Schizotypal personality disorder

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Odd and magical thinking is common among people with StPD.{{cite journal |vauthors=Fonseca-Pedrero E, Ortuño J, Debbané M, Chan RC, Cicero D, Zhang LC, Brenner C, Barkus E, Linscott RJ, Kwapil T, Barrantes-Vidal N, Cohen A, Raine A, Compton MT, Tone EB, Suhr J, Inchausti F, Bobes J, Fumero A, Giakoumaki S, Tsaousis I, Preti A, Chmielewski M, Laloyaux J, Mechri A, Aymen Lahmar M, Wuthrich V, Larøi F, Badcock JC, Jablensky A, Isvoranu AM, Epskamp S, Fried EI |date=October 2018 |title=The Network Structure of Schizotypal Personality Traits |journal=Schizophrenia Bulletin |volume=44 |issue=suppl_2 |pages=S468–S479 |doi=10.1093/schbul/sby044 |pmc=6188518 |pmid=29684178}}{{cite journal |vauthors=Davidson CA, Hoffman L, Spaulding WD |date=April 2016 |title=Schizotypal personality questionnaire--brief revised (updated): An update of norms, factor structure, and item content in a large non-clinical young adult sample |journal=Psychiatry Research |volume=238 |pages=345–355 |doi=10.1016/j.psychres.2016.01.053 |pmc=4834869 |pmid=27086255}}{{Cite journal |vauthors=Sokolova E, Andreyuk K, Ryzhov A |date=2021 |title=Relationship of abstract thinking to mentalization in schizophrenia |journal=European Psychiatry |language=en |volume=64 |issue=S1 |pages=S527 |doi=10.1192/j.eurpsy.2021.1407 |issn=0924-9338 |pmc=9475916}} They are more likely to believe in supernatural phenomena and entities.{{cite journal |vauthors=Crespi B, Dinsdale N, Read S, Hurd P |date=2019-03-08 |title=Spirituality, dimensional autism, and schizotypal traits: The search for meaning |journal=PLOS ONE |volume=14 |issue=3 |pages=e0213456 |bibcode=2019PLoSO..1413456C |doi=10.1371/journal.pone.0213456 |pmc=6407781 |pmid=30849096 |doi-access=free}}{{cite journal |vauthors=Carvalho LF, Sagradim DE, Pianowski G, Gonçalves AP |date=2020-10-19 |title=Relationship between religiosity domains and traits from borderline and schizotypal personality disorders in a Brazilian community sample |journal=Trends in Psychiatry and Psychotherapy |volume=42 |issue=3 |pages=239–246 |doi=10.1590/2237-6089-2019-0085 |pmc=7879071 |pmid=33084801 |s2cid=224828232}}{{Cite journal |vauthors=Breslin MJ, Lewis CA |date=2015-03-04 |title=Schizotypy and Religiosity: The Magic of Prayer |url=https://brill.com/view/journals/arp/37/1/article-p84_5.xml |journal=Archive for the Psychology of Religion |language=en |volume=37 |issue=1 |pages=84–97 |doi=10.1163/15736121-12341300 |issn=0084-6724 |s2cid=144734469}}{{Cite journal |vauthors=Byrom GN |date=2009 |title=Differential Relationships between Experiential and Interpretive Dimensions of Mysticism and Schizotypal Magical Ideation in a University Sample |url=http://journals.sagepub.com/doi/10.1163/157361209X424420 |journal=Archive for the Psychology of Religion |language=en |volume=31 |issue=2 |pages=127–150 |doi=10.1163/157361209X424420 |issn=0084-6724 |s2cid=143580864}} It is common for people with StPD to experience severe social anxiety and have paranoid ideation.{{cite journal |vauthors=Farsham A, Abbaslou T, Bidaki R, Bozorg B |date=April 2017 |title=Comparing Facial Emotional Recognition in Patients with Borderline Personality Disorder and Patients with Schizotypal Personality Disorder with a Normal Group |journal=Iranian Journal of Psychiatry |volume=12 |issue=2 |pages=87–92 |pmc=5483242 |pmid=28659980}}{{cite journal |vauthors=Dickey CC, McCarley RW, Niznikiewicz MA, Voglmaier MM, Seidman LJ, Kim S, Shenton ME |date=October 2005 |title=Clinical, cognitive, and social characteristics of a sample of neuroleptic-naive persons with schizotypal personality disorder |journal=Schizophrenia Research |volume=78 |issue=2–3 |pages=297–308 |doi=10.1016/j.schres.2005.05.016 |pmc=2766931 |pmid=15985362}} Ideas of reference are common in people with StPD.{{cite encyclopedia |encyclopedia=The Wiley Encyclopedia of Personality and Individual Differences |publisher=Wiley |date=2020-09-18 |edition=1st |pages=115–120 |language=en |doi=10.1002/9781118970843.ch283 |isbn=978-1-118-97074-4 |vauthors=Wong KK, Raine A |chapter=Schizotypal Personality Disorder |veditors=Carducci BJ, Nave CS, Mio JS, Riggio RE}}{{cite journal |vauthors=Hummelen B, Pedersen G, Karterud S |date=May 2012 |title=Some suggestions for the DSM-5 schizotypal personality disorder construct |journal=Comprehensive Psychiatry |volume=53 |issue=4 |pages=341–349 |doi=10.1016/j.comppsych.2011.05.009 |pmid=21741634}}{{cite journal |vauthors=Chan CC, Bulbena-Cabre A, Rutter S, Benavides C, McClure MM, Calabrese W, Rosell DR, Koenigsberg HW, Goodman M, New AS, Hazlett EA, Mercedes Perez-Rodriguez M |date=July 2019 |title=Comparison of self-report and clinician-rated schizotypal traits in schizotypal personality disorder and community controls |journal=Schizophrenia Research |volume=209 |pages=263–268 |doi=10.1016/j.schres.2018.12.050 |pmc=6614007 |pmid=30635257}} They can feel as if expressing themselves is dangerous. They may also feel that others are more competent, and have deeply entrenched and pervasive insecurities. Strange thinking patterns may be a defense mechanism against these feelings.{{cite journal |vauthors=Pattamanusorn N, Wongpakaran N, Thongpibul K, Wongpakaran T, Kuntawong P |date=May 2020 |title=Pathogenic beliefs among patients with schizotypal personality disorder |journal=Heliyon |language=English |volume=6 |issue=5 |pages=e03870 |bibcode=2020Heliy...603870P |doi=10.1016/j.heliyon.2020.e03870 |pmc=7200782 |pmid=32382682 |s2cid=218555815 |doi-access=free}} People with StPD usually have limited levels of self-awareness.{{cite journal |vauthors=Raballo A, Poletti M, Preti A, Parnas J |date=July 2021 |title=The Self in the Spectrum: A Meta-analysis of the Evidence Linking Basic Self-Disorders and Schizophrenia |journal=Schizophrenia Bulletin |volume=47 |issue=4 |pages=1007–1017 |doi=10.1093/schbul/sbaa201 |pmc=8266610 |pmid=33479736}} They may believe others think of them more negatively than they actually do.{{cite journal |vauthors=Carlson EN, Oltmanns TF |date=August 2015 |title=The Role of Metaperception in Personality Disorders: Do People with Personality Problems Know How Others Experience Their Personality? |journal=Journal of Personality Disorders |volume=29 |issue=4 |pages=449–467 |doi=10.1521/pedi.2015.29.4.449 |pmc=4760634 |pmid=26200846}}

Patients with StPD can have difficulties in recognizing their or others' emotions,{{cite journal |vauthors=Dickey CC, Panych LP, Voglmaier MM, Niznikiewicz MA, Terry DP, Murphy C, Zacks R, Shenton ME, McCarley RW |date=September 2011 |title=Facial emotion recognition and facial affect display in schizotypal personality disorder |journal=Schizophrenia Research |language=English |volume=131 |issue=1–3 |pages=242–249 |doi=10.1016/j.schres.2011.04.020 |pmc=3159849 |pmid=21640557}}{{cite journal |vauthors=Thakkar KN, Park S |date=September 2010 |title=Empathy, schizotypy, and visuospatial transformations |journal=Cognitive Neuropsychiatry |volume=15 |issue=5 |pages=477–500 |doi=10.1080/13546801003711350 |pmc=2933940 |pmid=20437282}} which can extend to difficulty expressing emotion.{{cite journal |vauthors=Dickey CC, Vu MA, Voglmaier MM, Niznikiewicz MA, McCarley RW, Panych LP |date=December 2012 |title=Prosodic abnormalities in schizotypal personality disorder |journal=Schizophrenia Research |volume=142 |issue=1–3 |pages=20–30 |doi=10.1016/j.schres.2012.09.006 |pmc=3502641 |pmid=23068317}}{{cite journal |vauthors=Phillips LK, Seidman LJ |date=September 2008 |title=Emotion processing in persons at risk for schizophrenia |journal=Schizophrenia Bulletin |volume=34 |issue=5 |pages=888–903 |doi=10.1093/schbul/sbn085 |pmc=2518637 |pmid=18644853}} They may have limited responses to others' emotions and can be ambivalent.{{cite journal |vauthors=van 't Wout M, Sanfey AG |date=January 2011 |title=Interactive decision-making in people with schizotypal traits: a game theory approach |journal=Psychiatry Research |volume=185 |issue=1–2 |pages=92–96 |doi=10.1016/j.psychres.2010.05.013 |pmc=2943544 |pmid=20538347}} It is common for people with StPD to derive limited joy from activities.{{cite journal |vauthors=Shi YF, Wang Y, Cao XY, Wang Y, Wang YN, Zong JG, Xu T, Tse VW, Hsi XL, Stone WS, Lui SS, Cheung EF, Chan RC |date=2012-05-16 |title=Experience of pleasure and emotional expression in individuals with schizotypal personality features |journal=PLOS ONE |volume=7 |issue=5 |pages=e34147 |bibcode=2012PLoSO...734147S |doi=10.1371/journal.pone.0034147 |pmc=3353966 |pmid=22615731 |doi-access=free}}{{cite journal |vauthors=Yan C, Liu WH, Cao Y, Chan RC |date=September 2011 |title=Self-reported pleasure experience and motivation in individuals with schizotypal personality disorders proneness |url=https://pubmed.ncbi.nlm.nih.gov/21921305/ |journal=East Asian Archives of Psychiatry |volume=21 |issue=3 |pages=115–122 |pmid=21921305}}{{cite journal |vauthors=Horan WP, Blanchard JJ, Clark LA, Green MF |date=September 2008 |title=Affective traits in schizophrenia and schizotypy |journal=Schizophrenia Bulletin |volume=34 |issue=5 |pages=856–874 |doi=10.1093/schbul/sbn083 |pmc=2632479 |pmid=18667393}} People with StPD are typically more socially isolated and uninterested in social situations than people without StPD,{{cite journal |vauthors=Geng FL, Xu T, Wang Y, Shi HS, Yan C, Neumann DL, Shum DH, Lui SS, Cheung EF, Chan RC |date=November 2013 |title=Developmental trajectories of schizotypal personality disorder-like behavioural manifestations: a two-year longitudinal prospective study of college students |journal=BMC Psychiatry |volume=13 |issue=1 |pages=323 |doi=10.1186/1471-244X-13-323 |pmc=3875349 |pmid=24289659 |doi-access=free}}{{cite journal |vauthors=Blanchard JJ, Aghevli M, Wilson A, Sargeant M |date=May 2010 |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 |doi=10.1016/j.schres.2009.10.028 |pmc=2856752 |pmid=19944570}}{{Cite journal |vauthors=Vinogradova M, Chepeliuk A, Dorofeeva O |date=2021 |title=Productivity of the performance of visual perceptual tasks and symptom severity in patients with schizotypal disorder |journal=European Psychiatry |language=en |volume=64 |issue=S1 |pages=S525 |doi=10.1192/j.eurpsy.2021.1402 |issn=0924-9338 |pmc=9476036}} although they are still likely to be socially active on the internet.{{cite journal |vauthors=Mittal VA, Tessner KD, Walker EF |date=August 2007 |title=Elevated social Internet use and schizotypal personality disorder in adolescents |journal=Schizophrenia Research |volume=94 |issue=1–3 |pages=50–57 |doi=10.1016/j.schres.2007.04.009 |pmc=2323598 |pmid=17532188}} Depersonalization,{{cite journal |vauthors=de Francisco Carvalho L, Magarotto Machado G, Padovani S, Pianowski G |date=December 2021 |title=Measuring pathological traits of the schizotypal personality disorder through the HiTOP model |journal=Scandinavian Journal of Psychology |volume=62 |issue=6 |pages=839–845 |doi=10.1111/sjop.12761 |pmid=34245006 |s2cid=235786787}}{{Citation |title=Depersonalization/Derealization Disorder and Schizotypal Personality Disorder |vauthors=Hamilton HK, Simeon D |date=2018-12-27 |work=Psychosis, Trauma and Dissociation |pages=241–256 |url=https://onlinelibrary.wiley.com/doi/10.1002/9781118585948.ch15 |access-date=2022-10-29 |veditors=Moskowitz A, Dorahy MJ, Schäfer I |edition=1st |publisher=Wiley |language=en |doi=10.1002/9781118585948.ch15 |isbn=978-1-119-95285-5 |s2cid=149618564}} derealization,{{Cite book |url=https://onlinelibrary.wiley.com/doi/book/10.1002/9781118585948 |title=Psychosis, Trauma and Dissociation: Evolving Perspectives on Severe Psychopathology |vauthors=Hamilton H, Simeon D |date=November 19, 2018 |publisher=Wiley |isbn=978-1-119-95285-5 |pages=241–256 |language=en |chapter=Depersonalization/Derealization Disorder and Schizotypal Personality Disorder |doi=10.1002/9781118585948.ch15 |chapter-url=https://onlinelibrary.wiley.com/doi/10.1002/9781118585948.ch15 |s2cid=149618564}} boredom,{{cite journal |vauthors=Zandersen M, Parnas J |date=January 2019 |title=Identity Disturbance, Feelings of Emptiness, and the Boundaries of the Schizophrenia Spectrum |journal=Schizophrenia Bulletin |volume=45 |issue=1 |pages=106–113 |doi=10.1093/schbul/sbx183 |pmc=6293220 |pmid=29373752}} and internal fantasies are common in patients with StPD. Abnormal facial expressions are also common in people with StPD, and they can have aberrant eye movements and difficulty responding to stimuli.{{cite journal |vauthors=Siever LJ, Coursey RD, Alterman IS, Buchsbaum MS, Murphy DL |date=December 1984 |title=Impaired smooth pursuit eye movement: vulnerability marker for schizotypal personality disorder in a normal volunteer population |journal=The American Journal of Psychiatry |volume=141 |issue=12 |pages=1560–1566 |doi=10.1176/ajp.141.12.1560 |pmid=6507660}}{{cite journal |vauthors=Hazlett EA, Buchsbaum MS, Zhang J, Newmark RE, Glanton CF, Zelmanova Y, Haznedar MM, Chu KW, Nenadic I, Kemether EM, Tang CY, New AS, Siever LJ |date=September 2008 |title=Frontal-striatal-thalamic mediodorsal nucleus dysfunction in schizophrenia-spectrum patients during sensorimotor gating |journal=NeuroImage |volume=42 |issue=3 |pages=1164–1177 |doi=10.1016/j.neuroimage.2008.05.039 |pmc=2548278 |pmid=18588988}}{{cite journal |vauthors=Siever LJ, Keefe R, Bernstein DP, Coccaro EF, Klar HM, Zemishlany Z, Peterson AE, Davidson M, Mahon T, Horvath T |date=June 1990 |title=Eye tracking impairment in clinically identified patients with schizotypal personality disorder |journal=The American Journal of Psychiatry |volume=147 |issue=6 |pages=740–745 |doi=10.1176/ajp.147.6.740 |pmid=2343917}}{{cite journal |vauthors=Siever LJ, Friedman L, Moskowitz J, Mitropoulou V, Keefe R, Roitman SL, Merhige D, Trestman R, Silverman J, Mohs R |date=August 1994 |title=Eye movement impairment and schizotypal psychopathology |journal=The American Journal of Psychiatry |volume=151 |issue=8 |pages=1209–1215 |doi=10.1176/ajp.151.8.1209 |pmid=8037257}}{{cite journal |vauthors=Cadenhead KS, Light GA, Geyer MA, Braff DL |date=January 2000 |title=Sensory gating deficits assessed by the P50 event-related potential in subjects with schizotypal personality disorder |journal=The American Journal of Psychiatry |volume=157 |issue=1 |pages=55–59 |doi=10.1176/ajp.157.1.55 |pmid=10618013 |s2cid=20139616}} They are often more prone to substance abuse or suicidal ideation.{{cite journal |vauthors=Raballo A, Parnas J |date=September 2011 |title=The silent side of the spectrum: schizotypy and the schizotaxic self |journal=Schizophrenia Bulletin |volume=37 |issue=5 |pages=1017–1026 |doi=10.1093/schbul/sbq008 |pmc=3160219 |pmid=20176859}}{{cite journal |vauthors=Fenton WS, McGlashan TH, Victor BJ, Blyler CR |date=February 1997 |title=Symptoms, subtype, and suicidality in patients with schizophrenia spectrum disorders |journal=The American Journal of Psychiatry |volume=154 |issue=2 |pages=199–204 |doi=10.1176/ajp.154.2.199 |pmid=9016268 |s2cid=33964324}} In an epidemiological study on suicidal behavior in StPD, even when sociodemographic factors were accounted for, people with StPD were 1.51 times more likely to attempt suicide. StPD is also often characterized as having similar symptoms as schizophrenia, but with less severe cognitive deficits.{{Cite journal |last1=Trotman |first1=H. |last2=McMillan |first2=A. |last3=Walker |first3=E. |date=2005-09-28 |title=Cognitive Function and Symptoms in Adolescents with Schizotypal Personality Disorder |url=https://academic.oup.com/schizophreniabulletin/article-lookup/doi/10.1093/schbul/sbj069 |journal=Schizophrenia Bulletin |language=en |volume=32 |issue=3 |pages=489–497 |doi=10.1093/schbul/sbj069 |issn=0586-7614 |pmc=2632245 |pmid=16611879}}

