Schizoid personality disorder#Depersonalization

The term schizoid was coined in 1908 by Eugen Bleuler to describe a human tendency to direct attention toward one's inner life and away from the external world. Bleuler describes these personalities as "comfortably dull and at the same time sensitive, people who in a narrow manner pursue vague purposes".{{cite journal |vauthors=Livesley WJ, West M |title=The DSM-III Distinction between schizoid and avoidant personality disorders |journal=Canadian Journal of Psychiatry |volume=31 |issue=1 |pages=59–62 |date=February 1986 |pmid=3948107 |doi=10.1177/070674378603100112 |s2cid=46283956}} This description echoes Bleuler's 1911 description of a personality pathology functionally related to schizophrenia, as described in his seminal work, Dementia Praecox or the Group of Schizophrenias.

August Hoch in 1910 introduced a very similar concept called the "shut-in" personality. Characteristics of it were reticence, reclusiveness, shyness and a preference for living in fantasy worlds, among others. In 1925, Russian psychiatrist Grunya Sukhareva described a "schizoid psychopathy" in a group of children, resembling today's SzPD and ASD.{{cn|date=February 2025}} About a decade later Pyotr Gannushkin also included Schizoids and Dreamers in his detailed typology of personality types.Both types shared a detachment from the world but Schizoids also showed eccentricity and paradoxicality of emotional life and behavior, emotional coldness and dryness, unpredictability combined with lack of intuition and ambivalence (e.g., simultaneous presence of both stubbornness and submissiveness). Characteristic of Dreamers were tenderness and fragility, receptiveness to beauty, weak-willedness and listlessness, luxuriant imagination, dereism and usually an inflated self-concept. (From: Gannushkin, P.B (1933). Manifestations of psychopathies: statics, dynamics, systematic aspects.)

It has been argued that descriptive tradition began in 1925 with the description of observable schizoid behaviors by Kretschmer. However, various theorist prior to Kretschmer described observable behaviours characteristic of schizoid personality as conceptualized by the early descriptive tradition, including Karl Kahlbaum in 1890, Emil Kraepelin in 1902 and 1919, Bleuler in 1911 and 1920, and Adolf Meyer in 1906, 1908, and 1912. Nevertheless, Kretschmer's seminal work involving schizoid personality, Physique and Character, was highly influential and constituted the most robust description of observable schizoid behaviours, and was notably descriptive for setting forth classifications based on these observable behaviours. However, it would be in error to claim that Kretschmer was operating solely from the descriptive tradition.

In Physique and Character, and under a specific influence of the Bleuler school, which Kretschmer failed to properly credit, the schizoid is organized into three characteristic groups:{{Cite book |vauthors=Kretschmer E |title=Physique and Character |publisher=Routledge (International Library of Psychology, 1999) |year=1931 |isbn=978-0-415-21060-7 |location=London |oclc=858861653}}

1. Unsociability, quietness, reservedness, seriousness and eccentricity.
2. Timidity, shyness with feelings, sensitivity, nervousness, excitability, fondness of nature and books.
3. Pliability, kindliness, honesty, indifference, silence and cold emotional attitudes.

These characteristics are thought to be precursors of the DSM-III subcategorization of the schizoid character into three distinct personality disorders: schizotypal, avoidant and schizoid. However, Kretschmer's divisions were dimensional, and Kretschmer himself did not conceive of separating these behaviors to the point of radical isolation but considered them to be simultaneously present as varying potentials in schizoid individuals. For Kretschmer, the majority of schizoid people are not either oversensitive or cold, but they are oversensitive and cold "at the same time" in quite different relative proportions, with a tendency to move along these dimensions from one behavior to the other. Though Krestchmer notes that as a schizoid individual ages, she tends to become more anaclitic. Moreover, as per Bleuler's various works on the fundamental features of schizophrenia, this "split" in temperamental characteristics was thought by Kretschmer to be a fundamental, defining feature of schizoid personality.

The second path to schizoid personality, that of dynamic psychiatry, began in 1924 with the influence of observations by descriptive psychiatrist Eugen Bleuler,Eugen Bleuler – Textbook of Psychiatry, New York: Macmillan (1924) who observed that the schizoid person and schizoid pathology were not things to be set apart, though Bleuler argued for this earlier, on schizophrenic diseases more generally, in Dementia Praecox or the Group of Schizophrenias. In addition, Bleuler himself was strongly influenced by earlier dynamic theorists, such as Sigmund Freud on the "day-dreamer" in 1908 and on secondary narcissism in 1914, and Carl Jung on introversion in 1917. Later, under the influence of Bleuler and others, Ronald Fairbairn's seminal work on the schizoid condition, which was divided into schizophrenia proper; the schizoid personality type, the schizoid character; and transient schizoid episodes, and from which most of what is known today about psychodynamic schizoid phenomena is derived, was presented in 1940. Here, Fairbairn delineated four central schizoid themes:

1. The need to regulate interpersonal distance as a central focus of concern.
2. The ability to mobilize self-preservative defenses and self-reliance.
3. A pervasive tension between the anxiety-laden need for attachment and the defensive need for distance that manifests in observable behavior as indifference.
4. An overvaluation of the inner world at the expense of the outer world.

Following Fairbairn's derivation of SzPD from a combination of derealization, depersonalization, splitting, the oral stage of making all subjects into partial objects, and intellectualization;{{cite book |last=Fairnbairn |first=Ronald |orig-year=1952 |date=1992 |title=Psychoanalytic Studies of Personality |publisher=Routledge |pages=1–20 |isbn=0-415-05174-6}} the dynamic psychiatry tradition has continued to produce rich explorations on the schizoid character, most notably from writers Nannarello (1953), Laing (1965), Winnicott (1965),Donald Winnicott (1965): [https://books.google.com/books?id=WbGIEhINP6kC The Maturational Processes and the Facilitating Environment: Studies in the Theory of Emotional Development]. Karnac Books. {{ISBN|9780946439843}}. Guntrip (1969), Khan (1974), Akhtar (1987), Seinfeld (1991), Manfield (1992) and Klein (1995).

The DSM-I had the diagnosis of schizoid personality, which was defined by avoidance of close relationships, inability to express aggressive feelings, and autistic thinking (thinking which is preoccupied with one's inner experience).{{Cite book |url=http://www.turkpsikiyatri.org/arsiv/dsm-1952.pdf |title=Diagnostic and Statistical Manual of Mental Disorders |publisher=American Psychiatric Association |edition=1st |location=Washington D.C. |page=35 |language=en |chapter=Schizoid personality |archive-url=https://web.archive.org/web/20220814181730/http://www.turkpsikiyatri.org/arsiv/dsm-1952.pdf |archive-date=August 14, 2022 |url-status=live}} The DSM-II later updated the definition to include daydreaming, detachment from reality, and sensitivity.{{Cite book |url=https://www.madinamerica.com/wp-content/uploads/2015/08/DSM-II.pdf |title=Diagnostic and Statistical Manual of Mental Disorders |publisher=American Psychiatric Association |year=1968 |edition=2nd |location=Washington D.C. |page=42 |language=en |chapter=Schizoid personality |archive-url=https://web.archive.org/web/20220425045939/https://www.madinamerica.com/wp-content/uploads/2015/08/DSM-II.pdf |archive-date=April 25, 2022 |url-status=live}} It was incorporated into the DSM-III as schizoid personality disorder to describe difficulties forming meaningful social relationships and a persistent pattern of disconnection and apathy.{{cite book |vauthors=Fariba KA, Madhanagopal N, Gupta V |chapter=Schizoid Personality Disorder |date=2022 |chapter-url=http://www.ncbi.nlm.nih.gov/books/NBK559234/ |title=StatPearls |archive-url=https://web.archive.org/web/20220809053124/https://www.ncbi.nlm.nih.gov/books/NBK559234/ |place=Treasure Island (FL) |publisher=StatPearls Publishing |language=en |pmid=32644660 |access-date=2022-09-24 |archive-date=August 9, 2022}}{{Cite book |last1=American Psychiatric Association |url=http://archive.org/details/diagnosticstatis00amer_1 |title=Diagnostic and statistical manual of mental disorders : DSM-III-R |last2=American Psychiatric Association. Work Group to Revise DSM-III |date=1987 |publisher=Washington, DC : American Psychiatric Association |others=Internet Archive |isbn=978-0-89042-018-8}} The diagnosis of SzPD made it to the DSM-IV and DSM-V.{{Cite book |vauthors=McGraw JG |chapter-url=https://brill.com/view/book/9789401207706/B9789401207706-s016.xml |chapter=DSM-IV Personality Disorders |date=2012-01-01 |title=Personality Disorders and States of Aloneness |publisher=Brill |isbn=978-94-012-0770-6 |series=Value Inquiry Book Series |volume=246 |pages=351–359 |language=en |doi=10.1163/9789401207706_016 |archive-url=https://web.archive.org/web/20220622063843/https://brill.com/view/book/9789401207706/B9789401207706-s016.xml |archive-date=June 22, 2022 |url-status=live}}

It remains unclear how prevalent the disorder is. It may be present in anywhere from 0.5% to 7% of the population and possibly 14% of the homeless population.{{Cite web |vauthors=Zimmerman M |title=Schizoid Personality Disorder (ScPD) – Psychiatric Disorders |url=https://www.msdmanuals.com/en-gb/professional/psychiatric-disorders/personality-disorders/schizoid-personality-disorder-scpd?ruleredirectid=382 |url-status=live |archive-url=https://web.archive.org/web/20220803201543/https://www.msdmanuals.com/en-gb/professional/psychiatric-disorders/personality-disorders/schizoid-personality-disorder-scpd |archive-date=August 3, 2022 |access-date=2022-09-24 |language=en-GB |via=MDS Manual}} Gender differences in this disorder are also unclear.{{cite journal |vauthors=Grant BF, Hasin DS, Stinson FS, Dawson DA, Chou SP, Ruan WJ, Pickering RP |title=Prevalence, correlates, and disability of personality disorders in the United States: results from the national epidemiologic survey on alcohol and related conditions |journal=The Journal of Clinical Psychiatry |volume=65 |issue=7 |pages=948–958 |date=July 2004 |pmid=15291684 |doi=10.4088/jcp.v65n0711}} Some research has suggested that this disorder may occur more frequently in men than women.{{Cite thesis |vauthors=Ethesham H |degree=Ph.D. |date=April 9, 2009 |title=A study of Hypnotherapy as a special treatment of dissociative, adjustment problems, Personality and Psychosomatic Disorders |url=https://core.ac.uk/download/pdf/11821735.pdf |url-status=live |publisher=Saurashtra University |pages=89–90, 133 |archive-url=https://web.archive.org/web/20171110025130/https://core.ac.uk/download/pdf/11821735.pdf |archive-date=November 10, 2017}}{{cite journal |vauthors=Fonseca-Pedrero E, Paino M, Santarén-Rosell M, Lemos-Giráldez S |title=Cluster A maladaptive personality patterns in a non-clinical adolescent population |journal=Psicothema |volume=25 |issue=2 |pages=171–178 |date=2013 |pmid=23628530 |doi=10.7334/psicothema2012.74 |hdl=10651/18609 |hdl-access=free}}{{cite journal |vauthors=Jane JS, Oltmanns TF, South SC, Turkheimer E |title=Gender bias in diagnostic criteria for personality disorders: an item response theory analysis |journal=Journal of Abnormal Psychology |volume=116 |issue=1 |pages=166–175 |date=February 2007 |pmid=17324027 |pmc=4372614 |doi=10.1037/0021-843X.116.1.166}} SzPD is uncommon in clinical settings (about 2.2%) and occurs more commonly in males. It is rare compared with other personality disorders.{{cite journal |vauthors=Coid J, Yang M, Tyrer P, Roberts A, Ullrich S |title=Prevalence and correlates of personality disorder in Great Britain |journal=The British Journal of Psychiatry |volume=188 |issue=5 |pages=423–431 |date=May 2006 |pmid=16648528 |doi=10.1192/bjp.188.5.423 |doi-access=free}} Philip Manfield suggests that the "schizoid condition", which roughly includes the DSM schizoid, avoidant and schizotypal personality disorders, is represented by "as many as forty percent of all personality disorders." Manfield adds: "This huge discrepancy [from the ten percent reported by therapists for the condition] is probably largely because someone with a schizoid disorder is less likely to seek treatment than someone with other axis-II disorders."{{Cite book |vauthors=Manfield P |url=https://archive.org/details/splitselfsplitob00manf/page/204 |title=Split self/split object: understanding and treating borderline, narcissistic, and schizoid disorders. |publisher=Jason Aronson |year=1992 |isbn=978-0-87668-460-3 |pages=[https://archive.org/details/splitselfsplitob00manf/page/204 204–207] |language=en}}{{cite journal |vauthors=Vaillant GE, Drake RE |title=Maturity of ego defenses in relation to DSM-III axis II personality disorder |journal=Archives of General Psychiatry |volume=42 |issue=6 |pages=597–601 |date=June 1985 |pmid=4004502 |doi=10.1001/archpsyc.1985.01790290079009 |url=https://jamanetwork.com/journals/jamapsychiatry/article-abstract/493590 |archive-url=https://web.archive.org/web/20201227103531/https://jamanetwork.com/journals/jamapsychiatry/article-abstract/493590 |archive-date=December 27, 2020}} A 2008 study assessing personality and mood disorder prevalence among homeless people at New York City drop-in centers reported an SzPD rate of 65% among this sample. The study did not assess homeless people who did not show up at drop-in centers, and the rates of most other personality and mood disorders within the drop-in centers were lower than that of SzPD. The authors noted the limitations of the study, including the higher male-to-female ratio in the sample and the absence of subjects outside the support system or receiving other support (e.g., shelters) as well as the absence of subjects in geographical settings outside New York City, a large city often considered a magnet for disenfranchised people.{{cite journal |vauthors=Connolly AJ, Cobb-Richardson P, Ball SA |title=Personality disorders in homeless drop-in center clients |journal=Journal of Personality Disorders |volume=22 |issue=6 |pages=573–588 |date=December 2008 |pmid=19072678 |doi=10.1521/pedi.2008.22.6.573 |url=http://www.ncsinc.org/images/pdfs/JPD_article_winter_2008.pdf |url-status=dead |archive-url=https://web.archive.org/web/20090617134208/http://www.ncsinc.org/images/pdfs/JPD_article_winter_2008.pdf |archive-date=2009-06-17}} A University of Colorado Colorado Springs study comparing personality disorders and Myers–Briggs Type Indicator types found that the disorder had a significant correlation with the Introverted (I) and Thinking (T) preferences.{{cite web |year=2001 |title=An Empirical Investigation of Jung's Personality Types and Psychological Disorder Features |url=http://www.uccs.edu/Documents/dsegal/An-empirical-investigation-Jungs-types-and-PD-features-JPT-2.pdf |url-status=live |archive-url=https://web.archive.org/web/20140125013714/http://www.uccs.edu/Documents/dsegal/An-empirical-investigation-Jungs-types-and-PD-features-JPT-2.pdf |archive-date=2014-01-25 |access-date=August 10, 2013 |publisher=Journal of Psychological Type/University of Colorado Colorado Springs}}

