Abstract
Schizophrenia and autism share neurobiological mechanisms and overlapping clinical features, often resulting in the emergence of autistic traits in early stages of psychosis. The PANSS Autism Severity Score (PAUSS) provides a rapid measure of autistic features within the standard PANSS assessment. We aimed to determine the prevalence of autistic features in first-episode psychosis (FEP), characterise their clinical, cognitive, and functional profile, and examine their impact on 2-year outcomes.A total of 328 FEP patients were included from the PEPs multicentre cohort, followed for 2 years. Autistic features were rated using PAUSS (cut-off ≥ 30), yielding autistic (n = 38) and non-autistic (n = 290) groups. Sociodemographic, clinical, cognitive, and functional variables were analysed. Longitudinal analyses examined symptomatic remission rates and trajectories of psychopathology and functioning using logistic regression and mixed-model ANOVA.The autistic group represented 11.6% of the sample. At baseline, they exhibited lower birth weight, greater medication side effects, higher general psychopathology and depressive severity, and poorer global functioning. Cognitively, they showed significant deficits in working memory, social cognition, and cognitive reserve compared to the non-autistic group. Over 2 years, this group was 3.6 times less likely to achieve symptomatic remission and consistently exhibited higher symptom severity and lower functioning across all follow-ups.Autistic features in FEP identify a subgroup with a possible distinct profile of neurodevelopmental markers, greater cognitive and functional impairments, and poorer clinical outcomes. Early identification may guide more personalised interventions, although further research is needed to refine PAUSS specificity and develop targeted, tailored treatments.