Diagnostic complexities of autism and psychosis: A commentary on the ANZJP GRADE guidelines for the management of schizophrenia

Abstract

The Australian and New Zealand Journal of Psychiatry GRADE Evidence Guidelines for Schizophrenia highlight the importance of considering psychiatric comorbidities, including autism spectrum disorder. These guidelines acknowledge that there is limited empirical research to guide the management of individuals with schizophrenia who also have these comorbid conditions. This lack of evidence poses challenges for clinicians, especially those working in early psychosis services, where the possibility of a missed diagnosis of autism spectrum disorder is increasingly being examined, and pre-existing diagnoses of autism spectrum disorder are not uncommon. This commentary explores the complex overlaps among shared histories, risk factors and symptomatology, as well as the difficulties stemming from the absence of validated assessment tools to aid in diagnostic clarification. Psychotic symptoms may complicate the recognition and differentiation of underlying neurodevelopmental characteristics of autism spectrum disorder. Considering the limited available evidence, practical guidance is offered to assist clinicians in their decision-making when a strong evidence base is lacking. In the context of early psychosis, diagnostic formulation should be considered provisional, with assessment of a possible a missed ASD diagnosis occurring after the stabilisation of psychotic symptoms wherever possible.

Keywords

Schizophrenia autism spectrum disorder early psychosis first episode psychosis

The ANZJP GRADE Evidence Guidelines for Schizophrenia acknowledge the importance of considering comorbidities, including autism spectrum disorder (ASD) (Suetani et al., 2026). These guidelines also emphasise that there is ‘. . . very little empirical research to guide us on the management of people with schizophrenia who have such comorbid conditions . . .’ (p. 30). This lack of evidence is problematic for clinicians, particularly those working in early psychosis services, where the question of a missed diagnosis of ASD is being increasingly considered (Treise et al., 2021), and a pre-existing diagnosis of ASD is not uncommon (Zheng et al., 2018). This commentary explores the complex overlap among shared history, risk factors and symptomatology, as well as the challenge posed by the lack of validated assessment tools to support diagnostic clarification. Based on limited available evidence, pragmatic guidance is provided to support clinician decision-making in the absence of a strong evidence base in the context of early psychosis.

ASD is a neurodevelopmental disorder where difficulties with social communication and restrictive/repetitive behaviours, interests or activities are evident from early childhood. In recent decades, there has been an increase in the proportion of people where the diagnosis is first made in youth and adulthood (i.e. ‘late diagnoses’) (Aggarwal and Angus, 2015; Carroll et al., 2025; Russell et al., 2025; Russell et al., 2022). This trend has coincided with increased public awareness of the disorder and the broadening of the diagnostic criteria following the shift from ‘autistic disorder’ in DSM-IV to ASD in DSM-5 (Harris, 2023; Murphy et al., 2016). Accompanying this broadening of the diagnostic boundaries is an increasing number of adults seeking assessment for ASD and a willingness for clinicians to assess adults for an ASD diagnosis (Carroll et al., 2025). It has been suggested that undiagnosed ASD is common in the general population and in those with mental illness (Fusar-Poli et al., 2020). However, diagnosing ASD in youth and adults is challenging, given the heterogeneous nature of the characteristics associated with this disorder (Carroll et al., 2025), and particular challenges arise in early psychosis services where ASD and psychosis have features in common (Russell et al., 2025; Treise et al., 2021).