Perfectionist and hypercritical parenting or cold,{{Cite journal |vauthors=Jenkins RL, Glickman S |date=1946 |title=Common syndromes in child psychiatry: II. The schizoid child. |url=http://doi.apa.org/getdoi.cfm?doi=10.1111/j.1939-0025.1946.tb05379.x |url-status=live |journal=American Journal of Orthopsychiatry |language=en |volume=16 |issue=2 |pages=255–261 |doi=10.1111/j.1939-0025.1946.tb05379.x |issn=1939-0025 |archive-url=https://web.archive.org/web/20180603191827/https://psycnet.apa.org/doiLanding?doi=10.1111%2Fj.1939-0025.1946.tb05379.x |archive-date=June 3, 2018}} neglectful, and distant parenting contribute to the onset of SzPD.{{cite journal |vauthors=Bogaerts S, Vanheule S, Desmet M |title=Personality disorders and romantic adult attachment: a comparison of secure and insecure attached child molesters |journal=International Journal of Offender Therapy and Comparative Criminology |volume=50 |issue=2 |pages=139–147 |date=April 2006 |pmid=16510885 |doi=10.1177/0306624X05278515 |s2cid=21792134}} For a person with SzPD, their parents likely were intolerant of their emotional experiences.{{cite journal |vauthors=Lenzenweger MF |title=A source, a cascade, a schizoid: a heuristic proposal from the Longitudinal Study of Personality Disorders |journal=Development and Psychopathology |volume=22 |issue=4 |pages=867–881 |date=November 2010 |pmid=20883587 |doi=10.1017/S0954579410000519 |s2cid=1163362}} They may have been forced to repress and compartmentalize their emotions, possibly resulting in the onset of difficulties expressing and processing emotional experiences.{{Cite journal |vauthors=Nirestean A, Lukacs E, Cimpan D, Taran L |date=2012 |title=Schizoid personality disorder-the peculiarities of their interpersonal relationships and existential roles: Complex case |url=https://onlinelibrary.wiley.com/doi/10.1002/pmh.1182 |journal=Personality and Mental Health |language=en |volume=6 |issue=1 |pages=69–74 |doi=10.1002/pmh.1182 |via=Wiley Online Library}} These difficulties lead to the child feeling rejected and developing the belief that the only safe environment is one where they are alone and inexpressive.{{Cite journal |vauthors=Ward S |year=2018 |title=The Black Hole: Exploring the Schizoid Personality Disorder, Dysfunction, and Deprivation with their Roots in the Prenatal and Perinatal Period |url=https://www.proquest.com/docview/2183511090 |journal=Journal of Prenatal & Perinatal Psychology & Health |language=en |volume=33 |issue=1 |access-date=2022-09-29 |id={{ProQuest|2183511090}} |via=ProQuest}}{{Cite journal |vauthors=Nirestean A, Lukacs E, Cimpan D, Taran L |date=2012 |title=Schizoid personality disorder-the peculiarities of their interpersonal relationships and existential roles: Complex case |url=https://onlinelibrary.wiley.com/doi/10.1002/pmh.1182 |url-status=live |journal=Personality and Mental Health |language=en |volume=6 |issue=1 |pages=69–74 |doi=10.1002/pmh.1182 |archive-url=https://web.archive.org/web/20150108011737/http://onlinelibrary.wiley.com:80/doi/10.1002/pmh.1182/full |archive-date=January 8, 2015}}{{cite journal |vauthors=Simon AE, Keller P, Cattapan K |title=Commentary about social avoidance and its significance in adolescents and young adults |journal=Psychiatry Research |volume=297 |pages=113718 |date=March 2021 |pmid=33465524 |doi=10.1016/j.psychres.2021.113718 |s2cid=231597645}}{{Cite thesis |vauthors=Wheeler Z |date=December 2013 |title=Treatment of schizoid personality: An analytic psychotherapy handbook |degree=PsyD |publisher=Pepperdine University |url=https://digitalcommons.pepperdine.edu/etd/413 |url-status=live |archive-url=https://web.archive.org/web/20210404084934/https://digitalcommons.pepperdine.edu/cgi/viewcontent.cgi?article=1412&context=etd |archive-date=April 4, 2021}} People with SzPD may also have internalized the belief that their emotions are dangerous to themselves and others due to the negative responses received from others.{{Cite journal |vauthors=Yontef G |date=December 28, 2017 |title=Psychotherapy of Schizoid Process |url=https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.549.1050&rep=rep1&type=pdf |url-status=live |journal=Transactional Analysis Journal |volume=31 |issue=1 |pages=7–23 |doi=10.1177/036215370103100103 |citeseerx=10.1.1.549.1050 |s2cid=15715220 |archive-url=https://web.archive.org/web/20210424011616/https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.549.1050&rep=rep1&type=pdf |archive-date=April 24, 2021 |via=CiteSeerX}}{{cite journal |vauthors=Waska RT |title=Schizoid anxiety: a reappraisal of the manic defense and the depressive position |journal=American Journal of Psychotherapy |volume=55 |issue=1 |pages=105–121 |date=2001-01-01 |pmid=11291187 |doi=10.1176/appi.psychotherapy.2001.55.1.105}}{{cite journal |vauthors=Bowins B |title=Personality disorders: a dimensional defense mechanism approach |journal=American Journal of Psychotherapy |volume=64 |issue=2 |pages=153–169 |date=2010 |pmid=20617788 |doi=10.1176/appi.psychotherapy.2010.64.2.153}} In their status of isolation and emotional bluntness they can be self-sufficient and safe.{{cite journal |vauthors=Kavaler-Adler S |title=Anatomy of regret: a developmental view of the depressive position and a critical turn toward love and creativity in the transforming schizoid personality |journal=American Journal of Psychoanalysis |volume=64 |issue=1 |pages=39–76 |date=March 2004 |pmid=14993841 |doi=10.1023/B:TAJP.0000017991.56175.ea |s2cid=41834652}}{{Cite book |vauthors=Orcutt C |url=https://books.google.com/books?id=jLNaIyVgYzAC |title=Trauma in Personality Disorder: A Clinician'S Handbook the Masterson Approach |date=2012-03-31 |publisher=AuthorHouse |isbn=978-1-4685-5814-2 |pages=120–123 |language=en}}{{self-published source|date=March 2023}} Childhood trauma can also contribute to feelings of emptiness in adulthood.{{Cite journal |vauthors=Martens WH |date=2010 |title=Schizoid personality disorder linked to unbearable and inescapable loneliness |url=https://scielo.isciii.es/scielo.php?script=sci_abstract&pid=S0213-61632010000100005&lng=es&nrm=iso&tlng=en |url-status=live |journal=The European Journal of Psychiatry |volume=24 |issue=1 |pages=38–45 |doi=10.4321/S0213-61632010000100005 |issn=0213-6163 |archive-url=https://web.archive.org/web/20160507224616/https://scielo.isciii.es/scielo.php?script=sci_arttext&pid=S0213-61632010000100005 |archive-date=May 7, 2016 |via=SciElo |doi-access=free}} Alcoholism in parents is associated with a heightened risk of developing SzPD.{{cite journal |vauthors=Morgan PT, Desai RA, Potenza MN |title=Gender-related influences of parental alcoholism on the prevalence of psychiatric illnesses: analysis of the National Epidemiologic Survey on Alcohol and Related Conditions |journal=Alcoholism: Clinical and Experimental Research |volume=34 |issue=10 |pages=1759–1767 |date=October 2010 |pmid=20645936 |pmc=2950877 |doi=10.1111/j.1530-0277.2010.01263.x}}

Sula Wolff, who did extensive research and clinical work with children and teenagers with schizoid symptoms, stated that "schizoid personality has a constitutional, probably genetic, basis."{{Cite book |vauthors=Wolff S |url=https://books.google.com/books?id=Oo9kWqaGqkoC |title=Loners: The Life Path of Unusual Children |date=1995 |publisher=Psychology Press |isbn=978-0-415-06665-5 |pages=35 |language=en}} Research on heritability and this disorder is lacking. Twin studies with SzPD traits (e.g., low sociability and low warmth) suggest that these traits are inherited. Besides this indirect evidence, the direct heritability estimates of SzPD range from 50% to 59%.{{Cite book |vauthors=Blaney PH, Krueger RF, Millon T |url=https://books.google.com/books?id=NQ0bBAAAQBAJ&pg=PA639 |title=Oxford Textbook of Psychopathology |date=2014-08-22 |publisher=Oxford University Press |isbn=978-0-19-981184-7 |pages=649 |language=en}} Earlier, less methodologically rigorous research had found the heritability rate to be 29%.{{cite journal |vauthors=Reichborn-Kjennerud T |title=The genetic epidemiology of personality disorders |journal=Dialogues in Clinical Neuroscience |volume=12 |issue=1 |pages=103–114 |date=2010 |pmid=20373672 |pmc=3181941 |doi=10.31887/DCNS.2010.12.1/trkjennerud}}

The pathophysiology of SzPD remains unclear. Genetic relationships with people who have schizophrenia spectrum disorders increase the risk of developing schizoid personality disorder.{{cite journal |vauthors=Chang CJ, Chen WJ, Liu SK, Cheng JJ, Yang WC, Chang HJ, Lane HY, Lin SK, Yang TW, Hwu HG |title=Morbidity risk of psychiatric disorders among the first degree relatives of schizophrenia patients in Taiwan |language=En |journal=Schizophrenia Bulletin |volume=28 |issue=3 |pages=379–392 |date=January 1, 2002 |pmid=12645671 |doi=10.1093/oxfordjournals.schbul.a006947 |doi-access=free}}{{cite journal |vauthors=Racioppi A, Sheinbaum T, Gross GM, Ballespí S, Kwapil TR, Barrantes-Vidal N |title=Prediction of prodromal symptoms and schizophrenia-spectrum personality disorder traits by positive and negative schizotypy: A 3-year prospective study |journal=PLOS ONE |volume=13 |issue=11 |pages=e0207150 |date=2018-11-08 |pmid=30408119 |pmc=6224105 |doi=10.1371/journal.pone.0207150 |bibcode=2018PLoSO..1307150R |doi-access=free}}{{cite journal |vauthors=Fogelson DL, Nuechterlein KH, Asarnow RF, Payne DL, Subotnik KL |title=Validity of the family history method for diagnosing schizophrenia, schizophrenia-related psychoses, and schizophrenia-spectrum personality disorders in first-degree relatives of schizophrenia probands |journal=Schizophrenia Research |volume=68 |issue=2–3 |pages=309–317 |date=June 2004 |pmid=15099612 |doi=10.1016/S0920-9964(03)00081-1 |s2cid=22761177}}{{cite journal |vauthors=Ahmed AO, Green BA, Buckley PF, McFarland ME |title=Taxometric analyses of paranoid and schizoid personality disorders |journal=Psychiatry Research |volume=196 |issue=1 |pages=123–132 |date=March 2012 |pmid=22377573 |doi=10.1016/j.psychres.2011.10.010 |s2cid=19969732}} People with SzPD can have a history of schizotypy before developing the disorder.{{cite journal |vauthors=Kotlicka-Antczak M, Karbownik MS, Pawełczyk A, Żurner N, Pawełczyk T, Strzelecki D, Urban-Kowalczyk M |title=A developmentally-stable pattern of premorbid schizoid-schizotypal features predicts psychotic transition from the clinical high-risk for psychosis state |journal=Comprehensive Psychiatry |volume=90 |pages=95–101 |date=April 2019 |pmid=30831438 |doi=10.1016/j.comppsych.2019.02.003 |s2cid=73478881 |doi-access=free}}{{cite journal |vauthors=Fogelson DL, Nuechterlein KH, Asarnow RA, Payne DL, Subotnik KL, Jacobson KC, Neale MC, Kendler KS |title=Avoidant personality disorder is a separable schizophrenia-spectrum personality disorder even when controlling for the presence of paranoid and schizotypal personality disorders The UCLA family study |journal=Schizophrenia Research |volume=91 |issue=1–3 |pages=192–199 |date=March 2007 |pmid=17306508 |pmc=1904485 |doi=10.1016/j.schres.2006.12.023}}{{cite journal |vauthors=Ford TC, Crewther DP |title=Factor Analysis Demonstrates a Common Schizoidal Phenotype within Autistic and Schizotypal Tendency: Implications for Neuroscientific Studies |journal=Frontiers in Psychiatry |volume=5 |pages=117 |date=2014 |pmid=25221527 |doi=10.3389/fpsyt.2014.00117 |pmc=4145657 |doi-access=free}}{{cite journal |vauthors=Via E, Orfila C, Pedreño C, Rovira A, Menchón JM, Cardoner N, Palao DJ, Soriano-Mas C, Obiols JE |title=Structural alterations of the pyramidal pathway in schizoid and schizotypal cluster A personality disorders |journal=International Journal of Psychophysiology |volume=110 |pages=163–170 |date=December 2016 |pmid=27535345 |doi=10.1016/j.ijpsycho.2016.08.006}} SzPD symptoms can be premorbid to schizophrenia.{{Cite web |vauthors=Herrera Rodríguez A |date=2013 |title=Schizophrenia at adolescence: the relationship between schizophrenia self-reported symptoms and substance abuse, schizoid personality disorder symptoms and migration history |url=https://dugi-doc.udg.edu/handle/10256/10537 |url-status=live |archive-url=https://web.archive.org/web/20220925191006/https://dugi-doc.udg.edu/handle/10256/10537?show=full |archive-date=September 25, 2022}}{{cite journal |vauthors=Díaz-Castro L, Hoffman K, Cabello-Rangel H, Arredondo A, Herrera-Estrella MÁ |title=Family History of Psychiatric Disorders and Clinical Factors Associated With a Schizophrenia Diagnosis |journal=Inquiry |volume=58 |pages=469580211060797 |date=2021 |pmid=34845937 |pmc=8673879 |doi=10.1177/00469580211060797}}{{cite journal |vauthors=Boldrini T, Tanzilli A, Di Cicilia G, Gualco I, Lingiardi V, Salcuni S, Tata MC, Vicari S, Pontillo M |title=Personality Traits and Disorders in Adolescents at Clinical High Risk for Psychosis: Toward a Clinically Meaningful Diagnosis |journal=Frontiers in Psychiatry |volume=11 |pages=562835 |date=2020 |pmid=33363479 |doi=10.3389/fpsyt.2020.562835 |pmc=7753018 |doi-access=free}}{{cite journal |vauthors=Chen CK, Lin SK, Sham PC, Ball D, Loh EW, Hsiao CC, Chiang YL, Ree SC, Lee CH, Murray RM |title=Pre-morbid characteristics and co-morbidity of methamphetamine users with and without psychosis |journal=Psychological Medicine |volume=33 |issue=8 |pages=1407–1414 |date=November 2003 |pmid=14672249 |doi=10.1017/S0033291703008353 |s2cid=44733368 |url=https://www.cambridge.org/core/journals/psychological-medicine/article/abs/premorbid-characteristics-and-comorbidity-of-methamphetamine-users-with-and-without-psychosis/867A38591939F3A64E9A1821BF075A76 |url-status=live |archive-url=https://web.archive.org/web/20220425153634/https://www.cambridge.org/core/journals/psychological-medicine/article/abs/premorbid-characteristics-and-comorbidity-of-methamphetamine-users-with-and-without-psychosis/867A38591939F3A64E9A1821BF075A76 |archive-date=April 25, 2022}}{{cite journal |vauthors=Green MF, Horan WP, Lee J, McCleery A, Reddy LF, Wynn JK |title=Social Disconnection in Schizophrenia and the General Community |journal=Schizophrenia Bulletin |volume=44 |issue=2 |pages=242–249 |date=February 2018 |pmid=28637195 |pmc=5814840 |doi=10.1093/schbul/sbx082}}{{cite journal |vauthors=Bolinskey PK, Smith EA, Schuder KM, Cooper-Bolinskey D, Myers KR, Hudak DV, James AV, Hunter HK, Novi JH, Guidi JP, Gonzalez Y, McTiernan EF, Arnold KM, Iati CA, Gottesman II |title=Schizophrenia spectrum personality disorders in psychometrically identified schizotypes at two-year follow-up |journal=Psychiatry Research |volume=252 |pages=289–295 |date=June 2017 |pmid=28288440 |doi=10.1016/j.psychres.2017.03.014 |s2cid=12367565}}

