical phenotypes in genes associated with monogenic forms of autism spectrum disorder (ASD), dystonia, epilepsy and schizophrenia.svg showing overlapping clinical phenotypes in genes associated with monogenic forms of autism, dystonia, epilepsy and schizophrenia:

{{legend|#007fff|Genes associated with epilepsy}}

{{legend|#007f7f|Genes associated with schizophrenia}}

{{legend|#d4aaff|Genes associated with autism spectrum disorder}}

{{legend|#ff0000|Genes associated with dystonia}}]]

Autism is correlated or co-occurring with several conditions.{{cite journal |vauthors=Levy SE, Mandell DS, Schultz RT |date=November 2009 |title=Autism |journal=The Lancet |volume=374 |issue=9701 |pages=1627–1638 |doi=10.1016/S0140-6736(09)61376-3 |pmc=2863325 |pmid=19819542}}{{Erratum|https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(11)61666-8/fulltext|doi=10.1016/S0140-6736(11)61666-8|checked=yes}} Comorbidity may increase with age and may complicate the course of youth on the autism spectrum and make intervention and therapy more difficult. Distinguishing between autism and other diagnoses can be challenging because the traits of autism often overlap with symptoms of other conditions, and the characteristics of autism make traditional diagnostic procedures difficult.{{cite journal |vauthors=Underwood L, McCarthy J, Tsakanikos E |date=September 2010 |title=Mental health of adults with autism spectrum disorders and intellectual disability |journal=Current Opinion in Psychiatry |volume=23 |issue=5 |pages=421–6 |doi=10.1097/YCO.0b013e32833cfc18 |pmid=20613532 |s2cid=13735841}}{{cite book |title=International handbook of autism and pervasive developmental disorders |vauthors=Helverschou SB, Bakken TL, Martinsen H |publisher=Springer |year=2011 |isbn=978-1-4419-8064-9 |veditors=Matson JL, Sturmey P |location=New York |pages=53–74 |chapter=Psychiatric Disorders in People with Autism Spectrum Disorders: Phenomenology and Recognition |oclc=746203105}} Common co-occurring conditions are:

• ADHD is sometimes co-occurring with autism (25% to 32%).{{Cite journal |last1=Lai |first1=Meng-Chuan |last2=Kassee |first2=Caroline |last3=Besney |first3=Richard |last4=Bonato |first4=Sarah |last5=Hull |first5=Laura |last6=Mandy |first6=William |last7=Szatmari |first7=Peter |last8=Ameis |first8=Stephanie H. |date=2019-10-01 |title=Prevalence of co-occurring mental health diagnoses in the autism population: a systematic review and meta-analysis |url=https://www.thelancet.com/journals/lanpsy/article/PIIS2215-0366(19)30289-5/abstract |journal=The Lancet Psychiatry |language=English |volume=6 |issue=10 |pages=819–829 |doi=10.1016/S2215-0366(19)30289-5 |issn=2215-0366 |pmid=31447415}} Characteristics similar to those of ADHD can be part of an autism diagnosis.{{cite journal |vauthors=Rommelse NN, Franke B, Geurts HM, Hartman CA, Buitelaar JK |date=March 2010 |title=Shared heritability of attention-deficit/hyperactivity disorder and autism spectrum disorder |journal=European Child & Adolescent Psychiatry |volume=19 |issue=3 |pages=281–95 |doi=10.1007/s00787-010-0092-x |pmc=2839489 |pmid=20148275}}
• Epilepsy occurs in about 10% of autistic people.{{Cite journal |last1=Liu |first1=Xian |last2=Sun |first2=Xin |last3=Sun |first3=Caihong |last4=Zou |first4=Mingyang |last5=Chen |first5=Yiru |last6=Huang |first6=Junping |last7=Wu |first7=Lijie |last8=Chen |first8=Wen-Xiong |date=2022 |title=Prevalence of epilepsy in autism spectrum disorders: A systematic review and meta-analysis |journal=Autism: The International Journal of Research and Practice |volume=26 |issue=1 |pages=33–50 |doi=10.1177/13623613211045029 |issn=1461-7005 |pmid=34510916}} The risk is higher for older autistic people and those with intellectual disability.{{cite journal |vauthors=Spence SJ, Schneider MT |date=June 2009 |title=The role of epilepsy and epileptiform EEGs in autism spectrum disorders |journal=Pediatric Research |volume=65 |issue=6 |pages=599–606 |doi=10.1203/PDR.0b013e31819e7168 |pmc=2692092 |pmid=19454962}}
• Intellectual disabilities are some of the most common co-occurring conditions with autism (30% to 40%).{{cite journal |last1=Sala |first1=G. |last2=Hooley |first2=M. |last3=Attwood |first3=T. |date=2019 |title=Autism and Intellectual Disability: A Systematic Review of Sexuality and Relationship Education |journal=Sexuality and Disability |volume=37 |issue=3 |pages=353–382 |doi=10.1007/s11195-019-09577-4 |s2cid=255011485}} As diagnosis is increasingly given to people with lower support needs, there is a tendency for the proportion with co-occurring intellectual disability to decrease over time.
• Various anxiety disorders tend to co-occur with autism, with overall co-occurring rates of 17% to 23%. Many anxiety disorders have characteristics that are better explained by autism itself or are hard to distinguish from autism's features.{{cite journal |vauthors=White SW, Oswald D, Ollendick T, Scahill L |date=April 2009 |title=Anxiety in children and adolescents with autism spectrum disorders |journal=Clinical Psychology Review |volume=29 |issue=3 |pages=216–229 |doi=10.1016/j.cpr.2009.01.003 |pmc=2692135 |pmid=19223098}}
• Rates of co-occurring depression in autistic people range from 9% to 13%.
• Obsessive-compulsive disorder (OCD) occurs in 7% to 10% of autistic people.
• Starting in adolescence, some people diagnosed with Asperger syndrome (26% in one sample){{cite journal |vauthors=Lugnegård T, Hallerbäck MU, Gillberg C |date=May 2012 |title=Personality disorders and autism spectrum disorders: what are the connections? |journal=Comprehensive Psychiatry |volume=53 |issue=4 |pages=333–40 |doi=10.1016/j.comppsych.2011.05.014 |pmid=21821235}} fall under the criteria for the similar-looking schizoid personality disorder, which is characterized by a lack of interest in social relationships, a tendency toward a solitary or sheltered lifestyle, secretiveness, emotional coldness, detachment, and apathy.{{cite journal |vauthors=Tantam D |date=December 1988 |title=Lifelong eccentricity and social isolation. II: Asperger's syndrome or schizoid personality disorder? |journal=The British Journal of Psychiatry |volume=153 |pages=783–91 |doi=10.1192/bjp.153.6.783 |pmid=3256377 |s2cid=39433805}}{{cite book |title=Integrated Treatment for Co-Occurring Disorders: Personality Disorders and Addiction |vauthors=Ekleberry SC |publisher=Routledge |year=2008 |isbn=978-0-7890-3693-3 |pages=31–32 |chapter=Cluster A - Schizoid Personality Disorder and Substance Use Disorders |chapter-url=https://books.google.com/books?id=O5HY1xcfjEcC&pg=PA31}}
• Genetic conditions: 10% to 15% of autism cases have an identifiable Mendelian (single-gene) condition, chromosome anomalies, or other genetic syndromes.{{cite journal |vauthors=Folstein SE, Rosen-Sheidley B |date=December 2001 |title=Genetics of autism: complex aetiology for a heterogeneous disorder |journal=Nature Reviews Genetics |volume=2 |issue=12 |pages=943–955 |doi=10.1038/35103559 |pmid=11733747 |s2cid=9331084}} An example is tuberous sclerosis, present in 1% to 4% of autistic people.{{cite journal |vauthors=Wiznitzer M |date=September 2004 |title=Autism and tuberous sclerosis |journal=Journal of Child Neurology |volume=19 |issue=9 |pages=675–9 |doi=10.1177/08830738040190090701 |pmid=15563013 |s2cid=38157900}}
• Gastrointestinal problems are one of the most commonly co-occurring medical conditions in autistic people.{{cite journal |vauthors=Israelyan N, Margolis KG |date=June 2018 |title=Serotonin as a link between the gut-brain-microbiome axis in autism spectrum disorders |journal=Pharmacological Research |type=Review |volume=132 |pages=1–6 |doi=10.1016/j.phrs.2018.03.020 |pmc=6368356 |pmid=29614380}} These are linked to greater social difficulties, irritability, language difficulties, mood changes, distressed behavior, and sleep problems.{{cite journal |vauthors=Wasilewska J, Klukowski M |year=2015 |title=Gastrointestinal symptoms and autism spectrum disorder: links and risks - a possible new overlap syndrome |journal=Pediatric Health, Medicine and Therapeutics |type=Review |volume=6 |pages=153–166 |doi=10.2147/PHMT.S85717 |pmc=5683266 |pmid=29388597 |doi-access=free}}{{cite journal |vauthors=Rao M, Gershon MD |date=September 2016 |title=The bowel and beyond: the enteric nervous system in neurological disorders |journal=Nature Reviews. Gastroenterology & Hepatology |type=Review |volume=13 |issue=9 |pages=517–528 |doi=10.1038/nrgastro.2016.107 |pmc=5005185 |pmid=27435372 |quote=immune dysregulation, GI inflammation, malfunction of the ANS, genetic and metabolic activity of the microbiome, and dietary metabolites may contribute to brain dysfunction and neuroinflammation depending upon individual genetic vulnerability}}
• Sleep problems affect about two-thirds of autistic people at some point in childhood. These most commonly include symptoms of insomnia, such as difficulty falling asleep, frequent nocturnal awakenings, and early-morning awakenings. Sleep problems are associated with difficult behaviors and family stress, and are often a focus of clinical attention over and above the autism diagnosis.{{cite journal |vauthors=Richdale AL, Schreck KA |date=December 2009 |title=Sleep problems in autism spectrum disorders: prevalence, nature, & possible biopsychosocial aetiologies |journal=Sleep Medicine Reviews |volume=13 |issue=6 |pages=403–411 |doi=10.1016/j.smrv.2009.02.003 |pmid=19398354}}
• Motor difficulties, including features of dyspraxia, are highly prevalent in autistic individuals,{{Cite journal |last1=Kangarani-Farahani |first1=Melika |last2=Malik |first2=Myrah Anum |last3=Zwicker |first3=Jill G. |date=2024-05-01 |title=Motor Impairments in Children with Autism Spectrum Disorder: A Systematic Review and Meta-analysis |url=https://link.springer.com/article/10.1007/s10803-023-05948-1 |journal=Journal of Autism and Developmental Disorders |language=en |volume=54 |issue=5 |pages=1977–1997 |doi=10.1007/s10803-023-05948-1 |pmid=36949273 |issn=1573-3432}} and there is a significant association between autism and joint hypermobility, which is also linked to Ehlers-Danlos Syndromes (EDS).{{Cite journal |last1=Kindgren |first1=Erik |last2=Quiñones Perez |first2=Antonia |last3=Knez |first3=Rajna |date=2021 |title=Prevalence of ADHD and Autism Spectrum Disorder in Children with Hypermobility Spectrum Disorders or Hypermobile Ehlers-Danlos Syndrome: A Retrospective Study |journal=Neuropsychiatric Disease and Treatment |volume=17 |pages=379–388 |doi=10.2147/NDT.S290494 |doi-access=free |issn=1176-6328 |pmc=7882457 |pmid=33603376}}
• A 2024 Danish cohort study found increased risks for a multitude of co-occurring physical diseases, especially in infancy.{{Cite journal |last1=Steinhausen |first1=Hans-Christoph |last2=Villumsen |first2=Martin Dalgaard |last3=Støving |first3=René Klinkby |last4=Bilenberg |first4=Niels |date=2024-07-27 |title=Complete Spectrum of Physical Comorbidities with Autism Spectrum Disorder in a Nationwide Cohort |journal=Journal of Autism and Developmental Disorders |doi=10.1007/s10803-024-06476-2 |issn=1573-3432 |pmid=39066972}}
• There is tentative evidence that gender dysphoria occurs more frequently in autistic people.{{cite journal |vauthors=Van Der Miesen AI, Hurley H, De Vries AL |year=2016 |title=Gender dysphoria and autism spectrum disorder: A narrative review |journal=International Review of Psychiatry |volume=28 |issue=1 |pages=70–80 |doi=10.3109/09540261.2015.1111199 |pmid=26753812 |s2cid=20918937 |doi-access=free}}{{cite journal |vauthors=Glidden D, Bouman WP, Jones BA, Arcelus J |date=January 2016 |title=Gender Dysphoria and Autism Spectrum Disorder: A Systematic Review of the Literature |url=https://figshare.com/articles/journal_contribution/9620366 |url-status=live |journal=Sexual Medicine Reviews |volume=4 |issue=1 |pages=3–14 |doi=10.1016/j.sxmr.2015.10.003 |pmid=27872002 |s2cid=3454600 |archive-url=https://web.archive.org/web/20231103124238/https://figshare.com/articles/journal_contribution/Gender_dysphoria_and_autism_spectrum_disorder_a_systematic_review_of_the_literature/9620366 |archive-date=3 November 2023 |access-date=19 June 2023}}