Understanding the similarities and overlaps between ASD and psychosis

It is unsurprising that there is significant overlap between the phenotypes of ASD and psychotic disorders such as schizophrenia (see Figure 1) (Trevisan et al., 2020; Zheng et al., 2018). The term ‘autism’ formed one of the pillars of Bleuler’s conceptualisation of schizophrenia, based on the observations of a preoccupation with one’s ‘inner life’ and social withdrawal (Evans, 2013). The apparent overlap is most often observed in domains that resemble ‘negative symptoms’ of psychosis, reflected in the absence of typical social and communicative behaviours (Trevisan et al., 2020). Negative symptoms in schizophrenia are characterised by affective blunting (e.g. reduced affective sharing, eye contact, facial expressivity and gestural communication), alogia (impoverished speech output) and anhedonia (reduced motivation for social and recreational engagement) (APA, 2022). Similarly, ASD is defined by persistent deficits in social–emotional reciprocity, including reduced emotional sharing or initiation of social interaction, as well as impairments in nonverbal communicative behaviours (e.g. eye contact, gesture use and facial expression) and reduced spontaneity in communication and conversational reciprocity (Kincaid et al., 2017; Marder and Umbricht, 2023; Mosolov and Yaltonskaya, 2021).

Figure 1.

Matrix of heuristics guidance for differentiating of autism spectrum disorder (ASD), autism spectrum disorder and psychosis (ASD-P) and psychotic disorders based on the limited available evidence^a.

In addition, several common features observed in ASD can mimic the ‘positive symptoms’ of psychotic disorders. Restricted interests, a rich fantasy life and concerns about persecution arising from recurrent negative evaluations by others, may resemble delusional thinking (Guerrera et al., 2024; Takara et al., 2015). Atypical perceptual and information processing in the auditory, visual and tactile domains may be misinterpreted as hallucinations (e.g. non-shared sensory experiences, increased sensory intensity, sensory distortion) (Milne et al., 2017). Furthermore, stereotypies and repetitive motor movements can resemble disorganised behaviour (Guerrera et al., 2024; Ribolsi et al., 2022).

The overlap in clinical features between ASD and schizophrenia may result from shared genetic and epidemiological risks (Cheung et al., 2010; Chisholm et al., 2015; Park et al., 2018) and neuroanatomical structural abnormalities (Diaz-Caneja et al., 2019). People diagnosed with ASD are at a greater risk of developing schizophrenia (odds ratio [OR] = 3.5, 95% confidence interval [CI] = [2.08, 6.05]) (Zheng et al., 2018), and rates of diagnosable ASD in people experiencing psychotic disorders are considerably higher than in the general population (Kincaid et al., 2017). The increasing recognition of the overlap between these conditions has contributed to conflicting concerns about ‘missed diagnoses’ and ‘misdiagnoses’ in people being supported for the first episode of psychosis (Bell et al., 2025; Treise et al., 2021; Zheng et al., 2018). Misattributing characteristics of ASD to a psychotic disorder risks iatrogenic harm (e.g. unnecessary exposure to antipsychotic medications), while misattributing psychotic symptoms to ASD (i.e. diagnostic overshadowing) delays appropriate care. Missing a comorbid diagnosis of ASD in a person experiencing psychosis reflects a missed opportunity to provide relevant scaffolding to support optimal functional outcomes (Fusar-Poli et al., 2022; Kentrou et al., 2024). However, a misdiagnosis of comorbid ASD in a person with schizophrenia can result in the provision of potentially inappropriate supports.

Overlapping and distinguishing characteristics of ASD, co-occurring ASD and psychosis (ASD-P), and primary psychotic disorders based on the limited available evidence are summarised in Figure 1. Taken together, these findings suggest that differentiation depends less on signs and symptoms observable in the current mental state examination, than on whether observed features represent continuity or discontinuity with prior functioning. In ASD, restricted interests and preoccupations, differences in social communication and atypical perceptual and information processing, by definition, reflect long-standing neurodevelopmental characteristics which are evident from childhood (APA, 2022). In primary psychotic disorders, delusions and hallucinations are sustained, represent new phenomena and are accompanied by a discernible shift in functioning (APA, 2022). In people who have ASD and later develop psychosis, a careful history along with detailed attention to phenomenology will enable identification in a change in an individual’s mental state and functioning from baseline with emergence of psychotic symptoms.