Prenatal malnutrition,{{cite journal |vauthors=Lumey LH, Stein AD, Susser E |title=Prenatal famine and adult health |journal=Annual Review of Public Health |volume=32 |pages=237–262 |date=2011 |pmid=21219171 |pmc=3857581 |doi=10.1146/annurev-publhealth-031210-101230}}{{cite journal |vauthors=de Rooij SR, Wouters H, Yonker JE, Painter RC, Roseboom TJ |title=Prenatal undernutrition and cognitive function in late adulthood |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=107 |issue=39 |pages=16881–16886 |date=September 2010 |pmid=20837515 |doi=10.1073/pnas.1009459107 |jstor=20779880 |pmc=2947913 |doi-access=free |bibcode=2010PNAS..10716881D}} premature birth, and low birth weight are all thought to play a role in the development of SzPD.{{cite journal |vauthors=Abel KM, Wicks S, Susser ES, Dalman C, Pedersen MG, Mortensen PB, Webb RT |title=Birth weight, schizophrenia, and adult mental disorder: is risk confined to the smallest babies? |journal=Archives of General Psychiatry |volume=67 |issue=9 |pages=923–930 |date=September 2010 |pmid=20819986 |doi=10.1001/archgenpsychiatry.2010.100 |url=http://archpsyc.ama-assn.org/cgi/reprint/67/9/923}}{{Cite conference |vauthors=Li T |conference=4th International Conference on Humanities Education and Social Sciences (ICHESS 2021) |date=24 December 2021 |pages=1657–1663 |title=An Overview of Schizoid Personality Disorder |url=https://www.atlantis-press.com/proceedings/ichess-21/125967236 |url-status=live |language=en |publisher=Atlantis Press |doi=10.2991/assehr.k.211220.280 |isbn=978-94-6239-495-7 |archive-url=https://web.archive.org/web/20220427112740/https://www.atlantis-press.com/proceedings/ichess-21/125967236 |archive-date=April 27, 2022 |doi-access=free}}{{cite journal |vauthors=Mather AA, Cox BJ, Enns MW, Sareen J |title=Associations between body weight and personality disorders in a nationally representative sample |language=en-US |journal=Psychosomatic Medicine |volume=70 |issue=9 |pages=1012–1019 |date=November 2008 |pmid=18842749 |doi=10.1097/PSY.0b013e318189a930 |s2cid=26386820}} SzPD is associated with reduced serotonergic and dopaminergic pathways in areas such as the frontal lobe, amygdala, and striatum.{{cite journal |vauthors=Laakso A, Vilkman H, Kajander J, Bergman J, paranta M, Solin O, Hietala J |title=Prediction of detached personality in healthy subjects by low dopamine transporter binding |journal=The American Journal of Psychiatry |volume=157 |issue=2 |pages=290–292 |date=February 2000 |pmid=10671406 |doi=10.1176/appi.ajp.157.2.290}}{{Cite journal |vauthors=Hemmati A, Rezaei F, Rahmani K, Shams-Alizadeh N, Davarinejad O, Shirzadi M, Komasi S |date=2022-01-01 |title=Differential profile of three overlap psychiatric diagnoses using temperament and character model: A systematic review and meta-analysis of avoidant personality disorder, schizoid personality disorder, and social anxiety disorder |url=https://www.anip.co.in/article.asp?issn=2588-8358;year=2022;volume=6;issue=1;spage=15;epage=26;aulast=Hemmati;type=0 |url-status=live |journal=Annals of Indian Psychiatry |language=en |volume=6 |issue=1 |pages=15 |doi=10.4103/aip.aip_148_21 |s2cid=248531934 |issn=2588-8358 |archive-url=https://web.archive.org/web/20220926210907/https://www.anip.co.in/article.asp?issn=2588-8358;year=2022;volume=6;issue=1;spage=15;epage=26;aulast=Hemmati;type=0 |archive-date=September 26, 2022 |doi-access=free}}{{cite journal |vauthors=Dolan M, Anderson IM, Deakin JF |title=Relationship between 5-HT function and impulsivity and aggression in male offenders with personality disorders |journal=The British Journal of Psychiatry |volume=178 |issue=4 |pages=352–359 |date=April 2001 |pmid=11282815 |doi=10.1192/bjp.178.4.352 |doi-access=free}}{{cite journal |vauthors=Zald DH, Treadway MT |title=Reward Processing, Neuroeconomics, and Psychopathology |journal=Annual Review of Clinical Psychology |volume=13 |pages=471–495 |date=May 2017 |pmid=28301764 |pmc=5958615 |doi=10.1146/annurev-clinpsy-032816-044957}} Traumatic brain injuries to the frontal lobe may also contribute to the onset of SzPD as that area of the brain controls areas such as emotion and socialization.{{Cite web |vauthors=Hadfield J |date=2014-04-09 |title=Head injuries can make children loners |url=https://news.byu.edu/news/head-injuries-can-make-children-loners |access-date=2022-10-02 |website=News |language=en}}{{cite journal |vauthors=Blanchard JJ, Aghevli M, Wilson A, Sargeant M |title=Developmental instability in social anhedonia: an examination of minor physical anomalies and clinical characteristics |journal=Schizophrenia Research |volume=118 |issue=1–3 |pages=162–167 |date=May 2010 |pmid=19944570 |doi=10.1016/j.schres.2009.10.028 |pmc=2856752}} Deficits in the right hemisphere of the brain may also be associated with SzPD.{{cite journal |vauthors=Wolff S |title='Schizoid' personality in childhood and adult life. I: The vagaries of diagnostic labelling |journal=The British Journal of Psychiatry |volume=159 |issue=5 |pages=615–620 |date=November 1991 |pmid=1756336 |doi=10.1192/bjp.159.5.615 |s2cid=8524074}} Lower levels of low-density lipoprotein cholesterol may be correlated with the presence of schizoid traits in women.{{cite journal |vauthors=Hayakawa K, Watabe M, Horikawa H, Sato-Kasai M, Shimokawa N, Nakao T, Kato TA |title=Low-Density Lipoprotein Cholesterol Is a Possible Blood Biomarker of Schizoid Personality Traits among Females |journal=Journal of Personalized Medicine |volume=12 |issue=2 |pages=131 |date=January 2022 |pmid=35207620 |doi=10.3390/jpm12020131 |pmc=8875671 |doi-access=free}} Excess indices in the left hemisphere may also be related to SzPD.{{Cite journal |vauthors=Pluzhnikov IV, Kaleda VG |date=2015-06-01 |title=Neuropsychological findings in personality disorders: A.R. Luria's Approach. |url=http://psychologyinrussia.com/volumes/pdf/2015_2/2015_2_113-125.pdf |journal=Psychology in Russia: State of the Art |language=en |volume=8 |issue=2 |pages=113–125 |doi=10.11621/pir.2015.0210 |issn=2074-6857}}

Traits of schizoid personality disorder appear in childhood and adolescence. Children with this disorder usually have poor relationships with others,{{Cite book |vauthors=Dobbert DL |url=https://books.google.com/books?id=rpFxDwAAQBAJ |title=Understanding Personality Disorders: An Introduction: An Introduction |date=2007-01-30 |publisher=ABC-CLIO |isbn=978-0-313-06804-1 |pages=17–21 |language=en}}{{cite journal |vauthors=Tackett JL, Balsis S, Oltmanns TF, Krueger RF |title=A unifying perspective on personality pathology across the life span: developmental considerations for the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders |journal=Development and Psychopathology |volume=21 |issue=3 |pages=687–713 |date=2009 |pmid=19583880 |pmc=2864523 |doi=10.1017/S095457940900039X}} social anxiety, internal fantasies, strange behavior, and hyperactivity. These behaviors can result in teasing and bullying at the hands of others.{{Cite thesis |vauthors=Kagan D |date=2004-05-04 |title=Positive reinforcement as an intervention for children with attention deficit hyperactivity disorder and schizoid personality disorder |degree=MA |publisher=Rowan University |url=https://rdw.rowan.edu/etd/1171 |url-status=live |archive-url=https://web.archive.org/web/20220925221126/https://rdw.rowan.edu/etd/1171/ |archive-date=September 25, 2022}}{{cite journal |vauthors=Weiss EM, Schulter G, Freudenthaler HH, Hofer E, Pichler N, Papousek I |title=Potential markers of aggressive behavior: the fear of other persons' laughter and its overlaps with mental disorders |journal=PLOS ONE |volume=7 |issue=5 |pages=e38088 |date=2012-05-31 |pmid=22675438 |pmc=3364988 |doi=10.1371/journal.pone.0038088 |bibcode=2012PLoSO...738088W |doi-access=free}} It is common for people with SzPD to have had major depressive disorder in childhood.{{cite journal |vauthors=Ramklint M, von Knorring AL, von Knorring L, Ekselius L |title=Child and adolescent psychiatric disorders predicting adult personality disorder: a follow-up study |journal=Nordic Journal of Psychiatry |volume=57 |issue=1 |pages=23–28 |date=2003-01-01 |pmid=12745785 |doi=10.1080/psc.57.1.23 |s2cid=45425586}} SzPD is associated with lower levels of achievement, a compromised quality of life,{{cite journal |vauthors=Sevilla-Llewellyn-Jones J, Cano-Domínguez P, de-Luis-Matilla A, Espina-Eizaguirre A, Moreno-Kustner B, Ochoa S |title=Subjective quality of life in recent onset of psychosis patients and its association with sociodemographic variables, psychotic symptoms and clinical personality traits |journal=Early Intervention in Psychiatry |volume=13 |issue=3 |pages=525–531 |date=June 2019 |pmid=29278295 |doi=10.1111/eip.12515 |s2cid=9806674}} and a worse outcome of treatment.{{cite journal |vauthors=Mulder RT, Joyce PR, Frampton CM, Luty SE, Sullivan PF |title=Six months of treatment for depression: outcome and predictors of the course of illness |journal=The American Journal of Psychiatry |volume=163 |issue=1 |pages=95–100 |date=January 2006 |pmid=16390895 |doi=10.1176/appi.ajp.163.1.95}} Treatment for this disorder is under-studied and poorly understood.{{cite journal |vauthors=Keown P, Holloway F, Kuipers E |title=The prevalence of personality disorders, psychotic disorders and affective disorders amongst the patients seen by a community mental health team in London |journal=Social Psychiatry and Psychiatric Epidemiology |volume=37 |issue=5 |pages=225–229 |date=May 2002 |pmid=12107714 |doi=10.1007/s00127-002-0533-z |s2cid=13401664 |url=https://doi.org/10.1007/s00127-002-0533-z |url-status=live |archive-url=https://web.archive.org/web/20220311144334/https://link.springer.com/article/10.1007/s00127-002-0533-z |archive-date=March 11, 2022}} There is no widely accepted and approved psychotherapy or medication for this disorder. It is one of the most poorly researched psychiatric disorders. Professionals may misunderstand the disorder and the client, potentially reinforcing a feeling of failure and negatively impacting their willingness to continue to commit to treatment. Clinicians tend to worry that they are incapable of properly treating the patient.{{cite journal |vauthors=Colli A, Tanzilli A, Dimaggio G, Lingiardi V |title=Patient personality and therapist response: an empirical investigation |journal=The American Journal of Psychiatry |volume=171 |issue=1 |pages=102–108 |date=January 2014 |pmid=24077643 |doi=10.1176/appi.ajp.2013.13020224 |url=https://ajp.psychiatryonline.org/doi/10.1176/appi.ajp.2013.13020224 |url-status=live |archive-url=https://web.archive.org/web/20220927182459/https://ajp.psychiatryonline.org/doi/10.1176/appi.ajp.2013.13020224 |archive-date=September 27, 2022}} It is rare for someone with this disorder to voluntarily seek treatment without a comorbid disorder or pressure from family or friends.{{cite journal |vauthors=Kelly BD, Casey P, Dunn G, Ayuso-Mateos JL, Dowrick C |title=The role of personality disorder in 'difficult to reach' patients with depression: findings from the ODIN study |journal=European Psychiatry |volume=22 |issue=3 |pages=153–159 |date=April 2007 |pmid=17127039 |doi=10.1016/j.eurpsy.2006.07.003 |hdl=10197/5863 |s2cid=7753444 |url=https://researchrepository.ucd.ie/handle/10197/5863 |url-status=live |archive-url=https://web.archive.org/web/20170814130103/http://researchrepository.ucd.ie/bitstream/handle/10197/5863/Kelly_Difficult_to_reach_ODIN.pdf?sequence=1 |archive-date=August 14, 2017 |hdl-access=free}} In treatment, people with SzPD are usually disinterested and often minimize symptoms. Patients with SzPD may fear losing their independence through therapy. Many schizoid individuals will avoid making the efforts required to establish a proper relationship with the therapist. It can be difficult for them to open up or discuss their emotions in therapy. Although people with this disorder can still improve, it is unlikely they will ever experience significant joy through social interaction.

