Autism spectrum disorder and psychosis: symptomatic overlap and diagnostic pitfalls in early intervention services

Background

The diagnostic boundary between autism spectrum disorder (ASD) and psychosis remains a clinically consequential and insufficiently resolved challenge in contemporary psychiatry. Both conditions share overlapping features across social cognition, communication, and behavioral domains, complicating early detection, risk stratification, and diagnostic accuracy [1,2]. Accumulating evidence suggests a substantial and clinically meaningful overlap between ASD and psychosis in early clinical presentations. In early intervention services for first-episode psychosis (FEP), ASD-related traits are frequently misinterpreted as negative symptoms or formal thought disorder. Conversely, emerging psychotic symptoms in individuals with ASD may be under-recognized or attributed to baseline neurodevelopmental characteristics. This bidirectional diagnostic uncertainty has direct implications for treatment selection, clinical trajectories, and long-term functional outcomes.

Objectives

To examine the symptomatic overlap between ASD and psychotic disorders, identify key diagnostic pitfalls in early intervention settings, and discuss implications for early detection and precision-oriented clinical care.

Methods

A narrative review of the literature was conducted, focusing on clinical phenomenology, developmental trajectories, and factors associated with diagnostic differentiation between ASD and early psychosis. Particular attention was given to studies addressing transition risk, functional outcomes, and challenges encountered in real-world early intervention services.

Results

ASD and psychosis demonstrate partial phenotypic overlap, particularly in domains of social withdrawal, pragmatic language abnormalities, and atypical behavioral patterns [1,3]. However, these similarities reflect distinct underlying mechanisms. ASD is characterized by early-onset and persistent neurodevelopmental alterations, whereas psychotic disorders typically involve a decline from premorbid functioning and the emergence of positive symptoms with impaired reality testing [4]. Epidemiological studies consistently indicate an increased risk of psychotic disorders among individuals with ASD [2,5], further complicating diagnostic boundaries in clinical practice. Inadequate assessment of developmental history contributes to frequent misclassification of autistic traits as psychotic phenomena. Literal thinking, idiosyncratic but non-delusional beliefs, and difficulties in social inference may be incorrectly labeled as paranoia or thought disorder. Conversely, early psychotic symptoms in ASD may be overlooked or minimized, delaying appropriate intervention. Current categorical diagnostic systems have been consistently associated with reduced diagnostic precision at the interface between neurodevelopmental and psychotic disorders. Time constraints and structural pressures in early intervention services further increase the risk of both overdiagnosis and underdiagnosis. These findings collectively underscore the need for structured, developmentally informed, and longitudinal assessment strategies.

Conclusions

The interface between ASD and psychosis represents a critical challenge for early intervention psychiatry, with significant implications for diagnostic precision and treatment outcomes. A longitudinal, developmentally informed, and phenomenologically grounded assessment framework is essential to improve diagnostic accuracy and guide individualized care. Moving toward dimensional approaches may enhance clinical decision-making and support more effective risk stratification. Strengthening clinician expertise in neurodevelopmental disorders within early psychosis services is crucial to optimize early detection, reduce diagnostic error, and improve outcomes in this complex clinical population. Bridging neurodevelopmental and psychotic phenotypes is key to improving stratification and precision in early psychiatric care.

References

1. Rapoport J, Chavez A, Greenstein D, Addington A, Gogtay N. Autism spectrum disorders and childhood-onset schizophrenia: clinical and biological contributions to a relationship revisited. J Am Acad Child Adolesc Psychiatry. 2009.
2. Hollander E, Kolevzon A, Coyle JT. Autism spectrum disorder and psychosis: shared neurobiology and clinical overlap. Harv Rev Psychiatry. 2020.
3. Varcin KJ, Jeste SS. The emergence of autism spectrum disorder and psychosis: shared pathways and distinguishing features. JAMA Psychiatry. 2017.
4. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 5th ed., Text Revision (DSM-5-TR). 2022.
5. Fusar-Poli P, Borgwardt S, Bechdolf A, et al. The psychosis high-risk state: a comprehensive review. JAMA Psychiatry. 2013.