Autism characteristics in young patients with first episode of schizophrenia spectrum disorder: findings from a 2-year longitudinal research

Purpose: The PANSS Autism Severity Score (PAUSS) is a recent popular measure of autistic characteristics in Schizophrenia Spectrum Disorders (SSD). Evidence on its factor structure, longitudinal course, and treatment response is poor. The main aims of this investigation were: to examine its internal consistency and factor configuration in young patients with first-episode SSD treated in an Early Intervention (EI) service, and to compare clinical outcomes between SSD individuals with or without “autistic features” across 2 years of follow-up, as well as their treatment response. Methods: SSD participants completed the Positive And Negative Syndrome Scale (PANSS), the Global Assessment of Functioning (GAF), and the Health of the Nation Outcome Scale (HoNOS) across the follow-up. Statistical tests included the α statistic, Exploratory Factor Analysis, Kaplan-Meyer survival analysis, mixed-design ANOVA, and multiple linear regression analysis. Results: 170 SSD individuals were enrolled (58 [34.1 %] scoring above the PAUSS cut-off [PAUSS+]). Internal consistency of the PAUSS was acceptable (α = .792). EFA identified a 3-factor model. At baseline, PAUSS + individuals showed greater severity in psychopathology and social decline. Across the follow-up, PAUSS + individuals had lower incidence rates of symptomatic remission. No PAUSS long-term stability was found, but a significant reduction that was predicted by lower antipsychotic dosage and higher number of case management sessions offered along the follow-up. Conclusions: The PAUSS seems to capture a SSD subgroup characterized by higher baseline severity levels in psychopathology and poorer outcomes.