{{Main|Autism therapies}}Currently, there is no cure for autism{{cite web |date=2 May 2019 |title=Fake and harmful autism 'treatments' |url=https://www.nhs.uk/conditions/autism/autism-and-everyday-life/fake-and-harmful-treatments/ |url-status=live |archive-url=https://web.archive.org/web/20221201180111/https://www.nhs.uk/conditions/autism/autism-and-everyday-life/fake-and-harmful-treatments/ |archive-date=1 December 2022 |access-date=29 April 2022 |website=nhs.uk |language=en}} and this may not be an appropriate goal.{{Cite journal |last1=Dwyer |first1=Patrick |last2=Gurba |first2=Ava N |last3=Kapp |first3=Steven K |last4=Kilgallon |first4=Elizabeth |last5=Hersh |first5=Lynnette H |last6=Chang |first6=David S |last7=Rivera |first7=Susan M |last8=Gillespie-Lynch |first8=Kristen |date=2024-09-18 |title=Community views of neurodiversity, models of disability and autism intervention: Mixed methods reveal shared goals and key tensions |url=https://journals.sagepub.com/doi/full/10.1177/13623613241273029 |journal=Autism |language=EN |page=13623613241273029 |doi=10.1177/13623613241273029 |pmid=39291753 |issn=1362-3613}}{{cite web |title=Making information and the words we use accessible |url=https://www.england.nhs.uk/learning-disabilities/about/get-involved/involving-people/making-information-and-the-words-we-use-accessible/ |url-status=live |archive-url=https://web.archive.org/web/20230716192201/https://www.england.nhs.uk/learning-disabilities/about/get-involved/involving-people/making-information-and-the-words-we-use-accessible/ |archive-date=16 July 2023 |access-date=29 April 2022 |website=NHS England}}{{cite web |title=How to talk about autism |url=https://www.autism.org.uk/what-we-do/help-and-support/how-to-talk-about-autism |url-status=live |archive-url=https://web.archive.org/web/20220307130201/https://www.autism.org.uk/what-we-do/help-and-support/how-to-talk-about-autism |archive-date=7 March 2022 |access-date=29 April 2022 |website=autism.org.uk |language=en}} Many within the autistic community oppose seeking a cure, a stance shared by prominent autistic individuals like Temple Grandin, who has stated she would remain autistic even if a cure existed.{{Cite web |title=Temple Grandin to Speak on the Value of Alternative Thinking |url=https://news.callutheran.edu/2024/01/temple-grandin-to-speak-on-the-value-of-alternative-thinking-2/ |access-date=16 June 2024 |website=California Lutheran University |language=en-US}}{{Cite web |title=Two presentations by Temple Grandin offered at MJC |url=https://www.mjc.edu/news/grandin |archive-url=https://web.archive.org/web/20240616214226/https://www.mjc.edu/news/grandin |archive-date=16 June 2024 |website=MJC.edu |publisher=Modesto Junior College}} Nevertheless, interventions targeting specific challenges or co-occurring conditions associated with autism are widely regarded as important.{{cite web |title=The psychiatric management of autism in adults (CR228) |url=https://www.rcpsych.ac.uk/improving-care/campaigning-for-better-mental-health-policy/college-reports/2020-college-reports/cr228 |url-status=live |archive-url=https://web.archive.org/web/20230602113739/https://www.rcpsych.ac.uk/improving-care/campaigning-for-better-mental-health-policy/college-reports/2020-college-reports/cr228 |archive-date=2 June 2023 |access-date=29 April 2022 |website=Royal College of Psychiatrists (UK) |language=en}} Perspectives on the goals of these interventions vary: the medical model of disability often focuses on addressing core characteristics such as social communication difficulties and restricted/repetitive behaviors.{{Citation |last1=Chapman |first1=Robert |title=Neurodiversity, Advocacy, Anti-Therapy |date=2022 |work=Handbook of Autism and Pervasive Developmental Disorder: Assessment, Diagnosis, and Treatment |pages=1519–1536 |editor-last=Matson |editor-first=Johnny L. |url=https://link.springer.com/chapter/10.1007/978-3-030-88538-0_67 |access-date=2025-04-29 |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-030-88538-0_67 |isbn=978-3-030-88538-0 |last2=Bovell |first2=Virginia |editor2-last=Sturmey |editor2-first=Peter}} In contrast, the neurodiversity movement supports interventions aimed at enhancing functional communication (spoken or non-spoken), managing related issues like anxiety or inertia, or addressing behaviors considered harmful, rather than seeking to alter core autistic features.{{Cite journal |last1=Leadbitter |first1=Kathy |last2=Buckle |first2=Karen Leneh |last3=Ellis |first3=Ceri |last4=Dekker |first4=Martijn |date=2021-04-12 |title=Autistic Self-Advocacy and the Neurodiversity Movement: Implications for Autism Early Intervention Research and Practice |journal=Frontiers in Psychology |language=English |volume=12 |doi=10.3389/fpsyg.2021.635690 |doi-access=free |pmid=33912110 |pmc=8075160 |issn=1664-1078}}

Some report that those who have limited support needs are likely to have lessened autistic features over time,{{cite journal |vauthors=Woodbury-Smith MR, Volkmar FR |date=June 2008 |title=Asperger syndrome |url=http://www.ssoar.info/ssoar/handle/document/12424 |url-status=live |journal=European Child & Adolescent Psychiatry |volume=18 |issue=1 |pages=2–11 |doi=10.1007/s00787-008-0701-0 |pmid=18563474 |s2cid=12808995 |archive-url=https://web.archive.org/web/20190331141120/https://www.ssoar.info/ssoar/handle/document/12424 |archive-date=31 March 2019 |access-date=21 September 2018}}{{cite journal |vauthors=Coplan J, Jawad AF |date=July 2005 |title=Modeling clinical outcome of children with autistic spectrum disorders |journal=Pediatrics |volume=116 |issue=1 |pages=117–22 |doi=10.1542/peds.2004-1118 |pmid=15995041 |s2cid=8440775}} while others argue that this perception is likely due to masking, i.e. the autistic person hiding their autistic characteristics to avoid stigma.{{Citation |last1=Kapp |first1=Steven K. |title=Lobbying Autism's Diagnostic Revision in the DSM-5 |date=2020 |work=Autistic Community and the Neurodiversity Movement: Stories from the Frontline |pages=167–194 |editor-last=Kapp |editor-first=Steven K. |url=https://link.springer.com/chapter/10.1007/978-981-13-8437-0_13 |access-date=2025-04-30 |place=Singapore |publisher=Springer |language=en |doi=10.1007/978-981-13-8437-0_13 |isbn=978-981-13-8437-0 |last2=Ne'eman |first2=Ari}} Factors such as developing spoken language before age six, having an IQ above 50, and possessing marketable skills are associated with a higher likelihood of independent living in adulthood.{{cite journal |vauthors=Tidmarsh L, Volkmar FR |date=September 2003 |title=Diagnosis and epidemiology of autism spectrum disorders |journal=Canadian Journal of Psychiatry |volume=48 |issue=8 |pages=517–525 |doi=10.1177/070674370304800803 |pmid=14574827 |s2cid=38070709 |doi-access=free}} Several therapies can help autistic children,{{cite web |title=10 Facts about Autism Spectrum Disorder (ASD) |url=https://www.acf.hhs.gov/ecd/10-facts-about-asd |url-status=live |archive-url=https://web.archive.org/web/20191106044902/https://www.acf.hhs.gov/ecd/10-facts-about-asd |archive-date=6 November 2019 |access-date=6 November 2019 |website=Early Childhood Development |language=en}} and no single one is best, with therapy typically tailored to the child's needs.{{cite journal |vauthors=Myers SM, Johnson CP |date=November 2007 |title=Management of children with autism spectrum disorders |journal=Pediatrics |volume=120 |issue=5 |pages=1162–1182 |doi=10.1542/peds.2007-2362 |pmid=17967921 |doi-access=free}} Studies of interventions have methodological problems that prevent definitive conclusions about efficacy,{{cite journal |display-authors=6 |vauthors=Ospina MB, Krebs Seida J, Clark B, Karkhaneh M, Hartling L, Tjosvold L, Vandermeer B, Smith V |year=2008 |title=Behavioural and developmental interventions for autism spectrum disorder: a clinical systematic review |journal=PLOS ONE |volume=3 |issue=11 |pages=e3755 |bibcode=2008PLoSO...3.3755O |doi=10.1371/journal.pone.0003755 |pmc=2582449 |pmid=19015734 |doi-access=free}} but the development of evidence-based interventions has advanced.{{cite journal |vauthors=Smith T, Iadarola S |date=2015 |title=Evidence Base Update for Autism Spectrum Disorder |journal=Journal of Clinical Child and Adolescent Psychology |publisher=Taylor & Francis |volume=44 |issue=6 |pages=897–922 |doi=10.1080/15374416.2015.1077448 |issn=1537-4416 |pmid=26430947}}

The main goals of therapy are to lessen associated difficulties and family distress, and to increase quality of life and functional independence. In general, higher IQs are correlated with higher responsiveness to interventions and larger intervention outcomes.{{cite journal |vauthors=Eldevik S, Hastings RP, Hughes JC, Jahr E, Eikeseth S, Cross S |date=May 2009 |title=Meta-analysis of Early Intensive Behavioral Intervention for children with autism |journal=Journal of Clinical Child and Adolescent Psychology |publisher=Taylor & Francis |volume=38 |issue=3 |pages=439–450 |citeseerx=10.1.1.607.9620 |doi=10.1080/15374410902851739 |pmid=19437303 |s2cid=205873629}} Behavioral, psychological, education, and skill-building interventions may be used to assist autistic people to learn daily life skills for living independently,{{cite journal |vauthors=Matson JL, Dempsey T, Fodstad JC |date=November 2009 |title=The effect of Autism Spectrum Disorders on adaptive independent living skills in adults with severe intellectual disability |journal=Research in Developmental Disabilities |publisher=Elsevier |volume=30 |issue=6 |pages=1203–1211 |doi=10.1016/j.ridd.2009.04.001 |eissn=1873-3379 |pmid=19450950}} as well as other social, communication, and language skills. Therapy also aims to reduce behaviors that are perceived as inappropriate and to build upon strengths.{{cite web |title=NIMH » Autism Spectrum Disorder |url=https://www.nimh.nih.gov/health/publications/autism-spectrum-disorder/index.shtml |url-status=live |archive-url=https://web.archive.org/web/20210423081752/https://www.nimh.nih.gov/health/publications/autism-spectrum-disorder/index.shtml |archive-date=23 April 2021 |access-date=8 April 2021 |website=National Institute of Mental Health (US) |publisher=National Institutes of Health (US)}} While medications have not been found to reduce autism's core features, they may be used for associated difficulties, such as irritability or inattention.{{cite journal |vauthors=Ji N, Findling RL |date=March 2015 |title=An update on pharmacotherapy for autism spectrum disorder in children and adolescents |journal=Current Opinion in Psychiatry |volume=28 |issue=2 |pages=91–101 |doi=10.1097/YCO.0000000000000132 |pmid=25602248 |s2cid=206141453}}

Certain interventions, such as intensive, sustained special education, remedial education programs, and behavior therapy, are considered beneficial early in life for autistic children to acquire self-care, social, and job skills. Available approaches include applied behavior analysis, developmental models, structured teaching, speech and language therapy, cognitive behavioral therapy,{{cite journal |display-authors=6 |vauthors=Wang X, Zhao J, Huang S, Chen S, Zhou T, Li Q, Luo X, Hao Y |date=May 2021 |title=Cognitive Behavioral Therapy for Autism Spectrum Disorders: A Systematic Review |journal=Pediatrics |publisher=American Academy of Pediatrics (AAP) |volume=147 |issue=5 |doi=10.1542/peds.2020-049880 |pmid=33888566 |s2cid=233370479 |doi-access=free}} social skills therapy, and occupational therapy.{{cite journal |vauthors=Myers SM, Johnson CP |date=November 2007 |title=Management of children with autism spectrum disorders |journal=Pediatrics |volume=120 |issue=5 |pages=1162–1182 |doi=10.1542/peds.2007-2362 |pmid=17967921 |doi-access=free}} These interventions, following the medical model, may either target autistic features comprehensively or focus on a specific area of difficulty.{{cite journal |vauthors=Smith T, Iadarola S |date=2015 |title=Evidence Base Update for Autism Spectrum Disorder |journal=Journal of Clinical Child and Adolescent Psychology |publisher=Taylor & Francis |volume=44 |issue=6 |pages=897–922 |doi=10.1080/15374416.2015.1077448 |issn=1537-4416 |pmid=26430947}}

File:Autistic boy receiving ABA therapy.jpg

Applied Behavior Analysis (ABA) is a behavioral therapy that aims to teach autistic children certain social and other behaviors by rewarding them for desired behaviors and, in some particularly controversial cases, also by punishing them for undesired behaviors.{{Cite journal |last=Kirkham |first=Patrick |date=2017-04-01 |title='The line between intervention and abuse' – autism and applied behaviour analysis |url=https://journals.sagepub.com/doi/10.1177/0952695117702571 |journal=History of the Human Sciences |language=EN |volume=30 |issue=2 |pages=107–126 |doi=10.1177/0952695117702571 |issn=0952-6951}} Early, intensive ABA therapy is considered effective in language skills, adaptive functioning, and intellectual performance in preschool children.{{Cite journal |last1=Reichow |first1=Brian |last2=Hume |first2=Kara |last3=Barton |first3=Erin E. |last4=Boyd |first4=Brian A. |date=2018-05-09 |title=Early intensive behavioral intervention (EIBI) for young children with autism spectrum disorders (ASD) |journal=The Cochrane Database of Systematic Reviews |volume=5 |issue=5 |pages=CD009260 |doi=10.1002/14651858.CD009260.pub3 |issn=1469-493X |pmc=6494600 |pmid=29742275}} Another review reported the lack of adverse event monitoring, although such adverse effects are possibly common.{{Cite journal |last1=Sandbank |first1=Micheal |last2=Bottema-Beutel |first2=Kristen |last3=LaPoint |first3=Shannon Crowley |last4=Feldman |first4=Jacob I. |last5=Barrett |first5=D. Jonah |last6=Caldwell |first6=Nicolette |last7=Dunham |first7=Kacie |last8=Crank |first8=Jenna |last9=Albarran |first9=Suzanne |last10=Woynaroski |first10=Tiffany |date=2023-11-14 |title=Autism intervention meta-analysis of early childhood studies (Project AIM): updated systematic review and secondary analysis |url=https://www.bmj.com/content/383/bmj-2023-076733 |journal=BMJ |language=en |volume=383 |pages=e076733 |doi=10.1136/bmj-2023-076733 |issn=1756-1833 |pmid=37963634|pmc=10644209 }}

Interventions for early childhood may be based on different theoretical frameworks, such as ABA (with its structured and naturalistic approaches) and Developmental Social Pragmatic (DSP) models. Research indicates that in acquiring spoken language, autistic children with higher receptive language skills tend to make progress with fewer hours (2.5 to 20 per week) of a naturalistic approach, whereas those with lower receptive language skills tend to show more progress only with a greater intensity of intervention (25 hours per week) using discrete trial training, a structured form of ABA.{{cite journal |vauthors=Brignell A, Chenausky KV, Song H, Zhu J, Suo C, Morgan AT |date=November 2018 |title=Communication interventions for autism spectrum disorder in minimally verbal children |journal=The Cochrane Database of Systematic Reviews |volume=2018 |issue=11 |pages=CD012324 |doi=10.1002/14651858.CD012324.pub2 |pmc=6516977 |pmid=30395694 |doi-access=free}}

A related type of intervention is parent training models. These teach parents to implement various ABA and DSP techniques themselves. Several parent-mediated behavioral therapies target social communication difficulties, while their effect on restricted and repetitive behaviors (RRBs) is uncertain.{{cite journal |vauthors=Harrop C |date=August 2015 |title=Evidence-based, parent-mediated interventions for young children with autism spectrum disorder: The case of restricted and repetitive behaviors |journal=Autism |language=en-US |volume=19 |issue=6 |pages=662–72 |doi=10.1177/1362361314545685 |pmid=25186943 |s2cid=32326472}} Similarly, teacher-implemented interventions that combine naturalistic ABA with a developmental social pragmatic approach have been associated with effects on young children's social-communication behaviors, although there is limited evidence regarding effects on broader autistic characteristics.