Screening and assessment for autistic and psychotic features

The differentiation described above highlights a central limitation of current assessment approaches. Validated screening and diagnostic tools for ASD and schizophrenia are designed to detect syndrome-specific symptom clusters rather than to determine whether observed features reflect pre-existing developmental characteristics or a change associated with emerging psychotic illness. Used in isolation, they cannot determine whether observed features reflect long-standing characteristics or recent change.

The Autism Diagnostic Observation Schedule (ADOS-2) and Autism Diagnostic Interview-Revised (ADI-R) are validated, commonly used tools for supporting the assessment and diagnosis of ASD in youth and adults in the general population (Frigaux et al., 2019; Mammarella et al., 2024). However, these tools have been found to have high false-positive rates in schizophrenia (Maddox, 2020; Nakamura et al., 2024). Similarly, tools like the Positive and Negative Syndrome Scale (PANSS) are well validated for assessing the presence and severity of symptoms in people experiencing psychotic disorders (Geck et al., 2025). However, these tools may have limited validity in assessment in the context of potential comorbidity (Zheng et al., 2018).

There has been increasing interest in screening for ASD in early psychosis populations (Treise et al., 2021) as well as for psychosis screening in children and adolescents diagnosed with ASD (Mammarella et al., 2024). This has coincided with efforts to develop tools for assessing autistic characteristics in the context of psychosis (Nibbio et al., 2022; Treise et al., 2021). However, given the engagement demands associated with structured diagnostic assessment tools for ASD, it is important to consider whether their use provides benefit in identifying people with ASD in the context of psychosis (Frigaux et al., 2019; Nibbio et al., 2022).

The PANSS Autism Severity Score (PAUSS) had been proposed as a brief measure derived from PANSS items and suggested as suitable for this purpose (Kastner et al., 2015). However, emerging evidence raises concerns about its validity, with findings indicating that PAUSS scores are more strongly associated with psychotic symptom severity than autistic traits (Chisholm et al., 2024; Pelizza et al., 2026; Zheng et al., 2021). Critically, studies have observed a lack of long-term stability in the PAUSS scores of people with first episode psychosis and established schizophrenia, suggesting it may reflect state-related features rather than underlying autism (Chisholm et al., 2024; Pelizza et al., 2026).

How should we be assessing for ASD in people with psychotic disorders?

There is a substantial risk of misdiagnosis when evaluating individuals for a potential ‘missed diagnosis’ of ASD in the context of the first episode of psychosis or an established psychotic disorder. Current evidence indicates that features resembling autism during acute psychosis may be transient and linked to the acute state (Pelizza et al., 2026). Furthermore, the persistence of these features is associated with the severity and treatment resistance of the psychotic disorder (Chisholm et al., 2019; Jeong et al., 2024). This complexity does not diminish the understanding of shared vulnerabilities and risk factors between ASD and psychosis; rather, it highlights the limitations of utilising present state and assessments conducted following the onset of psychosis as a basis for identifying a comorbid diagnosis of ASD.

ASD and other neurodevelopmental disorders (e.g. attention-deficit/hyperactivity disorder, specific learning disorders, intellectual disability) should be routinely considered in the assessment of an individual with psychosis. The absence of validated screening and diagnostic tools to assist in the identification of ASD in the context of psychosis poses a substantial challenge for clinicians. There is limited validation data supporting the use of measures such as the ADOS-2 and ADI-R in people diagnosed with psychotic disorders (Maddox, 2020; Trevisan et al., 2020). However, these standardised assessments are preferable to the PAUSS, for which there is growing evidence of a lack of validity in this context (Pelizza et al., 2026). Collateral information from caregivers to inform the developmental history, complemented by school reports and standardised assessments from childhood (if available) are informative for diagnosing ASD.