File:Thoma_Loneliness.jpg

SzPD is associated with a dismissive-avoidant attachment style.{{cite journal |vauthors=Mikulincer M, Shaver PR |title=An attachment perspective on psychopathology |journal=World Psychiatry |volume=11 |issue=1 |pages=11–15 |date=February 2012 |pmid=22294997 |pmc=3266769 |doi=10.1016/j.wpsyc.2012.01.003}}{{cite journal |vauthors=Westen D, Nakash O, Thomas C, Bradley R |title=Clinical assessment of attachment patterns and personality disorder in adolescents and adults |journal=Journal of Consulting and Clinical Psychology |volume=74 |issue=6 |pages=1065–1085 |date=December 2006 |pmid=17154736 |doi=10.1037/0022-006X.74.6.1065}}{{Cite book |vauthors=Sperry L |url=https://books.google.com/books?id=AMsmDAAAQBAJ |title=Handbook of Diagnosis and Treatment of DSM-5 Personality Disorders: Assessment, Case Conceptualization, and Treatment, Third Edition |date=2016-05-12 |publisher=Routledge |isbn=978-1-135-01922-8 |edition=3rd |language=en}} People with this disorder will rarely maintain close relationships and often exclusively choose to participate in solitary activities.{{Cite journal |vauthors=Căndel OS, Constantin T |date=June 30, 2017 |title=Antisocial and Schizoid Personality Disorder Scales: Conceptual bases and preliminary findings |url=http://www.rjap.psihologietm.ro/Download/rjap191_2.pdf |url-status=live |journal=Romanian Journal of Applied Psychology |location=Romania |publisher=West University of Timisoara Publishing Hous |volume=19 |issue=1 |doi=10.24913/rjap.19.1.02 |archive-url=https://web.archive.org/web/20171202064039/http://www.rjap.psihologietm.ro/Download/rjap191_2.pdf |archive-date=December 2, 2017}}{{Cite journal |vauthors=Carvalho LD, Salvador AP, Gonçalves AP |date=2020 |title=Development and Preliminary Psychometric Evaluation of the Dimensional Clinical Personality Inventory – Schizoid Personality Disorder Scale |url=http://pepsic.bvsalud.org/scielo.php?script=sci_abstract&pid=S1677-04712020000300008&lng=pt&nrm=iso&tlng=en |url-status=live |journal=Avaliação Psicológica |language=en |volume=19 |issue=3 |pages=289–297 |doi=10.15689/ap.2020.1903.16758.07 |s2cid=234916163 |issn=1677-0471 |archive-url=https://web.archive.org/web/20220802093122/http://pepsic.bvsalud.org/pdf/avp/v19n3/08.pdf |archive-date=August 2, 2022 |doi-access=free}}{{cite journal |vauthors=Brieger P, Sommer S, Blöink F, Marneros AA |title=The relationship between five-factor personality measurements and ICD-10 personality disorder dimensions: results from a sample of 229 subjects |journal=Journal of Personality Disorders |volume=14 |issue=3 |pages=282–290 |date=2000-09-01 |pmid=11019751 |doi=10.1521/pedi.2000.14.3.282}} People with schizoid personality disorder typically have no close friends or confidants, except for a close relative on occasions.

They usually prefer hobbies and activities that do not require interaction with others.{{Cite book |url=https://www.degruyter.com/document/doi/10.36019/9780813552347/html |title=Mental Health Disorders in Adolescents |vauthors=Hazen EP, Goldstein MA, Goldstein MC |date=2010-12-22 |publisher=Rutgers University Press |isbn=978-0-8135-5234-7 |pages=192–202 |language=en |chapter=Personality Disorders |doi=10.36019/9780813552347 |chapter-url=https://www.degruyter.com/document/doi/10.36019/9780813552347-016/html |s2cid=241632462}}{{cite journal |vauthors=Kwapil TR |title=Social anhedonia as a predictor of the development of schizophrenia-spectrum disorders |journal=Journal of Abnormal Psychology |volume=107 |issue=4 |pages=558–565 |date=November 1998 |pmid=9830243 |doi=10.1037/0021-843X.107.4.558 |url=http://libres.uncg.edu/ir/uncg/f/T_Kwapil_Social_1998.pdf}} People with SzPD may be averse to social situations due to difficulties deriving pleasure from physical or emotional sensations, rather than social anhedonia.{{cite journal |vauthors=Ross SR, Lutz CJ, Bailley SE |date=August 2002 |title=Positive and negative symptoms of schizotypy and the Five-factor model: a domain and facet level analysis |url=https://ecommons.udayton.edu/psy_fac_pub/15/ |url-status=live |journal=Journal of Personality Assessment |publisher=Psychology Faculty Publications |volume=79 |issue=1 |pages=53–72 |doi=10.1207/S15327752JPA7901_04 |pmid=12227668 |s2cid=6678948 |archive-url=https://web.archive.org/web/20170921232209/http://ecommons.udayton.edu/cgi/viewcontent.cgi?article=1013&context=psy_fac_pub |archive-date=September 21, 2017}}{{cite journal |vauthors=Cicero DC, Krieg A, Becker TM, Kerns JG |title=Evidence for the Discriminant Validity of the Revised Social Anhedonia Scale From Social Anxiety |journal=Assessment |volume=23 |issue=5 |pages=544–556 |date=October 2016 |pmid=26092042 |doi=10.1177/1073191115590851 |s2cid=3813109}}

One potential motivation for avoiding social situations is that they feel that it intrudes on their freedom.{{Cite book |vauthors=Materson J, Klein R |author-link=James F. Masterson |date=June 23, 2015 |title=Disorders of the Self: New Therapeutic Horizons: The Masterson Approach |url=https://www.routledge.com/Disorders-of-the-Self-New-Therapeutic-Horizons-The-Masterson-Approach/Masterson-MD-Klein-MD/p/book/9781138883741 |url-status=live |archive-url=https://web.archive.org/web/20220227090417/https://www.routledge.com/Disorders-of-the-Self-New-Therapeutic-Horizons-The-Masterson-Approach/Masterson-MD-Klein-MD/p/book/9781138883741 |archive-date=February 27, 2022 |access-date=2022-09-29 |publisher=Routledge |language=en |isbn=978-1-138-88374-1}} Relationships can feel suffocating for people with SzPD,{{cite book |vauthors=Winarick DJ |chapter=Schizoid Personality Disorder |date=2020-09-18 |title=The Wiley Encyclopedia of Personality and Individual Differences |pages=181–185 |veditors=Carducci BJ, Nave CS, Mio JS, Riggio RE |edition=1st |publisher=Wiley |language=en |doi=10.1002/9781119547181.ch294 |isbn=978-1-119-05747-5}} and they may think of them as opportunities for entrapment.{{cite journal |vauthors=Carbone JT, Holzer KJ, Vaughn MG, DeLisi M |title=Homicidal Ideation and Forensic Psychopathology: Evidence From the 2016 Nationwide Emergency Department Sample (NEDS) |journal=Journal of Forensic Sciences |volume=65 |issue=1 |pages=154–159 |date=January 2020 |pmid=31404481 |doi=10.1111/1556-4029.14156 |s2cid=199550054 |doi-access=free}}

Patients with this disorder are often independent and turn to themselves as sources of validation. They tend to be the happiest when in relationships in which their partner places few emotional or intimate demands on them and does not expect phatic or social niceties. It is not necessarily people they want to avoid, but negative or positive emotional expectations, emotional intimacy, and self-disclosure.{{Cite book |vauthors=Manfield P |url=https://archive.org/details/splitselfsplitob00manf/page/204 |title=Split self/split object: understanding and treating borderline, narcissistic, and schizoid disorders. |publisher=Jason Aronson |year=1992 |isbn=978-0-87668-460-3 |pages=[https://archive.org/details/splitselfsplitob00manf/page/204 204–207]}}

Patients with SzPD can feel as if close emotional bonds are dangerous to themselves and others.{{cite journal |vauthors=Guntrip H |title=A study of Fairbairn's theory of schizoid reactions |journal=The British Journal of Medical Psychology |volume=25 |issue=2–3 |pages=86–103 |date=September 1952 |pmid=12987588 |doi=10.1111/j.2044-8341.1952.tb00791.x}} They may have feelings of inadequacy or shame.{{cite journal |vauthors=Shedler J, Westen D |date=August 2004 |title=Refining personality disorder diagnosis: integrating science and practice |url=https://ajp.psychiatryonline.org/doi/10.1176/appi.ajp.161.8.1350 |url-status=live |journal=The American Journal of Psychiatry |volume=161 |issue=8 |pages=1350–1365 |doi=10.1176/appi.ajp.161.8.1350 |pmid=15285958 |archive-url=https://web.archive.org/web/20211128030147/https://ajp.psychiatryonline.org/doi/10.1176/appi.ajp.161.8.1350 |archive-date=November 28, 2021}} Some people with SzPD may experience a deep desire to connect with others, yet will be terrified by the dangers inherent in doing so.{{cite journal |vauthors=McWilliams N |title=Some thoughts about schizoid dynamics |journal=Psychoanalytic Review |volume=93 |issue=1 |pages=1–24 |date=February 2006 |pmid=16637769 |doi=10.1521/prev.2006.93.1.1}} Avoidance of social situations may be a method of avoiding being hurt or rejected.{{Cite journal |vauthors=Parpottas P |date=2012 |title=A critique on the use of standard psychopathological classifications in understanding human distress: The example of 'schizoid personality disorder'. |url=https://psycnet.apa.org/record/2012-08620-004 |url-status=live |journal=Counselling Psychology Review |language=en |location=Cyprus |volume=27 |issue=1 |pages=44–52 |doi=10.53841/bpscpr.2011.27.1.44 |s2cid=203062083 |archive-url=https://web.archive.org/web/20190818095303/https://psycnet.apa.org/record/2012-08620-004 |archive-date=August 18, 2019 |access-date=2022-09-26 |via=ResearchGate}}{{cite journal |vauthors=Akhtar S |title=The distinction between needs and wishes: implications for psychoanalytic theory and technique |journal=Journal of the American Psychoanalytic Association |volume=47 |issue=1 |pages=113–151 |date=1999 |pmid=10367274 |doi=10.1177/00030651990470010201 |s2cid=13250602 |author-link=Salman Akhtar}}

Individuals with SzPD can form relationships with others based on intellectual, physical, familial, occupational, or recreational activities, as long as there is no need for emotional intimacy. Donald Winnicott explains this is because schizoid individuals "prefer to make relationships on their own terms and not in terms of the impulses of other people." Failing to attain that, they prefer isolation.{{Cite book |vauthors=Winnicott D |title=The Family and Individual Development |publisher=Routledge |year=2006 |isbn=978-0-415-40277-4 |page=73}}

In general, friendship for schizoid individuals is usually limited to one other person, who is often also schizoid, forming what has been called a union of two eccentrics; "within it – the ecstatic cult of personality, outside it – everything is sharply rejected and despised".{{Cite book |last=Ernst Kretschmer |url=https://books.google.com/books?id=77n_AgAAQBAJ |title=Body structure and character. Studies on the constitution and theory of temperaments |date=March 2013 |publisher=Ripol Classic |isbn=978-5-458-35839-2 |language=ru |chapter=Chapter 10. Schizoid temperaments |chapter-url=http://sbiblio.com/biblio/archive/krechmer_stroenie/04.aspx}} Their unique lifestyle can lead to social rejection and people with SzPD are at a higher risk of facing bullying or homelessness.{{Cite journal |vauthors=Rouff L |date=April 2000 |title=Schizoid Personality Traits Among the Homeless Mentally Ill: A uantitative and Qualitative Report |journal=Journal of Social Distress and the Homeless |language=en |volume=9 |issue=2 |pages=127–141 |doi=10.1023/A:1009470318513 |hdl=2027.42/43983 |s2cid=39349719 |issn=1573-658X |via=SpringerLink |hdl-access=free}} This social rejection can reinforce their asocial behavior.

People with this disorder usually have little to no interest in sexual or romantic relationships; it is rare for people with SzPD to date or marry.{{Cite journal |vauthors=Fitzgerald CJ, Colarelli SM |date=2009-04-01 |title=Altruism and Reproductive Limitations |journal=Evolutionary Psychology |language=en |volume=7 |issue=2 |pages=147470490900700 |doi=10.1177/147470490900700207 |s2cid=146798018 |issn=1474-7049 |doi-access=free}}{{cite journal |vauthors=Koch J, Berner W, Hill A, Briken P |title=Sociodemographic and diagnostic characteristics of homicidal and nonhomicidal sexual offenders |journal=Journal of Forensic Sciences |volume=56 |issue=6 |pages=1626–1631 |date=November 2011 |pmid=21981447 |doi=10.1111/j.1556-4029.2011.01933.x |s2cid=26470567}}{{Cite journal |vauthors=Holtzman NS, Strube MJ |date=2013-12-01 |title=Above and beyond Short-Term Mating, Long-Term Mating is Uniquely Tied to Human Personality |journal=Evolutionary Psychology |language=en |volume=11 |issue=5 |pages=1101–1129 |doi=10.1177/147470491301100514 |pmid=24342881 |issn=1474-7049 |doi-access=free |pmc=10430001}} Sex often causes individuals with SzPD to feel that their personal space is being violated, and they commonly feel that masturbation or sexual abstinence is preferable to the emotional closeness they must tolerate when having sex.{{cite journal |vauthors=Nannarello JJ |title=Schizoid |journal=The Journal of Nervous and Mental Disease |volume=118 |issue=3 |pages=237–249 |date=September 1953 |pmid=13118367 |doi=10.1097/00005053-195309000-00004}} Significantly broadening this picture are notable exceptions of SzPD individuals who engage in occasional or even frequent sexual activities with others. Individuals with SzPD have long been noted to have an increased rate of unconventional sexual tendencies, though if present, these are rarely acted upon. Schizoid people are often labeled asexual or present with "a lack of sexual identity". Kernberg states that this apparent lack of sexuality does not represent a lack of sexual definition but rather a combination of several strong fixations to cope with the same conflicts. People with SzPD are often able to pursue any fantasies with content on the internet while remaining completely unengaged with the outside world.