ABA has faced significant criticism.{{Cite journal |last1=Sandoval-Norton |first1=Aileen Herlinda |last2=Shkedy |first2=Gary |last3=Shkedy |first3=Dalia |date=1 January 2019 |editor-last=Rushby |editor-first=Jacqueline Ann |title=How much compliance is too much compliance: Is long-term ABA therapy abuse? |journal=Cogent Psychology |language=en |volume=6 |issue=1 |doi=10.1080/23311908.2019.1641258 |issn=2331-1908 |doi-access=free }}{{Cite journal |last1=Shkedy |first1=Gary |last2=Shkedy |first2=Dalia |last3=Sandoval-Norton |first3=Aileen H. |date=June 2021 |title=Long-term ABA Therapy Is Abusive: A Response to Gorycki, Ruppel, and Zane |journal=Advances in Neurodevelopmental Disorders |language=en |volume=5 |issue=2 |pages=126–134 |doi=10.1007/s41252-021-00201-1 |issn=2366-7532 |doi-access=free}}{{Cite journal |last=Anderson |first=Laura K |date=April 2023 |title=Autistic experiences of applied behavior analysis |url=http://journals.sagepub.com/doi/10.1177/13623613221118216 |journal=Autism |language=en |volume=27 |issue=3 |pages=737–750 |doi=10.1177/13623613221118216 |pmid=35999706 |s2cid=251766661 |issn=1362-3613 |access-date=6 March 2024 |archive-date=9 September 2023 |archive-url=https://web.archive.org/web/20230909183256/https://journals.sagepub.com/doi/10.1177/13623613221118216 |url-status=live }} Sandoval-Norton et al. describe it as unethical and argue that it has unintended consequences, such as prompt dependency, susceptibility to psychological abuse, and overemphasis on compliance, which can create challenges as autistic children transition into adulthood. Increasingly, ABA is also criticized for trying to reduce or eliminate autistic behaviors to make children appear more neurotypical, rather than supporting them and respecting neurodiversity. Moreover, a problem with unreported conflicts of interest in ABA research has been described, with potential effects on the quality of evidence.{{Cite journal |last1=Bottema-Beutel |first1=Kristen |last2=Crowley |first2=Shannon |last3=Sandbank |first3=Micheal |last4=Woynaroski |first4=Tiffany G. |date=2021 |title=Research Review: Conflicts of Interest (COIs) in autism early intervention research - a meta-analysis of COI influences on intervention effects |journal=Journal of Child Psychology and Psychiatry, and Allied Disciplines |volume=62 |issue=1 |pages=5–15 |doi=10.1111/jcpp.13249 |issn=1469-7610 |pmc=7606324 |pmid=32353179}} In response, some ABA advocates suggest that instead of discontinuing the therapy, efforts should focus on increasing protections and ethical compliance when working with autistic children.{{Cite journal |last1=Gorycki |first1=Kathryn A. |last2=Ruppel |first2=Paula R. |last3=Zane |first3=Thomas |date=31 December 2020 |editor-last=Navalta |editor-first=Carryl P. |title=Is long-term ABA therapy abusive: A response to Sandoval-Norton and Shkedy |url=https://www.tandfonline.com/doi/full/10.1080/23311908.2020.1823615 |url-status=live |journal=Cogent Psychology |language=en |volume=7 |issue=1 |doi=10.1080/23311908.2020.1823615 |issn=2331-1908 |archive-url=https://web.archive.org/web/20230429165526/https://www.tandfonline.com/doi/full/10.1080/23311908.2020.1823615 |archive-date=29 April 2023 |access-date=6 March 2024 |hdl-access=free |hdl=1808/31691}}

Autistic people may be prescribed medication to manage specific co-occurring conditions or behaviors, such as ADHD, anxiety, aggression, or self-injurious behaviors, particularly when non-pharmacological interventions alone have been insufficient.{{cite journal |vauthors=Sanchack KE, Thomas CA |date=December 2016 |title=Autism Spectrum Disorder: Primary Care Principles |journal=American Family Physician |volume=94 |issue=12 |pages=972–979 |pmid=28075089}}{{cite journal |last1=Iffland |first1=Michelle |last2=Livingstone |first2=Nuala |last3=Jorgensen |first3=Mikaela |last4=Hazell |first4=Philip |last5=Gillies |first5=Donna |date=9 October 2023 |editor-last=Cochrane Developmental, Psychosocial and Learning Problems Group |title=Pharmacological intervention for irritability, aggression, and self-injury in autism spectrum disorder (ASD) |journal=The Cochrane Database of Systematic Reviews |language=en |volume=2023 |issue=10 |pages=CD011769 |doi=10.1002/14651858.CD011769.pub2 |pmc=10561353 |pmid=37811711}} Medications are not routinely recommended for autism's core features, such as social and communication difficulties or restricted and repetitive behaviors.{{cite journal |vauthors=Siafis S, Çıray O, Wu H, Schneider-Thoma J, Bighelli I, Krause M, Rodolico A, Ceraso A, Deste G, Huhn M, Fraguas D, San José Cáceres A, Mavridis D, Charman T, Murphy DG, Parellada M, Arango C, Leucht S |date=2022 |title=Pharmacological and dietary-supplement treatments for autism spectrum disorder: a systematic review and network meta-analysis |journal=Molecular Autism |volume=13 |issue=1 |page=10 |doi=10.1186/s13229-022-00488-4 |pmc=8896153 |pmid=35246237 |doi-access=free}}

More than half of autistic children in the United States are prescribed psychoactive drugs or anticonvulsants.{{cite journal |vauthors=Oswald DP, Sonenklar NA |date=June 2007 |title=Medication use among children with autism spectrum disorders |journal=Journal of Child and Adolescent Psychopharmacology |volume=17 |issue=3 |pages=348–355 |doi=10.1089/cap.2006.17303 |pmid=17630868}}{{cite journal |vauthors=Doyle CA, McDougle CJ |date=September 2012 |title=Pharmacologic treatments for the behavioral symptoms associated with autism spectrum disorders across the lifespan |journal=Dialogues in Clinical Neuroscience |volume=14 |issue=3 |pages=263–279 |doi=10.31887/DCNS.2012.14.3/cdoyle |pmc=3513681 |pmid=23226952}} Commonly used drug classes include antidepressants, stimulants, and antipsychotics. Among antipsychotics, risperidone and aripiprazole are the only medications approved by the U.S. Food and Drug Administration (FDA) specifically for reducing irritability, aggression, and self-injurious behaviors in autistic people.{{cite journal |vauthors=Ji N, Findling RL |date=March 2015 |title=An update on pharmacotherapy for autism spectrum disorder in children and adolescents |journal=Current Opinion in Psychiatry |volume=28 |issue=2 |pages=91–101 |doi=10.1097/YCO.0000000000000132 |pmid=25602248 |s2cid=206141453}}{{cite journal |vauthors=Leskovec TJ, Rowles BM, Findling RL |year=2008 |title=Pharmacological treatment options for autism spectrum disorders in children and adolescents |journal=Harvard Review of Psychiatry |volume=16 |issue=2 |pages=97–112 |doi=10.1080/10673220802075852 |pmid=18415882 |s2cid=26112061}} These drugs can have significant side effects—including weight gain, fatigue, drooling, and, in some cases, paradoxical increases in aggression—and responses to them may vary. The UK's National Health Service (NHS) cautions against the overprescription of antipsychotics and recommends their use only for specific indications, at the lowest effective dose and for the shortest duration necessary.{{Cite web |last=England |first=N. H. S. |title=NHS England » Stopping over medication of people with a learning disability and autistic people (STOMP) and supporting treatment and appropriate medication in paediatrics (STAMP) |url=https://www.england.nhs.uk/learning-disabilities/improving-health/stomp-stamp/ |access-date=2025-04-29 |website=www.england.nhs.uk |language=en-US}}

Some research suggests that risperidone and aripiprazole may also reduce restricted and repetitive behaviors (stimming), such as hand-flapping or body-rocking. But the evidence supporting this use has limitations, including study size and scope, alongside concerns about adverse effects.{{cite journal |display-authors=6 |vauthors=Ameis SH, Kassee C, Corbett-Dick P, Cole L, Dadhwal S, Lai MC, Veenstra-VanderWeele J, Correll CU |date=November 2018 |title=Systematic review and guide to management of core and psychiatric symptoms in youth with autism |journal=Acta Psychiatrica Scandinavica |volume=138 |issue=5 |pages=379–400 |doi=10.1111/acps.12918 |pmid=29904907 |s2cid=49209337}} A meta-analysis found no significant efficacy of these antipsychotics or SSRI antidepressants in reducing these behaviors.{{Cite journal |last1=Yu |first1=Yanjie |last2=Chaulagain |first2=Ashmita |last3=Pedersen |first3=Sindre Andre |last4=Lydersen |first4=Stian |last5=Leventhal |first5=Bennett L. |last6=Szatmari |first6=Peter |last7=Aleksic |first7=Branko |last8=Ozaki |first8=Norio |last9=Skokauskas |first9=Norbert |date=2020-03-12 |title=Pharmacotherapy of restricted/repetitive behavior in autism spectrum disorder:a systematic review and meta-analysis |journal=BMC Psychiatry |volume=20 |issue=1 |page=121 |doi=10.1186/s12888-020-2477-9 |doi-access=free |issn=1471-244X |pmc=7068977 |pmid=32164636}} Many autistic people and advocates also argue that stimming should be accepted, not treated.{{Cite journal |last1=Kapp |first1=Steven K. |last2=Steward |first2=Robyn |last3=Crane |first3=Laura |last4=Elliott |first4=Daisy |last5=Elphick |first5=Chris |last6=Pellicano |first6=Elizabeth |last7=Russell |first7=Ginny |date=2019 |title='People should be allowed to do what they like': Autistic adults' views and experiences of stimming |journal=Autism: The International Journal of Research and Practice |volume=23 |issue=7 |pages=1782–1792 |doi=10.1177/1362361319829628 |issn=1461-7005 |pmc=6728747 |pmid=30818970}} Stimulant medications like methylphenidate may reduce inattention or hyperactivity in some autistic children, particularly when ADHD is also present. Experimental approaches such as MDMA-assisted psychotherapy are being explored for social anxiety in autistic adults.{{Cite journal |last1=Danforth |first1=Alicia L. |last2=Struble |first2=Christopher M. |last3=Yazar-Klosinski |first3=Berra |last4=Grob |first4=Charles S. |date=2016-01-04 |title=MDMA-assisted therapy: A new treatment model for social anxiety in autistic adults |journal=Progress in Neuro-Psychopharmacology and Biological Psychiatry |volume=64 |pages=237–249 |doi=10.1016/j.pnpbp.2015.03.011 |issn=0278-5846 |pmid=25818246 |doi-access=free}}

A multitude of alternative therapies have been researched and implemented, and many have resulted in harm to autistic people.{{Cite journal |last1=Myers |first1=Scott M. |last2=Johnson |first2=Chris Plauché |last3=the Council on Children With Disabilities |date=2007-11-01 |title=Management of Children With Autism Spectrum Disorders |url=https://publications.aap.org/pediatrics/article/120/5/1162/71080/Management-of-Children-With-Autism-Spectrum?autologincheck=redirected |journal=Pediatrics |volume=120 |issue=5 |pages=1162–1182 |doi=10.1542/peds.2007-2362 |pmid=17967921 |issn=0031-4005}} For example, chelation therapy is not recommended for autistic people, since the associated risks outweigh any potential benefits.{{cite journal |vauthors=James S, Stevenson SW, Silove N, Williams K |date=May 2015 |title=Chelation for autism spectrum disorder (ASD) |journal=The Cochrane Database of Systematic Reviews |type=Review |issue=5 |pages=CD010766 |doi=10.1002/14651858.CD010766 |pmid=26106752 |doi-access=free |veditors=James S}} In 2005, botched chelation therapy killed a five-year-old autistic child.{{cite journal |vauthors=Levy SE, Hyman SL |date=October 2008 |title=Complementary and alternative medicine treatments for children with autism spectrum disorders |journal=Child and Adolescent Psychiatric Clinics of North America |type=Review |volume=17 |issue=4 |pages=803–20, ix |doi=10.1016/j.chc.2008.06.004 |pmc=2597185 |pmid=18775371}}{{cite journal |vauthors=Brown MJ, Willis T, Omalu B, Leiker R |date=August 2006 |title=Deaths resulting from hypocalcemia after administration of edetate disodium: 2003-2005 |url=http://pediatrics.aappublications.org/cgi/content/full/118/2/e534 |journal=Pediatrics |volume=118 |issue=2 |pages=e534–e536 |doi=10.1542/peds.2006-0858 |pmid=16882789 |s2cid=28656831 |archive-url=https://web.archive.org/web/20090727080307/http://pediatrics.aappublications.org/cgi/content/full/118/2/e534 |archive-date=27 July 2009}} Another alternative medicine practice with no evidence is CEASE therapy, a pseudoscientific mixture of homeopathy, supplements, and "vaccine detoxing".{{cite web |date=24 November 2021 |title=CEASE Therapy for Autism: the Controversy of a "Cure" |url=https://www.autismparentingmagazine.com/cease-therapy-controversy-cure/ |url-status=live |archive-url=https://web.archive.org/web/20220922123637/https://www.autismparentingmagazine.com/cease-therapy-controversy-cure/ |archive-date=22 September 2022 |access-date=22 September 2022 |website=Autism Parenting Magazine |vauthors=Loftus Y}} Medical authorities have discredited and condemned bleach-based approaches, such as chlorine dioxide solutions marketed as Miracle Mineral Solution (MMS), as dangerous and ineffective.{{Cite web |last=Commissioner |first=Office of the |date=2020-03-24 |title=FDA warns consumers about the dangerous and potentially life threatening side effects of Miracle Mineral Solution |url=https://www.fda.gov/news-events/press-announcements/fda-warns-consumers-about-dangerous-and-potentially-life-threatening-side-effects-miracle-mineral |access-date=2025-04-29 |website=FDA |language=en}} There is also no evidence for the efficacy of hyperbaric oxygen therapy and its use is not recommended.{{Cite journal |last1=Sakulchit |first1=Teeranai |last2=Ladish |first2=Chris |last3=Goldman |first3=Ran D. |date=June 2017 |title=Hyperbaric oxygen therapy for children with autism spectrum disorder |journal=Canadian Family Physician Medecin de Famille Canadien |volume=63 |issue=6 |pages=446–448 |issn=1715-5258 |pmc=5471082 |pmid=28615394}}