People with StPD tend to have cognitive impairments.{{cite journal |vauthors=Weiser M, Noy S, Kaplan Z, Reichenberg A, Yazvitsky R, Nahon D, Grotto I, Knobler HY |date=January 2003 |title=Generalized cognitive impairment in male adolescents with schizotypal personality disorder |journal=American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics |volume=116B |issue=1 |pages=36–40 |doi=10.1002/ajmg.b.10853 |pmid=12497611 |s2cid=24719039}} They can have abnormal perceptional and sensory experiences such as illusions.{{cite journal |vauthors=Hazlett EA, Rothstein EG, Ferreira R, Silverman JM, Siever LJ, Olincy A |date=February 2015 |title=Sensory gating disturbances in the spectrum: similarities and differences in schizotypal personality disorder and schizophrenia |journal=Schizophrenia Research |volume=161 |issue=2–3 |pages=283–290 |doi=10.1016/j.schres.2014.11.020 |pmc=4308515 |pmid=25482574}}{{cite journal |vauthors=Cohen AS, Auster TL, MacAulay RK, McGovern JE |date=October 2014 |title=Illusory superiority and schizotypal personality: explaining the discrepancy between subjective/objective psychopathology |journal=Personality Disorders |volume=5 |issue=4 |pages=413–418 |doi=10.1037/per0000080 |pmc=4372844 |pmid=25150366}} For example, someone with StPD may perceive colors as lighter or darker than others perceive them.{{cite journal |vauthors=Fonseca-Pedrero E, Badoud D, Antico L, Caputo GB, Eliez S, Schwartz S, Debbané M |date=March 2015 |title=Strange-face-in-the-mirror illusion and schizotypy during adolescence |journal=Schizophrenia Bulletin |volume=41 |issue=Suppl 2 |pages=S475–S482 |doi=10.1093/schbul/sbu196 |pmc=4373638 |pmid=25810060}} Facial perception may also be difficult for people with the disorder.{{cite journal |vauthors=Leonards U, Mohr C |date=September 2009 |title=Schizotypal personality traits influence idiosyncratic initiation of saccadic face exploration |journal=Vision Research |volume=49 |issue=19 |pages=2404–2413 |doi=10.1016/j.visres.2009.07.013 |pmid=19643123 |s2cid=16477946}}{{cite journal |vauthors=Ahn S, Lustenberger C, Jarskog LF, Fröhlich F |date=February 2020 |title=Neurophysiological substrates of configural face perception in schizotypy |journal=Schizophrenia Research |volume=216 |pages=389–396 |doi=10.1016/j.schres.2019.11.005 |pmc=7239709 |pmid=31801677}}{{cite journal |vauthors=Terrien S, Gobin P, Iakimova G, Coutté A, Thuaire F, Baltazart V, Mazzola-Pomietto P, Besche-Richard C |date=March 2016 |title=Electrophysiological correlates of emotional meaning in context in relation to facets of schizotypal personality traits: A dimensional study |journal=Psychiatry and Clinical Neurosciences |volume=70 |issue=3 |pages=141–150 |doi=10.1111/pcn.12366 |pmid=26482112 |s2cid=206256765 |doi-access=free}}{{cite journal |vauthors=Mitropoulou V, Harvey PD, Zegarelli G, New AS, Silverman JM, Siever LJ |date=October 2005 |title=Neuropsychological performance in schizotypal personality disorder: importance of working memory |journal=The American Journal of Psychiatry |volume=162 |issue=10 |pages=1896–1903 |doi=10.1176/appi.ajp.162.10.1896 |pmid=16199836}} They can see others as deformed, may misrecognize them, or can feel as if they are alien to them. People with StPD can have difficulty processing information such as speech or language.{{cite journal |vauthors=Rabella M, Grasa E, Corripio I, Romero S, Mañanas MÀ, Antonijoan RM, Münte TF, Pérez V, Riba J |date=2016-01-01 |title=Neurophysiological evidence of impaired self-monitoring in schizotypal personality disorder and its reversal by dopaminergic antagonism |journal=NeuroImage. Clinical |volume=11 |pages=770–779 |doi=10.1016/j.nicl.2016.05.019 |pmc=4909819 |pmid=27330977 |s2cid=14043730}}{{cite journal |vauthors=Niznikiewicz MA, Spencer KM, Dickey C, Voglmaier M, Seidman LJ, Shenton ME, McCarley RW |date=May 2009 |title=Abnormal pitch mismatch negativity in individuals with schizotypal personality disorder |journal=Schizophrenia Research |volume=110 |issue=1–3 |pages=188–193 |doi=10.1016/j.schres.2008.10.017 |pmc=4285443 |pmid=19327968}}{{cite journal |vauthors=Gilleen J, Tesse M, Velikonja T, Weiser M, Davidson M, Reichenberg A |date=September 2020 |title=Schizotypal traits and neuropsychological performance: The role of processing speed |journal=Schizophrenia Research |volume=223 |pages=128–134 |doi=10.1016/j.schres.2020.06.030 |pmc=7704687 |pmid=32631701 |s2cid=220325569}} They are more likely to speak slowly, with less fluctuation in pitch,{{cite journal |vauthors=Dickey CC, Morocz IA, Minney D, Niznikiewicz MA, Voglmaier MM, Panych LP, Khan U, Zacks R, Terry DP, Shenton ME, McCarley RW |date=August 2010 |title=Factors in sensory processing of prosody in schizotypal personality disorder: an fMRI experiment |journal=Schizophrenia Research |volume=121 |issue=1–3 |pages=75–89 |doi=10.1016/j.schres.2010.03.008 |pmc=2905482 |pmid=20362418}} and long pauses between speech. Patients with StPD may have a lower odor detection threshold,{{cite journal |vauthors=Mathur N, Dawes C, Moran PM |date=July 2019 |title=Olfactory threshold selectively predicts positive psychometric schizotypy |journal=Schizophrenia Research |volume=209 |pages=80–87 |doi=10.1016/j.schres.2019.05.014 |pmid=31160166 |s2cid=171091790 |doi-access=free}} and can have impaired auditory or olfactory processing.{{cite journal |vauthors=Brenner CA, Sporns O, Lysaker PH, O'Donnell BF |date=December 2003 |title=EEG synchronization to modulated auditory tones in schizophrenia, schizoaffective disorder, and schizotypal personality disorder |journal=The American Journal of Psychiatry |volume=160 |issue=12 |pages=2238–2240 |doi=10.1176/appi.ajp.160.12.2238 |pmid=14638599 |s2cid=10677570}} It is also common for people with StPD to struggle with context processing,{{cite journal |vauthors=Niznikiewicz MA, Shenton ME, Voglmaier M, Nestor PG, Dickey CC, Frumin M, Seidman LJ, Allen CG, McCarley RW |date=October 2002 |title=Semantic dysfunction in women with schizotypal personality disorder |journal=The American Journal of Psychiatry |volume=159 |issue=10 |pages=1767–1774 |doi=10.1176/appi.ajp.159.10.1767 |pmc=2845844 |pmid=12359685}}{{cite journal |vauthors=McClure MM, Barch DM, Flory JD, Harvey PD, Siever LJ |date=May 2008 |title=Context processing in schizotypal personality disorder: evidence of specificity of impairment to the schizophrenia spectrum |journal=Journal of Abnormal Psychology |volume=117 |issue=2 |pages=342–354 |doi=10.1037/0021-843X.117.2.342 |pmc=4176884 |pmid=18489210}} which cause them to form loose connections between events.{{cite journal |vauthors=Kiang M, Prugh J, Kutas M |date=February 2010 |title=An event-related brain potential study of schizotypal personality and associative semantic processing |journal=International Journal of Psychophysiology |series=Psychophysiology of Language Processes in Psychopathology |volume=75 |issue=2 |pages=119–126 |doi=10.1016/j.ijpsycho.2009.10.005 |pmc=2827666 |pmid=19818815}} In addition, people with StPD can have decreased capacities for multisensory integration or contrast sensitivity,{{cite journal |vauthors=Kent BW, Weinstein ZA, Passarelli V, Chen Y, Siever LJ |date=April 2011 |title=Deficient visual sensitivity in schizotypal personality disorder |journal=Schizophrenia Research |volume=127 |issue=1–3 |pages=144–150 |doi=10.1016/j.schres.2010.05.013 |pmc=2965789 |pmid=20541911}}{{cite journal |vauthors=Harper L, Spencer E, Davidson C, Hutchinson CV |date=January 2020 |title=Selectively reduced contrast sensitivity in high schizotypy |journal=Experimental Brain Research |volume=238 |issue=1 |pages=51–62 |doi=10.1007/s00221-019-05695-9 |pmc=6957544 |pmid=31781821}}{{cite journal |vauthors=Ferri F, Ambrosini E, Costantini M |date=December 2016 |title=Spatiotemporal processing of somatosensory stimuli in schizotypy |journal=Scientific Reports |volume=6 |issue=1 |pages=38735 |bibcode=2016NatSR...638735F |doi=10.1038/srep38735 |pmc=5146666 |pmid=27934937 |s2cid=11573502}}{{cite journal |vauthors=Dalal TC, Muller AM, Stevenson RA |date=February 2021 |title=The Relationship Between Multisensory Temporal Processing and Schizotypal Traits |url=https://osf.io/79hdz/ |journal=Multisensory Research |volume=34 |issue=5 |pages=511–529 |doi=10.1163/22134808-bja10044 |pmid=33706260 |s2cid=232206767}} either hyperreactive or impaired reactions to sensory input,{{cite journal |vauthors=Mannan MR, Hiramatsu KI, Hokama H, Ohta H |date=October 2001 |title=Abnormalities of auditory event-related potentials in students with schizotypal personality disorder |journal=Psychiatry and Clinical Neurosciences |volume=55 |issue=5 |pages=451–457 |doi=10.1046/j.1440-1819.2001.00889.x |pmid=11555339 |s2cid=21236561}}{{cite journal |vauthors=Niznikiewicz MA, Friedman M, Shenton ME, Voglmaier M, Nestor PG, Frumin M, Seidman L, Sutton J, McCarley RW |date=May 2004 |title=Processing sentence context in women with schizotypal personality disorder: an ERP study |journal=Psychophysiology |volume=41 |issue=3 |pages=367–371 |doi=10.1111/1469-8986.2004.00173.x |pmc=2794422 |pmid=15102121}}{{cite journal |vauthors=Dickey CC, Morocz IA, Niznikiewicz MA, Voglmaier M, Toner S, Khan U, Dreusicke M, Yoo SS, Shenton ME, McCarley RW |date=August 2008 |title=Auditory processing abnormalities in schizotypal personality disorder: an fMRI experiment using tones of deviant pitch and duration |journal=Schizophrenia Research |volume=103 |issue=1–3 |pages=26–39 |doi=10.1016/j.schres.2008.04.041 |pmc=3188851 |pmid=18555666}} slower response times, impaired attention,{{cite journal |vauthors=Hur JW, Kim T, Cho KI, Kwon JS |date=January 2021 |title=Attenuated Resting-State Functional Anticorrelation between Attention and Executive Control Networks in Schizotypal Personality Disorder |journal=Journal of Clinical Medicine |volume=10 |issue=2 |pages=312 |doi=10.3390/jcm10020312 |pmc=7829946 |pmid=33467694 |doi-access=free}}{{cite journal |vauthors=Trotman H, McMillan A, Walker E |date=July 2006 |title=Cognitive function and symptoms in adolescents with schizotypal personality disorder |journal=Schizophrenia Bulletin |volume=32 |issue=3 |pages=489–497 |doi=10.1093/schbul/sbj069 |pmc=2632245 |pmid=16611879}} poorer postural control,{{cite journal |vauthors=Apthorp D, Bolbecker AR, Bartolomeo LA, O'Donnell BF, Hetrick WP |date=April 2019 |title=Postural Sway Abnormalities in Schizotypal Personality Disorder |journal=Schizophrenia Bulletin |volume=45 |issue=3 |pages=512–521 |doi=10.1093/schbul/sby141 |pmc=6483590 |pmid=30376125}} and difficulties with decision-making.{{cite journal |vauthors=Niznikiewicz MA, Voglmaier MM, Shenton ME, Dickey CC, Seidman LJ, Teh E, Van Rhoads R, McCarley RW |date=October 2000 |title=Lateralized P3 deficit in schizotypal personality disorder |url=http://nrs.harvard.edu/urn-3:HUL.InstRepos:28520161 |journal=Biological Psychiatry |language=English |volume=48 |issue=7 |pages=702–705 |doi=10.1016/S0006-3223(00)00938-0 |pmc=2845845 |pmid=11032982 |s2cid=18619922}}{{cite journal |vauthors=Forsyth JK, Bolbecker AR, Mehta CS, Klaunig MJ, Steinmetz JE, O'Donnell BF, Hetrick WP |date=June 2012 |title=Cerebellar-dependent eyeblink conditioning deficits in schizophrenia spectrum disorders |journal=Schizophrenia Bulletin |volume=38 |issue=4 |pages=751–759 |doi=10.1093/schbul/sbq148 |pmc=3406528 |pmid=21148238}} They can have difficulties in memory,{{cite journal |vauthors=Farmer CM, O'Donnell BF, Niznikiewicz MA, Voglmaier MM, McCarley RW, Shenton ME |date=May 2000 |title=Visual perception and working memory in schizotypal personality disorder |journal=The American Journal of Psychiatry |volume=157 |issue=5 |pages=781–788 |doi=10.1176/appi.ajp.157.5.781 |pmc=2845849 |pmid=10784472}}{{cite journal |vauthors=Shin YW, Krishnan G, Hetrick WP, Brenner CA, Shekhar A, Malloy FW, O'Donnell BF |date=December 2010 |title=Increased temporal variability of auditory event-related potentials in schizophrenia and Schizotypal Personality Disorder |journal=Schizophrenia Research |volume=124 |issue=1–3 |pages=110–118 |doi=10.1016/j.schres.2010.08.008 |pmc=3009463 |pmid=20817485}}{{cite journal |vauthors=Goldstein KE, Hazlett EA, Savage KR, Berlin HA, Hamilton HK, Zelmanova Y, Look AE, Koenigsberg HW, Mitsis EM, Tang CY, McNamara M, Siever LJ, Cohen BH, New AS |date=April 2011 |title=Dorso- and ventro-lateral prefrontal volume and spatial working memory in schizotypal personality disorder |journal=Behavioural Brain Research |volume=218 |issue=2 |pages=335–340 |doi=10.1016/j.bbr.2010.11.042 |pmc=3049905 |pmid=21115066}} and may have frequent intrusive memories of events.{{cite journal |vauthors=Jones V, Steel C |date=September 2012 |title=Schizotypal personality and vulnerability to involuntary autobiographical memories |url=https://centaur.reading.ac.uk/27711/2/27711Schizotypal_Personality_and_Vulnerability_to_Involuntary_Autobiographical_Memories.pdf |journal=Journal of Behavior Therapy and Experimental Psychiatry |volume=43 |issue=3 |pages=871–876 |doi=10.1016/j.jbtep.2011.12.008 |pmid=22269251 |s2cid=7975363}} It is common for people with StPD to feel déjà vu or as if they can accurately predict future events due to abnormalities in the brain's memory storage.{{cite journal |vauthors=Arzy S, Mohr C, Molnar-Szakacs I, Blanke O |date=January 2011 |title=Schizotypal perceptual aberrations of time: correlation between score, behavior and brain activity |journal=PLOS ONE |volume=6 |issue=1 |pages=e16154 |bibcode=2011PLoSO...616154A |doi=10.1371/journal.pone.0016154 |pmc=3022658 |pmid=21267456 |doi-access=free}}

StPD was introduced in 1980 in the DSM-III.{{Cite journal |last1=Rosell |last2=Futterman |last3=McMaster |last4=Siever |date=July 16, 2014 |title=Schizotypal Personality Disorder: A Current Review |journal=Current Psychiatry Reports |volume=16 |issue=7 |page=452 |doi=10.1007/s11920-014-0452-1 |pmid=24828284 |pmc=4182925 }} Its inclusion provided a new classification for schizophrenia-spectrum disorders and of personality disorders that were previously unspecified.{{Cite journal |last1=Spitzer |last2=Endicott |date=1979 |title=Justification for Separating Schizotypal and Borderline Personality Disorders |url=https://academic.oup.com/schizophreniabulletin/article/5/1/95/1943773 |access-date=2023-04-10 |journal=Schizophrenia Bulletin|volume=5 |issue=1 |pages=95–104 |doi=10.1093/schbul/5.1.95 |pmid=441693 |doi-access=free }} Its diagnosis was developed through differentiating the classifications of borderline personality disorder, of which some of the diagnosed population demonstrated schizophrenia-spectrum traits. When the separation of borderline personality disorder and StPD was originally suggested by Spitzer and Endicott, Siever and Gunderson opposed the distinction.{{Cite web |title=APA PsycNet |url=https://psycnet.apa.org/record/1984-12429-001 |access-date=2023-04-10 |website=psycnet.apa.org |language=en}} Siever and Gunderson's opposition to Spitzer and Endicott was that StPD was related to schizophrenia.{{Cite journal |last1=Siever |first1=Larry J. |last2=Bernstein |first2=David P. |last3=Silverman |first3=Jeremy M. |date=31 Jan 2011 |title=Schizotypal Personality Disorder: A Review of Its Current Status |url=http://guilfordjournals.com/doi/10.1521/pedi.1991.5.2.178 |journal=Journal of Personality Disorders |language=en |volume=5 |issue=2 |pages=178–193 |doi=10.1521/pedi.1991.5.2.178 |issn=0885-579X}} Spitzer and Endicott stated "We believe, as do the authors, that the evidence for the genetic relationship between Schizotypal features and Chronic Schizophrenia is suggestive rather than proven". StPD was included in the DSM-IV and the DSM-V and saw little change in its diagnosis.{{Personality disorders sidebar}}

The reported prevalence of StPD in community studies ranges from 1.37% in a Norwegian sample, to 4.6% in an American sample.{{cite book |url=https://archive.org/details/diagnosticstatis0005unse/page/655 |title=Diagnostic and statistical manual of mental disorders : DSM-5 |publisher=American Psychiatric Association, American Psychiatric Association |year=2013 |isbn=978-0-89042-555-8 |pages=[https://archive.org/details/diagnosticstatis0005unse/page/655 655–659] |oclc=830807378}} A large American study found a lifetime prevalence of 3.9%, with somewhat higher rates among men (4.2%) than women (3.7%). It may be uncommon in clinical populations, with reported rates of up to 1.9%. It has been estimated to be prevalent among up to 5.2% of the general population.{{cite journal |vauthors=Pulay AJ, Stinson FS, Dawson DA, Goldstein RB, Chou SP, Huang B, Saha TD, Smith SM, Pickering RP, Ruan WJ, Hasin DS, Grant BF |date=2009-04-16 |title=Prevalence, correlates, disability, and comorbidity of DSM-IV schizotypal personality disorder: results from the wave 2 national epidemiologic survey on alcohol and related conditions |journal=Primary Care Companion to the Journal of Clinical Psychiatry |language=English |volume=11 |issue=2 |pages=53–67 |doi=10.4088/PCC.08m00679 |pmc=2707116 |pmid=19617934}} Together with other cluster A personality disorders, it is also very common among homeless people who show up at drop-in centers, according to a 2008 New York study. The study did not address homeless people who do not show up at drop-in centers.{{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 }} Schizotypal disorder may be overdiagnosed in Russia and other post-Soviet states.Быкова А. Ю., Беккер Р. А., Быков Ю. В. О трудностях дифференциальной диагностики между первичным деперсонализационно-дереализационным расстройством и шизотипическим расстройством // Siberian Journal of Life Sciences & Agriculture. — 2022. — Т. 14. — №. 1.