At present, there is no adequate substitute for a detailed developmental history, which includes screening for early features of ASD. The diagnostic value of the developmental history rests on the fact that features of ASD are, by definition, present from the early developmental period. Historically this was specified as before 36 months of age (DSM-IV-TR) (Wiggins et al., 2019); although no strict age cut-off is stipulated in DSM-5, it is acknowledged that features are typically evident within the first years of life (APA, 2022). As this precedes the prodrome of psychotic disorders by several years, documented continuity of social–communicative and restricted/repetitive features from early childhood provides evidence supporting ASD that is not confounded by emerging psychotic illness. For example, if a person consistently demonstrated age-appropriate social communication, flexibility, and imaginative and reciprocal play throughout early childhood, then ASD is unlikely. However, one of the challenges faced by clinicians in obtaining such a history in the context of concerns about a missed diagnosis of ASD beyond adolescence is the availability and reliability of collateral information about the early developmental years.

Where used, structured screening and diagnostic tools should be embedded within a comprehensive clinical assessment and interpreted in context, not as a diagnostic assessment in isolation. These tools complement a comprehensive assessment which includes current symptoms and developmental history, ideally provided by a parent or caregiver who has known the individual from childhood. These assessments should be deferred until the primary psychotic condition has been optimally managed (Treise et al., 2021), which may occur months or years after initial presentation. Determining a ‘missed diagnosis’ of ASD necessitates a focus on pre-morbid functioning and the developmental history, as corroborated by collateral sources (Ferrara et al., 2024). While standardised tools can assist in organising clinical observations, they should complement, rather than replace, longitudinal history-taking, multi-informant data and formulation-based clinical judgement. Guidance from subspecialist services (e.g. child/adolescent psychiatry and intellectual disability services) may be relevant to increasing confidence in the adequacy of the diagnostic assessment.

How should we be assessing for psychosis in people with autism?

People with ASD are at significantly higher risk of psychotic disorders than the general population (Davidson et al., 2014; Sunwoo et al., 2020). While there has been recent calls claiming ‘a priori screening of psychotic risk in neurodiverse populations is fundamental to prevent more serious conditions . . .’ (p. 16) (Mammarella et al., 2024), the implementation of such approaches is currently limited by the absence of validated screening tools for use in ASD populations. For screening to be appropriate, tools with strong validation data supporting its use in children, adolescents and adults diagnosed with ASD are needed.

The complexities of ASD mean that careful assessment is required when diagnosing a first episode of psychosis in this context. Common features of ASD can mimic positive psychotic symptoms, and the core features of ASD can overlap with, and at times resemble, some negative symptoms of psychosis. Individuals with ASD may demonstrate atypical perceptual experiences and idiosyncratic or unusual patterns of thinking, which can be misinterpreted as psychotic symptoms in some contexts (Takara et al., 2015). For example, atypical perceptual and information processing in the auditory, visual and tactile domains may be misinterpreted as perceptual disturbance (Milne et al., 2017). However, for a diagnosis of a psychotic disorder to be made, a comprehensive assessment to establish the presence of delusional thinking and/or hallucinations is needed, and where present, these symptoms must meet disorder-specific duration criteria (APA, 2022). Information from collateral sources will be important in establishing whether there has been a marked decline in functioning following the onset of psychotic symptoms, which is typical in psychotic disorders like schizophrenia. In undertaking these assessments, clinicians lacking familiarity with working with individuals with neurodevelopmental disorders should seek guidance from relevant subspecialist services.

Conclusion

The overlap between ASD and psychotic disorders presents a genuine diagnostic challenge, particularly in early intervention settings. Existing screening and diagnostic tools were not developed to resolve questions of comorbidity. Measures that quantify negative symptoms or autistic traits in isolation cannot establish whether observed features reflect long-standing characteristics or emerging psychotic illness. In the absence of validated instruments for comorbid presentations, structured tools should complement and be interpreted in the context of a comprehensive clinical and developmental assessment.