{{See also|Reduced affect display}}

Sensory or emotional experiences typically provide little enjoyment for people with SzPD.{{cite journal |vauthors=Hutsebaut J, Feenstra DJ, Kamphuis JH |title=Development and Preliminary Psychometric Evaluation of a Brief Self-Report Questionnaire for the Assessment of the DSM-5 level of Personality Functioning Scale: The LPFS Brief Form (LPFS-BF) |journal=Personality Disorders |volume=7 |issue=2 |pages=192–197 |date=April 2016 |pmid=26595344 |doi=10.1037/per0000159 |hdl=11245.1/3fc1adda-98da-455b-bebe-a8efc5c09f9f |url=http://doi.apa.org/getdoi.cfm?doi=10.1037/per0000159 |url-status=live |archive-url=https://web.archive.org/web/20220926185309/https://psycnet.apa.org/doiLanding?doi=10.1037%2Fper0000159 |archive-date=September 26, 2022 |hdl-access=free}}{{cite journal |vauthors=Joyce PR, McKenzie JM, Carter JD, Rae AM, Luty SE, Frampton CM, Mulder RT |title=Temperament, character and personality disorders as predictors of response to interpersonal psychotherapy and cognitive-behavioural therapy for depression |journal=The British Journal of Psychiatry |volume=190 |issue=6 |pages=503–508 |date=June 2007 |pmid=17541110 |doi=10.1192/bjp.bp.106.024737 |s2cid=21222621 |doi-access=free}} They rarely display strong emotions or react to anything.{{cite journal |vauthors=Brotto LA, Knudson G, Inskip J, Rhodes K, Erskine Y |title=Asexuality: a mixed-methods approach |journal=Archives of Sexual Behavior |volume=39 |issue=3 |pages=599–618 |date=June 2010 |pmid=19082703 |doi=10.1007/s10508-008-9434-x |s2cid=207089483 |url=https://doi.org/10.1007/s10508-008-9434-x |url-status=live |archive-url=https://web.archive.org/web/20220609011139/https://link.springer.com/article/10.1007/s10508-008-9434-x |archive-date=June 9, 2022}} People with SzPD can have difficulty expressing themselves and seem to be directionless or passive. Individuals with SzPD can also experience anhedonia.{{cite journal |vauthors=Martin EA, Cicero DC, Kerns JG |title=Social anhedonia, but not positive schizotypy, is associated with poor affective control |journal=Personality Disorders |volume=3 |issue=3 |pages=263–272 |date=July 2012 |pmid=22452767 |doi=10.1037/a0024488}} They can also have difficulty understanding others' emotions and social cues.{{Cite journal |vauthors=Smith A |date=2006-01-01 |title=Cognitive Empathy and Emotional Empathy in Human Behavior and Evolution |url=https://doi.org/10.1007/BF03395534 |url-status=live |journal=The Psychological Record |language=en |volume=56 |issue=1 |pages=3–21 |doi=10.1007/BF03395534 |s2cid=15189760 |issn=2163-3452 |archive-url=https://web.archive.org/web/20220904080718/https://link.springer.com/article/10.1007/BF03395534 |archive-date=September 4, 2022}}{{cite journal |vauthors=Booules-Katri TM, Pedreño C, Navarro JB, Pamias M, Obiols JE |title=Theory of Mind (ToM) Performance in High Functioning Autism (HFA) and Schizotypal-Schizoid Personality Disorders (SSPD) Patients |journal=Journal of Autism and Developmental Disorders |volume=49 |issue=8 |pages=3376–3386 |date=August 2019 |pmid=31104261 |doi=10.1007/s10803-019-04058-1 |s2cid=254567524}}{{cite journal |vauthors=Gagliardini G, Gullo S, Caverzasi E, Boldrini A, Blasi S, Colli A |title=Assessing mentalization in psychotherapy: first validation of the Mentalization Imbalances Scale |journal=Research in Psychotherapy |volume=21 |issue=3 |pages=339 |date=December 2018 |pmid=32913774 |pmc=7451352 |doi=10.4081/ripppo.2018.339}} It can be hard for people with SzPD to assess the impact of their actions in social situations.{{cite book |vauthors=Laing RD |title=The Divided Self: an Existential Study in Sanity and Madness |publisher=Penguin Books |year=1965 |isbn=978-0-14-020734-7 |location=Harmondsworth, Middlesex; Baltimore |pages=82–100 |chapter=The Inner Self in the Schizoid Condition |oclc=5212085 |author-link=R. D. Laing |chapter-url=https://books.google.com/books?id=4JT-12rMtJsC&pg=PT87}}{{Cite book |vauthors=Veague HB, Collins CE |url=https://books.google.com/books?id=EGZZgqcIkm0C |title=Personality Disorders |date=2007 |publisher=Infobase Publishing |isbn=978-1-4381-1839-0 |pages=21 |language=en}} People with this condition are often indifferent towards criticism or praise and can appear distant, aloof, or uncaring to others.{{cite journal |vauthors=Wang F, Chen W, Huang J, Xu P, He W, Chai H, Zhu J, Yu W, Chen L, Wang W |title=Preliminary study of relationships between hypnotic susceptibility and personality disorder functioning styles in healthy volunteers and personality disorder patients |journal=BMC Psychiatry |volume=11 |issue=1 |pages=121 |date=July 2011 |pmid=21801440 |pmc=3162494 |doi=10.1186/1471-244X-11-121 |doi-access=free}} They may avoid others and expressing themselves as a method of keeping others distant and preventing themselves from being hurt.{{Cite journal |vauthors=Fossati A |date=2012 |title=Shut in or split up? A commentary on Dr. Nirestean and colleagues' 'Schizoid personality disorder-the peculiarities of their interpersonal relationships and existential roles': Shut in or split up? |url=https://onlinelibrary.wiley.com/doi/10.1002/pmh.1179 |journal=Personality and Mental Health |language=en |volume=6 |issue=1 |pages=77–82 |doi=10.1002/pmh.1179 |via=Wiley Online Library}} Remaining alone and expressionless can feel safe and comfortable for people with SzPD.{{Cite journal |vauthors=Little R |date=2021-03-12 |title=Engaging With the Schizoid Compromise: A Response to Erskine's "Relational Withdrawal, Attunement to Silence: Psychotherapy of the Schizoid Process" |url=http://integrative-journal.com/index.php/ijip/article/view/165 |url-status=live |journal=International Journal of Integrative Psychotherapy |language=en |volume=11 |issue=1 |pages=29–54 |issn=2156-9703 |archive-url=https://web.archive.org/web/20211127003523/http://integrative-journal.com/index.php/ijip/article/view/165 |archive-date=November 27, 2021}} Expressing themselves can make them feel shame or discomfort. People with SzPD may feel inadequate and can be sensitive,{{cite journal |vauthors=Akhtar S |title=Schizoid personality disorder: a synthesis of developmental, dynamic, and descriptive features |journal=American Journal of Psychotherapy |volume=41 |issue=4 |pages=499–518 |date=October 1987 |pmid=3324773 |doi=10.1176/appi.psychotherapy.1987.41.4.499}} although they have difficulty expressing it. Alexithymia, or difficulties understanding one's own emotions, is common amongst people with SzPD.{{cite book |vauthors=Taylor GJ, Bagby RM, Parker JD |title=Disorders of Affect Regulation: Alexithymia in Medical and Psychiatric Illness |publisher=Cambridge University Press |year=1997 |isbn=978-0-521-45610-4 |location=Cambridge |pages=162–165}}{{Cite book |chapter-url=https://www.degruyter.com/document/doi/10.1515/9783110319453.145/html |chapter=Chapter 5. Hope and Alexithymia |date=2013-05-02 |publisher=De Gruyter |isbn=978-3-11-031945-3 |pages=153–157 |language=en |doi=10.1515/9783110319453.145 |title=Mixed Feelings}}{{cite journal |vauthors=Coolidge FL, Estey AJ, Segal DL, Marle PD |title=Are alexithymia and schizoid personality disorder synonymous diagnoses? |journal=Comprehensive Psychiatry |volume=54 |issue=2 |pages=141–148 |date=February 2013 |pmid=23021894 |doi=10.1016/j.comppsych.2012.07.005 |s2cid=15019411}} This leads to them isolating themselves to avoid the discomfort and stimulation that emotional experiences offer. According to Guntrip, Klein, and others, people with SzPD may possess a hidden sense of superiority and lack dependence on other people's opinions. This is very different from the grandiosity seen in narcissistic personality disorder, which is described as "burdened with envy" and with a desire to destroy or put down others. Additionally, schizoid individuals do not go out of their way to achieve social validation. Unlike narcissists, schizoid people will often keep their creations private to avoid unwelcome attention or the feeling that their ideas and thoughts are being appropriated by the public. When forced to rely on others, a person with SzPD may feel panic or terror.

Patients with SzPD often feel unreal, empty, and separate from their own emotions.{{Cite thesis |vauthors=Newberry MT |degree=Ph.D. |title=An exploration of the trauma histories, dissociative experiences and psychopathic features of murderers |url=https://core.ac.uk/outputs/30339635 |url-status=live |publisher=Brunel University |location=London |archive-url=https://web.archive.org/web/20220925141216/https://core.ac.uk/outputs/30339635 |archive-date=September 25, 2022}} They tend to perceive themselves as fundamentally different from others and can believe that they are fundamentally unlikeable.{{cite journal |vauthors=Fountoulakis KN, Iacovides A, Ioannidou C, Bascialla F, Nimatoudis I, Kaprinis G, Janca A, Dahl A |title=Reliability and cultural applicability of the Greek version of the International Personality Disorders Examination |journal=BMC Psychiatry |volume=2 |issue=1 |pages=6 |date=May 2002 |pmid=12019033 |pmc=116573 |doi=10.1186/1471-244X-2-6 |doi-access=free}} Other people often seem strange and incomprehensible to a person with SzPD. Reality can feel unenjoyable and uninteresting to people with SzPD. They have difficulty finding motivation and lack ambition.{{Cite thesis |vauthors=Mullins-Sweatt S |date=2004-06-04 |title=Personality Disorders as Maladaptive Variants of General Personality Traits: A Subclinical Approach |degree=MA |publisher=Morehead State University |url=https://scholarworks.moreheadstate.edu/msu_theses_dissertations/703 |url-status=live |archive-url=https://web.archive.org/web/20220925122409/https://scholarworks.moreheadstate.edu/msu_theses_dissertations/703/ |archive-date=September 25, 2022 |access-date=September 25, 2022}}{{cite journal |vauthors=Svrakic D, Divac-Jovanovic M, Azhar N |title=An Integrative Model and Dynamic Nosology of Personality Disorder: Part 2: Symptom-based pharmacotherapy |journal=Psychiatria Danubina |volume=31 |issue=1 |pages=2–17 |date=March 2019 |pmid=30948684 |doi=10.24869/psyd.2019.2 |s2cid=96434751 |doi-access=free}} Patients with SzPD often feel as if they are "going through the motions" or that "life passes them by."{{cite journal |vauthors=Hayward BA |title=Cluster A personality disorders: considering the 'odd-eccentric' in psychiatric nursing |journal=International Journal of Mental Health Nursing |volume=16 |issue=1 |pages=15–21 |date=February 2007 |pmid=17229270 |doi=10.1111/j.1447-0349.2006.00439.x |doi-access=free}}{{Cite book |url=https://www.degruyter.com/document/doi/10.18574/nyu/9781479804856.001.0001/html |title=Criminal Trials and Mental Disorders |vauthors=Hafemeister TL |date=2019-02-05 |publisher=New York University Press |isbn=978-1-4798-5075-4 |pages=36–37 |language=en |chapter=Mental Disorders and Criminal Behavior |doi=10.18574/nyu/9781479804856.003.0002 |chapter-url=https://www.degruyter.com/document/doi/10.18574/nyu/9781479804856.003.0002/html |s2cid=204639945}}{{Cite journal |vauthors=Gerson G |date=April 29, 2021 |title=Fairbairn, Winnicott, and Guntrip on the social significance of schizoids |journal=History of the Human Sciences |language=en |volume=35 |issue=3–4 |pages=144–167 |doi=10.1177/09526951211008078 |s2cid=235576284 |issn=0952-6951 |via=SAGE publications}} Many describe feeling as if they are observing life from a distance.{{cite book |vauthors=Magnavita JJ |url=https://books.google.com/books?id=zlFVfzH8orMC&pg=PA236 |title=Restructuring Personality Disorders: A Short-Term Dynamic Approach |publisher=The Guilford Press |year=1997 |isbn=978-1-57230-185-6 |location=New York |page=237}} Aaron Beck and his colleagues report that people with SzPD seem comfortable with their aloof lifestyle and consider themselves observers, rather than participants in the world around them. But they also mention that many of their schizoid patients recognize themselves as socially deviant (or even defective) when confronted with the different lives of ordinary people – especially when they read books or see movies focusing on relationships. Even when schizoid individuals may not long for closeness, they can become weary of being "on the outside, looking in". These feelings may lead to depression, depersonalization, or derealization. If they do, schizoid people often experience feeling "like a robot" or "going through life in a dream".{{cite book |vauthors=Beck AT, Freeman A |title=Cognitive Therapy of Personality Disorders |publisher=The Guilford Press |year=1990 |isbn=978-0-89862-434-2 |edition=1st |pages=125 (Millon),127–129 (cognitive therapy conceptualization) |chapter=Chapter 7 Schizoid and Schizotypal PD (p.120-146) |oclc=906420553 |author1-link=Aaron T. Beck}} People with SzPD may try to avoid all physical activity in order to become nobody and disconnect from reality. This can lead to the patient spending a large quantity of time sleeping and ignoring bodily functions such as hygiene.

{{See also|Maladaptive daydreaming}}

Although this disorder does not affect the patient's capacity to understand reality, they may engage in excessive daydreaming and introspection.{{Cite book |vauthors=Winnicott DW |url=https://books.google.com/books?id=JHMdZC08HhcC |title=Playing and Reality |publisher=Psychology Press |year=1991 |isbn=978-0-415-03689-4 |pages=26–28 |language=en}}{{Cite journal |vauthors=Madonna J |date=December 1, 2021 |title=Sensitivity, isolation, and loneliness in the treatment of schizoid personality disorder |journal=Modern Psychoanalysis |volume=45 |issue=2 |pages=155–175 |via=EBSCO}} Their daydreams can grow to consume most of their lives. Real life can become secondary to their fantasy,{{cite journal |vauthors=Chadwick PK |title=Peer-professional first person account: before psychosis—schizoid personality from the inside |journal=Schizophrenia Bulletin |volume=40 |issue=3 |pages=483–486 |date=May 2014 |pmid=24353095 |doi=10.1093/schbul/sbt182 |pmc=3984520 |url=https://academic.oup.com/schizophreniabulletin/article/40/3/483/1905514 |url-status=live |access-date=2022-09-26 |archive-url=https://web.archive.org/web/20220728194035/https://academic.oup.com/schizophreniabulletin/article/40/3/483/1905514 |archive-date=July 28, 2022}} and they can have complex lives and relationships which exist entirely inside of their internal fantasy. These daydreams may constitute a defense mechanism to protect the patient from the outside world and its difficulties.{{Cite journal |vauthors=Ceroni ML, Abude C |date=2019-04-01 |title=Compulsions and Personality Disorders: Homicides and Suicides: a Social Health Issue Based on Bioenergetic Analysis |url=https://bioenergetic-analysis.com/article/view/0743-4804-2019-29-79 |url-status=live |journal=Bioenergetic Analysis |language=en |volume=29 |issue=1 |pages=79–97 |doi=10.30820/0743-4804-2019-29-79 |s2cid=240883072 |issn=2747-8882 |archive-url=https://web.archive.org/web/20211026181509/https://bioenergetic-analysis.com/article/view/0743-4804-2019-29-79 |archive-date=2021-10-26}} Common themes in their internal fantasies are omnipotence and grandiosity. The related schizotypal personality disorder and schizophrenia are reported to have ties to creative thinking, and it is speculated that the internal fantasy aspect of SzPD may also be reflective of this thinking.{{cite journal |vauthors=Schuldberg D |year=2001 |title=Six subclinical spectrum traits in normal creativity |journal=Creativity Research Journal |volume=13 |issue=1 |pages=5–16 |doi=10.1207/s15326934crj1301_2 |s2cid=143791841}}{{Cite journal |vauthors=Domino G |year=2002 |title=Creativity and Ego Defense Mechanisms: Some Exploratory Empirical Evidence |journal=Creativity Research Journal |volume=14 |issue=1 |pages=17–25 |doi=10.1207/S15326934CRJ1401_2 |s2cid=152269910}}{{Cite journal |vauthors=Kinney DK, Richards R |year=2001 |title=Creativity in Offspring of Schizophrenic and Control Parents: An Adoption Study |url=https://www.researchgate.net/publication/233244470 |journal=Creativity Research Journal |volume=13 |issue=1 |pages=17–25 |doi=10.1207/S15326934CRJ1301_3 |s2cid=145560246}} Alternatively, there has been an especially large contribution of people with schizoid symptoms to science and theoretical areas of knowledge, including mathematics, physics, economics, etc. At the same time, people with SzPD are helpless at many practical activities because of their symptoms.{{Cite book |vauthors=Belorusov S |url=https://books.google.com/books?id=Xw_JDgAAQBAJ&pg=PT215 |title=Очерки душевной патологии. И возможности ее коррекции соотносительно с духовным измерением бытия |trans-title=Essays on mental pathology. And the possibilities of its correction in relation to the spiritual dimension of being |date=2017-09-05 |publisher=Litres |isbn=978-5-04-054833-0 |language=ru |quote=Especially important is the contribution of schizoid scientists in the theoretical fields of knowledge: mathematics, physics, economics. At the same time, schizoid individuals are absolutely helpless in practical activities.}}