People with StPD usually had symptoms of schizotypal personality disorder in childhood.{{cite journal | vauthors = Jones HP, Testa RR, Ross N, Seal ML, Pantelis C, Tonge B | title = The Melbourne assessment of Schizotypy in kids: a useful measure of childhood schizotypal personality disorder | journal = BioMed Research International | volume = 2015 | pages = 635732 | date = 2015-01-06 | pmid = 25629050 | doi = 10.1155/2015/635732 | pmc = 4300034 | doi-access = free }} Traits of StPD usually remain consistently present over time,{{cite journal | vauthors = Shea MT, Stout R, Gunderson J, Morey LC, Grilo CM, McGlashan T, Skodol AE, Dolan-Sewell R, Dyck I, Zanarini MC, Keller MB | title = Short-term diagnostic stability of schizotypal, borderline, avoidant, and obsessive-compulsive personality disorders | journal = The American Journal of Psychiatry | volume = 159 | issue = 12 | pages = 2036–2041 | date = December 2002 | pmid = 12450953 | doi = 10.1176/appi.ajp.159.12.2036 }}{{Cite encyclopedia | vauthors = Alphen SP, Heijnen-Kohl SM |date=2019-01-25 | chapter = Personality Disorders in Later Life |encyclopedia=Oxford Research Encyclopedia of Psychology |language=en |doi=10.1093/acrefore/9780190236557.013.420|isbn=978-0-19-023655-7 }} although can fluctuate greatly in severity and stability.{{cite journal | vauthors = Grilo CM, Sanislow CA, Gunderson JG, Pagano ME, Yen S, Zanarini MC, Shea MT, Skodol AE, Stout RL, Morey LC, McGlashan TH | title = Two-year stability and change of schizotypal, borderline, avoidant, and obsessive-compulsive personality disorders | journal = Journal of Consulting and Clinical Psychology | volume = 72 | issue = 5 | pages = 767–775 | date = October 2004 | pmid = 15482035 | pmc = 3289406 | doi = 10.1037/0022-006X.72.5.767 }}{{cite journal | vauthors = McGlashan TH, Grilo CM, Sanislow CA, Ralevski E, Morey LC, Gunderson JG, Skodol AE, Shea MT, Zanarini MC, Bender D, Stout RL, Yen S, Pagano M | title = Two-year prevalence and stability of individual DSM-IV criteria for schizotypal, borderline, avoidant, and obsessive-compulsive personality disorders: toward a hybrid model of axis II disorders | journal = The American Journal of Psychiatry | volume = 162 | issue = 5 | pages = 883–889 | date = May 2005 | pmid = 15863789 | doi = 10.1176/appi.ajp.162.5.883 | pmc = 3272783 }} DSM characterizes StPD as having nine major symptoms: ideas of reference, odd/magical beliefs, social anxiety, not having close friends, odd or eccentric behavior, odd speech, unusual perceptions, suspiciousness, schizo-obsessive behaviors{{Cite journal |last=Baer |first=Lee |date=1986-03-01 |title=Coexistent Obsessive-Compulsive Disorder and Schizotypal Personality Disorder: A Poor Prognostic Indicator |url=http://archpsyc.jamanetwork.com/article.aspx?doi=10.1001/archpsyc.1986.01800030114016 |journal=Archives of General Psychiatry |language=en |volume=43 |issue=3 |pages=296 |doi=10.1001/archpsyc.1986.01800030114016 |pmid=3954553 |issn=0003-990X}} and constricted affect.{{Cite journal |last1=Xi |first1=Chongqin |last2=Cai |first2=Yan |last3=Peng |first3=Siwei |last4=Lian |first4=Jie |last5=Tu |first5=Dongbo |date=2019-12-05 |title=A diagnostic classification version of Schizotypal Personality Questionnaire using diagnostic classification models |journal=International Journal of Methods in Psychiatric Research |volume=29 |issue=1 |pages=e1807 |doi=10.1002/mpr.1807 |issn=1049-8931 |pmc=7051843 |pmid=31808226}} StPD can be diagnosed alongside other disorders, including borderline personality disorder (BPD), attention-deficit disorder, social anxiety disorder, and autism spectrum disorder.{{Cite journal |last1=Kirchner |first1=Sophie K. |last2=Roeh |first2=Astrid |last3=Nolden |first3=Jana |last4=Hasan |first4=Alkomiet |date=2018-10-03 |title=Diagnosis and treatment of schizotypal personality disorder: evidence from a systematic review |journal=npj Schizophrenia |language=en |volume=4 |issue=1 |page=20 |doi=10.1038/s41537-018-0062-8 |issn=2334-265X |pmc=6170383 |pmid=30282970}} Comorbidities such as these can influence and potentially interfere with an individual's diagnosis of StPD. There may be gender differences in the symptomology of men and women with StPD.{{cite journal | vauthors = Dickey CC, McCarley RW, Voglmaier MM, Niznikiewicz MA, Seidman LJ, Demeo S, Frumin M, Shenton ME | title = An MRI study of superior temporal gyrus volume in women with schizotypal personality disorder | journal = The American Journal of Psychiatry | volume = 160 | issue = 12 | pages = 2198–2201 | date = December 2003 | pmid = 14638590 | doi = 10.1176/appi.ajp.160.12.2198 | pmc = 2826718 }} Women with the disorder might be more likely to have less severe cognitive deficits, and more severe social anxiety and magical thinking.{{cite journal | vauthors = Voglmaier MM, Seidman LJ, Niznikiewicz MA, Dickey CC, Shenton ME, McCarley RW | title = A comparative profile analysis of neuropsychological function in men and women with schizotypal personality disorder | journal = Schizophrenia Research | volume = 74 | issue = 1 | pages = 43–49 | date = April 2005 | pmid = 15694753 | doi = 10.1016/j.schres.2004.09.013 | pmc = 2772126 | s2cid = 17916499 | url = http://nrs.harvard.edu/urn-3:HUL.InstRepos:33766569 }}{{cite journal | vauthors = Voglmaier MM, Seidman LJ, Niznikiewicz MA, Madan A, Dickey CC, Shenton ME, McCarley RW | title = Dichotic listening in schizotypal personality disorder: evidence for gender and laterality effects | journal = Schizophrenia Research | volume = 115 | issue = 2–3 | pages = 290–292 | date = December 2009 | pmid = 19464150 | doi = 10.1016/j.schres.2009.04.028 | pmc = 3879145 | s2cid = 20730801 | url = http://nrs.harvard.edu/urn-3:HUL.InstRepos:28549217 }}{{cite journal | vauthors = Bora E, Baysan Arabaci L | title = Effect of age and gender on schizotypal personality traits in the normal population | journal = Psychiatry and Clinical Neurosciences | volume = 63 | issue = 5 | pages = 663–669 | date = October 2009 | pmid = 19674380 | doi = 10.1111/j.1440-1819.2009.02011.x | s2cid = 22072954 | doi-access = free }} Symptoms of depression in women with StPD have a more negative impact on cognitive functioning than in males diagnosed with StPD and depression. In males with the disorder, abstraction and verbal learning are more likely to be in deficit compared to women, who tend to be less vulnerable to verbal deficits. People with StPD are more likely to only have a high school education, to be unemployed,{{cite journal | vauthors = McClure MM, Harvey PD, Bowie CR, Iacoviello B, Siever LJ | title = Functional outcomes, functional capacity, and cognitive impairment in schizotypal personality disorder | journal = Schizophrenia Research | volume = 144 | issue = 1–3 | pages = 146–150 | date = March 2013 | pmid = 23375943 | doi = 10.1016/j.schres.2012.12.012 | pmc = 3572293 }} and to have significant functional impairment.{{cite journal | vauthors = Skodol AE, Gunderson JG, McGlashan TH, Dyck IR, Stout RL, Bender DS, Grilo CM, Shea MT, Zanarini MC, Morey LC, Sanislow CA, Oldham JM | title = Functional impairment in patients with schizotypal, borderline, avoidant, or obsessive-compulsive personality disorder | journal = The American Journal of Psychiatry | volume = 159 | issue = 2 | pages = 276–283 | date = February 2002 | pmid = 11823271 | doi = 10.1176/appi.ajp.159.2.276 }} The two traits of StPD which are least likely to change are paranoia and abnormal experiences.

StPD tends to develop in adolescence and early adulthood, accompanied by a gradual decline in functioning and the increased development of StPD symptoms. Adolescents with StPD were more likely to have performance deficits, especially in arithmetic, and to display significantly lower levels of executive functioning, similar to autism spectrum disorder. Compared to those without StPD, adolescents with StPD spend more time socializing on the Internet, such as on forums, chat rooms and cooperative computer games, and spend less time socializing in-person.{{Cite journal |last1=Mittal |first1=Vijay A. |last2=Tessner |first2=Kevin D. |last3=Walker |first3=Elaine F. |date=2007 |title=Elevated social Internet use and schizotypal personality disorder in adolescents |journal=Schizophrenia Research |language=en |volume=94 |issue=1–3 |pages=50–57 |doi=10.1016/j.schres.2007.04.009 |pmc=2323598 |pmid=17532188}} People who are treatment-resistant to obsessive–compulsive disorder (OCD) behavioral therapy and medication that also display odd or eccentric behaviors could contribute to the coexistence of obsessive–compulsive disorder with schizotypal disorder.