Although sometimes used for autistic people, no good evidence recommends a gluten- and casein-free diet as a standard intervention.{{cite journal |vauthors=Gogou M, Kolios G |date=June 2018 |title=Are therapeutic diets an emerging additional choice in autism spectrum disorder management? |journal=World Journal of Pediatrics |type=Review |volume=14 |issue=3 |pages=215–223 |doi=10.1007/s12519-018-0164-4 |pmid=29846886 |s2cid=44155118 |quote=Current literature knowledge provides evidence that ketogenic and casein/gluten-free diet may have their own place in our reserve for the therapeutic management of specific subsets of children with autism. ... More clinical studies about the effect of gluten/caseinfree diet in these patients are available. However, available data arise from studies with small sample size and are still controversial. In general, despite encouraging data, no definite proof still exists. Under this view, the use of therapeutic diets in children with autism should be restricted to specific subgroups, such as children with autism and epilepsy or specific inborn errors of metabolism (ketogenic diet), children with known food intolerance/allergy or even children with food intolerance markers (gluten- and casein-free diet). Their implementation should always be guided by health care practitioners.}}{{cite journal |vauthors=Marí-Bauset S, Zazpe I, Mari-Sanchis A, Llopis-González A, Morales-Suárez-Varela M |date=December 2014 |title=Evidence of the gluten-free and casein-free diet in autism spectrum disorders: a systematic review |journal=Journal of Child Neurology |volume=29 |issue=12 |pages=1718–1727 |doi=10.1177/0883073814531330 |pmid=24789114 |s2cid=19874518 |hdl-access=free |hdl=10171/37087}}{{cite journal |vauthors=Millward C, Ferriter M, Calver S, Connell-Jones G |date=April 2008 |title=Gluten- and casein-free diets for autistic spectrum disorder |journal=The Cochrane Database of Systematic Reviews |issue=2 |pages=CD003498 |doi=10.1002/14651858.CD003498.pub3 |pmc=4164915 |pmid=18425890 |quote=Knivsberg 2002 "monitoring of the compliance with diet was not carried out" ... "several reports of children 'sneaking food' from siblings or classmates" |veditors=Ferriter M}} Problems documented in studies that have shown effects include transgressions of the diet, small sample size, the heterogeneity of the participants, and the possibility of a placebo effect.{{cite journal |display-authors=6 |vauthors=Hyman SL, Stewart PA, Foley J, Cain U, Peck R, Morris DD, Wang H, Smith T |date=January 2016 |title=The Gluten-Free/Casein-Free Diet: A Double-Blind Challenge Trial in Children with Autism |journal=Journal of Autism and Developmental Disorders |volume=46 |issue=1 |pages=205–220 |doi=10.1007/s10803-015-2564-9 |pmid=26343026 |s2cid=12884691 |quote=20 natural challenges when parents reported that children by mistake consumed foods containing gluten or casein.}}{{cite journal |vauthors=Siafis S, Çıray O, Schneider-Thoma J, Bighelli I, Krause M, Rodolico A, Ceraso A, Deste G, Huhn M, Fraguas D, Mavridis D, Charman T, Murphy DG, Parellada M, Arango C, Leucht S |date=2020 |title=Placebo response in pharmacological and dietary supplement trials of autism spectrum disorder (ASD): systematic review and meta-regression analysis |journal=Molecular Autism |volume=11 |issue=1 |page=66 |doi=10.1186/s13229-020-00372-z |pmc=7448339 |pmid=32847616 |doi-access=free}} Autistic children's preference for unconventional foods as well as gatrointestinal problems and lack of exercise can lead to reduction in bone cortical thickness, and this risk is greater in those on casein-free diets, as a consequence of the low intake of calcium and vitamin D.{{cite journal |vauthors=Tye C, Runicles AK, Whitehouse AJ, Alvares GA |year=2019 |title=Characterizing the Interplay Between Autism Spectrum Disorder and Comorbid Medical Conditions: An Integrative Review |journal=Frontiers in Psychiatry |type=Review |volume=9 |page=751 |doi=10.3389/fpsyt.2018.00751 |pmc=6354568 |pmid=30733689 |doi-access=free}}

Results of a systematic review on interventions to address health outcomes among autistic adults found emerging evidence to support mindfulness-based interventions for improving mental health. This includes decreasing stress, anxiety, ruminating thoughts, anger, and aggression.{{cite journal |display-authors=6 |vauthors=Benevides TW, Shore SM, Andresen ML, Caplan R, Cook B, Gassner DL, Erves JM, Hazlewood TM, King MC, Morgan L, Murphy LE, Purkis Y, Rankowski B, Rutledge SM, Welch SP, Wittig K |date=August 2020 |title=Interventions to address health outcomes among autistic adults: A systematic review |journal=Autism |volume=24 |issue=6 |pages=1345–1359 |doi=10.1177/1362361320913664 |pmc=7787674 |pmid=32390461 |doi-access=free}} An updated Cochrane review (2022) found evidence that music therapy likely supports the development of skills in social interaction, verbal communication, and nonverbal communication.{{cite journal |vauthors=Geretsegger M, Fusar-Poli L, Elefant C, Mössler KA, Vitale G, Gold C |date=May 2022 |title=Music therapy for autistic people |journal=The Cochrane Database of Systematic Reviews |volume=2022 |issue=5 |pages=CD004381 |doi=10.1002/14651858.CD004381.pub4 |pmc=9082683 |pmid=35532041}} Some studies on pet therapy have also shown effects, but further research is needed.{{Cite journal |last1=Xiao |first1=Ningkun |last2=Bagayi |first2=Vaishnavi |last3=Yang |first3=Dandan |last4=Huang |first4=Xinlin |last5=Zhong |first5=Lei |last6=Kiselev |first6=Sergey |last7=Bolkov |first7=Mikhail A. |last8=Tuzankina |first8=Irina A. |last9=Chereshnev |first9=Valery A. |date=2024 |title=Effectiveness of animal-assisted activities and therapies for autism spectrum disorder: a systematic review and meta-analysis |journal=Frontiers in Veterinary Science |volume=11 |page=1403527 |doi=10.3389/fvets.2024.1403527 |doi-access=free |issn=2297-1769 |pmc=11184216 |pmid=38895710}}

{{Main|Causes of autism}}

The exact causes of autism are unknown,{{cite book |title=Handbook of autism and pervasive developmental disorder: assessment, diagnosis, and treatment |publisher=Springer Nature |year=2022 |isbn=978-3-030-88538-0 |editor1-last=Matson |editor1-first=Johnny L. |series=Autism and Child Psychopathology Series |location=Cham |page=18 |language=en |doi=10.1007/978-3-030-88538-0 |oclc=1341298051 |quote=To date no one genetic feature or environmental cause has proven etiological in explaining most cases autism or has been able to account for rising rates of autism. |editor2-last=Sturmey |editor2-first=Peter |s2cid=251520573}}{{cite book |last1=Sauer |first1=Ann Katrin |title=Autism spectrum disorders |last2=Stanton |first2=Janelle E. |last3=Hans |first3=Sakshi |last4=Grabrucker |first4=Andreas M. |publisher=Exon Publications |others=Andreas M. Grabrucker |year=2021 |isbn=978-0-6450017-8-5 |editor-last=Grabrucker |editor-first=Andreas M. |location=Brisbane, Australia |publication-place=Brisbane |publication-date=20 August 2021 |pages=1–16 |language=en |chapter=Autism Spectrum Disorders: Etiology and Pathology |doi=10.36255/exonpublications.autismspectrumdisorders.2021.etiology |oclc=1280592589 |pmid=34495611 |quote=The cause of ASD is unknown, but several genetic and non-genetic risk factors have been characterized that, alone or in combination, are implicated in the development of ASD. |doi-access=free}}{{cite journal |last1=Kałużna-Czaplińska |first1=Joanna |last2=Żurawicz |first2=Ewa |last3=Jóźwik-Pruska |first3=Jagoda |year=2018 |title=Focus on the Social Aspect of Autism |journal=Journal of Autism and Developmental Disorders |language=en |publisher=Springer Nature |publication-date=29 November 2017 |volume=48 |issue=5 |pages=1861–1867 |doi=10.1007/s10803-017-3407-7 |issn=1573-3432 |pmc=5889772 |pmid=29188587 |quote=Despite extensive ASD research lasting more than 60 years, its causes are still unknown.}}{{cite journal |last1=Medavarapu |first1=Srinivas |last2=Marella |first2=Lakshmi Lavanya |last3=Sangem |first3=Aneela |last4=Kairam |first4=Ram |year=2019 |title=Where is the Evidence? A Narrative Literature Review of the Treatment Modalities for Autism Spectrum Disorders |journal=Cureus |language=en |publisher=Springer Nature |publication-date=16 January 2019 |volume=11 |issue=1 |pages=e3901 |doi=10.7759/cureus.3901 |issn=2168-8184 |pmc=6424545 |pmid=30911457 |quote=It is important to realize that the etiology of autism is unknown and at present, there is no cure, although there are interventions that may be effective in alleviating some symptoms and improving skills that may help autistic persons lead more productive lives. |doi-access=free}} with genetics likely being the largest contributing factor. It was long presumed a single cause at genetic, cognitive, and neural levels underpinned the social and non-social features (the classic triad).{{cite journal |vauthors=Happé F, Ronald A |date=December 2008 |title=The 'fractionable autism triad': a review of evidence from behavioural, genetic, cognitive and neural research |journal=Neuropsychology Review |volume=18 |issue=4 |pages=287–304 |doi=10.1007/s11065-008-9076-8 |pmid=18956240 |s2cid=13928876}} Increasingly, autism is assumed to be a complex condition with distinct, often co-occurring, causes for its core aspects.{{cite journal |vauthors=Happé F, Ronald A, Plomin R |date=October 2006 |title=Time to give up on a single explanation for autism |journal=Nature Neuroscience |volume=9 |issue=10 |pages=1218–1220 |doi=10.1038/nn1770 |pmid=17001340 |doi-access=free}} It is unlikely that autism has a single cause; research has identified many factors as potential contributors, including genetics, prenatal and perinatal (shortly after birth) factors, neuroanatomical anomalies, and environmental factors. It is possible to identify general factors, but much more difficult to pinpoint specific ones.{{cite journal |vauthors=Tager-Flusberg H |year=2010 |title=The origins of social impairments in autism spectrum disorder: studies of infants at risk |journal=Neural Networks |volume=23 |issue=8–9 |pages=1072–6 |doi=10.1016/j.neunet.2010.07.008 |pmc=2956843 |pmid=20800990}} Research into causes is complex due to challenges in identifying distinct biological subgroups within the autistic population.{{cite journal |vauthors=Altevogt BM, Hanson SL, Leshner AI |date=June 2008 |title=Autism and the environment: challenges and opportunities for research |url=http://pediatrics.aappublications.org/cgi/content/full/121/6/1225 |journal=Pediatrics |volume=121 |issue=6 |pages=1225–1229 |doi=10.1542/peds.2007-3000 |pmid=18519493 |archive-url=https://web.archive.org/web/20100115140620/http://pediatrics.aappublications.org/cgi/content/full/121/6/1225 |archive-date=15 January 2010 |s2cid=24595814}}

{{Main|Heritability of autism}}

File:Autism susceptibility genes effect on brain structure.png |volume=9 |issue=48 |page=48 |date=2018 |pmid=30237867 |pmc=6139139 |doi=10.1186/s13229-018-0229-1 |doi-access=free}} most of which influence the brain structure in a similar way.]]

Autism has a strong genetic basis, although the genetics of autism are complex and it is unclear whether autism is explained more by rare mutations with major effects, or by rare multi-gene interactions of common genetic variants.{{cite journal |vauthors=Abrahams BS, Geschwind DH |date=May 2008 |title=Advances in autism genetics: on the threshold of a new neurobiology |journal=Nature Reviews. Genetics |volume=9 |issue=5 |pages=341–355 |doi=10.1038/nrg2346 |pmc=2756414 |pmid=18414403}}{{cite journal |vauthors=Buxbaum JD |year=2009 |title=Multiple rare variants in the etiology of autism spectrum disorders |journal=Dialogues in Clinical Neuroscience |volume=11 |issue=1 |pages=35–43 |doi=10.31887/DCNS.2009.11.1/jdbuxbaum |pmc=3181906 |pmid=19432386}} {{as of|2018}}, it appeared that between 74% and 93% of autism likelihood is heritable.{{cite journal |vauthors=Lord C, Elsabbagh M, Baird G, Veenstra-Vanderweele J |date=August 2018 |title=Autism spectrum disorder |journal=The Lancet |volume=392 |issue=10146 |pages=508–520 |doi=10.1016/S0140-6736(18)31129-2 |pmc=7398158 |pmid=30078460 |s2cid=51922565}} Numerous genes have been found, with most loci individually explaining less than 1% of autism cases{{cite journal |vauthors=Persico AM, Napolioni V |date=August 2013 |title=Autism genetics |journal=Behavioural Brain Research |volume=251 |pages=95–112 |doi=10.1016/j.bbr.2013.06.012 |pmid=23769996 |s2cid=15721666}} and having only small effects. While these genetic variants are associated with a higher likelihood of being autistic, they do not individually determine whether someone will be autistic.{{cite journal |vauthors=Werling DM, Brand H, An JY, Stone MR, Zhu L, Glessner JT, Collins RL, Dong S, Layer RM, Markenscoff-Papadimitriou E, Farrell A, Schwartz GB, Wang HZ, Currall BB, Zhao X, Dea J, Duhn C, Erdman CA, Gilson MC, Yadav R, Handsaker RE, Kashin S, Klei L, Mandell JD, Nowakowski TJ, Liu Y, Pochareddy S, Smith L, Walker MF, Waterman MJ, He X, Kriegstein AR, Rubenstein JL, Sestan N, McCarroll SA, Neale BM, Coon H, Willsey AJ, Buxbaum JD, Daly MJ, State MW, Quinlan AR, Marth GT, Roeder K, Devlin B, Talkowski ME, Sanders SJ |display-authors=6 |title=An analytical framework for whole-genome sequence association studies and its implications for autism spectrum disorder |journal=Nature Genetics |volume=50 |issue=5 |pages=727–736 |date=April 2018 |pmid=29700473 |pmc=5961723 |doi=10.1038/s41588-018-0107-y}} Complexity arises due to interactions among multiple genes, the environment, and heritable epigenetic factors (which influence gene expression without changing DNA sequence).{{cite journal |vauthors=Rapin I, Tuchman RF |date=October 2008 |title=Autism: definition, neurobiology, screening, diagnosis |journal=Pediatric Clinics of North America |volume=55 |issue=5 |pages=1129–46, viii |doi=10.1016/j.pcl.2008.07.005 |pmid=18929056}}

