Subgroups of Clinical High Risk for Psychosis Based on Baseline Antipsychotic Exposure: Clinical and Outcome Comparisons Across a 2-Year Follow-up Period

Background and Hypothesis: Antipsychotic (AP) prescription in clinical high risk for psychosis (CHR-P) subjects remains a divisive issue. Although official guidelines currently discourage AP treatment in CHR-P, it is common in clinical practice, especially for psychosis prevention. The aim of this study was to investigate whether baseline AP need (especially in high-dose) indexes a CHR-P subgroup with poorer prognosis and differs from AP-naïve subjects in terms of sociodemographic, clinical, and outcome parameters across a 2-year follow-up. Study Design: CHR-P participants were treated within an “Early Intervention in Psychosis” program and completed the Positive and Negative Syndrome Scale (PANSS) and the Global Assessment of Functioning (GAF) scale both at baseline and every 12 months. Individuals with baseline AP prescription were included in the high-dose or low-dose CHR-P-AP+ subgroup. The others were grouped as AP-naïve. Cox regression analyses and mixed-design ANOVA were performed. Study Results: 180 CHR-P individuals were enrolled (32 high-dose, 60 low-dose, and 88 AP-naïve). Compared to AP-naive, CHR-P AP+ subgroups showed older age and more severe clinical presentation. High-dose subgroup also had grater functioning decline at entry and poorer functional recovery at follow-up. No inter-group differences in psychosis transition and symptomatic remission were found. Significant improvement in clinical outcomes were found over time in all subgroups. Baseline AP prescription was specifically associated with a more relevant improvement in PANSS total score, and in negative and disorganized symptoms. Conclusions: Our results suggest that baseline AP need is an important prognostic parameter in CHR-P and should be considered in risk/benefit calculators.