Although environmental factors likely play an important role in the onset of the disorder, people who have relatives with schizotypy,{{cite journal | vauthors = Debbané M, Eliez S, Badoud D, Conus P, Flückiger R, Schultze-Lutter F | title = Developing psychosis and its risk states through the lens of schizotypy | journal = Schizophrenia Bulletin | volume = 41 | issue = Suppl 2 | pages = S396–S407 | date = March 2015 | pmid = 25548386 | pmc = 4373628 | doi = 10.1093/schbul/sbu176 }}{{cite journal | vauthors = Schultze-Lutter F, Nenadic I, Grant P | title = Psychosis and Schizophrenia-Spectrum Personality Disorders Require Early Detection on Different Symptom Dimensions | journal = Frontiers in Psychiatry | volume = 10 | pages = 476 | date = 2019 | pmid = 31354543 | doi = 10.3389/fpsyt.2019.00476 | pmc = 6637034 | doi-access = free }}{{cite journal | vauthors = Kemp KC, Bathery AJ, Barrantes-Vidal N, Kwapil TR | title = A brief questionnaire measure of multidimensional schizotypy predicts interview-rated symptoms and impairment | journal = PLOS ONE | volume = 15 | issue = 8 | pages = e0237614 | date = 2020-08-10 | pmid = 32776979 | pmc = 7416934 | doi = 10.1371/journal.pone.0237614 | bibcode = 2020PLoSO..1537614K | doi-access = free }} mood disorders,{{cite journal | vauthors = Squires-Wheeler E, Skodol AE, Bassett A, Erlenmeyer-Kimling L | title = DSM-III-R schizotypal personality traits in offspring of schizophrenic disorder, affective disorder, and normal control parents | journal = Journal of Psychiatric Research | volume = 23 | issue = 3–4 | pages = 229–239 | date = 1989 | pmid = 2635220 | pmc = 3160972 | doi = 10.1016/0022-3956(89)90028-9 }} or other disorders on the schizophrenia spectrum are at a higher likelihood of developing StPD.{{cite journal | vauthors = Tarbox SI, Pogue-Geile MF | title = A multivariate perspective on schizotypy and familial association with schizophrenia: a review | journal = Clinical Psychology Review | volume = 31 | issue = 7 | pages = 1169–1182 | date = November 2011 | pmid = 21855827 | doi = 10.1016/j.cpr.2011.07.002 | pmc = 3176972 }}{{cite journal | vauthors = Torti MC, Buzzanca A, Squarcione C, Salerno C, Mirigliani A, Di Fabio F, Biondi M | title = Schizotypy and personality profiles of Cluster A in a group of schizophrenic patients and their siblings | journal = BMC Psychiatry | volume = 13 | issue = 1 | pages = 245 | date = October 2013 | pmid = 24094118 | pmc = 3856523 | doi = 10.1186/1471-244X-13-245 | doi-access = free }} The COMT Val158Met polymorphism and its Val or Met allele are suspected to be associated with Schizotypal personality disorder.{{cite journal | vauthors = Skilleter AJ, Weickert CS, Moustafa AA, Gendy R, Chan M, Arifin N, Mitchell PB, Weickert TW | title = BDNF val66met genotype and schizotypal personality traits interact to influence probabilistic association learning | journal = Behavioural Brain Research | volume = 274 | pages = 137–142 | date = November 2014 | pmid = 25125238 | doi = 10.1016/j.bbr.2014.07.041 | s2cid = 18041054 | doi-access = free }}{{cite journal | vauthors = Siever LJ | title = Endophenotypes in the personality disorders | journal = Dialogues in Clinical Neuroscience | volume = 7 | issue = 2 | pages = 139–151 | date = 2005 | pmid = 16262209 | pmc = 3181730 | doi = 10.31887/DCNS.2005.7.2/lsiever }}{{cite journal | vauthors = Docherty AR, Sponheim SR | title = Anhedonia as a phenotype for the Val158Met COMT polymorphism in relatives of patients with schizophrenia | journal = Journal of Abnormal Psychology | volume = 117 | issue = 4 | pages = 788–798 | date = November 2008 | pmid = 19025226 | pmc = 2936689 | doi = 10.1037/a0013745 }}{{cite journal | vauthors = Leung WW, McClure MM, Siever LJ, Barch DM, Harvey PD | title = Catechol-O-methyltransferase Val158Met genotype in healthy and personality disorder individuals: Preliminary results from an examination of cognitive tests hypothetically differentially sensitive to dopamine functions | language = English | journal = Neuropsychiatric Disease and Treatment | volume = 3 | issue = 6 | pages = 925–934 | date = December 2007 | pmid = 19300629 | doi = 10.2147/NDT.S1500 | pmc = 2656336 | s2cid = 8816485 | doi-access = free }} These genes affect dopamine production in the brain,{{cite journal | vauthors = Sheldrick AJ, Krug A, Markov V, Leube D, Michel TM, Zerres K, Eggermann T, Kircher T | title = Effect of COMT val158met genotype on cognition and personality | journal = European Psychiatry | volume = 23 | issue = 6 | pages = 385–389 | date = September 2008 | pmid = 18755576 | doi = 10.1016/j.eurpsy.2008.05.002 | s2cid = 45960144 }}{{cite journal | vauthors = Steiner GZ, Fernandez FM, Coles M, Karamacoska D, Barkus E, Broyd SJ, Solowij N, Watson OT, Chiu CL, Lind JM, Barry RJ | title = Interrogating the Relationship Between Schizotypy, the Catechol-O-Methyltransferase (COMT) Val158Met Polymorphism, and Neuronal Oscillatory Activity | journal = Cerebral Cortex | volume = 29 | issue = 7 | pages = 3048–3058 | date = July 2019 | pmid = 30084963 | doi = 10.1093/cercor/bhy171 }}{{cite journal | vauthors = Barnett JH, Jones PB, Robbins TW, Müller U | title = Effects of the catechol-O-methyltransferase Val158Met polymorphism on executive function: a meta-analysis of the Wisconsin Card Sort Test in schizophrenia and healthy controls | journal = Molecular Psychiatry | volume = 12 | issue = 5 | pages = 502–509 | date = May 2007 | pmid = 17325717 | doi = 10.1038/sj.mp.4001973 | s2cid = 764484 | doi-access = free }} a neurochemical thought to be associated with schizotypal traits.{{cite journal | vauthors = Silberschmidt AL, Sponheim SR | title = Personality in relation to genetic liability for schizophrenia and bipolar disorder: differential associations with the COMT Val 108/158 Met polymorphism | journal = Schizophrenia Research | volume = 100 | issue = 1–3 | pages = 316–324 | date = March 2008 | pmid = 18201871 | doi = 10.1016/j.schres.2007.12.467 | pmc = 2682527 }}{{cite journal | vauthors = Giakoumaki SG, Roussos P, Bitsios P | title = Improvement of prepulse inhibition and executive function by the COMT inhibitor tolcapone depends on COMT Val158Met polymorphism | journal = Neuropsychopharmacology | volume = 33 | issue = 13 | pages = 3058–3068 | date = December 2008 | pmid = 18536698 | doi = 10.1038/npp.2008.82 | s2cid = 3130616 | doi-access = free }} The gene may also contribute to decreased levels of gray matter in the prefrontal cortex.{{Cite journal | vauthors = Rodríguez-Toscano E, Martínez K, Fraguas D, Janssen J, Pina-Camacho L, Arias B, Vieta E, Mezquida G, Amoretti S, Bernardo M, Castro-Fornieles J, Cuesta-Zorita MJ, Lobo A, González-Pinto A, Collado IC |date=2022-04-01 |title=Prefrontal abnormalities, executive dysfunction and symptoms severity are modulated by COMT Val158Met polymorphism in first episode psychosis |journal=Revista de Psiquiatría y Salud Mental |language=en |volume=15 |issue=2 |pages=74–87 |doi=10.1016/j.rpsm.2021.11.002 | pmid = 35840287 | s2cid = 244126716 |issn=1888-9891}}{{cite journal | vauthors = Thermenos HW, Keshavan MS, Juelich RJ, Molokotos E, Whitfield-Gabrieli S, Brent BK, Makris N, Seidman LJ | title = A review of neuroimaging studies of young relatives of individuals with schizophrenia: a developmental perspective from schizotaxia to schizophrenia | journal = American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics | volume = 162B | issue = 7 | pages = 604–635 | date = October 2013 | pmid = 24132894 | doi = 10.1002/ajmg.b.32170 | s2cid = 32797877 | doi-access = free }} This may lead to impaired capacities for decision-making,{{cite journal | vauthors = Roussos P, Giakoumaki SG, Rogdaki M, Pavlakis S, Frangou S, Bitsios P | title = Prepulse inhibition of the startle reflex depends on the catechol O-methyltransferase Val158Met gene polymorphism | journal = Psychological Medicine | volume = 38 | issue = 11 | pages = 1651–1658 | date = November 2008 | pmid = 18261249 | doi = 10.1017/S0033291708002912 | s2cid = 29311411 }} speech,{{cite journal | vauthors = Krug A, Markov V, Sheldrick A, Krach S, Jansen A, Zerres K, Eggermann T, Stöcker T, Shah NJ, Kircher T | title = The effect of the COMT val(158)met polymorphism on neural correlates of semantic verbal fluency | journal = European Archives of Psychiatry and Clinical Neuroscience | volume = 259 | issue = 8 | pages = 459–465 | date = December 2009 | pmid = 19381707 | doi = 10.1007/s00406-009-0010-8 | s2cid = 20321844 }} cognitive flexibility,{{cite journal | vauthors = Nolan KA, Bilder RM, Lachman HM, Volavka J | title = Catechol O-methyltransferase Val158Met polymorphism in schizophrenia: differential effects of Val and Met alleles on cognitive stability and flexibility | journal = The American Journal of Psychiatry | volume = 161 | issue = 2 | pages = 359–361 | date = February 2004 | pmid = 14754787 | doi = 10.1176/appi.ajp.161.2.359 }} and altered perceptual experiences.{{cite journal | vauthors = Demily C, Louchart-de-la-Chapelle S, Nkam I, Ramoz N, Denise P, Nicolas A, Savalle C, Thibaut F | title = Does COMT val158met polymorphism influence P50 sensory gating, eye tracking or saccadic inhibition dysfunctions in schizophrenia? | journal = Psychiatry Research | volume = 246 | pages = 738–744 | date = December 2016 | pmid = 27825784 | doi = 10.1016/j.psychres.2016.07.066 | s2cid = 207452788 }} The rs1006737 polymorphism of the CACNA1C gene is also believed to have a part in schizotypal symptoms.{{cite journal | vauthors = Krautheim JT, Straube B, Dannlowski U, Pyka M, Schneider-Hassloff H, Drexler R, Krug A, Sommer J, Rietschel M, Witt SH, Kircher T | title = Outgroup emotion processing in the vACC is modulated by childhood trauma and CACNA1C risk variant | journal = Social Cognitive and Affective Neuroscience | volume = 13 | issue = 3 | pages = 341–348 | date = March 2018 | pmid = 29385621 | pmc = 5836282 | doi = 10.1093/scan/nsy004 }} It may lead to a significantly increased physiological response to stress through the cortisol awakening response in the brain.{{cite journal | vauthors = Klaus K, Butler K, Gutierrez H, Durrant SJ, Pennington K | title = Interactive effects of early life stress and CACNA1C genotype on cortisol awakening response | journal = Biological Psychology | volume = 136 | pages = 22–28 | date = July 2018 | pmid = 29733866 | doi = 10.1016/j.biopsycho.2018.05.002 | s2cid = 13679165 | url = http://eprints.lincoln.ac.uk/id/eprint/32007/2/Kristel_2018CACNA1C%20%28002%29.pdf }}{{Cite thesis |title=Investigating Individual Differences in Acute Psychosocial Stress Reactivity and Evaluation of Wearable Devices for Heart Rate Variability Measurement |url=https://eprints.lincoln.ac.uk/id/eprint/48484/ |publisher=University of Lincoln |date=2021 |degree=mres |language=en | vauthors = Youngs MA }}{{cite journal | vauthors = Weinstein DD, Diforio D, Schiffman J, Walker E, Bonsall R | title = Minor physical anomalies, dermatoglyphic asymmetries, and cortisol levels in adolescents with schizotypal personality disorder | journal = The American Journal of Psychiatry | volume = 156 | issue = 4 | pages = 617–623 | date = April 1999 | pmid = 10200743 | doi = 10.1176/ajp.156.4.617 | s2cid = 9094296 }}{{cite journal | vauthors = Pasparakis E, Koiliari E, Zouraraki C, Tsapakis EM, Roussos P, Giakoumaki SG, Bitsios P | title = The effects of the CACNA1C rs1006737 A/G on affective startle modulation in healthy males | journal = European Psychiatry | volume = 30 | issue = 4 | pages = 492–498 | date = June 2015 | pmid = 25841664 | doi = 10.1016/j.eurpsy.2015.03.004 | s2cid = 30938090 }} It may also negatively affect reward processing in the brain and lead to anhedonia or depression in patients.{{cite journal | vauthors = Lancaster TM, Heerey EA, Mantripragada K, Linden DE | title = CACNA1C risk variant affects reward responsiveness in healthy individuals | journal = Translational Psychiatry | volume = 4 | issue = 10 | pages = e461 | date = October 2014 | pmid = 25290268 | doi = 10.1038/tp.2014.100 | pmc = 4350510 | s2cid = 1654916 }}{{cite journal | vauthors = Green EK, Grozeva D, Jones I, Jones L, Kirov G, Caesar S, Gordon-Smith K, Fraser C, Forty L, Russell E, Hamshere ML, Moskvina V, Nikolov I, Farmer A, McGuffin P, Holmans PA, Owen MJ, O'Donovan MC, Craddock N | title = The bipolar disorder risk allele at CACNA1C also confers risk of recurrent major depression and of schizophrenia | journal = Molecular Psychiatry | volume = 15 | issue = 10 | pages = 1016–1022 | date = October 2010 | pmid = 19621016 | doi = 10.1038/mp.2009.49 | pmc = 3011210 | s2cid = 6297556 }} These factors possibly lead to the development of Schizotypal traits.{{cite journal | vauthors = Roussos P, Bitsios P, Giakoumaki SG, McClure MM, Hazlett EA, New AS, Siever LJ | title = CACNA1C as a risk factor for schizotypal personality disorder and schizotypy in healthy individuals | journal = Psychiatry Research | volume = 206 | issue = 1 | pages = 122–123 | date = March 2013 | pmid = 22985546 | doi = 10.1016/j.psychres.2012.08.039 | pmc = 4176879 }} The zinc-finger protein ZNF804A likely affects the levels of paranoia, anxiety, and ideas of reference in StPD.{{cite journal | vauthors = Stefanis NC, Hatzimanolis A, Avramopoulos D, Smyrnis N, Evdokimidis I, Stefanis CN, Weinberger DR, Straub RE | title = Variation in psychosis gene ZNF804A is associated with a refined schizotypy phenotype but not neurocognitive performance in a large young male population | journal = Schizophrenia Bulletin | volume = 39 | issue = 6 | pages = 1252–1260 | date = November 2013 | pmid = 23155182 | pmc = 3796069 | doi = 10.1093/schbul/sbs110 }}{{cite journal | vauthors = Lencz T, Szeszko PR, DeRosse P, Burdick KE, Bromet EJ, Bilder RM, Malhotra AK | title = A schizophrenia risk gene, ZNF804A, influences neuroanatomical and neurocognitive phenotypes | journal = Neuropsychopharmacology | volume = 35 | issue = 11 | pages = 2284–2291 | date = October 2010 | pmid = 20664580 | doi = 10.1038/npp.2010.102 | pmc = 2939918 | s2cid = 19216888 }}{{cite journal | vauthors = Yasuda Y, Hashimoto R, Ohi K, Fukumoto M, Umeda-Yano S, Yamamori H, Okochi T, Iwase M, Kazui H, Iwata N, Takeda M | title = Impact on schizotypal personality trait of a genome-wide supported psychosis variant of the ZNF804A gene | journal = Neuroscience Letters | volume = 495 | issue = 3 | pages = 216–220 | date = May 2011 | pmid = 21457757 | doi = 10.1016/j.neulet.2011.03.069 | s2cid = 45364708 }} This gene is also thought to negatively impact attention in people with StPD.{{cite journal | vauthors = Del Re EC, Bergen SE, Mesholam-Gately RI, Niznikiewicz MA, Goldstein JM, Woo TU, Shenton ME, Seidman LJ, McCarley RW, Petryshen TL | title = Analysis of schizophrenia-related genes and electrophysiological measures reveals ZNF804A association with amplitude of P300b elicited by novel sounds | journal = Translational Psychiatry | volume = 4 | issue = 1 | pages = e346 | date = January 2014 | pmid = 24424392 | doi = 10.1038/tp.2013.117 | pmc = 3905227 | s2cid = 16062551 }} It may lead to an increased level of white matter volume in the frontal lobe.{{cite journal | vauthors = Wassink TH, Epping EA, Rudd D, Axelsen M, Ziebell S, Fleming FW, Monson E, Ho BC, Andreasen NC | title = Influence of ZNF804a on brain structure volumes and symptom severity in individuals with schizophrenia | journal = Archives of General Psychiatry | volume = 69 | issue = 9 | pages = 885–892 | date = September 2012 | pmid = 22945618 | doi = 10.1001/archgenpsychiatry.2011.2116 | pmc = 3852666 }} Another gene, the NOTCH4 is thought to relate to Schizophrenia spectrum disorders.{{cite journal | vauthors = Wassink TH, Nopoulos P, Pietila J, Crowe RR, Andreasen NC | title = NOTCH4 and the frontal lobe in schizophrenia | journal = American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics | volume = 118B | issue = 1 | pages = 1–7 | date = April 2003 | pmid = 12627456 | doi = 10.1002/ajmg.b.10071 | s2cid = 23380937 | doi-access = free }}{{cite journal | vauthors = DiLalla LF, McCrary M, Diaz E | title = A review of endophenotypes in schizophrenia and autism: The next phase for understanding genetic etiologies | journal = American Journal of Medical Genetics. Part C, Seminars in Medical Genetics | volume = 175 | issue = 3 | pages = 354–361 | date = September 2017 | pmid = 28661580 | doi = 10.1002/ajmg.c.31566 | s2cid = 4441493 }} It can lead to disruptions in the occipital cortex, and therefore symptoms of schizotypy.{{cite journal | vauthors = Xie X, Zu M, Zhang L, Bai T, Wei L, Huang W, Ji GJ, Qiu B, Hu P, Tian Y, Wang K | title = A common variant of the NOTCH4 gene modulates functional connectivity of the occipital cortex and its relationship with schizotypal traits | journal = BMC Psychiatry | volume = 20 | issue = 1 | pages = 363 | date = July 2020 | pmid = 32646407 | pmc = 7346398 | doi = 10.1186/s12888-020-02773-z | doi-access = free }} The GLRA1 and the p250GAP genes are also potentially associated with StPD.{{cite journal | vauthors = Bulbena-Cabre A, Bassir Nia A, Perez-Rodriguez MM | title = Current Knowledge on Gene-Environment Interactions in Personality Disorders: an Update | journal = Current Psychiatry Reports | volume = 20 | issue = 9 | pages = 74 | date = August 2018 | pmid = 30094700 | doi = 10.1007/s11920-018-0934-7 | s2cid = 51954090 }}{{Cite journal | vauthors = Köse SS, Erbaş O |date=2020 |title=Personality disorders diagnosis, causes, and treatments |journal=Demiroglu Science University Florence Nightingale Journal of Transplantation |volume=5 |issue=2 |pages=022–031 |doi=10.5606/dsufnjt.2020.013 |s2cid=234447745 |issn=2667-6680|doi-access=free }}{{cite journal | vauthors = Ma G, Fan H, Shen C, Wang W | title = Genetic and Neuroimaging Features of Personality Disorders: State of the Art | journal = Neuroscience Bulletin | volume = 32 | issue = 3 | pages = 286–306 | date = June 2016 | pmid = 27037690 | pmc = 5563771 | doi = 10.1007/s12264-016-0027-8 }} It may lead to abnormally low levels of Glutamic acids in the NMDA receptors, which impairs memory and learning.{{cite journal | vauthors = Vora AK, Fisher AM, New AS, Hazlett EA, McNamara M, Yuan Q, Zhou Z, Hodgkinson C, Goldman D, Siever LJ, Roussos P, Perez-Rodriguez MM | title = Dimensional Traits of Schizotypy Associated With Glycine Receptor GLRA1 Polymorphism: An Exploratory Candidate-Gene Association Study | journal = Journal of Personality Disorders | volume = 32 | issue = 3 | pages = 421–432 | date = June 2018 | pmid = 28758885 | pmc = 5856645 | doi = 10.1521/pedi_2017_31_303 }}{{cite journal | vauthors = Ohi K, Hashimoto R, Nakazawa T, Okada T, Yasuda Y, Yamamori H, Fukumoto M, Umeda-Yano S, Iwase M, Kazui H, Yamamoto T, Kano M, Takeda M | title = The p250GAP gene is associated with risk for schizophrenia and schizotypal personality traits | journal = PLOS ONE | volume = 7 | issue = 4 | pages = e35696 | date = 2012-04-18 | pmid = 22530067 | pmc = 3329470 | doi = 10.1371/journal.pone.0035696 | bibcode = 2012PLoSO...735696O | doi-access = free }}{{cite journal | vauthors = Walter EE, Fernandez F, Snelling M, Barkus E | title = Genetic Consideration of Schizotypal Traits: A Review | journal = Frontiers in Psychology | volume = 7 | pages = 1769 | date = 2016 | pmid = 27895608 | doi = 10.3389/fpsyg.2016.01769 | pmc = 5108787 | doi-access = free }}{{cite journal | vauthors = Lett TA, Voineskos AN, Kennedy JL, Levine B, Daskalakis ZJ | title = Treating working memory deficits in schizophrenia: a review of the neurobiology | language = English | journal = Biological Psychiatry | volume = 75 | issue = 5 | pages = 361–370 | date = March 2014 | pmid = 24011822 | doi = 10.1016/j.biopsych.2013.07.026 | s2cid = 23781971 | doi-access = free }} StPD may stem from abnormalities in Chromosome 22.{{cite journal | vauthors = Esterberg ML, Trotman HD, Brasfield JL, Compton MT, Walker EF | title = Childhood and current autistic features in adolescents with schizotypal personality disorder | journal = Schizophrenia Research | volume = 104 | issue = 1–3 | pages = 265–273 | date = September 2008 | pmid = 18554872 | doi = 10.1016/j.schres.2008.04.029 | pmc = 4416647 }}{{cite journal | vauthors = Shapiro DI, Cubells JF, Ousley OY, Rockers K, Walker EF | title = Prodromal symptoms in adolescents with 22q11.2 deletion syndrome and schizotypal personality disorder | journal = Schizophrenia Research | volume = 129 | issue = 1 | pages = 20–28 | date = June 2011 | pmid = 21507614 | doi = 10.1016/j.schres.2011.03.030 | pmc = 3100383 }}{{cite journal | vauthors = Esposito CM, Enrico P, Sciortino D, Caletti E, Marchetti GB, Cesaretti C, Oldani L, Fiorentini A, Brambilla P | title = Case Report: The Association Between Chromosomal Anomalies and Cluster A Personality Disorders: The Case of Two Siblings With 16p11.2 Deletion and a Review of the Literature | journal = Frontiers in Psychiatry | volume = 12 | pages = 689359 | date = 2021 | pmid = 34168584 | doi = 10.3389/fpsyt.2021.689359 | pmc = 8217436 | doi-access = free }}