Typically, autism is not traceable to a single-gene (Mendelian) mutation or chromosome anomaly, and no associated genetic syndrome selectively causes autism. If autism is one characteristic of a broader medical condition, such as fragile X syndrome, it is referred to as syndromic autism, as opposed to non-syndromic or idiopathic autism, which is typically polygenic without a known cause.{{Cite journal |last1=Fernandez |first1=Bridget A. |last2=Scherer |first2=Stephen W. |date=2017 |title=Syndromic autism spectrum disorders: moving from a clinically defined to a molecularly defined approach |journal=Dialogues in Clinical Neuroscience |volume=19 |issue=4 |pages=353–371 |doi=10.31887/DCNS.2017.19.4/sscherer |issn=1958-5969 |pmc=5789213 |pmid=29398931}} Syndromic autism is present in approximately 25% of autistic people.{{Cite journal |last1=Wiśniowiecka-Kowalnik |first1=Barbara |last2=Nowakowska |first2=Beata Anna |date=2019-02-01 |title=Genetics and epigenetics of autism spectrum disorder—current evidence in the field |journal=Journal of Applied Genetics |language=en |volume=60 |issue=1 |pages=37–47 |doi=10.1007/s13353-018-00480-w |issn=2190-3883 |pmc=6373410 |pmid=30627967}} Research has suggested that autistic people with intellectual disability tend to have rarer, more impactful, genetic mutations than those found in people diagnosed solely with autism.{{cite journal |last1=Jensen |first1=M. |last2=Smolen |first2=C. |last3=Girirajan |first3=S. |date=2020 |title=Gene discoveries in autism are biased towards co-occuring with intellectual disability |journal=Journal of Medical Genetics |volume=57 |issue=9 |pages=647–652 |doi=10.1136/jmedgenet-2019-106476 |pmc=7483239 |pmid=32152248}} A number of genetic syndromes causing intellectual disability may also be co-occurring with autism, including fragile X, Down, Prader-Willi, Angelman, Williams syndrome,{{cite journal |vauthors=Zafeiriou DI, Ververi A, Vargiami E |date=June 2007 |title=Childhood autism and associated comorbidities |journal=Brain & Development |volume=29 |issue=5 |pages=257–272 |doi=10.1016/j.braindev.2006.09.003 |pmid=17084999 |s2cid=16386209}} branched-chain keto acid dehydrogenase kinase deficiency,{{cite web |last=Schenkman |first=Lauren |date=21 February 2023 |title=Dietary changes ease traits in rare autism-linked condition |url=https://www.spectrumnews.org/news/dietary-changes-ease-traits-in-rare-autism-linked-condition/ |access-date=23 February 2023 |website=Spectrum |language=en-US |archive-date=25 March 2023 |archive-url=https://web.archive.org/web/20230325004116/https://www.spectrumnews.org/news/dietary-changes-ease-traits-in-rare-autism-linked-condition/ |url-status=live}} and SYNGAP1-related intellectual disability.{{cite journal |display-authors=6 |vauthors=Satterstrom FK, Kosmicki JA, Wang J, Breen MS, De Rubeis S, An JY, Peng M, Collins R, Grove J, Klei L, Stevens C, Reichert J, Mulhern MS, Artomov M, Gerges S, Sheppard B, Xu X, Bhaduri A, Norman U, Brand H, Schwartz G, Nguyen R, Guerrero EE, Dias C, Betancur C, Cook EH, Gallagher L, Gill M, Sutcliffe JS, Thurm A, Zwick ME, Børglum AD, State MW, Cicek AE, Talkowski ME, Cutler DJ, Devlin B, Sanders SJ, Roeder K, Daly MJ, Buxbaum JD |date=February 2020 |title=Large-Scale Exome Sequencing Study Implicates Both Developmental and Functional Changes in the Neurobiology of Autism |journal=Cell |volume=180 |issue=3 |pages=568–584.e23 |doi=10.1016/j.cell.2019.12.036 |pmc=7250485 |pmid=31981491}}{{cite journal |vauthors=Holder Jr JL, Hamdan FF, Michaud JL |date=2019 |title=SYNGAP1-Related Intellectual Disability |url=https://www.ncbi.nlm.nih.gov/books/NBK537721/ |journal=Gene Reviews |type=Review |pmid=30789692 |access-date=25 July 2020 |archive-date=2 April 2021 |archive-url=https://web.archive.org/web/20210402192137/https://www.ncbi.nlm.nih.gov/books/NBK537721/ |url-status=live}}

Current research suggests that autism is associated with a large number of genes—potentially numbering in the hundreds or thousands—that influence neural development and connectivity. These genes are involved in key neuronal processes such as protein synthesis, synaptic activity, cell adhesion, and the formation and remodeling of synapses, as well as the regulation of excitatory and inhibitory neurotransmission. Studies have identified lower expression of genes linked to the inhibitory neurotransmitter gamma-aminobutyric acid, alongside higher expression of genes associated with glial (e.g., astrocytes) and immune (e.g., microglia) cells, correlating with higher numbers of these cells in postmortem brain tissue. Genes associated with variation in the mTOR signaling pathway, which is involved in cell growth and survival, are also under investigation.{{cite journal |vauthors=Chen JA, Peñagarikano O, Belgard TG, Swarup V, Geschwind DH |date=2015 |title=The emerging picture of autism spectrum disorder: genetics and pathology |journal=Annual Review of Pathology: Mechanisms of Disease |type=Review |volume=10 |pages=111–44 |doi=10.1146/annurev-pathol-012414-040405 |pmid=25621659 |doi-access=free}} Some hypotheses from evolutionary psychiatry propose that certain autism-associated genes may persist in the population due to their potential links to traits such as intelligence, systemising abilities, or innovation.{{cite journal |vauthors=Crespi BJ |title=Autism As a Disorder of High Intelligence |journal=Frontiers in Neuroscience |volume=10 |page=300 |date=30 June 2016 |pmid=27445671 |pmc=4927579 |doi=10.3389/fnins.2016.00300 |doi-access=free}}{{cite book |vauthors=Baron-Cohen S |title=The pattern seekers: how autism drives human invention |date=10 November 2020 |publisher=Basic Books |isbn=978-1-5416-4713-8|oclc=1204602315}}

If parents have one autistic child, the chance of having a second autistic child ranges from 7% to 20%. If the autistic child is an identical twin, the other will be autistic 36% to 95% of the time. A fraternal twin is autistic up to 31% of the time.{{cite journal |last1=Rosenberg |first1=RE |last2=Law |first2=JK |last3=Yenokyan |first3=G |last4=McGready |first4=J |last5=Kauffman |first5=WE |last6=Law |first6=PA |date=October 2009 |title=Characteristics and concordance of autism spectrum disorders among 277 twin pairs |journal=Archives of Pediatrics & Adolescent Medicine |volume=163 |issue=10 |pages=907–914 |doi=10.1001/archpediatrics.2009.98 |pmid=19805709}} Although autism is highly heritable, many autistic individuals have only non-autistic family members. In some cases, this may be explained by de novo structural variations—such as deletions, duplications, or inversions—that arise spontaneously during meiosis and are not present in the parents' genomes.{{cite journal |vauthors=Cook EH, Scherer SW |date=October 2008 |title=Copy-number variations associated with neuropsychiatric conditions |journal=Nature |volume=455 |issue=7215 |pages=919–923 |bibcode=2008Natur.455..919C |doi=10.1038/nature07458 |pmid=18923514 |s2cid=4377899}}{{cite journal |display-authors=6 |vauthors=Brandler WM, Antaki D, Gujral M, Noor A, Rosanio G, Chapman TR, Barrera DJ, Lin GN, Malhotra D, Watts AC, Wong LC, Estabillo JA, Gadomski TE, Hong O, Fajardo KV, Bhandari A, Owen R, Baughn M, Yuan J, Solomon T, Moyzis AG, Maile MS, Sanders SJ, Reiner GE, Vaux KK, Strom CM, Zhang K, Muotri AR, Akshoomoff N, Leal SM, Pierce K, Courchesne E, Iakoucheva LM, Corsello C, Sebat J |date=April 2016 |title=Frequency and Complexity of De Novo Structural Mutation in Autism |journal=American Journal of Human Genetics |volume=98 |issue=4 |pages=667–679 |doi=10.1016/j.ajhg.2016.02.018 |pmc=4833290 |pmid=27018473}}{{cite journal |vauthors=Beaudet AL |date=May 2007 |title=Autism: highly heritable but not inherited |journal=Nature Medicine |volume=13 |issue=5 |pages=534–536 |doi=10.1038/nm0507-534 |pmid=17479094 |s2cid=11673879}} The likelihood of being autistic is greater with older fathers than with older mothers; two potential explanations are the known increase in the number of mutations in older sperm and the hypothesis that men marry later if they carry a genetic predisposition and show some signs of autism.{{Cite journal |last=Geschwind |first=Daniel H. |date=2008-10-31 |title=Autism: Many Genes, Common Pathways? |journal=Cell |language=English |volume=135 |issue=3 |pages=391–395 |doi=10.1016/j.cell.2008.10.016 |issn=0092-8674 |pmc=2756410 |pmid=18984147}}

Certain factors during pregnancy and birth may increase the likelihood of autism,{{cite journal |last1=Wang |first1=Chengzhong |last2=Geng |first2=Hua |last3=Liu |first3=Weidong |last4=Zhang |first4=Guiqin |year=2017 |title=Prenatal, perinatal, and postnatal factors associated with autism: A meta-analysis |journal=Medicine |publisher=Lippincott Williams & Wilkins |volume=96 |issue=18 |pages=e6696 |doi=10.1097/MD.0000000000006696 |pmc=5419910 |pmid=28471964}} although no single factor is conclusive and study results are often inconsistent.{{cite journal |vauthors=Gardener H, Spiegelman D, Buka SL |date=August 2011 |title=Perinatal and neonatal risk factors for autism: a comprehensive meta-analysis |journal=Pediatrics |volume=128 |issue=2 |pages=344–55 |doi=10.1542/peds.2010-1036 |pmc=3387855 |pmid=21746727}} These factors include advanced parental age,{{cite journal |last1=Sandin |first1=Sven |last2=Hultman |first2=Christina M. |last3=Kolevzon |first3=Alexander |last4=Gross |first4=Raz |last5=MacCabe |first5=James H. |last6=Reichenberg |first6=Abraham |year=2012 |title=Advancing Maternal Age Is Associated With Increasing Risk for Autism: A Review and Meta-Analysis |journal=Journal of the American Academy of Child & Adolescent Psychiatry |publisher=Elsevier |volume=51 |issue=5 |pages=477–486.e1 |doi=10.1016/j.jaac.2012.02.018 |pmid=22525954}}{{cite journal |last1=de Kluiver |first1=Hilde |last2=Buizer-Voskamp |first2=Jacobine E. |last3=Dolan |first3=Conor V. |last4=Boomsma |first4=Dorret I. |year=2017 |title=Paternal age and psychiatric disorders: A review |journal=American Journal of Medical Genetics |publisher=Wiley-Blackwell |volume=174 |issue=3 |pages=202–213 |doi=10.1002/ajmg.b.32508 |pmc=5412832 |pmid=27770494}} maternal health conditions (e.g., gestational diabetes, infections, inflammation{{cite journal |vauthors=Vohr BR, Poggi Davis E, Wanke CA, Krebs NF |date=April 2017 |title=Neurodevelopment: The Impact of Nutrition and Inflammation During Preconception and Pregnancy in Low-Resource Settings |journal=Pediatrics |type=Review |volume=139 |issue=Suppl 1 |pages=S38–S49 |doi=10.1542/peds.2016-2828F |pmid=28562247 |s2cid=28637473 |doi-access=free}}), exposure to certain medications (e.g., valproate), and some environmental exposures like significant air pollution during pregnancy.{{cite journal |display-authors=6 |vauthors=Lam J, Sutton P, Kalkbrenner A, Windham G, Halladay A, Koustas E, Lawler C, Davidson L, Daniels N, Newschaffer C, Woodruff T |year=2016 |title=A Systematic Review and Meta-Analysis of Multiple Airborne Pollutants and Autism Spectrum Disorder |journal=PLOS ONE |volume=11 |issue=9 |pages=e0161851 |bibcode=2016PLoSO..1161851L |doi=10.1371/journal.pone.0161851 |pmc=5031428 |pmid=27653281 |doi-access=free}} While many environmental factors have been investigated, few have established links, and some prominent claims (e.g. vaccines or parenting styles) have been disproven.{{Cite journal |last=Amaral |first=David G. |date=2017 |title=Examining the Causes of Autism |journal=Cerebrum: The Dana Forum on Brain Science |volume=2017 |pages=cer–01–17 |issn=1524-6205 |pmc=5501015 |pmid=28698772}}

{{Main|Vaccines and autism|MMR vaccine and autism}}

Parents may first become aware of autistic characteristics in their child around the time of a routine vaccination. This has led to unsupported and disproven theories blaming vaccine "overload", the vaccine preservative thiomersal, or the MMR vaccine for causing autism.{{cite journal |vauthors=Gerber JS, Offit PA |date=February 2009 |title=Vaccines and autism: a tale of shifting hypotheses |journal=Clinical Infectious Diseases |volume=48 |issue=4 |pages=456–461 |doi=10.1086/596476 |pmc=2908388 |pmid=19128068}} In 1998, British physician and academic Andrew Wakefield led a fraudulent, litigation-funded study that suggested that the MMR vaccine may cause autism.{{cite news |url=https://www.thetimes.co.uk/article/mmr-doctor-andrew-wakefield-fixed-data-on-autism-mgj82qsk50g |title=MMR doctor Andrew Wakefield fixed data on autism |vauthors=Deer B |date=8 February 2009 |newspaper=The Sunday Times |access-date=19 January 2019 |archive-date=20 March 2017 |archive-url=https://web.archive.org/web/20170320003216/http://www.thesundaytimes.co.uk/sto/public/news/article148992.ece |url-status=live}}{{cite news |url=https://www.theguardian.com/society/2010/feb/02/lancet-retracts-mmr-paper |title=Lancet retracts 'utterly false' MMR paper |vauthors=Boseley S |date=2 February 2010 |newspaper=The Guardian |access-date=19 January 2019 |archive-date=17 January 2021 |archive-url=https://web.archive.org/web/20210117232206/https://www.theguardian.com/society/2010/feb/02/lancet-retracts-mmr-paper |url-status=live}}{{cite book |chapter=Influenza Vaccine |chapter-url=https://nap.nationalacademies.org/read/13164/chapter/8 |title=Adverse Effects of Vaccines: Evidence and Causality |url=https://www.nap.edu/read/13164/ |doi=10.17226/13164 |pmid=24624471 |isbn=978-0-309-21435-3 |others=Committee to Review Adverse Effects of Vaccines, Board on Population Health and Public Health Practice |veditors=Stratton K, Ford A, Rusch E, Clayton EW |editor-link4=Ellen Wright Clayton |location=Washington, D.C. |publisher=Institute of Medicine/National Academies Press |date=August 2011 |access-date=19 January 2019 |archive-date=27 August 2021 |archive-url=https://web.archive.org/web/20210827234139/https://www.nap.edu/read/13164/chapter/1 |url-status=live}}{{cite journal |vauthors=Flaherty DK |title=The vaccine-autism connection: a public health crisis caused by unethical medical practices and fraudulent science |journal=The Annals of Pharmacotherapy |volume=45 |issue=10 |pages=1302–1304 |date=October 2011 |pmid=21917556 |doi=10.1345/aph.1Q318 |s2cid=39479569}}{{cite journal |vauthors=Godlee F, Smith J, Marcovitch H |date=January 2011 |title=Wakefield's article linking MMR vaccine and autism was fraudulent |journal=British Medical Journal |volume=342 |pages=c7452 |doi=10.1136/bmj.c7452 |pmid=21209060 |s2cid=43640126}} His co-authors have since recanted the claims made in the study.{{cite magazine |first=Maggie |last=McKee |date=4 March 2004 |title=Controversial MMR and autism study retracted |magazine=New Scientist |url=https://www.newscientist.com/article/dn4743-controversial-mmr-and-autism-study-retracted/ |archive-url=https://web.archive.org/web/20070813055100/http://www.newscientist.com/article.ns?id=dn4743 |archive-date=13 August 2007 |access-date=21 October 2015}}