The risks of misclassification are substantial and bidirectional. Over-diagnosing psychosis in autistic individuals may result in unnecessary pharmacological treatment and reinforce stigma. Conversely, under-recognising psychosis in individuals with ASD may prolong the duration of untreated psychosis, delay access to evidence-based early intervention and contribute to poorer symptomatic and functional outcomes. Failing to identify co-occurring ASD in people with psychotic disorders may limit access to appropriate supports and adjustments. In presentations where autism and psychosis may be co-occurring, diagnostic certainty is rarely achievable in the acute phase. Symptoms may mask or mimic underlying neurodevelopmental characteristics. Diagnostic formulation should therefore remain provisional, and consideration of a missed ASD diagnosis should, where possible, follow stabilisation of psychotic symptoms.

Footnotes

Declaration of conflicting interests

The authors declared the following potential conflicts of interest with respect to the research, authorship and/or publication of this article: S.P. is supported by a Metro North Clinician Research Fellowship (2024-2027) and has received honoraria in the past 5 years from CSL Seqirus, Lundbeck/Otsuka, Johnson & Johnson, RANZCP, Queensland Psychotherapy Training, and Tasmania Health. The employers of JGS (University of Queensland and QIMR Berghofer Medical Research Institute) have received funds to support research from Janssen Cilag, Otsuka and Lundbeck in return for JGS delivering lectures at educational events and participating on advisory boards. S.S. was an author of the ANZJP GRADE Guidelines. All other authors have no additional conflicts of interest to declare. No specific funding was received for this project.

Funding

The authors received no financial support for the research, authorship and/or publication of this article.

ORCID iDs

Kirk Chalmers

Kirsty Laurie

Shuichi Suetani

Catherine Franklin

James G Scott

Stephen Parker

References

Aggarwal

Angus

(2015) Misdiagnosis versus missed diagnosis: Diagnosing autism spectrum disorder in adolescents. Australasian Psychiatry 23: 120–123.

APA (2022) Diagnostic and Statistical Manual of Mental Disorders: DSM-5-TR. Washington, DC: American Psychiatric Association Publishing.

Bakken

Sandberg

Axmon

(2024) Schizophrenia in children, adults and older people with intellectual disability compared with the general population: A Swedish register study (IDcare). General Psychiatry 37: e101673.

Bechi

Agostoni

Buonocore

, et al. (2020) The influence of premorbid adjustment and autistic traits on social cognitive dysfunction in schizophrenia. Journal of the International Neuropsychological Society 26: 276–285.

Bell

Parson

Daneman

, et al. (2025) Psychosis: A link between autism and schizophrenia spectrum disorders. Current Behavioral Neuroscience Reports 12: 11.

Calkova

Vaskinn

Mørch-Johnsen

, et al. (2026) Early versus adult onset of schizophrenia: An examination of premorbid and current IQ. Schizophrenia Research: Cognition 43: 100397.

Carroll

Thom

McDougle

(2025) The differential diagnosis of autism spectrum disorder in adults. Expert Review of Neurotherapeutics 25: 635–648.

Cavallo

Di Caro

Marchese

, et al. (2026) Unraveling the roots of paranoid thinking: The role of childhood maltreatment, failures in mentalizing, and defense mechanisms. Psychoanalytic Psychology 43: 12–22.

Cheang

RTS

Skjevling

Blakemore

AIF

, et al. (2024) Do you feel me? Autism, empathic accuracy and the double empathy problem. Autism 29(9): 2315–2327.

10.

Cheung

Fung

, et al. (2010) Autistic disorders and schizophrenia: Related or remote? An anatomical likelihood estimation. PLoS One 5(8): e12233.

11.

Chisholm

Lin

Abu-Akel

, et al. (2015) The association between autism and schizophrenia spectrum disorders: A review of eight alternate models of co-occurrence. Neuroscience and Biobehavioral Reviews 55: 173–183.

12.

Chisholm

Pelton

Duncan

, et al. (2019) A cross-sectional examination of the clinical significance of autistic traits in individuals experiencing a first episode of psychosis. Psychiatry Research 282: 112623.