Symptoms of SzPD such as isolation and the blunted affect put people with schizoid personality disorder at a higher risk of suicide and non-suicidal self-harm.{{cite journal |vauthors=Del Bello V, Verdolini N, Pauselli L, Attademo L, Bernardini F, Quartesan R, Moretti P |title=Personality and psychotic symptoms as predictors of self-harm and attempted suicide |journal=Psychiatria Danubina |volume=27 |issue=Suppl 1 |pages=S285–S291 |date=September 2015 |pmid=26417781}}{{cite journal |vauthors=Levi Y, Horesh N, Fischel T, Treves I, Or E, Apter A |title=Mental pain and its communication in medically serious suicide attempts: an "impossible situation" |journal=Journal of Affective Disorders |volume=111 |issue=2–3 |pages=244–250 |date=December 2008 |pmid=18436309 |doi=10.1016/j.jad.2008.02.022}} This may be because their reduced capacities for emotion prevent them from properly dealing with strife. Their solitary nature may contribute by preventing them from finding relief in relationships. Demonstrative suicides or suicide blackmail, as seen in cluster B personality disorders such as borderline, histrionic, or antisocial, are extremely rare among schizoid individuals.{{Cite journal |vauthors=Anatolyevna PE, Sergeevich PB |year=2011 |title=Расстройства Личности у Пациентов, Совершивших Суицидальные Попытки |trans-title=Personality Disorders in Patients Who Have Committed Suicide Attempts |url=https://cyberleninka.ru/article/n/rasstroystva-lichnosti-u-patsientov-sovershivshih-suitsidalnye-popytki |journal=Российский психиатрический журнал |issue=3 |pages=48–51 |issn=1560-957X}} As in other clinical mental health settings, among suicidal inpatients, individuals with SzPD are not as well represented as some other groups. A 2011 study on suicidal inpatients at a Moscow hospital found that schizoid individuals were the least common patients, while those with cluster B personality disorders were the most common.

A study that looked at the body mass index (BMI) of a sample of male adolescents diagnosed with either SzPD or Asperger syndrome{{Cite journal |last=Hebebrand |first=J. |last2=Hennighausen |first2=K. |last3=Nau |first3=S. |last4=Himmelmann |first4=G. W. |last5=Schulz |first5=E. |last6=Schäfer |first6=H. |last7=Remschmidt |first7=H. |date=1997 |title=Low body weight in male children an adolescents with schizoid personality disorder or Asperger's disorder |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1600-0447.1997.tb09906.x |journal=Acta Psychiatrica Scandinavica |language=en |volume=96 |issue=1 |pages=64–67 |doi=10.1111/j.1600-0447.1997.tb09906.x |issn=1600-0447 |quote=This study explored the hypothesis that body weight is reduced in male children and adolescents with schizoid personality disorder or Asperger's disorder. The body weights of 33 consecutively admitted male subjects with one of these disorders were retrospectively assessed with percentiles for the body mass index (BMI).}} found that the BMI of all patients was significantly below normal. Clinical records indicated abnormal eating behavior by some patients. Some patients would only eat when alone and refused to eat out. Restrictive diets and fears of disease were also found. It was suggested that the anhedonia of SzPD may also affect eating, leading schizoid individuals to not enjoy it.{{cite journal |vauthors=Hebebrand J, Henninghausen K, Nau S, Himmelmann GW, Schulz E, Schäfer H, Remschmidt H |title=Low body weight in male children and adolescents with schizoid personality disorder or Asperger's disorder |journal=Acta Psychiatrica Scandinavica |volume=96 |issue=1 |pages=64–67 |date=July 1997 |pmid=9259226 |doi=10.1111/j.1600-0447.1997.tb09906.x |s2cid=41103333 |doi-access=free}} Alternatively, it was suggested that schizoid individuals may not feel hunger as strongly as others or not respond to it, a certain withdrawal "from themselves".

Very little data exists for rates of substance use disorder among people with SzPD, but existing studies suggest they are less likely to have substance abuse problems than the general population. One study found that significantly fewer boys with SzPD had alcohol problems than a control group of non-schizoid people.{{cite journal |vauthors=Wolff S, Cull A |title='Schizoid' personality and antisocial conduct: a retrospective case not study |journal=Psychological Medicine |volume=16 |issue=3 |pages=677–687 |date=August 1986 |pmid=3763781 |doi=10.1017/S0033291700010424 |s2cid=35166577}} Another study evaluating personality disorder profiles in substance abusers found that substance abusers who showed schizoid symptoms were more likely to abuse one substance rather than many, in contrast to other personality disorders such as borderline, antisocial, or histrionic, which were more likely to abuse many.{{cite journal |vauthors=Skinstad AH, Swain A |title=Comorbidity in a clinical sample of substance abusers |journal=The American Journal of Drug and Alcohol Abuse |volume=27 |issue=1 |pages=45–64 |date=February 2001 |pmid=11373036 |doi=10.1081/ADA-100103118 |s2cid=2619787}} American psychotherapist Sharon Ekleberry states that the impoverished social connections experienced by people with SzPD limit their exposure to the drug culture and that they have limited inclination to learn how to do illegal drugs. Describing them as "highly resistant to influence", she additionally states that even if they could access illegal drugs, they would be disinclined to use them in public or social settings, and because they would be more likely to use alcohol or cannabis alone than for social disinhibition, they would not be particularly vulnerable to negative consequences in early use.{{Cite book |vauthors=Ekleberry SC |title=Integrated Treatment for Co-Occurring Disorders: Personality Disorders and Addiction |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}} People with SzPD are at a lower risk of substance abuse issues than people with other personality disorders.{{Cite journal |vauthors=DiClemente CC, Prochaska JO |date=January 1982 |title=Self-change and therapy change of smoking behavior: A comparison of processes of change in cessation and maintenance |url=https://dx.doi.org/10.1016/0306-4603%2882%2990038-7 |url-status=live |journal=Addictive Behaviors |language=en |volume=7 |issue=2 |pages=133–142 |doi=10.1016/0306-4603(82)90038-7 |pmid=7102444 |issn=0306-4603 |archive-url=https://web.archive.org/web/20210812233113/https://www.sciencedirect.com/science/article/abs/pii/0306460382900387 |archive-date=August 12, 2021}}{{cite journal |vauthors=Ayerbe L, Forgnone I, Foguet-Boreu Q, González E, Addo J, Ayis S |title=Disparities in the management of cardiovascular risk factors in patients with psychiatric disorders: a systematic review and meta-analysis |journal=Psychological Medicine |volume=48 |issue=16 |pages=2693–2701 |date=December 2018 |pmid=29490716 |doi=10.1017/s0033291718000302 |s2cid=206257607 |url=https://kclpure.kcl.ac.uk/portal/en/publications/disparities-in-the-management-of-cardiovascular-risk-factors-in-patients-with-psychiatric-disorders(fc8193c9-de51-447e-8626-62542e98b347).html}} They may form relationships with their substances as a substitute for human contact or to cope with emotional issues.{{Cite journal |vauthors=El Rasheed AH, Elserafy DM, Marey MA, Hashem RE |date=2022-08-01 |title=Mood regulation, alexithymia, and personality disorders in female patients with opioid use disorders |journal=Middle East Current Psychiatry |volume=29 |issue=1 |pages=57 |doi=10.1186/s43045-022-00222-z |s2cid=251229937 |issn=2090-5416 |doi-access=free}}{{cite journal |vauthors=Armstrong RH |title=Schizoid phenomena in substance abusers |journal=Journal of Addictive Diseases |volume=21 |issue=3 |pages=73–85 |date=2002-06-17 |pmid=12095001 |doi=10.1300/J069v21n03_06 |s2cid=19376882}} People with SzPD may desire psychedelic drugs more than other kinds.{{Cite book |vauthors=Ekleberry SC |url=https://books.google.com/books?id=3gbGBQAAQBAJ |title=Integrated Treatment for Co-Occurring Disorders: Personality Disorders and Addiction |date=2011-04-27 |publisher=Routledge |isbn=978-1-136-91493-5 |language=en}}

Many schizoid individuals display an engaging, interactive personality, contradicting the observable characteristic emphasized by the DSM-5 and ICD-10 definitions of the schizoid personality. Guntrip (using ideas of Klein, Fairbairn, and Winnicott) classifies these individuals as "secret schizoids", who behave with socially available, interested, engaged, and involved interaction yet remain emotionally withdrawn and sequestered within the safety of the internal world.{{cite book |vauthors=Falk A |url=https://books.google.com/books?id=tcTpj4MMqxIC&pg=PA98 |title=Islamic Terror: Conscious and Unconscious Motives |publisher=ABC-CLIO |year=2008 |isbn=978-0-313-35764-0 |pages=98}} Klein distinguishes between a "classic" SzPD and a "secret" SzPD, which occur "just as often" as each other. Klein cautions one should not misidentify the schizoid person as a result of the patient's defensive, compensatory interaction with the external world. He suggests one ask the person what their subjective experience is, to detect the presence of the schizoid refusal of emotional intimacy and preference for objective fact. A 2013 study looking at personality disorders and Internet use found that being online more hours per day predicted signs of SzPD. Additionally, SzPD correlated with lower phone call use and fewer Facebook friends.{{Cite journal |vauthors=Rosen LD, Whaling K, Rab S, Carrier LM, Cheever NA |year=2013 |title=Is Facebook creating "iDisorders"? The link between clinical symptoms of psychiatric disorders and technology use, attitudes and anxiety |journal=Computers in Human Behavior |volume=29 |issue=3 |pages=1243–1254 |doi=10.1016/j.chb.2012.11.012 |s2cid=16532971 |issn=0747-5632}}

Descriptions of the schizoid personality as "hidden" behind an outward appearance of emotional engagement have been recognized since 1940, with Fairbairn's description of "schizoid exhibitionism", in which the schizoid individual can express a great deal of feeling and make what appear to be impressive social contacts yet, in reality, gives nothing and loses nothing. Because they are "playing a part", their personality is not involved. According to Fairbairn, the person disowns the part they are playing, and the schizoid individual seeks to preserve their personality intact and immune from compromise.{{cite book |vauthors=Fairbairn WR |url=https://books.google.com/books?id=LwxoUHnyvj0C |title=Psychoanalytic Studies of the Personality |date=2013 |publisher=Routledge |isbn=978-1-134-84213-1 |pages=3–17 |author-link=Ronald Fairbairn}} The schizoid person's false persona is based on what those around them define as normal or good behavior, as a form of compliance. Further references to the secret schizoid come from Masud Khan,{{Cite book |vauthors=Khan M |title=The Privacy of the Self – Papers on Psychoanalytic Theory and Technique |publisher=International Universities Press |year=1974 |isbn=978-0-8236-4310-3 |location=New York |page=70 |chapter=The Role of phobic and counter-phobic mechanisms and separation anxiety in schizoid character formation |author-link=Masud Khan}} Jeffrey Seinfeld,{{cite book |vauthors=Seinfeld J |url=https://books.google.com/books?id=r9ZrAAAAMAAJ |title=The Empty Core: An Object Relations Approach to Psychotherapy of the Schizoid Personality |publisher=J. Aronson |year=1991 |isbn=978-0-87668-611-9 |quote=Seinfeld writes: "The schizoid may also seem to be sociable and involved in relationships. However, he is frequently playing a role and not 'fully' involved, unconsciously disowning this role..."}} and Philip Manfield. These scholars described secret schizoids as people who enjoy public speaking engagements but experience great difficulty during the breaks when audience members would attempt to engage them emotionally. These references expose the problems in relying on outer observable behavior for assessing the presence of personality disorders in certain individuals.

• Agoraphobia{{cite journal |vauthors=Koch J, Modesitt T, Palmer M, Ward S, Martin B, Wyatt R, Thomas C |title=Review of pharmacologic treatment in cluster A personality disorders |journal=The Mental Health Clinician |volume=6 |issue=2 |pages=75–81 |date=March 2016 |pmid=29955451 |pmc=6007578 |doi=10.9740/mhc.2016.03.75}}
• Avoidant personality disorder
• Antisocial personality disorder{{citation needed|date=April 2024}}
• Borderline personality disorder{{Cite journal |last1=Pietrzak |first1=Robert H. |last2=Goldstein |first2=Risë B. |last3=Southwick |first3=Steven M. |last4=Grant |first4=Bridget F. |date=May 2011 |title=Personality Disorders Associated with Full and Partial Posttraumatic Stress Disorder in the U.S. Population: Results from Wave 2 of the National Epidemiologic Survey on Alcohol and Related Conditions |journal=Journal of Psychiatric Research |volume=45 |issue=5 |pages=678–686 |doi=10.1016/j.jpsychires.2010.09.013 |issn=0022-3956 |pmc=3388551 |pmid=20950823}}
• Post-traumatic stress disorder{{cite journal |vauthors=Borroni S, Masci E, Franzoni C, Somma A, Fossati A |title=The Co-Occurrence of Trauma Related Disorder and Borderline Personality Disorder: AQ Study on a Clinical Sample of Patients Seeking Psychotherapy Treatment |journal=Psychiatry Research |volume=295 |pages=113587 |date=January 2021 |pmid=33349435 |doi=10.1016/j.psychres.2020.113587 |s2cid=227133276 |url=https://www.sciencedirect.com/science/article/pii/S0165178120332480 |url-status=live |archive-url=https://web.archive.org/web/20220923162546/https://www.sciencedirect.com/science/article/abs/pii/S0165178120332480 |archive-date=September 23, 2022}}
• Major depressive disorder{{Cite journal |last1=Corruble |first1=E. |last2=Ginestet |first2=D. |last3=Guelfi |first3=J.D. |date=April 1996 |title=Comorbidity of personality disorders and unipolar major depression: A review |url=http://dx.doi.org/10.1016/0165-0327(95)00091-7 |journal=Journal of Affective Disorders |volume=37 |issue=2–3 |pages=157–170 |doi=10.1016/0165-0327(95)00091-7 |pmid=8731079 |issn=0165-0327}}
• Generalized anxiety disorder
• Panic disorder{{Citation |last1=Navinés |first1=Ricard |title=Panic Disorder and Personality Disorder Comorbidity |date=2016 |url=https://doi.org/10.1007/978-3-319-12538-1_10 |work=Panic Disorder: Neurobiological and Treatment Aspects |pages=169–184 |editor-last=Nardi |editor-first=Antonio Egidio |access-date=2023-12-30 |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-319-12538-1_10 |isbn=978-3-319-12538-1 |last2=Egmond |first2=Elfi |last3=Martín-Santos |first3=Rocío |editor2-last=Freire |editor2-first=Rafael Christophe R.}}
• Paranoid personality disorder
• Social anxiety disorder
• Schizotypal personality disorder{{cite journal |vauthors=Raine A |title=Schizotypal personality: neurodevelopmental and psychosocial trajectories |journal=Annual Review of Clinical Psychology |volume=2 |issue=1 |pages=291–326 |date=2006-04-01 |pmid=17716072 |doi=10.1146/annurev.clinpsy.2.022305.095318}}
• Obsessive–compulsive disorder

