Abstract
OBJECTIVE: The overlap versus independence of autism spectrum disorder (ASD) and schizophrenia is a topic that has garnered the attention of generations of clinicians and scientists. Although high rates of psychotic symptoms have been identified in individuals with ASD, the nature, prevalence, and prognostic significance of subclinical psychotic experiences in ASD remain poorly understood. METHOD: This study sought to compare baseline characteristics, clinical profiles, and conversion outcomes between young individuals at clinical high risk for psychosis (CHR) who presented with or without a prior ASD diagnosis during the second phase of the North American Prodrome Longitudinal Study (NAPLS, N = 764). RESULTS: Patients with CHR and ASD (CHR/ASD+, n = 26) tended to exhibit greater social and social cognitive difficulties, but expressed relatively levels of core psychosis symptoms similar to those of to patients with CHR but no ASD (CHR/ASD-). Risk for conversion to co-occurring psychosis (18.2% CHR/ASD+ versus 16.8% CHR/ASD-) was equivalent between CHR/ASD+ and CHR/ASD- groups, and the NAPLS2 Psychosis Risk Calculator predicted conversion to psychosis equally well across groups. CONCLUSION: These results suggest that baseline psychosis symptoms, predictors of risk for conversion, and ultimate conversion rates are similar in patients with CHR with and without ASD. They further suggest that ASD must not be considered a mutually exclusive diagnosis when such youth present in CHR settings. Future research is needed to better track trajectories in larger cohorts of individuals with CHR and comorbid ASD and to understand whether treatment recommendations effective in the broader CHR population are useful for this particular population as well.