Exposure to influenza during week 23 of gestation is associated with a higher likelihood of developing StPD. Poor nutrition in childhood may also contribute to the onset of StPD by altering the course of brain development.{{cite journal | vauthors = Venables PH, Raine A | title = Poor nutrition at age 3 and schizotypal personality at age 23: the mediating role of age 11 cognitive functioning | journal = The American Journal of Psychiatry | volume = 169 | issue = 8 | pages = 822–830 | date = August 2012 | pmid = 22772085 | doi = 10.1176/appi.ajp.2012.11081173 }} Numerous areas of the brain are thought to be associated with StPD. Higher levels of dopamine in the brain,{{cite journal | vauthors = Howes OD, Bose SK, Turkheimer F, Valli I, Egerton A, Valmaggia LR, Murray RM, McGuire P | title = Dopamine synthesis capacity before onset of psychosis: a prospective [18F]-DOPA PET imaging study | journal = The American Journal of Psychiatry | volume = 168 | issue = 12 | pages = 1311–1317 | date = December 2011 | pmid = 21768612 | doi = 10.1176/appi.ajp.2011.11010160 | pmc = 3682447 }}{{cite journal | vauthors = Woodward ND, Cowan RL, Park S, Ansari MS, Baldwin RM, Li R, Doop M, Kessler RM, Zald DH | title = Correlation of individual differences in schizotypal personality traits with amphetamine-induced dopamine release in striatal and extrastriatal brain regions | journal = The American Journal of Psychiatry | volume = 168 | issue = 4 | pages = 418–426 | date = April 2011 | pmid = 21159728 | pmc = 3770457 | doi = 10.1176/appi.ajp.2010.10020165 }} possibly specifically the D1 receptor,{{cite journal | vauthors = Pekcec A, Schülert N, Stierstorfer B, Deiana S, Dorner-Ciossek C, Rosenbrock H | title = Targeting the dopamine D₁ receptor or its downstream signalling by inhibiting phosphodiesterase-1 improves cognitive performance | journal = British Journal of Pharmacology | volume = 175 | issue = 14 | pages = 3021–3033 | date = July 2018 | pmid = 29726015 | pmc = 6016630 | doi = 10.1111/bph.14350 }}{{Cite journal | vauthors = Chemerinski E, Siever LJ, Koenigsberg HW |date=2005-12-01 |title=Dopamine regulation in schizotypal personality disorder and psychosis |journal=Current Psychosis & Therapeutics Reports |language=en |volume=3 |issue=4 |pages=162–168 |doi=10.1007/BF02629449 |s2cid=144051452 |issn=1545-8091 |via=SpringerLink}}{{cite journal | vauthors = Goldman-Rakic PS, Castner SA, Svensson TH, Siever LJ, Williams GV | title = Targeting the dopamine D1 receptor in schizophrenia: insights for cognitive dysfunction | journal = Psychopharmacology | volume = 174 | issue = 1 | pages = 3–16 | date = June 2004 | pmid = 15118803 | doi = 10.1007/s00213-004-1793-y | s2cid = 25015952 }} might contribute to the development of StPD. StPD is associated with heightened dopaminergic activity in the striatum.{{cite journal | vauthors = Kirschner M, Hager OM, Muff L, Bischof M, Hartmann-Riemer MN, Kluge A, Habermeyer B, Seifritz E, Tobler PN, Kaiser S | title = Ventral Striatal Dysfunction and Symptom Expression in Individuals With Schizotypal Personality Traits and Early Psychosis | journal = Schizophrenia Bulletin | volume = 44 | issue = 1 | pages = 147–157 | date = January 2018 | pmid = 27798223 | pmc = 5767950 | doi = 10.1093/schbul/sbw142 }}{{cite journal | vauthors = Waltmann M, O'Daly O, Egerton A, McMullen K, Kumari V, Barker GJ, Williams SC, Modinos G | title = Multi-echo fMRI, resting-state connectivity, and high psychometric schizotypy | journal = NeuroImage. Clinical | volume = 21 | pages = 101603 | date = 2019-01-01 | pmid = 30503214 | doi = 10.1016/j.nicl.2018.11.013 | pmc = 6413302 | s2cid = 53873865 }}{{Cite journal | vauthors = Siever LJ, Davis KL |date=2004-03-01 |title=The Pathophysiology of Schizophrenia Disorders: Perspectives From the Spectrum |url=https://ajp.psychiatryonline.org/doi/10.1176/appi.ajp.161.3.398?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed |journal=American Journal of Psychiatry |volume=161 |issue=3 |pages=398–413 |language=en |doi=10.1176/appi.ajp.161.3.398|pmid=14992962 }}{{cite journal | vauthors = Rössler J, Unterassner L, Wyss T, Haker H, Brugger P, Rössler W, Wotruba D | title = Schizotypal Traits are Linked to Dopamine-Induced Striato-Cortical Decoupling: A Randomized Double-Blind Placebo-Controlled Study | journal = Schizophrenia Bulletin | volume = 45 | issue = 3 | pages = 680–688 | date = April 2019 | pmid = 29878280 | pmc = 6483584 | doi = 10.1093/schbul/sby079 }} Their symptoms may also stem from higher presynaptic dopamine release.{{cite journal | vauthors = Miyake N, Thompson J, Skinbjerg M, Abi-Dargham A | title = Presynaptic dopamine in schizophrenia | journal = CNS Neuroscience & Therapeutics | volume = 17 | issue = 2 | pages = 104–109 | date = April 2011 | pmid = 21199451 | pmc = 6493810 | doi = 10.1111/j.1755-5949.2010.00230.x }}{{cite journal | vauthors = Fervaha G, Remington G | title = Neuroimaging findings in schizotypal personality disorder: a systematic review | journal = Progress in Neuro-Psychopharmacology & Biological Psychiatry | volume = 43 | pages = 96–107 | date = June 2013 | pmid = 23220094 | doi = 10.1016/j.pnpbp.2012.11.014 | s2cid = 25236324 }}{{cite journal | vauthors = Howes OD, Bose SK, Turkheimer F, Valli I, Egerton A, Valmaggia LR, Murray RM, McGuire P | title = Dopamine synthesis capacity before onset of psychosis: a prospective [18F]-DOPA PET imaging study | journal = The American Journal of Psychiatry | volume = 168 | issue = 12 | pages = 1311–1317 | date = December 2011 | pmid = 21768612 | pmc = 3682447 | doi = 10.1176/appi.ajp.2011.11010160 }}{{cite journal | vauthors = Egerton A, Chaddock CA, Winton-Brown TT, Bloomfield MA, Bhattacharyya S, Allen P, McGuire PK, Howes OD | title = Presynaptic striatal dopamine dysfunction in people at ultra-high risk for psychosis: findings in a second cohort | journal = Biological Psychiatry | volume = 74 | issue = 2 | pages = 106–112 | date = July 2013 | pmid = 23312565 | doi = 10.1016/j.biopsych.2012.11.017 | series = Corticostriatal Networks, Psychopathology, and Treatment | s2cid = 25232879 }} People with StPD may also have decreased volumes of grey or white matter in their caudate nucleus,{{cite journal | vauthors = Levitt JJ, Westin CF, Nestor PG, Estepar RS, Dickey CC, Voglmaier MM, Seidman LJ, Kikinis R, Jolesz FA, McCarley RW, Shenton ME | title = Shape of caudate nucleus and its cognitive correlates in neuroleptic-naive schizotypal personality disorder | language = English | journal = Biological Psychiatry | volume = 55 | issue = 2 | pages = 177–184 | date = January 2004 | pmid = 14732598 | doi = 10.1016/j.biopsych.2003.08.005 | pmc = 2793335 }}{{cite journal | vauthors = Haidar H, Bouix S, Levitt JJ, McCarley RW, Shenton ME, Soul JS | title = Characterizing the shape of anatomical structures with Poisson's equation | journal = IEEE Transactions on Medical Imaging | volume = 25 | issue = 10 | pages = 1249–1257 | date = October 2006 | pmid = 17024829 | doi = 10.1109/TMI.2006.881378 | pmc = 2785042 }} which leads to difficulties in speech.{{cite conference | vauthors = Niethammer M, Reuter M, Wolter FE, Bouix S, Peinecke N, Koo MS, Shenton ME | conference= Medical Image Computing and Computer-Assisted Intervention – MICCAI 2007 | title = Global Medical Shape Analysis Using the Laplace-Beltrami Spectrum | series = Lecture Notes in Computer Science | volume = 4791 | issue = Pt 1 | pages = 850–857 | date = 2007 | pmid = 18051138 | pmc = 2782516 | doi = 10.1007/978-3-540-75757-3_103 | isbn = 978-3-540-75756-6 }}{{cite journal | vauthors = Koo MS, Levitt JJ, McCarley RW, Seidman LJ, Dickey CC, Niznikiewicz MA, Voglmaier MM, Zamani P, Long KR, Kim SS, Shenton ME | title = Reduction of caudate nucleus volumes in neuroleptic-naïve female subjects with schizotypal personality disorder | journal = Biological Psychiatry | volume = 60 | issue = 1 | pages = 40–48 | date = July 2006 | pmid = 16460694 | pmc = 2768064 | doi = 10.1016/j.biopsych.2005.09.028 }}{{cite journal | vauthors = Levitt JJ, Styner M, Niethammer M, Bouix S, Koo MS, Voglmaier MM, Dickey CC, Niznikiewicz MA, Kikinis R, McCarley RW, Shenton ME | title = Shape abnormalities of caudate nucleus in schizotypal personality disorder | journal = Schizophrenia Research | volume = 110 | issue = 1–3 | pages = 127–139 | date = May 2009 | pmid = 19328654 | doi = 10.1016/j.schres.2008.11.012 | pmc = 2756791 }}{{cite journal | vauthors = Levitt JJ, McCarley RW, Dickey CC, Voglmaier MM, Niznikiewicz MA, Seidman LJ, Hirayasu Y, Ciszewski AA, Kikinis R, Jolesz FA, Shenton ME | title = MRI study of caudate nucleus volume and its cognitive correlates in neuroleptic-naive patients with schizotypal personality disorder | journal = The American Journal of Psychiatry | volume = 159 | issue = 7 | pages = 1190–1197 | date = July 2002 | pmid = 12091198 | doi = 10.1176/appi.ajp.159.7.1190 | pmc = 2826363 }} People with StPD likely have a reduced volume in their temporal lobes,{{cite journal | vauthors = Dickey CC, McCarley RW, Voglmaier MM, Niznikiewicz MA, Seidman LJ, Hirayasu Y, Fischer I, Teh EK, Van Rhoads R, Jakab M, Kikinis R, Jolesz FA, Shenton ME | title = Schizotypal personality disorder and MRI abnormalities of temporal lobe gray matter | language = English | journal = Biological Psychiatry | volume = 45 | issue = 11 | pages = 1393–1402 | date = June 1999 | pmid = 10356620 | doi = 10.1016/S0006-3223(99)00030-X | pmc = 2832794 | s2cid = 9398471 | url = http://nrs.harvard.edu/urn-3:HUL.InstRepos:28501043 }}{{cite journal | vauthors = Zhu Y, Tang Y, Zhang T, Li H, Tang Y, Li C, Luo X, He Y, Lu Z, Wang J | title = Reduced functional connectivity between bilateral precuneus and contralateral parahippocampus in schizotypal personality disorder | journal = BMC Psychiatry | volume = 17 | issue = 1 | pages = 48 | date = February 2017 | pmid = 28152990 | pmc = 5288938 | doi = 10.1186/s12888-016-1146-5 | doi-access = free }}{{cite journal | vauthors = Dickey CC, Shenton ME, Hirayasu Y, Fischer I, Voglmaier MM, Niznikiewicz MA, Seidman LJ, Fraone S, McCarley RW | title = Large CSF volume not attributable to ventricular volume in schizotypal personality disorder | journal = The American Journal of Psychiatry | volume = 157 | issue = 1 | pages = 48–54 | date = January 2000 | pmid = 10618012 | doi = 10.1176/ajp.157.1.48 | pmc = 2832789 }} possibly specifically the left hemisphere. The reduced levels of gray matter in these areas may be linked to their negative symptoms.{{cite journal | vauthors = Asami T, Whitford TJ, Bouix S, Dickey CC, Niznikiewicz M, Shenton ME, Voglmaier MM, McCarley RW | title = Globally and locally reduced MRI gray matter volumes in neuroleptic-naive men with schizotypal personality disorder: association with negative symptoms | journal = JAMA Psychiatry | volume = 70 | issue = 4 | pages = 361–372 | date = April 2013 | pmid = 23389420 | doi = 10.1001/jamapsychiatry.2013.665 | doi-access = free }} Reduced volume of gray or white matter in the superior temporal gyrus or the transverse temporal gyrus are thought to lead to issues with speech,{{cite journal | vauthors = Dickey CC, McCarley RW, Voglmaier MM, Frumin M, Niznikiewicz MA, Hirayasu Y, Fraone S, Seidman LJ, Shenton ME | title = Smaller left Heschl's gyrus volume in patients with schizotypal personality disorder | journal = The American Journal of Psychiatry | volume = 159 | issue = 9 | pages = 1521–1527 | date = September 2002 | pmid = 12202272 | doi = 10.1176/appi.ajp.159.9.1521 | pmc = 2832788 }}{{cite journal | vauthors = Dickey CC, McCarley RW, Voglmaier MM, Niznikiewicz MA, Seidman LJ, Frumin M, Toner S, Demeo S, Shenton ME | title = A MRI study of fusiform gyrus in schizotypal personality disorder | journal = Schizophrenia Research | volume = 64 | issue = 1 | pages = 35–39 | date = November 2003 | pmid = 14511799 | doi = 10.1016/S0920-9964(02)00529-7 | pmc = 2848253 | s2cid = 8218211 | url = http://nrs.harvard.edu/urn-3:HUL.InstRepos:28520542 }}{{cite journal | vauthors = Lener MS, Wong E, Tang CY, Byne W, Goldstein KE, Blair NJ, Haznedar MM, New AS, Chemerinski E, Chu KW, Rimsky LS, Siever LJ, Koenigsberg HW, Hazlett EA | title = White matter abnormalities in schizophrenia and schizotypal personality disorder | journal = Schizophrenia Bulletin | volume = 41 | issue = 1 | pages = 300–310 | date = January 2015 | pmid = 24962608 | pmc = 4266294 | doi = 10.1093/schbul/sbu093 }} memory, and hallucinations.{{cite journal | vauthors = Dickey CC, McCarley RW, Shenton ME | title = The brain in schizotypal personality disorder: a review of structural MRI and CT findings | journal = Harvard Review of Psychiatry | volume = 10 | issue = 1 | pages = 1–15 | date = 2002 | pmid = 11751641 | pmc = 2854016 | doi = 10.1080/10673220216201 }}{{cite journal | vauthors = Goldstein KE, Hazlett EA, New AS, Haznedar MM, Newmark RE, Zelmanova Y, Passarelli V, Weinstein SR, Canfield EL, Meyerson DA, Tang CY, Buchsbaum MS, Siever LJ | title = Smaller superior temporal gyrus volume specificity in schizotypal personality disorder | journal = Schizophrenia Research | volume = 112 | issue = 1–3 | pages = 14–23 | date = July 2009 | pmid = 19473820 | doi = 10.1016/j.schres.2009.04.027 | pmc = 2782902 }} Deficits in the gray matter volume of the temporal lobe and prefrontal cortex are likely associated with impairments in cognitive function, sensory processing, speech, executive function, decision-making, and emotional processing present in people with StPD.{{cite journal | vauthors = Takayanagi Y, Sasabayashi D, Takahashi T, Furuichi A, Kido M, Nishikawa Y, Nakamura M, Noguchi K, Suzuki M | title = Reduced Cortical Thickness in Schizophrenia and Schizotypal Disorder | journal = Schizophrenia Bulletin | volume = 46 | issue = 2 | pages = 387–394 | date = February 2020 | pmid = 31167030 | pmc = 7406196 | doi = 10.1093/schbul/sbz051 }}{{Cite journal | vauthors = Perez-Rodriguez MM, Zaluda L, New AS |date= April 2013 |title=Biological Advances in Personality Disorders |url=https://focus.psychiatryonline.org/doi/10.1176/appi.focus.11.2.146 |journal=FOCUS |volume=11 |issue=2 |pages=146–154 |doi=10.1176/appi.focus.11.2.146 |issn=1541-4094}} StPD symptoms may also be influenced by reduced internal capsule,{{cite journal | vauthors = Hazlett EA, Collazo T, Zelmanova Y, Entis JJ, Chu KW, Goldstein KE, Roussos P, Haznedar MM, Koenigsberg HW, New AS, Buchsbaum MS, Hershowitz JP, Siever LJ, Byne W | title = Anterior limb of the internal capsule in schizotypal personality disorder: fiber-tract counting, volume, and anisotropy | journal = Schizophrenia Research | volume = 141 | issue = 2–3 | pages = 119–127 | date = November 2012 | pmid = 22995934 | doi = 10.1016/j.schres.2012.08.022 | pmc = 3742803 }}{{cite journal | vauthors = Suzuki M, Zhou SY, Hagino H, Takahashi T, Kawasaki Y, Nohara S, Yamashita I, Matsui M, Seto H, Kurachi M | title = Volume reduction of the right anterior limb of the internal capsule in patients with schizotypal disorder | journal = Psychiatry Research | volume = 130 | issue = 3 | pages = 213–225 | date = April 2004 | pmid = 15135156 | doi = 10.1016/j.pscychresns.2004.01.001 | s2cid = 40481295 }}{{cite journal | vauthors = Hazlett EA, Goldstein KE, Kolaitis JC | title = A review of structural MRI and diffusion tensor imaging in schizotypal personality disorder | journal = Current Psychiatry Reports | volume = 14 | issue = 1 | pages = 70–78 | date = February 2012 | pmid = 22006127 | pmc = 3256320 | doi = 10.1007/s11920-011-0241-z }} which carries information to the cerebral cortex.{{cite journal | vauthors = Hazlett EA, Goldstein KE, Tajima-Pozo K, Speidel ER, Zelmanova Y, Entis JJ, Silverman JM, New AS, Koenigsberg HW, Haznedar MM, Byne W, Siever LJ | title = Cingulate and temporal lobe fractional anisotropy in schizotypal personality disorder | journal = NeuroImage | volume = 55 | issue = 3 | pages = 900–908 | date = April 2011 | pmid = 21223999 | doi = 10.1016/j.neuroimage.2010.12.082 | pmc = 3262398 }} People with StPD can also have impairments in the uncinate fasciculus, which connects parts of the limbic system.{{cite journal | vauthors = Gurrera RJ, Nakamura M, Kubicki M, Dickey CC, Niznikiewicz MA, Voglmaier MM, McCarley RW, Shenton ME, Westin CF, Maier SE, Seidman LJ | title = The uncinate fasciculus and extraversion in schizotypal personality disorder: a diffusion tensor imaging study | journal = Schizophrenia Research | volume = 90 | issue = 1–3 | pages = 360–362 | date = February 2007 | pmid = 17126532 | doi = 10.1016/j.schres.2006.10.003 | pmc = 1876710 }} People with StPD have reduced levels of gray matter in their middle frontal gyrus and Brodmann area 10.{{cite journal | vauthors = Lagioia A, Eliez S, Schneider M, Simons JS, Van der Linden M, Debbané M | title = Neural correlates of reality monitoring during adolescence | journal = NeuroImage | volume = 55 | issue = 3 | pages = 1393–1400 | date = April 2011 | pmid = 21195192 | doi = 10.1016/j.neuroimage.2010.12.058 | hdl = 2268/242658 | s2cid = 757306 | url = https://orbi.uliege.be/bitstream/2268/242658/1/Lagioia_Neuralcorrelates_2011-ppa.pdf }} Although, not as reduced as patients with Schizophrenia. Possibly preventing them from developing schizophrenia.{{cite journal | vauthors = Liu K, Zhang T, Zhang Q, Sun Y, Wu J, Lei Y, Chu WC, Mok VC, Wang D, Shi L | title = Characterization of the Fiber Connectivity Profile of the Cerebral Cortex in Schizotypal Personality Disorder: A Pilot Study | journal = Frontiers in Psychology | volume = 7 | pages = 809 | date = 2016 | pmid = 27303358 | doi = 10.3389/fpsyg.2016.00809 | pmc = 4884735 | doi-access = free }} Increased gyrification in gyri by the cerebellum may lead to dysconnectivity in the brain, and therefore, schizotypal symptoms.{{cite journal | vauthors = Sasabayashi D, Takayanagi Y, Takahashi T, Nemoto K, Furuichi A, Kido M, Nishikawa Y, Nakamura M, Noguchi K, Suzuki M | title = Increased brain gyrification in the schizophrenia spectrum | journal = Psychiatry and Clinical Neurosciences | volume = 74 | issue = 1 | pages = 70–76 | date = January 2020 | pmid = 31596011 | doi = 10.1111/pcn.12939 | s2cid = 203985518 | doi-access = free }}{{cite journal | vauthors = Hazlett EA, Buchsbaum MS, Haznedar MM, Newmark R, Goldstein KE, Zelmanova Y, Glanton CF, Torosjan Y, New AS, Lo JN, Mitropoulou V, Siever LJ | title = Cortical gray and white matter volume in unmedicated schizotypal and schizophrenia patients | journal = Schizophrenia Research | volume = 101 | issue = 1–3 | pages = 111–123 | date = April 2008 | pmid = 18272348 | doi = 10.1016/j.schres.2007.12.472 | pmc = 2672563 | s2cid = 12723481 }} They may also have a hyporeactive,{{cite journal | vauthors = Perez-Rodriguez MM, New AS, Goldstein KE, Rosell D, Yuan Q, Zhou Z, Hodgkinson C, Goldman D, Siever LJ, Hazlett EA | title = Brain-derived neurotrophic factor Val66Met genotype modulates amygdala habituation | journal = Psychiatry Research: Neuroimaging | volume = 263 | pages = 85–92 | date = May 2017 | pmid = 28371657 | doi = 10.1016/j.pscychresns.2017.03.008 | pmc = 5856456 }} or hyperreactive amygdala.{{cite journal | vauthors = Stanfield AC, Philip RC, Whalley H, Romaniuk L, Hall J, Johnstone EC, Lawrie SM | title = Dissociation of Brain Activation in Autism and Schizotypal Personality Disorder During Social Judgments | journal = Schizophrenia Bulletin | volume = 43 | issue = 6 | pages = 1220–1228 | date = October 2017 | pmid = 29088456 | pmc = 5737648 | doi = 10.1093/schbul/sbx083 }} As well as hyperactive pituitary glands and putamens.{{cite journal | vauthors = Chemerinski E, Byne W, Kolaitis JC, Glanton CF, Canfield EL, Newmark RE, Haznedar MM, Novakovic V, Chu KW, Siever LJ, Hazlett EA | title = Larger putamen size in antipsychotic-naïve individuals with schizotypal personality disorder | journal = Schizophrenia Research | volume = 143 | issue = 1 | pages = 158–164 | date = January 2013 | pmid = 23187070 | doi = 10.1016/j.schres.2012.11.003 | pmc = 3634353 }}{{cite journal | vauthors = Romo-Nava F, Hoogenboom WS, Pelavin PE, Alvarado JL, Bobrow LH, Macmaster FP, Keshavan M, McCarley RW, Shenton ME | title = Pituitary volume in schizophrenia spectrum disorders | journal = Schizophrenia Research | volume = 146 | issue = 1–3 | pages = 301–307 | date = May 2013 | pmid = 23522905 | doi = 10.1016/j.schres.2013.02.024 | pmc = 3760333 }} It is also possible that lower capacities for prepulse inhibition plays a role in StPD.{{cite journal | vauthors = Cadenhead KS, Light GA, Geyer MA, McDowell JE, Braff DL | title = Neurobiological measures of schizotypal personality disorder: defining an inhibitory endophenotype? | journal = The American Journal of Psychiatry | volume = 159 | issue = 5 | pages = 869–871 | date = May 2002 | pmid = 11986147 | doi = 10.1176/appi.ajp.159.5.869 }}{{cite journal | vauthors = Hazlett EA, Levine J, Buchsbaum MS, Silverman JM, New A, Sevin EM, Maldari LA, Siever LJ | title = Deficient attentional modulation of the startle response in patients with schizotypal personality disorder | journal = The American Journal of Psychiatry | volume = 160 | issue = 9 | pages = 1621–1626 | date = September 2003 | pmid = 12944337 | doi = 10.1176/appi.ajp.160.9.1621 }}{{cite journal | vauthors = Cadenhead KS, Swerdlow NR, Shafer KM, Diaz M, Braff DL | title = Modulation of the startle response and startle laterality in relatives of schizophrenic patients and in subjects with schizotypal personality disorder: evidence of inhibitory deficits | journal = The American Journal of Psychiatry | volume = 157 | issue = 10 | pages = 1660–1668 | date = October 2000 | pmid = 11007721 | doi = 10.1176/appi.ajp.157.10.1660 }}{{cite journal | vauthors = Cadenhead KS, Geyer MA, Braff DL | title = Impaired startle prepulse inhibition and habituation in patients with schizotypal personality disorder | journal = The American Journal of Psychiatry | volume = 150 | issue = 12 | pages = 1862–1867 | date = December 1993 | pmid = 8238643 | doi = 10.1176/ajp.150.12.1862 }} Research has suggested that people with StPD can have higher concentrations of Homovanillic acids.{{cite journal | vauthors = Siever LJ, Amin F, Coccaro EF, Trestman R, Silverman J, Horvath TB, Mahon TR, Knott P, Altstiel L, Davidson M | title = CSF homovanillic acid in schizotypal personality disorder | journal = The American Journal of Psychiatry | volume = 150 | issue = 1 | pages = 149–151 | date = January 1993 | pmid = 8417559 | doi = 10.1176/ajp.150.1.149 }} Abnormalities in the cave of septum pellucidum may also be present.{{cite journal | vauthors = Kwon JS, Shenton ME, Hirayasu Y, Salisbury DF, Fischer IA, Dickey CC, Yurgelun-Todd D, Tohen M, Kikinis R, Jolesz FA, McCarley RW | title = MRI study of cavum septi pellucidi in schizophrenia, affective disorder, and schizotypal personality disorder | journal = The American Journal of Psychiatry | volume = 155 | issue = 4 | pages = 509–515 | date = April 1998 | pmid = 9545997 | doi = 10.1176/ajp.155.4.509 | pmc = 2826366 }} In people predisposed to the development of Schizophrenia spectrum disorders, the consumption of cannabis can induce the onset of StPD or other disorders with psychotic symptoms.{{cite journal | vauthors = Anglin DM, Corcoran CM, Brown AS, Chen H, Lighty Q, Brook JS, Cohen PR | title = Early cannabis use and schizotypal personality disorder symptoms from adolescence to middle adulthood | journal = Schizophrenia Research | volume = 137 | issue = 1–3 | pages = 45–49 | date = May 2012 | pmid = 22325079 | doi = 10.1016/j.schres.2012.01.019 | pmc = 3591468 }}{{cite journal | vauthors = Davis GP, Compton MT, Wang S, Levin FR, Blanco C | title = Association between cannabis use, psychosis, and schizotypal personality disorder: findings from the National Epidemiologic Survey on Alcohol and Related Conditions | journal = Schizophrenia Research | volume = 151 | issue = 1–3 | pages = 197–202 | date = December 2013 | pmid = 24200416 | doi = 10.1016/j.schres.2013.10.018 | pmc = 3877688 }}{{cite journal | vauthors = Hjorthøj C, Albert N, Nordentoft M | title = Association of Substance Use Disorders With Conversion From Schizotypal Disorder to Schizophrenia | journal = JAMA Psychiatry | volume = 75 | issue = 7 | pages = 733–739 | date = July 2018 | pmid = 29710317 | doi = 10.1001/jamapsychiatry.2018.0568 | pmc = 6145672 | s2cid = 13966874 }}{{cite journal | vauthors = Fridberg DJ, Vollmer JM, O'Donnell BF, Skosnik PD | title = Cannabis users differ from non-users on measures of personality and schizotypy | journal = Psychiatry Research | volume = 186 | issue = 1 | pages = 46–52 | date = March 2011 | pmid = 20813412 | doi = 10.1016/j.psychres.2010.07.035 | pmc = 3036782 }}