13.

Chisholm

Schirmbeck

Pinkham

, et al. (2024) A cross-sectional conceptual replication and longitudinal evaluation of the PANSS-autism-severity-score measure suggests it does not capture autistic traits in individuals with psychosis. Schizophr Bull 51: 186–197.

14.

Cochran

Dvir

Frazier

(2013) ‘Autism-plus’ spectrum disorders: Intersection with psychosis and the schizophrenia spectrum. Child and Adolescent Psychiatric Clinics of North America 22: 609–627.

15.

Cuevas-Esteban

Serrat

Iglesias-Gonzalez

, et al. (2025) Catatonia in first-episode psychosis: Prevalence and psychopathological association. Bjpsych Open 11: e220.

16.

Davidson

Greenwood

Stansfield

, et al. (2014) Prevalence of Asperger syndrome among patients of an Early Intervention in Psychosis team. Early Intervention in Psychiatry 8: 138–146.

17.

De Crescenzo

Postorino

Siracusano

, et al. (2019) Autistic symptoms in schizophrenia spectrum disorders: A systematic review and meta-analysis. Frontiers in Psychiatry 10: 78.

18.

De Rossi

Georgiades

(2022) Thinking biases and their role in persecutory delusions: A systematic review. Early Intervention in Psychiatry 16: 1278–1296.

19.

Diaz-Caneja

Schnack

Martinez

, et al. (2019) Neuroanatomical deficits shared by youth with autism spectrum disorders and psychotic disorders. Human Brain Mapping 40: 1643–1653.

20.

Evans

(2013) How autism became autism: The radical transformation of a central concept of child development in Britain. History of the Human Sciences 26: 3–31.

21.

Ferrara

Curtarello

EMA

Simonelli

, et al. (2024) First-episode psychosis and autism spectrum disorder: A scoping review and a guide to overcome diagnostic challenges. International Journal of Mental Health 53: 4–35.

22.

Frigaux

Evrard

Lighezzolo-Alnot

(2019) ADI-R and ADOS and the differential diagnosis of autism spectrum disorders: Interests, limits and openings. Encephale 45: 441–448.

23.

Fusar-Poli

Bisso

Concas

, et al. (2020) Psychometric properties of the Autism Spectrum Disorder in Adults Screening Questionnaire (ASDASQ) in a sample of Italian psychiatric outpatients. Research in Autism Spectrum Disorders 78: 101668.

24.

Fusar-Poli

Brondino

Politi

, et al. (2022) Missed diagnoses and misdiagnoses of adults with autism spectrum disorder. European Archives of Psychiatry and Clinical Neuroscience 272: 187–198.

25.

Geck

Roithmeier

Bühner

, et al. (2025) COSMIN systematic review and meta-analysis of the measurement properties of the Positive and Negative Syndrome Scale (PANSS). eClinicalMedicine 82: 103155.

26.

Guerrera

Pontillo

Chieppa

, et al. (2024) Autism Spectrum Disorder and Early Psychosis: A narrative review from a neurodevelopmental perspective. Frontiers in Psychiatry 15: 1362511.

27.

Harris

(2023) Autism prevalence has been on the rise in the US for decades-and that’s progress. JAMA 329: 1724–1726.

28.

Jeong

Kim

, et al. (2024) Clinical, cognitive, and functional characteristics of recent-onset psychosis with autistic features: A 2-year longitudinal study. Schizophrenia Research 270: 304–316.

29.

Kastner

Begemann

Michel

, et al. (2015) Autism beyond diagnostic categories: Characterization of autistic phenotypes in schizophrenia. BMC Psychiatry 15: 115.

30.

Kentrou

Livingston

Grove

, et al. (2024) Perceived misdiagnosis of psychiatric conditions in autistic adults. eClinicalMedicine 71: 102586.

31.

Kincaid

Doris

Shannon

, et al. (2017) What is the prevalence of autism spectrum disorder and ASD traits in psychosis? A systematic review. Psychiatry Research 250: 99–105.