Several studies have reported an overlap or comorbidity with autism spectrum disorder and Asperger syndrome.{{cite journal |vauthors=Hummelen B, Pedersen G, Wilberg T, Karterud S |title=Poor Validity of the DSM-IV Schizoid Personality Disorder Construct as a Diagnostic Category |journal=Journal of Personality Disorders |volume=29 |issue=3 |pages=334–346 |date=June 2015 |pmid=25248009 |doi=10.1521/pedi_2014_28_159}}{{cite journal |vauthors=Gadow KD |title=Association of schizophrenia spectrum and autism spectrum disorder (ASD) symptoms in children with ASD and clinic controls |journal=Research in Developmental Disabilities |volume=34 |issue=4 |pages=1289–1299 |date=April 2013 |pmid=23417134 |doi=10.1016/j.ridd.2013.01.011}}{{cite journal |vauthors=Wolff S |title='Schizoid' personality in childhood and adult life. III: The childhood picture |journal=The British Journal of Psychiatry |volume=159 |issue=5 |pages=629–635 |date=November 1991 |pmid=1756338 |doi=10.1192/bjp.159.5.629 |s2cid=26445266 |url=https://www.cambridge.org/core/journals/the-british-journal-of-psychiatry/article/abs/schizoid-personality-in-childhood-and-adult-life-iii-the-childhood-picture/1EA3B194FADC3226A671286BA57A98F1 |url-status=live |archive-url=https://web.archive.org/web/20210525181644/https://www.cambridge.org/core/journals/the-british-journal-of-psychiatry/article/abs/schizoid-personality-in-childhood-and-adult-life-iii-the-childhood-picture/1EA3B194FADC3226A671286BA57A98F1 |archive-date=May 25, 2021}} Asperger syndrome had traditionally been called "schizoid disorder of childhood",{{cite journal |vauthors=Wolff S, Barlow A |title=Schizoid personality in childhood: a comparative study of schizoid, autistic and normal children |journal=Journal of Child Psychology and Psychiatry, and Allied Disciplines |volume=20 |issue=1 |pages=29–46 |date=January 1979 |pmid=422686 |doi=10.1111/j.1469-7610.1979.tb01704.x}}{{Cite book |url=http://ndl.ethernet.edu.et/bitstream/123456789/76260/1/25.pdf |title=Asperger Syndrome |vauthors=Wolff S |date=18 February 2000 |publisher=The Guilford Press |isbn=978-1-57230-534-2 |veditors=Klin A, Volkmar F, Sparrow S |edition=1st |location=New York |publication-date=February 18, 2020 |pages=278–309 |language=en |chapter=Schizoid Personality in Childhood and Asperger Syndrome |archive-url=https://web.archive.org/web/20210806170142/http://ndl.ethernet.edu.et/bitstream/123456789/76260/1/25.pdf |archive-date=August 6, 2021 |url-status=live}}{{cite journal |vauthors=Wolff S |title=The history of autism |journal=European Child & Adolescent Psychiatry |volume=13 |issue=4 |pages=201–208 |date=August 2004 |pmid=15365889 |doi=10.1007/s00787-004-0363-5 |url=https://link.springer.com/article/10.1007/s00787-004-0363-5 |url-status=live |publisher=Springer Publishing |s2cid=37414040 |publication-date=August 19, 2004 |archive-url=https://web.archive.org/web/20220926224443/https://link.springer.com/article/10.1007/s00787-004-0363-5 |archive-date=September 26, 2022 |author-link=Sula Wolff}} and Eugen Bleuler coined both the terms "autism" and "schizoid" to describe withdrawal to an internal fantasy, against which any influence from outside becomes an intolerable disturbance.{{cite journal |vauthors=Kuhn R |title=Eugen Bleuler's concepts of psychopathology |journal=History of Psychiatry |volume=15 |issue=59 Pt 3 |pages=361–366 |date=September 2004 |pmid=15386868 |doi=10.1177/0957154X04044603 |s2cid=5317716}} The quote is a translation of Bleuler's 1910 original. In a 2012 study of a sample of 54 young adults with Asperger syndrome, it was found that 26% of them also met the criteria for SzPD, the highest comorbidity out of any personality disorder in the sample (the other comorbidities were 19% for obsessive–compulsive personality disorder, 13% for avoidant personality disorder and one female with schizotypal personality disorder). Additionally, twice as many men with Asperger syndrome met the criteria for SzPD than women. While 41% of the whole sample were unemployed with no occupation, this rose to 62% for the Asperger's and SzPD comorbid group. Tantam suggested that Asperger syndrome may confer an increased risk of developing SzPD. A 2019 study found that 54% of a group of males aged 11 to 25 with Asperger syndrome showed significant SzPD traits, with 6% meeting full diagnostic criteria for SzPD, compared to 0% of a control group.

In the 2012 study, it was noted that the DSM may complicate diagnosis by requiring the exclusion of a pervasive developmental disorder (PDD) before establishing a diagnosis of SzPD. The study found that social interaction impairments, stereotyped behaviors, and specific interests were more severe in the individuals with Asperger syndrome also fulfilling SzPD criteria, against the notion that social interaction skills are unimpaired in SzPD. The authors believe that a substantial subgroup of people with autism spectrum disorder or PDD have clear "schizoid traits" and correspond largely to the "loners" in Lorna Wing's classification The autism spectrum (Lancet 1997), described by Sula Wolff. The authors of the 2019 study hypothesized that it is extremely likely that historic cohorts of adults diagnosed with SzPD either also had childhood-onset autistic syndromes or were misdiagnosed. They stressed that further research to clarify overlap and distinctions between these two syndromes was strongly warranted, especially given that high-functioning autism spectrum disorders are now recognized in around 1% of the population.{{Cite journal |vauthors=Cook M |date=2019-05-03 |title=Pronounced Overlap of Autistic and Schizoid Personality Trait Burden in Adolescence |url=https://insar.confex.com/insar/2019/webprogram/Paper30221.html |url-status=live |archive-url=https://web.archive.org/web/20210308124022/https://insar.confex.com/insar/2019/webprogram/Paper30221.html |archive-date=March 8, 2021 |website=IMFAR |language=en}}

There are no effective medications for schizoid personality disorder. However, certain medications may reduce the symptoms of SzPD and treat co-occurring mental disorders. Since the symptoms of SzPD mirror the negative symptoms of schizophrenia, antipsychotics have been suggested as a potentially effective medication for SzPD.{{cite journal |vauthors=Di Lorenzo R, Tondelli G, Genedani S |title=Effectiveness of clozapine and olanzapine: a comparison in severe, psychotically ill patients |journal=The International Journal of Neuropsychopharmacology |volume=4 |issue=2 |pages=135–137 |date=June 2001 |pmid=11466163 |doi=10.1017/S1461145701002309 |s2cid=38376261 |doi-access=free |hdl=11380/303581 |hdl-access=free}}{{cite journal |vauthors=Di Lorenzo R, Amoretti A, Forghieri M, Fiorini F, Genedani S, Rigatelli M |title=Aripiprazole: effectiveness and safety under naturalistic conditions |journal=Experimental and Clinical Psychopharmacology |volume=15 |issue=6 |pages=569–575 |date=December 2007 |pmid=18179310 |doi=10.1037/1064-1297.15.6.569}} Originally, low doses of atypical antipsychotics like risperidone or olanzapine were used to alleviate social deficits and blunted affect.{{Cite book |url=https://link.springer.com/book/10.1007/978-1-4757-6876-3 |title=Treatment of Personality Disorders |year=1999 |publisher=Springer |language=en |doi=10.1007/978-1-4757-6876-3 |isbn=978-1-4419-3326-3 |s2cid=12323092 |veditors=Derksen J, Maffei C, Groen H}}{{cite book |vauthors=Lee R, Coccaro E |chapter=The Psychopharmacological Treatment of Personality Disorders |date=2002-07-30 |title=Biological Psychiatry |pages=1419–1429 |veditors=D'Haenen H, den Boer JA, Willner P |place=Chichester, UK |publisher=John Wiley & Sons, Ltd |language=en |doi=10.1002/0470854871.chxxvi9 |isbn=978-0-471-49198-9}}{{cite journal |vauthors=Newton-Howes G, Tyrer P |title=Pharmacotherapy for personality disorders |journal=Expert Opinion on Pharmacotherapy |volume=4 |issue=10 |pages=1643–1649 |date=October 2003 |pmid=14521475 |doi=10.1517/14656566.4.10.1643 |s2cid=5747195}} However, a 2012 review concluded that atypical antipsychotics were ineffective for treating personality disorders. Antidepressants, SSRIs,{{Cite book |url=https://link.springer.com/book/10.1007/978-3-7091-1501-5 |title=Psychiatric Drugs in Children and Adolescents |year=2014 |pages=477–478 |language=en |doi=10.1007/978-3-7091-1501-5 |isbn=978-3-7091-1500-8 |via=SpringerLink |veditors=Gerlach M, Warnke A, Greenhill L}} anxiolytics, bupropion, modafinil,{{cite journal |vauthors=Scoriels L, Jones PB, Sahakian BJ |title=Modafinil effects on cognition and emotion in schizophrenia and its neurochemical modulation in the brain |journal=Neuropharmacology |volume=64 |pages=168–184 |date=January 2013 |pmid=22820555 |doi=10.1016/j.neuropharm.2012.07.011 |s2cid=17975469}} benzodiazepines,{{cite book |vauthors=Cloninger CR, Svrakic DM |chapter=Personality Disorders |date=2008 |title=The Medical Basis of Psychiatry |pages=471–483 |veditors=Fatemi SH, Clayton PJ |place=Totowa, NJ |publisher=Humana Press |language=en |doi=10.1007/978-1-59745-252-6_28 |isbn=978-1-59745-252-6 |via=SpringerLink}}{{cite journal |vauthors=Simoni-Wastila L, Ross-Degnan D, Mah C, Gao X, Brown J, Cosler LE, Fanning T, Gallagher P, Salzman C, Soumerai SB |title=A retrospective data analysis of the impact of the New York triplicate prescription program on benzodiazepine use in medicaid patients with chronic psychiatric and neurologic disorders |journal=Clinical Therapeutics |volume=26 |issue=2 |pages=322–336 |date=February 2004 |pmid=15038954 |doi=10.1016/S0149-2918(04)90030-6}} and biofeedback{{cite journal |vauthors=Sumpf M, Jentschke S, Koelsch S |date=2015-06-17 |title=Effects of Aesthetic Chills on a Cardiac Signature of Emotionality |journal=PLOS ONE |volume=10 |issue=6 |pages=e0130117 |bibcode=2015PLoSO..1030117S |doi=10.1371/journal.pone.0130117 |pmc=4470584 |pmid=26083383 |doi-access=free}} may also be effective treatments.

File:Cognitive_behavioral_therapy_-_basic_tenets.svg, a kind of Psychotherapy used to treat SzPD]]