Unique environmental factors, which differ from shared sibling experiences, have been found to play a role in the development of StPD and its dimensions. There is evidence to suggest that parenting styles, early separation, childhood trauma, and childhood neglect can lead to the development of schizotypal traits.{{cite journal | vauthors = Dong F, Liu J, Hodgson NA, Medoff-Cooper B | title = Early life factors of schizotypal personality disorder in adolescents: A systematic review | journal = Journal of Psychiatric and Mental Health Nursing | volume = 28 | issue = 6 | pages = 1092–1112 | date = December 2021 | pmid = 33502097 | doi = 10.1111/jpm.12733 | s2cid = 231761157 }}Deidre M. Anglina, Patricia R. Cohenab, Henian Chena (2008) Duration of early maternal separation and prediction of schizotypal symptoms from early adolescence to midlife, Schizophrenia Research Volume 103, Issue 1, Pages 143–150 (August 2008)Howard Berenbaum, Ph.D., Eve M. Valera, Ph.D. and John G. Kerns, Ph.D. (2003) Psychological Trauma and Schizotypal Symptoms, Oxford Journals, Medicine, Schizophrenia Bulletin Volume 29, Number 1 Pp. 143–152 Neglect, abuse, stress,{{cite journal | vauthors = Tessner KD, Mittal V, Walker EF | title = Longitudinal study of stressful life events and daily stressors among adolescents at high risk for psychotic disorders | journal = Schizophrenia Bulletin | volume = 37 | issue = 2 | pages = 432–441 | date = March 2011 | pmid = 19734244 | pmc = 3044629 | doi = 10.1093/schbul/sbp087 }} trauma,{{cite journal | vauthors = Liu J, Gong J, Nie G, He Y, Xiao B, Shen Y, Luo X | title = The mediating effects of childhood neglect on the association between schizotypal and autistic personality traits and depression in a non-clinical sample | journal = BMC Psychiatry | volume = 17 | issue = 1 | pages = 352 | date = October 2017 | pmid = 29065890 | pmc = 5655952 | doi = 10.1186/s12888-017-1510-0 | doi-access = free }}{{cite journal | vauthors = Anglin DM, Cohen PR, Chen H | title = Duration of early maternal separation and prediction of schizotypal symptoms from early adolescence to midlife | journal = Schizophrenia Research | volume = 103 | issue = 1–3 | pages = 143–150 | date = August 2008 | pmid = 18407465 | doi = 10.1016/j.schres.2008.02.016 | pmc = 2603441 }}{{cite journal | vauthors = Berenbaum H, Thompson RJ, Milanek ME, Boden MT, Bredemeier K | title = Psychological trauma and schizotypal personality disorder | journal = Journal of Abnormal Psychology | volume = 117 | issue = 3 | pages = 502–519 | date = August 2008 | pmid = 18729605 | doi = 10.1037/0021-843X.117.3.502 }} or family dysfunction during childhood may increase the risk of developing schizotypal personality disorder.{{cite journal | vauthors = Lentz V, Robinson J, Bolton JM | title = Childhood adversity, mental disorder comorbidity, and suicidal behavior in schizotypal personality disorder | journal = The Journal of Nervous and Mental Disease | volume = 198 | issue = 11 | pages = 795–801 | date = November 2010 | pmid = 21048469 | doi = 10.1097/NMD.0b013e3181f9804c | s2cid = 205882039 }}{{cite journal | vauthors = Ericson M, Tuvblad C, Raine A, Young-Wolff K, Baker LA | title = Heritability and longitudinal stability of schizotypal traits during adolescence | journal = Behavior Genetics | volume = 41 | issue = 4 | pages = 499–511 | date = July 2011 | pmid = 21369821 | pmc = 3123391 | doi = 10.1007/s10519-010-9401-x }}{{cite journal | vauthors = Wong KK, Raine A | title = Developmental Aspects of Schizotypy and Suspiciousness: a Review | journal = Current Behavioral Neuroscience Reports | volume = 5 | issue = 1 | pages = 94–101 | date = 2018-03-01 | pmid = 29577010 | pmc = 5857559 | doi = 10.1007/s40473-018-0144-y }} There is also evidence indicating that disruptions in brain development during the prenatal period could affect the development of StPD.{{cite journal | vauthors = Machón RA, Huttunen MO, Mednick SA, Sinivuo J, Tanskanen A, Bunn Watson J, Henriksson M, Pyhälä R | title = Adult schizotypal personality characteristics and prenatal influenza in a Finnish birth cohort | journal = Schizophrenia Research | volume = 54 | issue = 1–2 | pages = 7–16 | date = March 2002 | pmid = 11853973 | doi = 10.1016/S0920-9964(01)00346-2 | s2cid = 20875584 }} Over time, children learn to interpret social cues and respond appropriately but for unknown reasons this process does not work well for people with this disorder.{{cite web |last=Mayo Clinic Staff |title=Schizotypal personality disorder |url=http://www.mayoclinic.com/health/schizotypal-personality-disorder/DS00830/DSECTION=causes |url-status=dead |archive-url=https://web.archive.org/web/20120309231644/http://www.mayoclinic.com:80/health/schizotypal-personality-disorder/DS00830/DSECTION=causes |archive-date=9 March 2012 |access-date=21 February 2012 |publisher=Mayo Clinic}} During childhood, people with StPD may have seen little emotional expression from their parents. Another possibility is that they were excessively criticized or felt like they were constantly under threat,{{cite journal | vauthors = Dizinger JM, Doll CM, Rosen M, Gruen M, Daum L, Schultze-Lutter F, Betz L, Kambeitz J, Vogeley K, Haidl TK | title = Does childhood trauma predict schizotypal traits? A path modelling approach in a cohort of help-seeking subjects | journal = European Archives of Psychiatry and Clinical Neuroscience | volume = 272 | issue = 5 | pages = 909–922 | date = August 2022 | pmid = 34982217 | pmc = 9279245 | doi = 10.1007/s00406-021-01373-6 }} potentially resulting in the onset of social anxiety, strange thinking patterns,{{cite journal | vauthors = Powers AD, Thomas KM, Ressler KJ, Bradley B | title = The differential effects of child abuse and posttraumatic stress disorder on schizotypal personality disorder | journal = Comprehensive Psychiatry | volume = 52 | issue = 4 | pages = 438–445 | date = 2011-07-01 | pmid = 21683181 | doi = 10.1016/j.comppsych.2010.08.001 | pmc = 3122145 }} and blunted affect present in StPD.{{cite journal | vauthors = Cohen P, Chen H, Gordon K, Johnson J, Brook J, Kasen S | title = Socioeconomic background and the developmental course of schizotypal and borderline personality disorder symptoms | journal = Development and Psychopathology | volume = 20 | issue = 2 | pages = 633–650 | date = 2008 | pmid = 18423098 | doi = 10.1017/S095457940800031X | pmc = 3857688 }}{{cite journal | vauthors = Velikonja T, Velthorst E, McClure MM, Rutter S, Calabrese WR, Rosell D, Koenigsberg HW, Goodman M, New AS, Hazlett EA, Perez-Rodriguez MM | title = Severe childhood trauma and clinical and neurocognitive features in schizotypal personality disorder | journal = Acta Psychiatrica Scandinavica | volume = 140 | issue = 1 | pages = 50–64 | date = July 2019 | pmid = 30951190 | doi = 10.1111/acps.13032 | s2cid = 96436653 }} Their difficulties in social situations might eventually cause the individual to withdraw from most social interactions, thus leading to asociality.{{cite journal | vauthors = Roitman SE, Cornblatt BA, Bergman A, Obuchowski M, Mitropoulou V, Keefe RS, Silverman JM, Siever LJ | title = Attentional functioning in schizotypal personality disorder | journal = The American Journal of Psychiatry | volume = 154 | issue = 5 | pages = 655–660 | date = May 1997 | pmid = 9137121 | doi = 10.1176/ajp.154.5.655 }} Children with schizotypal symptoms usually are more likely to indulge in internal fantasies,{{cite journal | vauthors = Esterberg ML, Goulding SM, Walker EF | title = Cluster A Personality Disorders: Schizotypal, Schizoid and Paranoid Personality Disorders in Childhood and Adolescence | journal = Journal of Psychopathology and Behavioral Assessment | volume = 32 | issue = 4 | pages = 515–528 | date = December 2010 | pmid = 21116455 | pmc = 2992453 | doi = 10.1007/s10862-010-9183-8 }} more anxious, socially isolated, and more sensitive to criticism.{{cite journal | vauthors = Olin SS, Raine A, Cannon TD, Parnas J, Schulsinger F, Mednick SA | title = Childhood behavior precursors of schizotypal personality disorder | journal = Schizophrenia Bulletin | volume = 23 | issue = 1 | pages = 93–103 | date = 1997 | pmid = 9050116 | doi = 10.1093/schbul/23.1.93 | doi-access = free }} People with the most severe cases of StPD usually have a combination of childhood trauma and a genetic basis for their condition.{{cite journal | vauthors = Raine A, Wong KK, Liu J | title = The Schizotypal Personality Questionnaire for Children (SPQ-C): Factor Structure, Child Abuse, and Family History of Schizotypy | journal = Schizophrenia Bulletin | volume = 47 | issue = 2 | pages = 323–331 | date = March 2021 | pmid = 32674122 | pmc = 8370046 | doi = 10.1093/schbul/sbaa100 }}{{cite journal | vauthors = Berenbaum H, Valera EM, Kerns JG | title = Psychological trauma and schizotypal symptoms | journal = Schizophrenia Bulletin | volume = 29 | issue = 1 | pages = 143–152 | date = 2003 | pmid = 12908670 | doi = 10.1093/oxfordjournals.schbul.a006985 | doi-access = free }}

The latest edition of the Diagnostic and Statistical Manual of Mental Disorders, namely the DSM-5-TR, defines STPD as "a pattern of acute discomfort in close relationships, cognitive or perceptual distortions, and eccentricities of behavior" 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=978-0-89042-575-6 |editor-last=American Psychiatric Association |edition=Fifth edition, text revision |location=Washington, DC |pages=733-734}} The diagnosis is based on at least five out of nine 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=744-745}} 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.

