Late Recognition of Autism Previously Diagnosed as Schizophrenia Following a Brief Psychotic Episode: A Case Report.

Autism is a neurodevelopmental condition characterized by differences in social communication and patterns of behavior, interests, or activities. Many individuals remain unrecognized until adulthood or later life, particularly those who develop adaptive strategies that allow them to navigate social and environmental demands. This may complicate clinical interpretation when psychiatric symptoms arise. We present the case of a 74-year-old individual whose first contact with mental health services occurred at age 23 following a brief psychotic episode, leading to a long-standing diagnosis within the schizophrenia spectrum. Over subsequent decades, there was no recurrence of psychotic experiences or evidence of progressive functional decline. A later longitudinal reassessment, informed by developmental history, collateral information, and standardized instruments, identified a pattern of traits consistent with previously unrecognized autism. Antipsychotic medication was gradually discontinued without adverse clinical outcomes. This case highlights the importance of integrating developmental trajectories and longitudinal course into psychiatric evaluation, particularly in individuals with well-established adaptive functioning. It also illustrates how enduring neurodevelopmental differences may be misinterpreted as chronic psychiatric conditions when assessment relies predominantly on cross-sectional symptomatology.