Two versions of the vaccine causation hypothesis were that autism results from brain damage caused by either the MMR vaccine itself, or by mercury used as a vaccine preservative.{{cite journal |vauthors=Tan M, Parkin JE |title=Route of decomposition of thiomersal (thimerosal) |journal=International Journal of Pharmaceutics |volume=208 |issue=1–2 |pages=23–34 |date=November 2000 |pmid=11064208 |doi=10.1016/S0378-5173(00)00514-7}} No convincing scientific evidence supports these claims. They are biologically implausible, and further evidence continues to refute them, including the observation that the rate of autism continues to climb despite elimination of thimerosal from most routine vaccines given to children from birth to 6 years of age.{{cite web |title=Understanding Vaccines, Mercury and Thimerosal |url=https://www.fda.gov/media/83535/download |website=Food and Drug Administration |access-date=6 July 2023 |archive-date=6 May 2023 |archive-url=https://web.archive.org/web/20230506050839/https://www.fda.gov/media/83535/download |url-status=live}}{{cite journal |last=Dona |first=Asif |date=2006 |title=Immunizations and Autism: A Review of the Literature |url=https://www.cambridge.org/core/services/aop-cambridge-core/content/view/16B999364BFFD9F0DA3B09F25C1DE28C/S031716710000528Xa.pdf/immunizations-and-autism-a-review-of-the-literature.pdf |journal=Canadian Journal of Neurological Sciences |volume=33 |issue=4 |pages=341–346 |doi=10.1017/S031716710000528X |pmid=17168158 |s2cid=4670282 |access-date=6 July 2023 |archive-date=7 July 2023 |archive-url=https://web.archive.org/web/20230707171814/https://www.cambridge.org/core/services/aop-cambridge-core/content/view/16B999364BFFD9F0DA3B09F25C1DE28C/S031716710000528Xa.pdf/immunizations-and-autism-a-review-of-the-literature.pdf |url-status=live}}{{cite web |title=Thimerosal questions and answers |url=https://www.fda.gov/vaccines-blood-biologics/vaccines/thimerosal-vaccines-questions-and-answers |website=US FDA |date=18 February 2021 |access-date=6 July 2023 |archive-date=18 April 2023 |archive-url=https://web.archive.org/web/20230418195953/https://www.fda.gov/vaccines-blood-biologics/vaccines/thimerosal-vaccines-questions-and-answers |url-status=live}}{{cite journal |vauthors=Waterhouse L |title=Autism overflows: increasing prevalence and proliferating theories |journal=Neuropsychology Review |volume=18 |issue=4 |pages=273–286 |date=December 2008 |pmid=19015994 |doi=10.1007/s11065-008-9074-x |s2cid=8863638}}{{cite web |title=87% of Flu Vaccine Doses have Reduced or "no" (only trace amounts of) Thimerosal |url=https://www.cdc.gov/flu/prevent/vaxsupply.htm |website=Centers for Disease Control and Prevention |date=16 September 2022 |access-date=6 July 2023 |archive-date=7 July 2023 |archive-url=https://web.archive.org/web/20230707162416/https://www.cdc.gov/flu/prevent/vaxsupply.htm |url-status=live}}

A 2014 meta-analysis examined ten major studies on autism and vaccines involving 1.25 million children worldwide; it concluded that neither the vaccine preservative thimerosal (mercury), nor the MMR vaccine, which has never contained thimerosal,{{cite web |title=Frequently Asked Questions about Thimerosal |url=https://www.cdc.gov/vaccinesafety/concerns/thimerosal/faqs.html |access-date=21 February 2017 |publisher=Centers for Disease Control and Prevention |archive-date=7 May 2019 |archive-url=https://web.archive.org/web/20190507032946/https://www.cdc.gov/vaccinesafety/concerns/thimerosal/faqs.html |url-status=live}} lead to autism.{{cite journal |vauthors=Taylor LE, Swerdfeger AL, Eslick GD |title=Vaccines are not associated with autism: an evidence-based meta-analysis of case-control and cohort studies |journal=Vaccine |volume=32 |issue=29 |pages=3623–3629 |date=June 2014 |pmid=24814559 |doi=10.1016/j.vaccine.2014.04.085}} Despite this, misplaced parental concern has led to lower rates of childhood immunizations, outbreaks of previously controlled childhood diseases in some countries, and the preventable deaths of several children.Vaccines and autism:

• {{cite journal |vauthors=Doja A, Roberts W |date=November 2006 |title=Immunizations and autism: a review of the literature |journal=The Canadian Journal of Neurological Sciences. Le Journal Canadien des Sciences Neurologiques |volume=33 |issue=4 |pages=341–346 |doi=10.1017/s031716710000528x |pmid=17168158 |doi-access=free}}
• {{cite journal |vauthors=Gerber JS, Offit PA |date=February 2009 |title=Vaccines and autism: a tale of shifting hypotheses |journal=Clinical Infectious Diseases |volume=48 |issue=4 |pages=456–461 |doi=10.1086/596476 |pmc=2908388 |pmid=19128068}}
• {{cite journal |vauthors=Gross L |date=May 2009 |title=A broken trust: lessons from the vaccine--autism wars |journal=PLOS Biology |volume=7 |issue=5 |pages=e1000114 |doi=10.1371/journal.pbio.1000114 |pmc=2682483 |pmid=19478850 |doi-access=free}}
• {{cite journal |vauthors=Paul R |date=June 2009 |title=Parents ask: Am I risking autism if I vaccinate my children? |journal=Journal of Autism and Developmental Disorders |volume=39 |issue=6 |pages=962–963 |doi=10.1007/s10803-009-0739-y |pmid=19363650 |s2cid=34467853}}
• {{cite journal |vauthors=Poland GA, Jacobson RM |date=January 2011 |title=The age-old struggle against the antivaccinationists |journal=New England Journal of Medicine |volume=364 |issue=2 |pages=97–99 |doi=10.1056/NEJMp1010594 |pmid=21226573 |doi-access=free}}{{cite journal |vauthors=McBrien J, Murphy J, Gill D, Cronin M, O'Donovan C, Cafferkey MT |date=July 2003 |title=Measles outbreak in Dublin, 2000 |journal=The Pediatric Infectious Disease Journal |volume=22 |issue=7 |pages=580–584 |doi=10.1097/00006454-200307000-00002 |pmid=12867830}}

Various theoretical frameworks attempt to integrate these underlying genetic and environmental causes with observed neurobiological findings and behavioral traits. For instance, the Intense World Theory proposes that a higher neural responsiveness in autism leads to more intense sensory perception, attention, memory, and emotional responses, shaping the individual's experience.{{Cite journal |last1=Markram |first1=Kamila |last2=Markram |first2=Henry |date=2010-12-21 |title=The Intense World Theory – A Unifying Theory of the Neurobiology of Autism |journal=Frontiers in Human Neuroscience |language=English |volume=4 |page=224 |doi=10.3389/fnhum.2010.00224 |doi-access=free |pmid=21191475 |pmc=3010743 |issn=1662-5161}} The Enhanced Perceptual Functioning (EPF) model of autism posits that superior and more independent functioning of auditory and visual perception is the root cause of the specific pattern of cognitive, behavioral, and neural performance observed in autistic people.{{Citation |last1=Mukerji |first1=Cora |title=Enhanced Perceptual Functioning |date=2013 |encyclopedia=Encyclopedia of Autism Spectrum Disorders |pages=1117–1118 |editor-last=Volkmar |editor-first=Fred R. |url=https://link.springer.com/referenceworkentry/10.1007/978-1-4419-1698-3_723 |access-date=2025-04-30 |place=New York, NY |publisher=Springer |language=en |doi=10.1007/978-1-4419-1698-3_723 |isbn=978-1-4419-1698-3 |last2=Mottron |first2=Laurent |last3=McPartland |first3=James C.}} The model asserts the fundamental importance of perception, arguing it is more central to the autistic phenotype than social or higher-order cognitive processes.

Beyond these overarching models of causation and brain function, numerous cognitive theories have been developed to explain specific patterns of information processing common in autistic individuals, thereby shedding light on aspects of the autistic phenotype.{{Cite book |last1=Fletcher-Watson |first1=Sue |title=Autism: A New Introduction to Psychological Theory and Current Debate |last2=Happé |first2=Francesca |date=2019 |publisher=Taylor & Francis Group |isbn=978-1-138-10612-3 |edition=2nd |location=Milton}} Examples include theories suggesting a tendency to focus on details over the broader context (weak central coherence theory), and distinct cognitive styles related to analyzing systems versus empathizing with others (empathising–systemising theory). While these cognitive accounts describe how autistic traits may manifest, they are generally viewed as explanations of the behavioral and cognitive consequences of the underlying neurobiological development rather than primary causes themselves.

{{See also|Evolutionary psychology|Pleiotropy#Autism and schizophrenia}}

Research exploring the evolutionary benefits of autism and associated genes has suggested that autistic people may have played a "unique role in technological spheres and understanding of natural systems" in the course of human development.{{cite web |vauthors=Spikins P |title=How our autistic ancestors played an important role in human evolution |url=https://theconversation.com/how-our-autistic-ancestors-played-an-important-role-in-human-evolution-73477 |website=The Conversation |language=en |date=27 March 2017 |access-date=28 June 2022 |archive-date=28 June 2022 |archive-url=https://web.archive.org/web/20220628105438/https://theconversation.com/how-our-autistic-ancestors-played-an-important-role-in-human-evolution-73477 |url-status=live}}{{cite book |vauthors=Spikins P |veditors=Fitzgerald M |title=Recent Advances in Autism Spectrum Disorders |volume=II |date=6 March 2013 |language=en |chapter=The Stone Age Origins of Autism}} It has been suggested that autism may have arisen as "a slight trade off for other traits that are seen as highly advantageous", providing "advantages in tool making and mechanical thinking", with speculation that the condition may "reveal itself to be the result of a balanced polymorphism, like sickle cell anemia, that is advantageous in a certain mixture of genes and disadvantageous in specific combinations".{{cite journal |vauthors=Lomelin DE |title=An Examination of Autism Spectrum Disorders in Relation to Human Evolution and Life History Theory |journal=Nebraska Anthropologist |date=2010 |volume=57 |url=https://digitalcommons.unl.edu/nebanthro/57/ |access-date=28 June 2022 |archive-date=9 May 2022 |archive-url=https://web.archive.org/web/20220509140740/https://digitalcommons.unl.edu/nebanthro/57/ |url-status=live}} In 2011, a paper in Evolutionary Psychology proposed that autistic traits, including increased spatial intelligence, concentration and memory, could have been naturally selected to enable self-sufficient foraging in a more (although not completely) solitary environment. This is called the "Solitary Forager Hypothesis".{{cite journal |vauthors=Reser JE |title=Conceptualizing the autism spectrum in terms of natural selection and behavioral ecology: the solitary forager hypothesis |journal=Evolutionary Psychology |volume=9 |issue=2 |pages=207–238 |date=May 2011 |pmid=22947969 |doi=10.1177/147470491100900209 |s2cid =25378900 |doi-access=free|pmc=10480880 }}{{cite news |title=Autism may have had advantages in humans' hunter-gatherer past, researcher believes |url=https://www.sciencedaily.com/releases/2011/06/110603122849.htm |website=ScienceDaily |agency=University of Southern California |language=en |date=3 June 2011 |access-date=28 June 2022 |archive-date=28 June 2022 |archive-url=https://web.archive.org/web/20220628105438/https://www.sciencedaily.com/releases/2011/06/110603122849.htm |url-status=live}}{{cite web |vauthors=Rudacille D |title=Lonely hunters |url=https://www.spectrumnews.org/opinion/lonely-hunters/ |website=Spectrum News |date=8 July 2011 |access-date=28 June 2022 |archive-date=16 August 2022 |archive-url=https://web.archive.org/web/20220816004226/https://www.spectrumnews.org/opinion/lonely-hunters/ |url-status=live}} A 2016 paper examines Asperger syndrome as "an alternative prosocial adaptive strategy" that may have developed as a result of the emergence of "collaborative morality" in the context of small-scale hunter-gathering, i.e., where "a positive social reputation for making a contribution to group wellbeing and survival" becomes more important than complex social understanding.{{cite journal |vauthors=Spikins P, Wright B, Hodgson D |title=Are there alternative adaptive strategies to human pro-sociality? The role of collaborative morality in the emergence of personality variation and autistic traits |journal=Time and Mind |date=1 October 2016 |volume=9 |issue=4 |pages=289–313 |doi=10.1080/1751696X.2016.1244949 |s2cid=151820168 |issn=1751-696X |doi-access=free}}

Some research suggests that recent human evolution may be a driving force in the rise of autism in recent human populations. Studies in evolutionary medicine indicate that as cultural evolution outpaces biological evolution, disorders linked to bodily dysfunction increase in prevalence due to lack of contact with pathogens and negative environmental conditions that once widely affected ancestral populations. Because natural selection favors reproduction over health and longevity, the lack of this impetus to adapt to certain harmful circumstances creates a tendency for genes in descendant populations to over-express themselves, which may contribute to mental conditions and autoimmune diseases, for example.{{cite news |last=Harvard University |date=11 January 2020 |title=Ongoing human evolution could explain recent rise in certain disorders |work=ScienceDaily |url=https://www.sciencedaily.com/releases/2010/01/100111102538.htm |access-date=24 May 2020 |archive-date=6 February 2017 |archive-url=https://web.archive.org/web/20170206012836/https://www.sciencedaily.com/releases/2010/01/100111102538.htm |url-status=live}} Conversely, noting the failure to find specific alleles that reliably cause autism or rare mutations that account for more than 5% of the heritable variation in autism established by twin and adoption studies, research in evolutionary psychiatry has concluded that it is unlikely that there is selection pressure for autism when considering that autistic people and their siblings tend to have fewer offspring on average than non-autistic people, and instead that autism is probably better explained as a by-product of adaptive traits caused by antagonistic pleiotropy and by genes that are retained due to a fitness landscape with an asymmetric distribution.{{cite book|last=Nesse|first=Randolph M.|author-link=Randolph M. Nesse|year=2019|chapter=14. Minds Unbalanced on Fitness Cliffs|title=Good Reasons for Bad Feelings: Insights from the Frontier of Evolutionary Psychiatry|place=New York|publisher=Dutton|pages=245–261|isbn=978-1-101-98566-3}}{{cite book|last=Nesse|first=Randolph M.|editor-last=Buss|editor-first=David M.|editor-link=David Buss|year=2016|orig-date=2005|chapter=43. Evolutionary Psychology and Mental Health|title=The Handbook of Evolutionary Psychology, Volume 2: Integrations|place=Hoboken, NJ|publisher=Wiley|edition=2nd|pages=1018–1019|isbn=978-1-118-75580-8}}{{cite magazine|last=Nesse|first=Randolph M.|date=March 4, 2019|title=The Puzzle of the Unbalanced Mind|magazine=Psychology Today|url=https://www.psychologytoday.com/us/articles/201903/the-puzzle-the-unbalanced-mind|access-date=October 13, 2024}}

{{Main|Epidemiology of autism}}

The World Health Organization estimates about 1 in 100 children were autistic between 2012 and 2021 with a trend of increasing prevalence over time. But this estimate may reflect an underestimate of prevalence in low- and middle-income countries.{{cite web |date=30 March 2022 |title=Autism |url=https://www.who.int/news-room/fact-sheets/detail/autism-spectrum-disorders |access-date=8 May 2022 |website=World Health Organization |language=en |archive-date=10 April 2020 |archive-url=https://web.archive.org/web/20200410103835/https://www.who.int/news-room/fact-sheets/detail/autism-spectrum-disorders |url-status=live}} The number of people diagnosed has increased considerably since the 1990s, and research suggests this may be due to increased recognition of autism.{{cite journal |display-authors=6 |vauthors=Russell G, Stapley S, Newlove-Delgado T, Salmon A, White R, Warren F, Pearson A, Ford T |date=August 2021 |title=Time trends in autism diagnosis over 20 years: a UK population-based cohort study |journal=Journal of Child Psychology and Psychiatry, and Allied Disciplines |issn=0021-9630 |eissn=1469-7610 |oclc=01307942 |volume=63 |issue=6 |pages=674–682 |doi=10.1111/jcpp.13505 |pmid=34414570 |quote=The figure starkly illustrates an overall 787% increase in recorded incidence of autism diagnosis over 20 years. |s2cid=237242123 |doi-access=free|hdl=10871/126929 |hdl-access=free}}