StPD is characterized by five or more of the following:{{Cite web |title=Schizotypal Personality Disorder (STPD) - Psychiatric Disorders |url=https://www.merckmanuals.com/professional/psychiatric-disorders/personality-disorders/schizotypal-personality-disorder-stpd |access-date=2023-03-11 |website=Merck Manuals Professional Edition |language=en-US}}

• Ideas of reference (but not delusions of reference)
• Odd beliefs or magical thinking (e.g. the supernatural or special connection or bond to an abuser)
• Unusual perceptional experiences (hearing a voice, dissociative experiences, illusions, etc.)
• Odd thought and speech (e.g. jumping from one topic to another)
• Eccentric behavior and/or appearance
• Paranoid ideation
• Moods and facial expressions that don't match each other or the situation
• Few to no close supports
• Excessive social anxiety that remains even with familiar people

These symptoms must have begun by early adulthood.

{{Further|Alternative DSM-5 model for personality disorders}}

Section III of both the DSM-5 and DSM-5-TR contains the Alternative DSM-5 Model for Personality Disorders (AMPD). The AMPD defines six specific personality disorders – one of them being STPD – in terms of a description of the disorder; the characteristic manner in which the disorder impacts personality functioning, i.e. identity, self-direction, empathy and intimacy (criterion A); a listing and description of the pathological personality traits associated with the disorder (criterion B); and a section dedicated to specifiers.{{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=761-770}}

General personality impairment in individuals with STPD, according to the AMPD, involves a fragmented sense of self and difficulty distinguishing personal identity from others. Emotional expression may appear unusual or disconnected from the situation. They often lack clear goals or consistent personal values. Understanding social dynamics is challenging, leading to frequent misinterpretations of others' intentions. Close relationships are difficult to maintain due to suspicion and discomfort in social settings. A diagnosis requires impairment in at least two of these areas. At least two of these elements must have a "moderate or greater impairment".{{Cite book |title=Diagnostic and statistical manual of mental disorders: DSM-5 |date=2013 |publisher=American Psychiatric Association |isbn=978-0-89042-554-1 |editor-last=American Psychiatric Association |edition=5th |location=Washington, D.C |pages=769-770 |editor-last2=American Psychiatric Association}} The AMPD lists six pathological traits, from the domains of detachment and psychoticism for STPD. Any four or more of these are required for a diagnosis to be made. Other traits can be included in the diagnosis as specifiers.

The patient must also meet the general criteria C through G for a personality disorder, which state that the traits and symptoms being displayed by the patient must be stable and unchanging over time with an onset of at least adolescence or early adulthood, visible in a variety of situations, not caused by another mental disorder, not caused by a substance or medical condition, and abnormal in comparison to a person's developmental stage and culture/religion.

Personality disorders 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 (6D10.0), moderate (6D10.1), severe (6D10.2), or severity unspecified (6D10.Z). As such, there is no specific PD diagnosis for STPD.

On the other hand, neither the ICD-10 nor the ICD-11 conceptualize STPD as being a personality disorder. Instead, it is listed together with psychotic disorders as "Schizotypal disorder" ([https://icd.who.int/browse/2025-01/mms/en#18178000 6A22]) in the ICD-11, and as ([https://icd.who.int/browse10/2019/en#/F21 F21]) in the ICD-10.

Differential diagnosis with the following disorders should also be considered:

• Other disorders with psychotic symptoms: (e.g., schizophrenia, bipolar disorder, or depressive disorder with psychotic features)
• Paranoid, schizoid, or avoidant personality disorders
• Dissociative identity disorder (DID){{citation needed|date=April 2023}}
• Communication disorders{{citation needed|date=December 2023}}

There are various methods of screening for schizotypal personality. The Schizotypal Personality Questionnaire (SPQ) measures nine traits of StPD using a self-report assessment.{{cite journal |vauthors=Barrantes-Vidal N, Grant P, Kwapil TR |date=March 2015 |title=The role of schizotypy in the study of the etiology of schizophrenia spectrum disorders |journal=Schizophrenia Bulletin |volume=41 |issue=Suppl 2 |pages=S408–S416 |doi=10.1093/schbul/sbu191 |pmc=4373635 |pmid=25810055}} The nine traits referenced are Ideas of Reference, Excessive Social Anxiety, Odd Beliefs or Magical Thinking, Unusual Perceptual Experiences, Odd or Eccentric Behavior, No Close Friends, Odd Speech, Constricted Affect, and Suspiciousness. A study found that of the participants who scored in the top 10th percentile of all the SPQ scores, 55% were clinically diagnosed with StPD.{{cite journal |vauthors=Raine A |date=1991 |title=The SPQ: a scale for the assessment of schizotypal personality based on DSM-III-R criteria |journal=Schizophrenia Bulletin |volume=17 |issue=4 |pages=555–564 |doi=10.1093/schbul/17.4.555 |pmid=1805349 |doi-access=free}} It has been adapted into a computerized adaptive version, known as the SPQ-CAT.{{cite journal |vauthors=Moore TM, Calkins ME, Reise SP, Gur RC, Gur RE |date=May 2018 |title=Development and public release of a computerized adaptive (CAT) version of the Schizotypal Personality Questionnaire |journal=Psychiatry Research |volume=263 |pages=250–256 |doi=10.1016/j.psychres.2018.02.022 |pmc=5911247 |pmid=29625786 |s2cid=5004186}} A method that measures the risk of developing psychosis through self-reports is the Wisconsin Schizotypy Scale (WSS).{{Cite journal |vauthors=Winterstein BP, Silvia PJ, Kwapil TR, Kaufman JC, Reiter-Palmon R, Wigert |date=2011 |title=Brief assessment of schizotypy: Developing short forms of the Wisconsin Schizotypy Scales |journal=Personality and Individual Differences |language=en |volume=51 |issue=8 |pages=920–924 |doi=10.1016/j.paid.2011.07.027 |doi-access=free}} The WSS divides schizotypal personality traits into 4 scales for Perceptual Aberration, Magical Ideation, Revised Social Anhedonia, and Physical Anhedonia.[http://apps.who.int/classifications/icd10/browse/2015/en#/F21 Schizotypal Disorder] {{Webarchive|url=https://web.archive.org/web/20151102042503/http://apps.who.int/classifications/icd10/browse/2015/en#/F21#/F21|date=2015-11-02}} in ICD-10: [https://www.who.int/classifications/icd/en/bluebook.pdf#84 Clinical descriptions and guidelines.] {{Webarchive|url=https://web.archive.org/web/20140323025330/http://www.who.int/classifications/icd/en/bluebook.pdf#84#84|date=2014-03-23}}{{cite journal |vauthors=Gross GM, Mellin J, Silvia PJ, Barrantes-Vidal N, Kwapil TR |date=October 2014 |title=Comparing the factor structure of the Wisconsin Schizotypy Scales and the Schizotypal Personality Questionnaire |url=http://libres.uncg.edu/ir/uncg/f/T_Kwapil_Comparing_2014.pdf |journal=Personality Disorders |volume=5 |issue=4 |pages=397–405 |doi=10.1037/per0000090 |pmid=25314229}} A comparison of the SPQ and the WSS suggests that these measures should be cautiously used for screening of StPD.

When screening for StPD, it is difficult to distinguish between schizotypal personality disorder and autism spectrum disorder.{{cite journal |last1=Parvaiz |first1=Rizwan |last2=Vindbjerg |first2=Erik |last3=Crespi |first3=Bernard |last4=Happe |first4=Francesca |last5=Schalbroeck |first5=Rik |last6=Al-Sayegh |first6=Zainab |last7=Danielsen |first7=Ida-Marie |last8=Tonge |first8=Bruce |last9=Videbech |first9=Poul |last10=Abu-Akel |first10=Ahmad |date=2023-03-28 |title=Protocol for the development and testing of the schiZotypy Autism Questionnaire (ZAQ) in adults: a new screening tool to discriminate autism spectrum disorder from schizotypal disorder |journal=BMC Psychiatry |publisher=Springer Science and Business Media LLC |volume=23 |issue=1 |page=200 |doi=10.1186/s12888-023-04690-3 |issn=1471-244X |pmc=10044373 |pmid=36978026 |doi-access=free}} In order to develop better screening tools, researchers are looking into the importance of ipseity disturbance, which is characteristic of schizophrenia spectrum disorders such as StPD but not of autism.{{cite journal |last1=Nilsson |first1=Maria |last2=Arnfred |first2=Sidse |last3=Carlsson |first3=Jessica |last4=Nylander |first4=Lena |last5=Pedersen |first5=Lennart |last6=Mortensen |first6=Erik Lykke |last7=Handest |first7=Peter |date=2019-05-03 |title=Self-Disorders in Asperger Syndrome Compared to Schizotypal Disorder: A Clinical Study |journal=Schizophrenia Bulletin |publisher=Oxford University Press |volume=46 |issue=1 |pages=121–129 |doi=10.1093/schbul/sbz036 |issn=0586-7614 |pmc=6942161 |pmid=34688345 |doi-access=free}}

Theodore Millon proposes two subtypes of schizotypal personality.{{cite book |author-link=Theodore Millon |title=Personality disorders in modern life |vauthors=Millon T |publisher=Wiley |year=2004 |isbn=978-0-471-23734-1 |page=403 |chapter=Chapter 12 – The Schizotypal Personality |oclc=57291241 |chapter-url=http://dlia.ir/Scientific/e_book/Medicine/Internal_Medicine/RC_435_571_Psychiatry_/017437.pdf#420 |archive-url=https://web.archive.org/web/20170207112700/http://dlia.ir/Scientific/e_book/Medicine/Internal_Medicine/RC_435_571_Psychiatry_/017437.pdf |archive-date=2017-02-07}}{{cite web |author=The Millon Personality Group |date=8 March 2017 |title=Eccentric/Schizotypal Personality |url=http://www.millonpersonality.com/theory/diagnostic-taxonomy/schizotypal.htm |url-status=live |archive-url=https://web.archive.org/web/20170308045332/http://www.millonpersonality.com/theory/diagnostic-taxonomy/schizotypal.htm |archive-date=8 March 2017 |access-date=5 April 2019 |website=Millon Theory}} Any individual with schizotypal personality disorder may exhibit either one of the following somewhat different subtypes (note that Millon believes it is rare for a personality to show one pure variant, but rather a mixture of one major variant with one or more secondary variants):

Millon's typology of personality disorders was influential in the development of the DSM-III, particularly with respect to distinguishing between schizoid, schizotypal and avoidant personality disorders.{{cite journal |last1=Livesley |first1=W. John |last2=West |first2=Malcolm |year=1986 |title=The DSM-III Distinction between Schizoid and Avoidant Personality Disorders |journal=The Canadian Journal of Psychiatry |publisher=SAGE Publications |volume=31 |issue=1 |pages=59–62 |doi=10.1177/070674378603100112 |issn=0706-7437 |pmid=3948107 |s2cid=46283956}} These had previously been considered different surface-level expressions of the same underlying personality structure, and some psychologists, particularly those working in psychoanalytic or psychodynamic traditions, still take these personality disorders to be essentially similar.{{cite book |author-last=McWilliams |author-first=Nancy |author-link=Nancy McWilliams |title=Psychoanalytic Diagnosis: Understanding Personality Structure in the Clinical Process |title-link=Psychoanalytic Diagnosis |publisher=The Guilford Press |year=2011 |isbn=978-1-60918-494-0 |edition=2nd |page=199}}{{cite book |title=Psychodynamic Diagnostic Manual |title-link=Psychodynamic Diagnostic Manual |publisher=The Guilford Press |year=2017 |isbn=978-1-4625-3055-7 |editor-last1=McWilliams |editor-first1=Nancy |edition=2nd |editor-last2=Lingiardi |editor-first2=Vittorio}}

• Antisocial personality disorder
• Avoidant personality disorder
• Bipolar disorder{{cite journal |vauthors=Correll CU, Smith CW, Auther AM, McLaughlin D, Shah M, Foley C, Olsen R, Lencz T, Kane JM, Cornblatt BA |date=October 2008 |title=Predictors of remission, schizophrenia, and bipolar disorder in adolescents with brief psychotic disorder or psychotic disorder not otherwise specified considered at very high risk for schizophrenia |journal=Journal of Child and Adolescent Psychopharmacology |volume=18 |issue=5 |pages=475–490 |doi=10.1089/cap.2007.110 |pmc=2779049 |pmid=18928412}}
• Borderline personality disorder{{cite journal |vauthors=Pulay AJ, Stinson FS, Dawson DA, Goldstein RB, Chou SP, Huang B, Saha TD, Smith SM, Pickering RP, Ruan WJ, Hasin DS, Grant BF |date=2009 |title=Prevalence, correlates, disability, and comorbidity of DSM-IV schizotypal personality disorder: results from the wave 2 national epidemiologic survey on alcohol and related conditions |journal=Primary Care Companion to the Journal of Clinical Psychiatry |volume=11 |issue=2 |pages=53–67 |doi=10.4088/pcc.08m00679 |pmc=2707116 |pmid=19617934}}
• Dysthymia{{cite book |title=Comprehensive handbook of psychopathology |vauthors=Sutker P |publisher=Kluwer Academic |year=2002 |isbn=978-0-306-46490-4 |edition=3rd |oclc=50322422}}
• Narcissistic personality disorder
• Obsessive–compulsive disorder{{cite journal |vauthors=Perris F, Fabrazzo M, De Santis V, Luciano M, Sampogna G, Fiorillo A, Catapano F |date=2019 |title=Comorbidity of Obsessive-Compulsive Disorder and Schizotypal Personality Disorder: Clinical Response and Treatment Resistance to Pharmacotherapy in a 3-Year Follow-Up Naturalistic Study |journal=Frontiers in Psychiatry |volume=10 |pages=386 |doi=10.3389/fpsyt.2019.00386 |pmc=6589899 |pmid=31263430 |doi-access=free}}{{cite book |title=Essential psychiatry |vauthors=Murray R |publisher=Cambridge University Press |year=2008 |isbn=978-0-521-60408-6 |edition=4th |oclc=298067373}}{{cite journal |vauthors=Attademo L, Bernardini F |date=October 2021 |title=Schizotypal personality disorder in clinical obsessive-compulsive disorder samples: a brief overview |journal=CNS Spectrums |volume=26 |issue=5 |pages=468–480 |doi=10.1017/S1092852920001716 |pmid=32713392 |s2cid=220796175}}{{Cite journal |vauthors=Fossati A, Borroni S |date=2008 |title=When 'entities' are as intrusive as obsessions: A case study of the co-occurrence of obsessive–compulsive disorder and schizotypal personality disorder diagnoses |url=https://onlinelibrary.wiley.com/doi/10.1002/pmh.42 |journal=Personality and Mental Health |language=en |volume=2 |issue=3 |pages=192–200 |doi=10.1002/pmh.42}}{{cite journal |vauthors=Cavanna AE, Robertson MM, Critchley HD |date=December 2007 |title=Schizotypal personality traits in Gilles de la Tourette syndrome |journal=Acta Neurologica Scandinavica |volume=116 |issue=6 |pages=385–391 |doi=10.1111/j.1600-0404.2007.00879.x |pmc=2275799 |pmid=17986097}}
• Major depressive disorder
• Paranoid personality disorder{{cite book |title=Psychiatry |vauthors=Tasman A |publisher=Wiley-Blackwell |year=2008 |isbn=978-0-470-06571-6 |edition=3rd |oclc=264703257}}
• Post-traumatic stress disorder
• Schizoid personality disorder
• Schizophrenia{{cite journal |vauthors=Walker E, Kestler L, Bollini A, Hochman KM |year=2004 |title=Schizophrenia: etiology and course |journal=Annual Review of Psychology |publisher=Annual Reviews |volume=55 |issue=1 |pages=401–430 |doi=10.1146/annurev.psych.55.090902.141950 |pmid=14744221}}{{cite journal |vauthors=Raine A |year=2006 |title=Schizotypal personality: neurodevelopmental and psychosocial trajectories |journal=Annual Review of Clinical Psychology |volume=2 |pages=291–326 |doi=10.1146/annurev.clinpsy.2.022305.095318 |pmid=17716072}}{{cite journal |vauthors=Matsui M, Sumiyoshi T, Kato K, Yoneyama E, Kurachi M |date=April 2004 |title=Neuropsychological profile in patients with schizotypal personality disorder or schizophrenia |journal=Psychological Reports |publisher=SAGE Publications |volume=94 |issue=2 |pages=387–397 |doi=10.2466/pr0.94.2.387-397 |pmid=15154161 |s2cid=41869819}}{{cite journal |vauthors=Haznedar MM, Buchsbaum MS, Hazlett EA, Shihabuddin L, New A, Siever LJ |date=December 2004 |title=Cingulate gyrus volume and metabolism in the schizophrenia spectrum |journal=Schizophrenia Research |volume=71 |issue=2–3 |pages=249–262 |doi=10.1016/j.schres.2004.02.025 |pmid=15474896 |s2cid=28889346}}
• Substance use disorders{{cite journal |vauthors=Kerridge BT, Saha TD, Hasin DS |date=2014 |title=DSM-IV schizotypal personality disorder: a taxometric analysis among individuals with and without substance use disorders in the general population |journal=Mental Health and Substance Use |volume=7 |issue=4 |pages=446–460 |doi=10.1080/17523281.2014.946076 |pmc=4549000 |pmid=26322122}}
• Social anxiety disorder
• Dissociative identity disorder{{Cite journal |last1=Giesbrecht |first1=Timo |last2=Merckelbach |first2=Harald |last3=Kater |first3=Maartje |last4=Sluis |first4=Anne Fetsje |date=October 2007 |title=Why dissociation and schizotypy overlap: the joint influence of fantasy proneness, cognitive failures, and childhood trauma |url=https://pubmed.ncbi.nlm.nih.gov/18043521/ |journal=The Journal of Nervous and Mental Disease |volume=195 |issue=10 |pages=812–818 |doi=10.1097/NMD.0b013e3181568137 |issn=0022-3018 |pmid=18043521 |s2cid=45086235}}@unknown{unknown,

author = {Šram, Zlatko},

year = {2018},

month = {03},

title = {Childhood Trauma, the Occult, Dissociative Identity Disorder, and Schizotypal Personality Disorder: Relations on a Sample of Psychiatric Outpatients}