Treatment for this disorder uses a combination of cognitive-behavioral therapy and psychodynamic psychotherapy.{{Cite journal |vauthors=Devany K, Poerwandari EK |date=2020-09-08 |title=Integrating cognitive-behavioral therapy and gratitude therapy for treating somatic symptom disorder with schizoid-avoidant personality features: A case report |url=https://publication.k-pin.org/index.php/jpu/article/view/127 |url-status=live |journal=Jurnal Psikologi Ulayat: Indonesian Journal of Indigenous Psychology |language=en |volume=7 |issue=2 |pages=113–121 |doi=10.24854/jpu127 |issn=2580-1228 |s2cid=229359467 |archive-url=https://web.archive.org/web/20210513180808/https://publication.k-pin.org/index.php/jpu/article/view/127 |archive-date=May 13, 2021 |doi-access=free}}{{cite journal |vauthors=Osma J, Sánchez-Gómez A, Peris-Baquero Ó |title=Applying the unified protocol to a single case of major depression with schizoid and depressive personality traits |journal=Psicothema |volume=30 |issue=4 |pages=364–369 |date=November 2018 |pmid=30353835 |doi=10.7334/psicothema2018.41 |s2cid=53026709}} These techniques can be used to help patients identify their defense mechanisms and change them.{{Cite journal |vauthors=Mankiewicz P, Renton J |date=November 29, 2017 |title=Increasing Psychosocial Health with Cognitive Therapy in Schizoid Personality Disorder: A Single Subject Design |url=https://www.athensjournals.gr/health/2019-6-4-1-Mankiewicz.pdf |url-status=live |journal=Athens Journal of Health & Medical Sciences |language=english |volume=6 |issue=4 |pages=197–212 |doi=10.30958/ajhms.6-4-1 |s2cid=213432301 |archive-url=https://web.archive.org/web/20190803001211/https://www.athensjournals.gr/reviews/2019-3127-AJHMS-PDF.pdf |archive-date=August 3, 2019 |via=Semantic Scholar}}{{Cite journal |vauthors=Haimowitz C |date=2000-01-01 |title=Maybe It's Not "Kick Me" After All: Transactional Analysis and Schizoid Personality Disorder |url=https://doi.org/10.1177/036215370003000109 |journal=Transactional Analysis Journal |volume=30 |issue=1 |pages=84–90 |doi=10.1177/036215370003000109 |s2cid=148445150 |issn=0362-1537}} Therapists attempt to establish healthy relationships with their clients,{{cite journal |vauthors=Ward RK |title=Assessment and management of personality disorders |journal=American Family Physician |volume=70 |issue=8 |pages=1505–1512 |date=October 2004 |pmid=15526737 |url=https://www.aafp.org/dam/brand/aafp/pubs/afp/issues/2004/1015/p1505.pdf |url-status=live |archive-url=https://web.archive.org/web/20220927212841/https://www.aafp.org/pubs/afp/issues/2004/1015/p1505.html |archive-date=September 27, 2022}} helping to combat their internalized belief that relationships are harmful and unhelpful. Relationships with a therapist can seem terrifying and intrusive to a person with SzPD.{{Cite journal |vauthors=Roberts D |title=Differential interventions in psychotherapy of borderline, narcissistic, and schizoid personality disorders: the Masterson approach |journal=Clinical Psychology and Psychotherapy |year=1997 |publication-date=January 5, 1999 |volume=4 |issue=4 |pages=233–245 |doi=10.1002/(SICI)1099-0879(199712)4:4<233::AID-CPP141>3.0.CO;2-F}}{{cite journal |vauthors=Coen SJ |title=How to play with patients who would rather remain remote |journal=Journal of the American Psychoanalytic Association |volume=53 |issue=3 |pages=811–834 |date=2005 |pmid=16187635 |doi=10.1177/00030651050530030601 |s2cid=34224809}} They may feel as if they need to alter or hide their feelings to meet the therapist's demands or expectations. To combat this, therapists try to gradually increase their patient's emotional expression. Expressing too much too early can lead to their ending therapy. Treatment must be person centered, with clients feeling understood and well regarded.{{Cite journal |vauthors=Little R |date=2001-01-01 |title=Schizoid Processes: Working with the Defenses of the Withdrawn Child Ego State |journal=Transactional Analysis Journal |volume=31 |issue=1 |pages=33–43 |doi=10.1177/036215370103100105 |s2cid=4649876 |issn=0362-1537}}{{Cite journal |vauthors=Erskine RG |date=2020-12-23 |title=Relational Withdrawal, Attunement to Silence: Psychotherapy of the Schizoid Process |url=https://www.integrative-journal.com/index.php/ijip/article/view/161 |url-status=live |journal=International Journal of Integrative Psychotherapy |language=en |volume=11 |issue=1 |pages=14–28 |issn=2156-9703 |archive-url=https://web.archive.org/web/20220122195257/https://www.integrative-journal.com/index.php/ijip/article/view/161/0 |archive-date=January 22, 2022}} This can allow them to connect with and understand their emotions.{{Cite journal |vauthors=Kramer U, Meystre C |date=2010-05-26 |title=Assimilation process in a psychotherapy with a client presenting schizoid personality disorder |journal= Schweizer Archiv für Neurologie und Psychiatrie|volume=161 |language=en |issue=4 |pages=128–134 |doi=10.4414/sanp.2010.02162 |doi-broken-date=3 December 2024 |doi-access=free}}{{Cite journal |vauthors=New AS |date=2012 |title=Commentary on 'Schizoid personality disorder-the peculiarities of their interpersonal relationships and existential roles' by Nirestean, et al.: Commentary |url=https://onlinelibrary.wiley.com/doi/10.1002/pmh.1180 |journal=Personality and Mental Health |language=en |volume=6 |issue=1 |pages=83–85 |doi=10.1002/pmh.1180}}{{cite journal |vauthors=Orcutt C |title=Schizoid Fantasy: Refuge or Transitional Location? |journal=Clinical Social Work Journal |volume=46 |issue=1 |pages=42–47 |date=2018 |pmid=29540940 |pmc=5840255 |doi=10.1007/s10615-017-0629-2}} When people with SzPD do not have their feelings validated, this will confirm their belief that expressing themselves is dangerous. Therapists attempt to avoid intruding on their patients' lives or restricting their freedoms, so as to prevent them from feeling as if therapy is intolerable. Because of this, therapy is usually less structured than treatment programs for other disorders. Patients may benefit from long-term treatment lasting several years.{{cite journal |vauthors=Josephs L, Anderson E, Bernard A, Fatzer K, Streich J |title=Assessing progress in analysis interminable |journal=Journal of the American Psychoanalytic Association |volume=52 |issue=4 |pages=1185–1214 |year=2004 |pmid=15686090 |doi=10.1177/00030651040520041301 |s2cid=39374240}} Inpatient care may be effective for treating SzPD and other Cluster A disorders.{{cite journal |vauthors=Bartak A, Andrea H, Spreeuwenberg MD, Thunnissen M, Ziegler UM, Dekker J, Bouvy F, Hamers EF, Meerman AM, Busschbach JJ, Verheul R, Stijnen T, Emmelkamp PM |title=Patients with cluster a personality disorders in psychotherapy: an effectiveness study |language=english |journal=Psychotherapy and Psychosomatics |volume=80 |issue=2 |pages=88–99 |date=2011 |pmid=21196806 |doi=10.1159/000320587 |s2cid=20759978 |url=https://www.karger.com/Article/FullText/320587 |url-status=live |archive-url=https://web.archive.org/web/20220809072729/https://www.karger.com/Article/Abstract/320587 |archive-date=August 9, 2022 |hdl=1765/23043 |hdl-access=free}}

The original concept of the schizoid character developed by Ernst Kretschmer in the 1920s comprised a mix of avoidant, schizotypal, and schizoid traits. It was not until 1980 and the work of Theodore Millon that led to splitting this concept into three personality disorders (now schizoid, schizotypal, and avoidant). This caused debate about whether this was accurate or if these traits were different expressions of a single personality disorder. It has also been argued due to the poor consistency and efficiency of diagnosis due to overlapping traits that SzPD should be removed altogether from the DSM. A 2012 article suggested that two different disorders may better represent SzPD: one affect-constricted disorder (belonging to schizotypal PD) and a seclusive disorder (belonging to avoidant PD). They called for the replacement of the SzPD category from future editions of the DSM with a dimensional model which would allow for the description of schizoid traits on an individual basis.

Some critics such as Nancy McWilliams of Rutgers University and Panagiotis Parpottas of European University Cyprus argue that the definition of SzPD is flawed due to cultural bias and that it does not constitute a mental disorder but simply an avoidant attachment style requiring a more distant emotional proximity.{{cite book |vauthors=McWilliams N |url=https://books.google.com/books?id=BzPOAWB2DncC&pg=PA196 |title=Psychoanalytic Diagnosis: Understanding Personality Structure in the Clinical Process |date=2011 |publisher=Guilford Press |isbn=978-1-60918-494-0 |edition=2nd |location=New York |page=196 |author-link=Nancy McWilliams}} If that is true, then many of the more problematic reactions these individuals show in social situations may be partly accounted for by the judgments commonly imposed on people with this style.

Similarly, John Oldham, using a dimensional approach, thinks that most people with schizoid character features do not have a full-blown personality disorder.{{cite journal |last1=Hurt |first1=Avery |title=What Is Schizoid Personality Disorder And How Does It Affect Mental Health? |journal=Discover Magazine |date=Jun 28, 2023 |url=https://www.discovermagazine.com/mind/what-is-schizoid-personality-disorder-and-how-does-it-affect-mental-health |access-date=26 November 2023}} Impairment is mandatory for any behavior to be diagnosed as a personality disorder.

The latest edition of the Diagnostic and Statistical Manual of Mental Disorders, namely the DSM-5-TR, defines SzPD as "a pattern of detachment from social relationships and a restricted range of emotional expression" in the section II chapter on personality disorders.{{Cite book |title=Diagnostic and statistical manual of mental disorders: DSM-5-TR™ |date=2022 |publisher=American Psychiatric Association Publishing |isbn=978-0-89042-576-3 |editor-last=American Psychiatric Association |edition=Fifth edition, text revision |location=Washington, DC |pages=733–734}} The diagnosis is based on at least four out of seven diagnostic criteria being met.{{Cite book |title=Diagnostic and statistical manual of mental disorders: DSM-5-TR™ |date=2022 |publisher=American Psychiatric Association Publishing |isbn=978-0-89042-576-3 |editor-last=American Psychiatric Association |edition=Fifth edition, text revision |location=Washington, DC |pages=741–745}} The criteria have been retained from the DSM-IV-TR. In addition to the aforementioned criteria, a diagnosis requires that the condition is not merely a part of the manifestation of a disorder causing psychosis, such as schizophrenia, nor of autism spectrum disorder or "the physiological effects of another medical condition".

The Alternative DSM-5 Model for Personality Disorders (AMPD) does not list schizoid personality disorder as its own diagnostic entity.{{Cite book |title=Diagnostic and statistical manual of mental disorders: DSM-5 |date=2013 |publisher=American psychiatric association |isbn=978-0-89042-554-1 |edition=5th |location=Washington |pages=761}} However, it is stated in the AMPD that what is conceptualized as SzPD can instead be diagnosed as Personality Disorder - Trait Specified,{{Cite book |title=Diagnostic and statistical manual of mental disorders: DSM-5 |date=2013 |publisher=American psychiatric association |isbn=978-0-89042-554-1 |edition=5th |location=Washington |pages=771}} which is a dimensional diagnosis for personality disorders found in the alternative model.

Personality disorder can also be diagnosed in accordance with the International Classification of Diseases, the latest edition of which is the ICD-11. The ICD-11 personality disorder section differs substantially from the previous edition, ICD-10. All distinct PDs have been merged into one: personality disorder ([https://icd.who.int/browse/2025-01/mms/en#941859884 6D10]), which can be coded as mild ([https://icd.who.int/browse/2025-01/mms/en#263226710 6D10.0]), moderate ([https://icd.who.int/browse/2025-01/mms/en#758339377 6D10.1]), severe ([https://icd.who.int/browse/2025-01/mms/en#40156192 6D10.2]), or severity unspecified ([https://icd.who.int/browse/2025-01/mms/en#941859884%2Funspecified 6D10.Z]).{{Cite journal |last1=Bach |first1=Bo |last2=First |first2=Michael B. |date=2018-10-29 |title=Application of the ICD-11 classification of personality disorders |journal=BMC Psychiatry |volume=18 |issue=1 |pages=351 |doi=10.1186/s12888-018-1908-3 |doi-access=free |issn=1471-244X |pmc=6206910 |pmid=30373564}} Thus, there is no diagnosis specifically for SzPD. On the other hand, the ICD-10 has a diagnostic category specifically for schizoid personality disorder, with the code ([https://icd.who.int/browse10/2019/en#/F60.1 F60.1]).{{Cite journal |last1=Sass |first1=Henning |last2=Schwarte |first2=Reinhild |date=December 2006 |title=Schizoid Personality Disorder |url=https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=745f5d7dc6acbf08d6528315634497fcaa225d8e#page=129 |journal=WPA/ISSPD Educational Program on Personality Disorders |pages=129 |archive-url=https://web.archive.org/web/20250403201622/https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=745f5d7dc6acbf08d6528315634497fcaa225d8e#page=129 |archive-date=3 April 2025}}

Ralph Klein, Clinical Director of the Masterson Institute, delineates the following nine characteristics of the schizoid personality as described by Harry Guntrip:{{rp|13–23}}

• Introversion
• Withdrawnness
• Narcissism
• Self-sufficiency
• A sense of superiority
• Loss of affect
• Loneliness
• Depersonalization
• Regression

The description of Guntrip's nine characteristics should clarify some differences between the traditional DSM portrait of SzPD and the traditional informed object relations view. All nine characteristics are consistent. Most, if not all, must be present to diagnose a schizoid disorder.

Theodore Millon restricted the term "schizoid" to those personalities who lack the capacity to form social relationships. He characterizes their way of thinking as being vague and void of thoughts and as sometimes having a "defective perceptual scanning". Because they often do not perceive cues that trigger affective responses, they experience fewer emotional reactions.Aaron T. Beck; Arthur Freeman (1990). "Chapter 7 Schizoid and Schizotypal PD (p.120-146)". Cognitive Therapy of Personality Disorders (1st ed.). The Guilford Press. pp. 125 (Millon), 127–129 (cognitive therapy conceptualization). {{isbn|9780898624342}}. {{oclc|906420553}}{{Cite book |vauthors=DiGiuseppe R, Tafrate RC |url=https://books.google.com/books?id=kYsRDAAAQBAJ&q=schizoid+%22perceptual+scanning%22&pg=PA207 |title=Understanding Anger Disorders |date=2007 |publisher=Oxford University Press, USA |isbn=978-0-19-517079-5 |pages=207 |language=en}}

For Millon, SzPD is distinguished from other personality disorders in that it is "the personality disorder that lacks a personality." He criticizes that this may be due to the current diagnostic criteria: They describe SzPD only by an absence of certain traits, which results in a "deficit syndrome" or "vacuum". Instead of delineating the presence of something, they mention solely what is lacking. Therefore, it is hard to describe and research such a concept.

He identified four subtypes of SzPD. Any schizoid individual may exhibit none or one of the following:{{Cite web |title=Millon Theory – Retiring/Schizoid Personality |url=https://www.millonpersonality.com/theory/diagnostic-taxonomy/schizoid.htm |url-status=live |archive-url=https://web.archive.org/web/20211102134147/https://www.millonpersonality.com/theory/diagnostic-taxonomy/schizoid.htm |archive-date=November 2, 2021 |access-date=2022-09-29 |website=millonpersonality.com}}

American psychoanalyst Salman Akhtar provided a comprehensive phenomenological profile of SzPD in which classic and contemporary descriptive views are synthesized with psychoanalytic observations. This profile is summarized in the table reproduced below that lists clinical features that involve six areas of psychosocial functioning and are organized by "overt" and "covert" manifestations.

"Overt" and "covert" are intended to denote seemingly contradictory aspects that may both simultaneously be present in an individual. These designations do not necessarily imply their conscious or unconscious existence. The covert characteristics are by definition difficult to discern and not immediately apparent. Additionally, the lack of data on the frequency of many of the features makes their relative diagnostic weight difficult to distinguish at this time. However, Akhtar states that his profile has several advantages over the DSM in terms of maintaining historical continuity of the use of the word schizoid, valuing depth and complexity over descriptive oversimplification and helping provide a more meaningful differential diagnosis of SzPD from other personality disorders.

{{Portal|Psychology

}}

• Alexithymia
• Asociality
• Cognitive disengagement syndrome
• Counterphobic attitude
• Dissociation (psychology)
• Hermit
• Hikikomori
• Recluse
• Schizothymia
• Schizotypy
• Social disorder
• Social isolation
• Schizoid avoidant behavior
• Schizotypal personality disorder

{{Reflist}}

{{sister project links|wikt=Schizoid personality disorder|c=Category:Schizoid personality disorder|n=no|q=no|s=no|b=Textbook of Psychiatry/Personality Disorders|v=no|d=Q498237}}

• [https://press.ici-berlin.org/catalogue/doi/10.37050/hs-01 David Kishik, "Self Study: Notes on the Schizoid Condition"]
• [https://web.archive.org/web/20130531220453/http://www.points-and-positions.de/e107_files/downloads/The%20Biological%20Foundations%20of%20the%20Schizoid%20Process.pdf The Biological foundations of the Schizoid Process]
• [https://web.archive.org/web/20210730021704/https://www.nytimes.com/2006/11/21/health/psychology/21case.html?ex=1321765200&en=6030af72aae03e77&ei=5088partner=rssnyt&emc=rss NY Times article "Like a Fish Needs a Bicycle: For Some People, Intimacy Is Toxic"]
• Psychology Today (2017): [https://www.psychologytoday.com/blog/personality-quotient/201701/the-disappearance-the-schizoid-personality The Disappearance of the Schizoid Personality]

{{Medical resources

| ICD11 = {{ICD11|6D10}}

|ICD10={{ICD10|F|60|1|f|60}}

|ICD9={{ICD9|301.20}}

|MedlinePlus=000920

|MeshID=D012557

|SNOMED CT=52954000}}

{{ICD-10 personality disorders}}

{{Authority control}}

Cluster A personality disorders

Schizophrenia