32.

Kyriakopoulos

Stringaris

Manolesou

, et al. (2015) Determination of psychosis-related clinical profiles in children with autism spectrum disorders using latent class analysis. European Child & Adolescent Psychiatry 24: 301–307.

33.

Larson

Wagner

Jones

, et al. (2017) Psychosis in autism: Comparison of the features of both conditions in a dually affected cohort. The British Journal of Psychiatry 210: 269–275.

34.

Lau

DTY

Chan

MMY

FYM

, et al. (2026) Cognitive profiles in adolescents and young adults with co-occurring autism and first-episode psychosis: A preliminary neuropsychological investigation. Psych Journal 15: e70073.

35.

Maddox

(2020) The accuracy of the ADOS-2 in identifying autism among adults with complex psychiatric conditions. In: Volkmar

(ed.) Encyclopedia of Autism Spectrum Disorders. New York: Springer, pp. 1–2.

36.

Maenner

(2023) Prevalence and characteristics of autism spectrum disorder among children aged 8 years – Autism and Developmental Disabilities Monitoring Network, 11 sites, United States, 2020. MMWR. Surveillance Summaries 72: 1–14.

37.

Maltman

DaWalt

Hong

, et al. (2021) Brief report: Socioeconomic factors associated with minimally verbal status in individuals with ASD. Journal of Autism and Developmental Disorders 51: 2139–2145.

38.

Mammarella

Monducci

Maffucci

, et al. (2024) Assessment of psychotic risk in a sample of children and adolescents with autism spectrum disorder compared to a group of ‘Clinical high risk’ patients: A preliminary study. Children 11: 372.

39.

Marder

Umbricht

(2023) Negative symptoms in schizophrenia: Newly emerging measurements, pathways, and treatments. Schizophrenia Research 258: 71–77.

40.

Michel

Kindler

Kaess

(2022) Traumatic experiences in childhood and the development of psychosis spectrum disorders. European Child & Adolescent Psychiatry 31: 211–213.

41.

Milne

Dickinson

Smith

(2017) Adults with autism spectrum conditions experience increased levels of anomalous perception. Plos One 12: e0177804.

42.

Mosolov

Yaltonskaya

(2021) Primary and secondary negative symptoms in schizophrenia. Frontiers in Psychiatry 12: 766692.

43.

Murphy

Wilson

Robertson

, et al. (2016) Autism spectrum disorder in adults: Diagnosis, management, and health services development. Neuropsychiatric Disease and Treatment 12: 1669–1686.

44.

Nakamura

Hanawa

Seki

, et al. (2024) Predictive model using autism diagnostic observation schedule, second edition for differential diagnosis between schizophrenia and autism spectrum disorder. Frontiers in Psychiatry 15: 1493158.

45.

Nibbio

Barlati

Calzavara-Pinton

, et al. (2022) Assessment and correlates of autistic symptoms in Schizophrenia Spectrum Disorders measured with the PANSS Autism Severity Score: A systematic review. Frontiers in Psychiatry 13: 934005.

46.

Ozbek

Sut

Bora

(2023) Comparison of social cognition and neurocognition in schizophrenia and autism spectrum disorder: A systematic review and meta-analysis. Neuroscience and Biobehavioral Reviews 155: 105441.

47.

Park

MTM

Raznahan

Shaw

, et al. (2018) Neuroanatomical phenotypes in mental illness: Identifying convergent and divergent cortical phenotypes across autism, ADHD and schizophrenia. Journal of Psychiatry & Neuroscience 43: 201–212.

48.

Pelizza

Federico

Leuci

, et al. (2026) What does the PANSS Autism Severity Score (PAUSS) really measure in patients with first episode psychosis? Critical considerations. Journal of Autism and Developmental Disorders. Epub ahead of print 10 January. DOI: 10.1007/s10803-025-07197-w.