}https://www.researchgate.net/publication/323526162_Childhood_Trauma_the_Occult_Dissociative_Identity_Disorder_and_Schizotypal_Personality_Disorder_Relations_on_a_Sample_of_Psychiatric_Outpatients{{Cite web |title=APA PsycNet |url=https://psycnet.apa.org/record/2009-02549-015 |access-date=2023-03-12 |website=psycnet.apa.org |language=en}}

File:Risperidone-3D-balls.png of Risperidone, a drug used to treat StPD]]

File:Cognitive behavioral therapy - basic tenets.svg, a type of therapy used to treat StPD]]StPD is rarely seen as the primary reason for treatment in a clinical setting, but it often occurs as a comorbid finding with other mental disorders. When patients with StPD have prescribed pharmaceuticals, they are usually prescribed antipsychotics.{{cite journal | vauthors = Bachetti MC, Cirimbilli F, Pierotti V, Menculini G, Tortorella A, Moretti P | title = A Dual Therapeutic Setting Model Experience for Schizotypal Personality Disorder in an Inpatient Unit | journal = Psychiatria Danubina | volume = 32 | issue = Suppl 1 | pages = 194–199 | date = September 2020 | pmid = 32890389 | url = https://www.psychiatria-danubina.com/UserDocsImages/pdf/dnb_vol32_noSuppl%201/dnb_vol32_noSuppl%201_194.pdf | publication-place = Zagreb }}{{cite journal | vauthors = Rass O, Forsyth JK, Krishnan GP, Hetrick WP, Klaunig MJ, Breier A, O'Donnell BF, Brenner CA | title = Auditory steady state response in the schizophrenia, first-degree relatives, and schizotypal personality disorder | journal = Schizophrenia Research | volume = 136 | issue = 1–3 | pages = 143–149 | date = April 2012 | pmid = 22285558 | doi = 10.1016/j.schres.2012.01.003 | pmc = 3298621 }}{{cite journal | vauthors = Dadić-Hero E, Ruzić K, Medved P, Tatalović-Vorkapić S, Graovac M | title = Antipsychotic side-effect - potential risk of patients rejecting their treatments | journal = Psychiatria Danubina | volume = 22 | issue = 1 | pages = 105–107 | date = March 2010 | pmid = 20305602 | url = https://pubmed.ncbi.nlm.nih.gov/20305602/ }} However, the use of neuroleptic drugs in the schizotypal population is in great doubt.{{cite book |title=Handbook of personality disorders : theory, research, and treatment |vauthors=Livesley W |publisher=Guilford Press |year=2001 |isbn=978-1-57230-629-5 |oclc=45750508}} The antipsychotics which show promise as treatments for StPD include olanzapine,{{cite journal | vauthors = Keshavan M, Shad M, Soloff P, Schooler N | title = Efficacy and tolerability of olanzapine in the treatment of schizotypal personality disorder | journal = Schizophrenia Research | volume = 71 | issue = 1 | pages = 97–101 | date = November 2004 | pmid = 15374577 | doi = 10.1016/j.schres.2003.12.008 | s2cid = 12551427 }} risperidone,{{cite journal | vauthors = McClure MM, Koenigsberg HW, Reynolds D, Goodman M, New A, Trestman R, Silverman J, Harvey PD, Siever LJ | title = The effects of risperidone on the cognitive performance of individuals with schizotypal personality disorder | language = en-US | journal = Journal of Clinical Psychopharmacology | volume = 29 | issue = 4 | pages = 396–398 | date = August 2009 | pmid = 19593186 | doi = 10.1097/JCP.0b013e3181accfd9 | pmc = 4176874 }}{{cite journal | vauthors = Kirchner SK, Roeh A, Nolden J, Hasan A | title = Diagnosis and treatment of schizotypal personality disorder: evidence from a systematic review | journal = npj Schizophrenia | volume = 4 | issue = 1 | pages = 20 | date = October 2018 | pmid = 30282970 | doi = 10.1038/s41537-018-0062-8 | pmc = 6170383 | s2cid = 52914783 }} haloperidol,{{cite journal | vauthors = Jakobsen KD, Skyum E, Hashemi N, Schjerning O, Fink-Jensen A, Nielsen J | title = Antipsychotic treatment of schizotypy and schizotypal personality disorder: a systematic review | journal = Journal of Psychopharmacology | volume = 31 | issue = 4 | pages = 397–405 | date = April 2017 | pmid = 28347257 | doi = 10.1177/0269881117695879 | s2cid = 12170130 }} and thiothixene.{{Citation | vauthors = Miyazaki M, Simeon D, Hollander E |title=Treatment of Personality Disorders |date=2017-05-01 |url=https://psychiatryonline.org/doi/10.1176/appi.books.9781615371624.as51 |work=The American Psychiatric Association Publishing Textbook of Psychopharmacology |publisher=American Psychiatric Association Publishing |doi=10.1176/appi.books.9781615371624.as51 |isbn=978-1-58562-523-9 |access-date=2022-10-27 }} The antidepressant fluoxetine may also be helpful.{{cite journal | vauthors = Markovitz PJ, Calabrese JR, Schulz SC, Meltzer HY | title = Fluoxetine in the treatment of borderline and schizotypal personality disorders | journal = The American Journal of Psychiatry | volume = 148 | issue = 8 | pages = 1064–1067 | date = August 1991 | pmid = 1853957 | doi = 10.1176/ajp.148.8.1064 }} While people with schizotypal personality disorder and other attenuated psychotic-spectrum disorders may have a good outcome with neuroleptics in the short term, long-term follow-up suggests significant impairment in daily functioning compared to schizotypal and even schizophrenic people without antipsychotic drug exposure.{{cite journal | vauthors = Harrow M, Jobe TH, Faull RN, Yang J | title = A 20-Year multi-followup longitudinal study assessing whether antipsychotic medications contribute to work functioning in schizophrenia | journal = Psychiatry Research | volume = 256 | pages = 267–274 | date = October 2017 | pmid = 28651219 | pmc = 5661946 | doi = 10.1016/j.psychres.2017.06.069 }} Positive, negative, and depressive symptoms were shown to be improved by the use of olanzapine, an antipsychotic.{{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 }} Those with comorbid OCD and StPD were most positively affected by the use of olanzapine and showed worse outcomes with the use of clomipramine, an antidepressant. Antidepressants are also sometimes prescribed, whether for StPD proper or for comorbid anxiety and depression. However, there is some ambiguity in the efficacy of antidepressants, as many studies have only tested people with StPD and comorbid obsessive-compulsive disorder or borderline personality disorder. They have shown little efficacy for treating dysthymia and anhedonia related to StPD. Both of these medications are the most frequently prescribed medication for StPD, though the use and efficacy of them should be evaluated differently for every case. The use of stimulants has also shown some efficacy, especially for those with worsened cognitive and attentional issues. Patients who have concurrent psychosis should be monitored more closely if stimulants are used as part of their treatment. Other drugs which may be effective include pergolide,{{cite journal | vauthors = McClure MM, Harvey PD, Goodman M, Triebwasser J, New A, Koenigsberg HW, Sprung LJ, Flory JD, Siever LJ | title = Pergolide treatment of cognitive deficits associated with schizotypal personality disorder: continued evidence of the importance of the dopamine system in the schizophrenia spectrum | journal = Neuropsychopharmacology | volume = 35 | issue = 6 | pages = 1356–1362 | date = May 2010 | pmid = 20130535 | doi = 10.1038/npp.2010.5 | pmc = 3055340 | s2cid = 7149320 }} guanfacine,{{Cite journal | vauthors = Graff FS, McClure MM, Siever LJ |date=2014-12-01 |title=Remediation and Cognitive Enhancers in Schizotypal Personality Disorder |journal=Current Treatment Options in Psychiatry |language=en |volume=1 |issue=4 |pages=369–375 |doi=10.1007/s40501-014-0027-0 |s2cid=145447269 |issn=2196-3061|doi-access=free }}{{cite journal | vauthors = McClure MM, Graff F, Triebwasser J, Perez-Rodriguez M, Rosell DR, Koenigsberg H, Hazlett EA, Siever LJ, Harvey PD, New AS | title = Guanfacine Augmentation of a Combined Intervention of Computerized Cognitive Remediation Therapy and Social Skills Training for Schizotypal Personality Disorder | journal = The American Journal of Psychiatry | volume = 176 | issue = 4 | pages = 307–314 | date = April 2019 | pmid = 30654644 | doi = 10.1176/appi.ajp.2018.18030349 | pmc = 6443471 | s2cid = 58626454 }}{{cite journal | vauthors = McClure MM, Barch DM, Romero MJ, Minzenberg MJ, Triebwasser J, Harvey PD, Siever LJ | title = The effects of guanfacine on context processing abnormalities in schizotypal personality disorder | journal = Biological Psychiatry | volume = 61 | issue = 10 | pages = 1157–1160 | date = May 2007 | pmid = 16950221 | doi = 10.1016/j.biopsych.2006.06.034 | series = Multiple Genotypes and Brain Development in Schizophrenia | s2cid = 17772053 | doi-access = free }}{{cite journal | vauthors = Arnsten AF, Jin LE | title = Guanfacine for the treatment of cognitive disorders: a century of discoveries at Yale | journal = The Yale Journal of Biology and Medicine | volume = 85 | issue = 1 | pages = 45–58 | date = March 2012 | pmid = 22461743 | pmc = 3313539 }} and dihydrexidine.{{cite journal | vauthors = Rosell DR, Zaluda LC, McClure MM, Perez-Rodriguez MM, Strike KS, Barch DM, Harvey PD, Girgis RR, Hazlett EA, Mailman RB, Abi-Dargham A, Lieberman JA, Siever LJ | title = Effects of the D1 dopamine receptor agonist dihydrexidine (DAR-0100A) on working memory in schizotypal personality disorder | journal = Neuropsychopharmacology | volume = 40 | issue = 2 | pages = 446–453 | date = January 2015 | pmid = 25074637 | doi = 10.1038/npp.2014.192 | pmc = 4443959 | s2cid = 30635726 }}{{cite journal | vauthors = Arnsten AF, Girgis RR, Gray DL, Mailman RB | title = Novel Dopamine Therapeutics for Cognitive Deficits in Schizophrenia | journal = Biological Psychiatry | volume = 81 | issue = 1 | pages = 67–77 | date = January 2017 | pmid = 26946382 | doi = 10.1016/j.biopsych.2015.12.028 | series = Dopamine Hypothesis of Schizophrenia | pmc = 4949134 }}{{Cite journal | vauthors = McClure M, Perez-Rodriguez MM, Rosell D, Ejebe K, Siever L, New A |date=2019 |title=T38. Dopamine Enhancement of Verbal Learning in the Schizophrenia Spectrum |journal=Schizophrenia Bulletin |volume=45 |issue=Suppl 2 |pages=S218 |doi=10.1093/schbul/sbz019.318 |issn=0586-7614 |pmc=6455598 }}

According to Theodore Millon, schizotypal personality disorder is one of the most straightforward personality disorders to identify but one of the most difficult to treat with psychotherapy. Cognitive remediation therapy,{{cite journal | vauthors = McGurk SR | title = Cognitive Remediation and Social Skills Training for Schizotypal Personality Disorder: Greater Gains With Guanfacine? | journal = The American Journal of Psychiatry | volume = 176 | issue = 4 | pages = 265–266 | date = April 2019 | pmid = 30929501 | doi = 10.1176/appi.ajp.2019.19020144 | s2cid = 89618769 | doi-access = free }}{{Cite journal | vauthors = McClure M, Graff F, Perez-Rodriguez M, Rosell D, Hazlett E, New AS, Harvey P, Siever L |date=2017-03-01 |title=SA25. Guanfacine Augmentation of Cognitive Remediation Therapy in the Schizophrenia Spectrum: Prospects for Improving Cognitive Performance and Functional Skills |journal=Schizophrenia Bulletin |language=en |volume=43 |issue=suppl_1 |pages=S122 |doi=10.1093/schbul/sbx023.024 |pmc=5475916 |issn=0586-7614}} metacognitive therapy, supportive psychotherapy,{{Citation | vauthors = Stone MH |title=Paranoid, Schizotypal, and Schizoid Personality Disorders |date=2014-05-05 |url=https://psychiatryonline.org/doi/10.1176/appi.books.9781585625048.gg68 |work=Gabbard?s Treatments of Psychiatric Disorders |publisher=American Psychiatric Publishing |doi=10.1176/appi.books.9781585625048.gg68 |isbn=978-1-58562-442-3 |access-date=2022-10-30}} social skills training{{Cite journal |last1=McClure |first1=Margaret M. |last2=Graff |first2=Fiona |last3=Triebwasser |first3=Joseph |last4=Perez-Rodriguez |first4=Mercedes |last5=Rosell |first5=Daniel R. |last6=Koenigsberg |first6=Harold |last7=Hazlett |first7=Erin A. |last8=Siever |first8=Larry J. |last9=Harvey |first9=Philip D. |last10=New |first10=Antonia S. |date=2019-01-18 |title=Guanfacine Augmentation of a Combined Intervention of Computerized Cognitive Remediation Therapy and Social Skills Training for Schizotypal Personality Disorder |journal=American Journal of Psychiatry |language=en |volume=176 |issue=4 |pages=307–314 |doi=10.1176/appi.ajp.2018.18030349 |issn=0002-953X |pmc=6443471 |pmid=30654644}} and cognitive-behavioral therapy can be effective treatments for the disorder.{{cite journal | vauthors = Jeppesen UN, Due AS, Mariegaard L, Pinkham A, Vos M, Veling W, Nordentoft M, Glenthøj LB | title = Face Your Fears: Virtual reality-based cognitive behavioral therapy (VR-CBT) versus standard CBT for paranoid ideations in patients with schizophrenia spectrum disorders: a randomized clinical trial | journal = Trials | volume = 23 | issue = 1 | pages = 658 | date = August 2022 | pmid = 35971137 | pmc = 9377061 | doi = 10.1186/s13063-022-06614-0 | doi-access = free }}{{Cite journal | vauthors = Ryan A, Macdonald A, Walker E |date=2013 |title=The Treatment of Adolescents With Schizotypal Personality Disorder and Related Conditions: A Practice-Oriented Review of the Literature |url=http://doi.wiley.com/10.1111/cpsp.12050 |journal=Clinical Psychology: Science and Practice |language=en |volume=20 |issue=4 |pages=408–424 |doi=10.1111/cpsp.12050 |via=Wiley Online Library}} Increased social interaction with others may be able to help limit symptoms of StPD.{{cite journal | vauthors = Raine A, Mellingen K, Liu J, Venables P, Mednick SA | title = Effects of environmental enrichment at ages 3-5 years on schizotypal personality and antisocial behavior at ages 17 and 23 years | journal = The American Journal of Psychiatry | volume = 160 | issue = 9 | pages = 1627–1635 | date = September 2003 | pmid = 12944338 | doi = 10.1176/appi.ajp.160.9.1627 }} Support is crucial for schizotypal patients with predominant paranoid symptoms because they may have difficulties even in highly structured groups.{{cite book |title=The American Psychiatric Publishing textbook of personality disorders |vauthors=Oldham J, Skodol AE, Bender DS |publisher=American Psychiatric Pub |year=2005 |isbn=978-1-58562-159-0 |oclc=56733258 |author2-link=Andrew E. Skodol}} Persons with StPD usually consider themselves to be simply eccentric or nonconformist; the degree to which they consider their social nonconformity a problem differs from the degree to which it is viewed as a problem in psychiatry. It is difficult to gain rapport with people with StPD because increasing familiarity and intimacy often increase their level of anxiety and discomfort.{{cite journal |vauthors=Siever LJ |year=1992 |title=Schizophrenia spectrum disorders |journal=Review of Psychiatry |volume=11 |pages=25–42}} Therapy for StPD must be flexible to face emergencies or unique challenges.

{{Portal|Psychology

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• Boundaries of the mind
• DSM-5 codes (personality disorders)
• Paranoid personality disorder
• Schizoid personality disorder
• Schizophrenia
• Schizothymia
• Schizotypy
• Dissociative identity disorder
• Chūnibyō

{{Reflist}}

{{Medical resources|ICD10={{ICD10|F|21||f|20}}|ICD9={{ICD9|301.22}}|MeshID=D012569|MedlinePlus=001525}}{{ICD-10 personality disorders}}

Category:Paranoia

Category:Cluster A personality disorders

Category:Schizophrenia

Category:Schizophrenia or other primary psychotic disorders