Males are about three times more likely to be diagnosed with autism than females.{{Cite journal |last1=Loomes |first1=Rachel |last2=Hull |first2=Laura |last3=Mandy |first3=William Polmear Locke |date=2017-06-01 |title=What Is the Male-to-Female Ratio in Autism Spectrum Disorder? A Systematic Review and Meta-Analysis |url=https://www.jaacap.org/article/S0890-8567(17)30152-1/abstract |journal=Journal of the American Academy of Child & Adolescent Psychiatry |language=English |volume=56 |issue=6 |pages=466–474 |doi=10.1016/j.jaac.2017.03.013 |issn=0890-8567 |pmid=28545751}} Several theories about the higher prevalence in males have been investigated.{{cite journal |vauthors=Chaste P, Leboyer M |date=September 2012 |title=Autism risk factors: genes, environment, and gene-environment interactions |journal=Dialogues in Clinical Neuroscience |volume=14 |issue=3 |pages=281–292 |doi=10.31887/DCNS.2012.14.3/pchaste |pmc=3513682 |pmid=23226953}} Girls, for example, are more likely to have associated cognitive disability, suggesting that less obvious forms of autism are likely being missed in girls and women.{{sfn|ICD-11|loc="Females diagnosed with autism spectrum disorder are more frequently diagnosed with co-occurring disorders of intellectual development, suggesting that less severe presentations may go undetected as compared to males"}} Prevalence differences may also be a result of gender differences in expression of characteristics, with autistic women and girls showing less atypical behaviors and therefore being less likely to be diagnosed with autism.{{cite journal |vauthors=Tsakanikos E, Underwood L, Kravariti E, Bouras N, McCarthy J |title=Gender differences in co-morbid psychopathology and clinical management in adults with autism spectrum disorders |journal=Research in Autism Spectrum Disorders |volume=5 |issue=2 |year=2011 |pages=803–808 |issn=1750-9467 |doi=10.1016/j.rasd.2010.09.009}} Most professionals believe that race, ethnicity, and socioeconomic background do not affect the occurrence of autism.{{cite journal |vauthors=Bertoglio K, Hendren RL |date=March 2009 |title=New developments in autism |journal=Psychiatric Clinics of North America |volume=32 |issue=1 |pages=1–14 |doi=10.1016/j.psc.2008.10.004 |pmid=19248913}}

The Centers for Disease Control's Autism and Developmental Disabilities Monitoring (ADDM) Network reported that approximately 1 in 31 children in the United States is diagnosed with autism, based on data collected in 2022.{{Cite web |last=CDC |date=2025-04-18 |title=Data and Statistics on Autism Spectrum Disorder |url=https://www.cdc.gov/autism/data-research/index.html |access-date=2025-04-25 |website=Autism Spectrum Disorder (ASD) |language=en-us}} For 2016 data, the estimate was 1 in 54, compared to 1 in 68 in 2010 and 1 in 150 in 2000. Diagnostic criteria for autism have changed significantly since the 1980s; for example, U.S. special-education autism classification was introduced in 1994.{{cite journal |display-authors=6 |vauthors=Newschaffer CJ, Croen LA, Daniels J, Giarelli E, Grether JK, Levy SE, Mandell DS, Miller LA, Pinto-Martin J, Reaven J, Reynolds AM, Rice CE, Schendel D, Windham GC |year=2007 |title=The epidemiology of autism spectrum disorders |journal=Annual Review of Public Health |volume=28 |pages=235–58 |doi=10.1146/annurev.publhealth.28.021406.144007 |pmid=17367287 |doi-access=free}}

In the UK, from 1998 to 2018, autism diagnoses increased by 787%. This is largely attributable to changes in diagnostic practices, referral patterns, availability of services, age at diagnosis, and public awareness,{{cite journal |vauthors=Fombonne E |date=June 2009 |title=Epidemiology of pervasive developmental disorders |journal=Pediatric Research |volume=65 |issue=6 |pages=591–598 |doi=10.1203/PDR.0b013e31819e7203 |pmid=19218885 |doi-access=free}}{{cite journal |vauthors=Wing L, Potter D |year=2002 |title=The epidemiology of autistic spectrum disorders: is the prevalence rising? |journal=Developmental Disabilities Research Reviews |volume=8 |issue=3 |pages=151–161 |doi=10.1002/mrdd.10029 |pmid=12216059}}{{cite journal |vauthors=Gernsbacher MA, Dawson M, Goldsmith HH |date=April 2005 |title=Three Reasons Not to Believe in an Autism Epidemic |journal=Current Directions in Psychological Science |volume=14 |issue=2 |pages=55–58 |doi=10.1111/j.0963-7214.2005.00334.x |pmc=4232964 |pmid=25404790}} particularly among women, though unidentified environmental factors cannot be ruled out.{{cite journal |vauthors=Rutter M |date=January 2005 |title=Incidence of autism spectrum disorders: changes over time and their meaning |journal=Acta Paediatrica |volume=94 |issue=1 |pages=2–15 |doi=10.1111/j.1651-2227.2005.tb01779.x |pmid=15858952 |s2cid=79259285}} It has been established that vaccination is not a factor for autism likelihood and is does not increase autism prevalence rates, if any change in the actual rate of autism (not just diagnosis) exists at all.

Research indicates that autistic people are significantly more likely to be LGBT than the general population.{{Cite journal |last1=Graham Holmes |first1=Laura |last2=Ames |first2=Jennifer L. |last3=Massolo |first3=Maria L. |last4=Nunez |first4=Denise M. |last5=Croen |first5=Lisa A. |date=2022-04-01 |title=Improving the Sexual and Reproductive Health and Health Care of Autistic People |url=https://publications.aap.org/pediatrics/article/149/Supplement%204/e2020049437J/185641/Improving-the-Sexual-and-Reproductive-Health-and?autologincheck=redirected |journal=Pediatrics |volume=149 |issue=Supplement 4 |pages=e2020049437J |doi=10.1542/peds.2020-049437J |pmid=35363286 |issn=0031-4005}} Autistic people are also significantly more likely to be non-theistic than members of the general population.{{Cite journal |last1=Norenzayan |first1=Ara |last2=Gervais |first2=Will M. |last3=Trzesniewski |first3=Kali H. |date=2012-05-30 |title=Mentalizing Deficits Constrain Belief in a Personal God |journal=PLOS ONE |language=en |volume=7 |issue=5 |pages=e36880 |doi=10.1371/journal.pone.0036880 |doi-access=free |issn=1932-6203 |pmc=3364254 |pmid=22666332|bibcode=2012PLoSO...736880N }}

In 1912, Swiss psychiatrist Paul Bleuler coined the German term Autismus in the context of describing a symptom of schizophrenia. Rendered in English as autism, the term derives from the Greek word autos ("self") and suffix -ismos, denoting an action or state, and conveys the notion of "morbid self-absorption".{{cite web |title=Origin and history of autism |url=https://www.etymonline.com/word/autism |publisher=Etymonline }} In the 1920s, Grunya Sukhareva adopted the term to describe subjects who are autistic in the modern sense.

{{Main|Societal and cultural aspects of autism}}

File:Greta_Thunberg_in_2022.jpg likened her autism to a "superpower", crediting her success to her focused interests.{{Cite news |title=Greta Thunberg: 'I really see the value of friendship. Apart from the climate, almost nothing else matters' |url=https://www.theguardian.com/environment/ng-interactive/2021/sep/25/greta-thunberg-i-really-see-the-value-of-friendship-apart-from-the-climate-almost-nothing-else-matters |access-date=16 June 2024 |work=The Guardian |date=25 September 2021 |language=en |vauthors=Hattenstone S, Fischer H |archive-url=https://web.archive.org/web/20250406060618/https://www.theguardian.com/environment/ng-interactive/2021/sep/25/greta-thunberg-i-really-see-the-value-of-friendship-apart-from-the-climate-almost-nothing-else-matters |archive-date=6 April 2025}}]]

An autistic culture has emerged, accompanied by the autistic rights and neurodiversity movements, that argues autism should be accepted as a difference to be accommodated instead of cured,{{cite web |date=26 June 2006 |title=Autism Movement Seeks Acceptance, Not Cures |url=https://www.npr.org/templates/story/story.php?storyId=5488463 |access-date=10 November 2015 |publisher=NPR |vauthors=Shapiro J |archive-date=10 May 2019 |archive-url=https://web.archive.org/web/20190510154818/https://www.npr.org/templates/story/story.php?storyId=5488463 |url-status=live}}{{cite magazine |title=Autistic and proud of it |url=https://www.newscientist.com/article/mg18625041-500-autistic-and-proud-of-it/ |access-date=10 November 2015 |publisher=Reed Elsevier |issn=0262-4079 |magazine=New Scientist |vauthors=Trivedi B |archive-date=23 April 2019 |archive-url=https://web.archive.org/web/20190423120053/https://www.newscientist.com/article/mg18625041-500-autistic-and-proud-of-it/ |url-status=live}}{{cite book |title=The Economic World |publisher=Chronicle Publishing Company |year=1917 |location=New York city |page=366}}

{{cite journal |vauthors=Silverman C |year=2008 |title=Fieldwork on another planet: social science perspectives on the autism spectrum |journal=BioSocieties |volume=3 |issue=3 |pages=325–341 |doi=10.1017/S1745855208006236 |s2cid=145379758 |doi-access=free}} although a minority of autistic people might still accept a cure.{{cite web |date=23 March 2022 |title=Results and Analysis of the Autistic Not Weird 2022 Autism Survey - Autistic Not Weird |url=https://autisticnotweird.com/autismsurvey/ |access-date=29 April 2022 |language=en-GB |archive-date=8 June 2023 |archive-url=https://web.archive.org/web/20230608144053/https://autisticnotweird.com/autismsurvey/ |url-status=live}} Worldwide, events related to autism include World Autism Awareness Day, Autism Sunday, Autistic Pride Day, Autreat, and others.{{cite web |title=World Autism Awareness Day, 2 April |url=https://www.un.org/en/events/autismday/ |access-date=17 November 2015 |publisher=United Nations |archive-date=31 March 2018 |archive-url=https://web.archive.org/web/20180331054119/https://www.un.org/en/events/autismday/ |url-status=live}}{{cite web |date=18 June 2015 |title=Autistic Pride Day 2015: A Message to the Autistic Community |url=http://autisticadvocacy.org/2015/06/autistic-pride-day-2015-a-message-to-the-autistic-community/ |access-date=18 November 2015 |vauthors=Bascom J |archive-date=19 November 2015 |archive-url=https://web.archive.org/web/20151119190817/http://autisticadvocacy.org/2015/06/autistic-pride-day-2015-a-message-to-the-autistic-community/ |url-status=live}}{{cite web |year=2010 |title=Autism Sunday – Home |url=http://www.autismsunday.co.uk/ |archive-url=https://web.archive.org/web/20100303043146/http://www.autismsunday.co.uk/ |archive-date=3 March 2010 |access-date=17 November 2015 |website=Autism Sunday}}{{cite web |year=2013 |title=About Autreat |url=http://www.autreat.com/autreat.html |access-date=17 November 2015 |publisher=Autreat.com |archive-date=1 December 2015 |archive-url=https://web.archive.org/web/20151201181250/http://www.autreat.com/autreat.html |url-status=live}}

Social-science scholars study those with autism in hopes to learn more about "autism as a culture, transcultural comparisons ... and research on social movements." Many autistic people have been successful in their fields.{{cite journal |vauthors=Russell G, Kapp SK, Elliott D, Elphick C, Gwernan-Jones R, Owens C |title=Mapping the Autistic Advantage from the Accounts of Adults Diagnosed with Autism: A Qualitative Study |journal=Autism in Adulthood |date=13 April 2019 |volume=1 |issue=2 |pages=124–133 |doi=10.1089/aut.2018.0035 |pmid=31058260 |pmc=6493410 |s2cid=142504027}}

Focused interests are commonly found in autistic people, sometimes leading to hobbies, vast collections, and activism. Environmental activist Greta Thunberg has spoken favorably about her autism diagnosis, saying that autism can be a source of life purpose, as well as forming the basis of careers, hobbies, and friendships.{{Cite web |last=Silberman |first=Steve |date=6 May 2019 |title=Greta Thunberg became a climate activist not in spite of her autism, but because of it |url=https://www.vox.com/first-person/2019/5/6/18531551/greta-thunberg-autism-aspergers |access-date=16 June 2024 |website=Vox |language=en-US}}{{Cite web |last=Ryan |first=Maggie |date=12 April 2024 |title=These 12 Celebrities With Autism Are Opening Up About Life on the Spectrum |url=https://www.sheknows.com/health-and-wellness/slideshow/2992980/celebrities-with-autism/ |access-date=16 June 2024 |website=SheKnows |language=en-US}}

Some autistic people, as well as a growing number of researchers,{{cite journal |vauthors=Pellicano E, den Houting J |date=April 2022 |title=Annual Research Review: Shifting from 'normal science' to neurodiversity in autism science |journal=Journal of Child Psychology and Psychiatry, and Allied Disciplines |volume=63 |issue=4 |pages=381–396 |doi=10.1111/jcpp.13534 |issn=0021-9630 |eissn=1469-7610 |oclc=01307942 |pmc=9298391 |pmid=34730840 |s2cid=241118562}} have advocated a shift in attitudes toward the view that autism is a difference, rather than a disease that ought to be treated or cured.{{cite journal |journal=Disability & Society |year=2007 |volume=22 |issue=7 |pages=761–76 |title='Surplus suffering': differences between organizational understandings of Asperger's syndrome and those people who claim the 'disorder' |vauthors=Clarke J, van Amerom G |doi=10.1080/09687590701659618 |s2cid=145736625}}{{cite journal |journal=Focus Autism Other Dev Disabl |year=2002 |volume=17 |issue=3 |pages=186–91 |title=Is Asperger syndrome necessarily viewed as a disability? |vauthors=Baron-Cohen S |doi=10.1177/10883576020170030801 |s2cid=145629311}} A preliminary, freely readable draft, with slightly different wording in the quoted text, is in: {{cite web |url=http://autismresearchcentre.com/docs/papers/2002_BC_ASDisability.pdf |access-date=2 December 2008 |year=2002 |vauthors=Baron-Cohen S|title=Is Asperger's syndrome necessarily a disability? |publisher=Autism Research Centre |location=Cambridge |archive-url=https://web.archive.org/web/20081217140628/http://autismresearchcentre.com/docs/papers/2002_BC_ASDisability.pdf |archive-date=17 December 2008}} Critics have bemoaned the entrenchment of some of these groups' opinions, and that they speak to a select group of autistic people with limited difficulties.{{cite journal |vauthors=Morgan J |date=1 October 2016 |title=Autism spectrum disorder: difference or disability? |url=https://www.thelancet.com/journals/laneur/article/PIIS1474-4422(16)30002-3/abstract |journal=The Lancet Neurology |language=en |volume=15 |issue=11 |page=1126 |doi=10.1016/S1474-4422(16)30002-3 |issn=1474-4422 |s2cid=54341655}}{{cite news |title=A medical condition or just a difference? The question roils autism community. |language=en-US |newspaper=The Washington Post |url=https://www.washingtonpost.com/national/health-science/a-medical-condition-or-just-a-difference-the-question-roils-autism-community/2019/05/03/87e26f7e-6845-11e9-8985-4cf30147bdca_story.html |access-date=15 October 2021 |issn=0190-8286}}