49.

Punsoda-Puche

Barajas

Mamano-Grande

, et al. (2024) Relationship between social cognition and premorbid adjustment in psychosis: A systematic review. Schizophrenia (Heidelb) 10: 36.

50.

Ribolsi

Fiori Nastro

Pelle

, et al. (2022) Recognizing psychosis in autism spectrum disorder. Frontiers in Psychiatry 13: 768586.

51.

Russell

McFayden

McAllister

, et al. (2025) Who, when, where, and why: A systematic review of ‘late diagnosis’ in autism. Autism Research 18: 22–36.

52.

Russell

Stapley

Newlove-Delgado

, et al. (2022) Time trends in autism diagnosis over 20 years: A UK population-based cohort study. Journal of Child Psychology and Psychiatry, and Allied Disciplines 63: 674–682.

53.

Solmi

Pigato

Roiter

, et al. (2018) Prevalence of catatonia and its moderators in clinical samples: Results from a meta-analysis and meta-regression analysis. Schizophr Bull 44: 1133–1150.

54.

Song

Yao

Kowalec

, et al. (2022) The impact of educational attainment, intelligence and intellectual disability on schizophrenia: A Swedish population-based register and genetic study. Molecular Psychiatry 27: 2439–2447.

55.

Suetani

Dark

Every-Palmer

, et al. (2026) Australian and New Zealand Journal of Psychiatry Grading of Recommendations, Assessment, Development and Evaluations (GRADE) guidelines for the management of schizophrenia. Australian and New Zealand Journal of Psychiatry 60: 367–404.

56.

Sunwoo

O’Connell

Brown

, et al. (2020) Prevalence and outcomes of young people with concurrent autism spectrum disorder and first episode of psychosis. Schizophrenia Research 216: 310–315.

57.

Takara

Kondo

Kuba

(2015) How and why is autism spectrum disorder misdiagnosed in adult patients? From diagnostic problem to management for adjustment. Mental Health in Family Medicine 11: 73–88.

58.

Tantam

Girgis

(2009) Recognition and treatment of Asperger syndrome in the community. British Medical Bulletin 89: 41–62.

59.

Treise

Simmons

Marshall

, et al. (2021) Autism spectrum disorder in early intervention in psychosis services: Implementation and findings of a 3-step screening and diagnostic protocol. Journal of Psychiatric Practice 27: 23–32.

60.

Trevisan

Foss-Feig

Naples

, et al. (2020) Autism spectrum disorder and schizophrenia are better differentiated by positive symptoms than negative symptoms. Frontiers in Psychiatry 11: 548.

61.

Van Schalkwyk

Peluso

Qayyum

, et al. (2015) Varieties of misdiagnosis in ASD: An illustrative case series. Journal of Autism and Developmental Disorders 45: 911–918.

62.

Vivanti

Lombardo

Zitter

, et al. (2025) Proportion and profile of autistic children not acquiring spoken language despite receiving evidence-based early interventions. Journal of Clinical Child & Adolescent Psychology. Epub ahead of print 20 November. DOI: 10.1080/15374416.2025.2579286.

63.

Wiggins

Rice

Barger

, et al. (2019) DSM-5 criteria for autism spectrum disorder maximizes diagnostic sensitivity and specificity in preschool children. Social Psychiatry and Psychiatric Epidemiology 54: 693–701.

64.

Yurumez

Temelturk

Kaymak

, et al. (2024) Catatonia in autism spectrum disorders: Prevalence, functional impact, and diagnostic insights. Psychiatry Research 342: 116250.

65.

Zheng

Chua

Tang

, et al. (2021) Autistic traits in first-episode psychosis: Rates and association with 1-year recovery outcomes. Early Intervention in Psychiatry 15: 849–855.

66.

Zheng

Zou

(2018) Association between schizophrenia and autism spectrum disorder: A systematic review and meta-analysis. Autism Research 11: 1110–1119.