The neurodiversity movement and the autism rights movement are social movements within the context of disability rights, emphasizing the concept of neurodiversity, which describes the autism spectrum as a result of healthy and valuable variations in the human brain rather than a disorder to be cured.{{cite news |last=Solomon |first=Andrew |date=25 May 2008 |title=The autism rights movement |url=https://nymag.com/news/features/47225/ |url-status=live |archive-url=https://web.archive.org/web/20080527025140/http://nymag.com/news/features/47225/ |archive-date=27 May 2008 |access-date=27 May 2008 |work=New York Magazine |issn=0028-7369 |vauthors=}}{{cite news |last=Hill |first=Amelia |date=31 July 2023 |title=Autism could be seen as part of personality for some diagnosed, experts say |url=https://www.theguardian.com/society/2023/jul/31/autism-could-be-seen-as-part-of-personality-for-some-diagnosed-experts-say |url-status=live |archive-url=https://web.archive.org/web/20230801022836/https://www.theguardian.com/society/2023/jul/31/autism-could-be-seen-as-part-of-personality-for-some-diagnosed-experts-say |archive-date=1 August 2023 |access-date=1 August 2023 |newspaper=The Guardian}} The autism rights movement advocates including greater acceptance of autistic behaviors, therapies that focus on coping skills rather than imitating the behaviors of those without autism,{{cite web |vauthors=Ratner P |title=Should Autism Be Cured or Is "Curing" Offensive? |url=https://bigthink.com/paul-ratner/should-autism-be-cured-or-is-curing-offfensive |website=Big Think |access-date=16 June 2019 |date=10 July 2016}} and the recognition of the autistic community as a minority group.

Autism rights or neurodiversity advocates believe that the autism spectrum is genetic and should be accepted as a healthy variation in the human genome. These movements are not without detractors; a common argument against neurodiversity activists is that most of them have relatively low support needs, or are self-diagnosed, and do not represent the views of autistic people with higher support needs.{{cite journal |vauthors=McGee M |date=August 2012 |title=Neurodiversity |journal=Contexts |volume=11 |issue=3 |pages=12–13 |doi=10.1177/1536504212456175 |s2cid=220720495 |doi-access=free}}{{cite web |vauthors=Sarrett J |date=April 2016 |title=Biocertification and Neurodiversity the Role and Implications of Self-Diagnosis in Autistic Communities |url=https://www.researchgate.net/publication/291949788 |access-date=6 March 2022 |website=www.researchgate.net}} Jacquiline den Houting explores this critique, determining that the voices of low-support needs autistics are "some of the most influential within the neurodiversity movement, although admittedly these voices are a minority within the advocacy community"; she suggests this is in part a shortcoming of the wider neurotypical community, referencing nonspeaking self-advocate Amy Sequenzia's writing.{{cite journal |last1=den Houting |first1=J. |date=2019 |title=Neurodiversity: An insider's perspective. |journal=Autism |volume=23 |issue=2 |pages=271–273 |doi=10.1177/1362361318820762 |pmid=30556743 |s2cid=58767898 |doi-access=free}}{{cite book |editor-last=Bascom |editor-first=Julia |last=Sequenzia |first=Amy |date=7 December 2012 |title=Loud Hands: Autistic People, Speaking |publisher=The Autistic Press |pages=159–160 |isbn=978-1-938800-02-3}}{{Undue weight inline|1=Neurodiversity criticism discussion|date=June 2023}} Pier Jaarsma and Stellan Welin make the argument that only autistic people with lower support needs should be included under the neurodiversity banner, as autism with high support needs may rightfully be viewed as a disability.{{cite journal |last1=Jaarsma |first1=Pier |last2=Welin |first2=Stellan |date=1 March 2012 |title=Autism as a Natural Human Variation: Reflections on the Claims of the Neurodiversity Movement |journal=Health Care Analysis |language=en |volume=20 |issue=1 |pages=20–30 |doi=10.1007/s10728-011-0169-9 |pmid=21311979 |s2cid=18618887 |issn=1573-3394 |url=http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-72172}} The concept of neurodiversity is contentious in autism advocacy and research groups and has led to infighting.{{cite journal |last=Morgan |first=Jules |date=1 October 2016 |title=Autism spectrum disorder: difference or disability? |url=https://www.thelancet.com/journals/laneur/article/PIIS1474-4422(16)30002-3/fulltext |journal=The Lancet Neurology |language=English |volume=15 |issue=11 |page=1126 |doi=10.1016/S1474-4422(16)30002-3 |s2cid=54341655 |issn=1474-4422}}

Since 2011, the Autistic Self Advocacy Network has celebrated April as Autism Acceptance Month. In 2021, the Autism Society of America urged organizations to retitle Autism Awareness Day as Autism Acceptance Day, to focus on "more fully integrating those 1 in 54 Americans living with autism into our social fabric".

In 1963, the British National Autistic Society chose a puzzle piece as its logo, due to its view of autistic people as suffering from a "puzzling" condition.{{Cite web |date=2019-04-20 |title=The Autism Puzzle Piece: A symbol that's going to stay or go? |url=https://the-art-of-autism.com/the-autism-puzzle-piece-a-symbol-of-what/ |access-date=2024-11-28 |website=The Art of Autism |language=en-US}}{{cite web |last=Solomon |first=Debra |date=2 May 2018 |title=The History of the Autism Puzzle Piece Ribbon {{!}} Autism Career Coach Queens |url=https://spectrumroadmap.com/the-history-of-the-autism-puzzle-piece-ribbon/ |access-date=10 October 2023 |website=Spectrum Strategies |language=en-US}} The logo, designed by board member Gerald Gasson, consisted of a green and black puzzle piece with four knobs, with a crying child at its center. Other organizations and advocates adopted the puzzle piece as a symbol of autism, including American organization Autism Speaks, which uses a puzzle piece with one knob, two holes, one edge.

In 1999, the Autism Society of America designed the puzzle ribbon (an awareness ribbon patterned with red, yellow, cyan, and blue puzzle pieces) as a symbol of autism awareness.

The puzzle symbol is controversial among autism advocates and rejected by many. It has been criticized as outdated, now that autism is better understood, as well as implying that autistic people are mysterious or incomplete, and for its association with Autism Speaks.{{Cite web |last=Valerie |date=28 March 2022 |title=Why The Puzzle Piece Isn't Used in Autism Acceptance |url=https://www.123shoot.com/nothing-missing-why-the-puzzle-piece-isnt-used-in-autism-acceptance/ |access-date=16 June 2024 |website=Rock Paper Scissors |language=en-US}} The autism rights movement and neurodiversity advocates have criticized Autism Speaks for its view of autism as a disease to be cured.{{cite web |last1=Matthews |first1=Dylan |date=August 31, 2015 |title=We've called autism a disease for decades. We were wrong. |url=https://www.vox.com/2015/8/31/9233295/autism-rights-kanner-asperger |url-status=live |archive-url=https://web.archive.org/web/20190429115212/https://www.vox.com/2015/8/31/9233295/autism-rights-kanner-asperger |archive-date=April 29, 2019 |access-date=June 15, 2019 |website=Vox}}{{Cite news |last=Picciuto |first=Elizabeth |date=February 25, 2015 |title=They Don't Want an Autism Cure |url=http://www.thedailybeast.com/articles/2015/02/25/they-don-t-want-an-autism-cure.html |url-status=live |archive-url=https://web.archive.org/web/20150228201924/http://www.thedailybeast.com/articles/2015/02/25/they-don-t-want-an-autism-cure.html |archive-date=February 28, 2015 |access-date=March 1, 2015 |work=The Daily Beast}}{{cite news |last=Berrington |first=Lucy |date=November 14, 2013 |title=A Reporter's Guide to the Autism Speaks Debacle |url=https://www.psychologytoday.com/gb/blog/aspergers-alive/201311/reporters-guide-the-autism-speaks-debacle |access-date=August 10, 2022 |work=Psychology Today}}

File:National Autistic Society Puzzle Piece logo 1963.webp|National Autistic Society logo, circa 2000

File:Autism awareness ribbon-20051114.png|Autism awareness ribbon, used by Autism Speaks from 2005

File:Autism Speaks Rebrand.png|Current logo of Autism Speaks

In 2004, neurodiversity advocates Amy and Gwen Nelson designed the "rainbow infinity symbol", originally as the logo for their advocacy group Aspies For Freedom. Many adopted the infinity symbol as a symbol for the autism spectrum. The prismatic colors are often associated with the neurodiversity movement in general.{{cite web |last=Morgan |first=Julian |date=11 March 2018 |title=Going Gold For Autism Acceptance |url=https://www.autisticuk.org/post/going-gold-for-autism-acceptance |access-date=10 October 2023 |website=Autistic UK CIC |language=en}}

In 2018, Julian Morgan wrote the article "Light It Up Gold", a response to the "Light It Up Blue" awareness campaign Autism Speaks launched in 2007.{{cite magazine |last=Willingham |first=Emily |title=No Foolin': Forget About Autism Awareness And Lighting Up Blue |url=https://www.forbes.com/sites/emilywillingham/2017/04/01/no-foolin-forget-about-autism-awareness-and-lighting-up-blue/ |access-date=10 October 2023 |magazine=Forbes |language=en}}{{cite web |last=Franco |first=Janelle |date=2014 |url=https://campussuite-storage.s3.amazonaws.com/prod/1558550/996e2c54-539e-11e8-b9a1-0a0344361b00/1954741/f51bb58c-a4c7-11e9-8c86-121ab0aa6810/file/puzzlepieceproject_educational_tool_kit.pdf |title=Puzzle Piece Project and Autism Awareness Month |publisher=Autism Speaks}} Morgan pushed to use gold to symbolize autism, due its chemical symbol Au, from the Latin {{Lang|la|Aurum}}.

File:Autism spectrum infinity awareness symbol.svg|Autism infinity symbol from 2013, featuring a rainbow gradient from left to right

File:Autism golden infinity loop.png | Gold infinity loop, following Julian Morgan's 2018 push to use gold for autism

An autistic pride flag was created in 2005 by Aspies For Freedom for the first Autistic Pride Day, featuring a rainbow infinity symbol on a white background.{{Cite web |last=Advocate |first=Nova Scotia |date=16 March 2019 |title=News release: Neurodiversity flag raising for World Autism Acceptance Day |url=https://nsadvocate.org/2019/03/16/news-release-neurodiversity-flag-raising-for-world-autism-acceptance-day/ |access-date=8 June 2024 |website=Nova Scotia Advocate |language=en-CA}}

As the rainbow infinity on a white background has become increasingly viewed as representative of neurodiversity in general, several designs have been proposed for an autistic-specific flag.{{cite news |last1=Staff |first1=AU-TI Media |title=Autistic Pride Flag: Is it time to choose an official symbol? |url=https://au-ti.com/2023/06/30/autistic-pride-flag-is-it-time-to-choose-an-official-symbol/ |work=AU-TI |date=30 June 2023}} In 2023, the People's History Museum featured a 2015 autistic pride design by Joseph Redford, featuring a rainbow infinity symbol, a green background for being true to one's nature, and a purple background for neurodiversity.{{cite web |last1=Museum |first1=People's History |title=Nothing About Us Without Us |url=https://phm.org.uk/wp-content/uploads/2023/01/3.-Nauwu-Us-Large-Print-guide-14pt-@-Peoples-History-Museum.pdf |website=People's History Museum |access-date=27 June 2024 |date=16 October 2023 |archive-url=https://web.archive.org/web/20250314201055/https://phm.org.uk/wp-content/uploads/2023/01/3.-Nauwu-Us-Large-Print-guide-14pt-@-Peoples-History-Museum.pdf |archive-date=14 March 2025}}

File:Neurodiversity-2013-Flag.png | An autistic/neurodiversity pride flag featuring a rainbow infinity, based on a design from 2013

File:Autistic Pride Flag (purple and green).svg | The 2015 autistic pride flag by Joseph Redford

{{div col|colwidth=35em}}

• Outline of autism
• Animal model of autism
• Autism and memory
• Autism in popular culture
• Autistic art
• Controversies in autism
• Discrimination against autistic people
• Global perceptions of autism
• History of autism
• List of autistic fictional characters
• List of films about autism
• Violence and autism

{{div col end}}

{{Notelist}}

{{Reflist|colwidth=30em}}

• {{cite book |title=Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR) |title-link=DSM-5-TR |chapter=Neurodevelopmental Disorders |publisher=American Psychiatric Association |place=Washington, DC |date=18 March 2022 |lccn=2021051782 |isbn=978-0-89042-577-0 |ref={{harvid|DSM-5-TR}}}}
• {{cite encyclopedia |title=6A02 Autism spectrum disorder |date=February 2022 |orig-date=adopted in 2019 |url=https://icd.who.int/browse11/l-m/en#/http://id.who.int/icd/entity/437815624 |encyclopedia=International Classification of Diseases 11th Revision (ICD-11) |publisher=World Health Organization |access-date=14 May 2022 |id={{ICD11|6A02|437815624}} |ref={{harvid|ICD-11}}}}

{{Library resources box |onlinebooks=yes}}

• {{Commons cat inline}}
• {{Wikiquote inline}}
• [https://www.who.int/news-room/fact-sheets/detail/autism-spectrum-disorders World Health Organization fact sheet on autism]
• [https://www.autistica.org.uk/what-is-autism/suicide-and-autism Suicide and autism]. Autistica.

{{Medical condition classification and resources

| ICD11 = {{ICD11|6A02}}

| ICD10 = {{ICD10|F84.0}}

| ICD9 = {{ICD9|299.00}}

| OMIM = 209850

| MeSH = D000067877

| Curlie = Health/Mental_Health/Disorders/Neurodevelopmental/Autism_Spectrum

| MedlinePlus = 001526

| eMedicine_mult = {{eMedicine2|ped|180}}

| PatientUK = autism

}}

{{Pervasive developmental disorders}}

{{Autism resources}}

{{Mental and behavioural disorders|selected=neurological}}

{{Digital media use and mental health}}

{{Nonverbal communication}}

{{Subject bar|c=Category:Autism|b=y|q=Autism|d=Q1436063|n=Category:Autism|wikt=autism spectrum}}

{{Authority control}}

Category:Autism spectrum disorders

Category:Developmental psychology

Category:Learning disabilities