Association between the exposome score for schizophrenia and functioning in remitted first-episode psychosis: results...

Environmental risk factors contribute to functional impairment, which can persist even after symptomatic remission of a first episode of psychosis (FEP). To quantify this effect, we calculated the association between exposome score for schizophrenia (ES-SCZ), a cumulative environmental liability score, and functioning in remitted FEP patients.

Data of 286 participants were derived from the HAMLETT study. General functioning was assessed using the Global Assessment of Functioning (GAF) scale at baseline, when participants were in remission for 3-6 months. ES-SCZ was calculated based on previously validated estimates and included childhood adversity domains (emotional and physical neglect; emotional, physical and sexual abuse; and bullying), cannabis use, hearing impairment, and winter birth. The association between ES-SCZ and GAF was evaluated in three multiple linear regression models, with each successive model including additional covariates.

ES-SCZ was negatively associated with the GAF score, even after accounting for age, sex at birth, education, migrant status, antipsychotic type, and FEP duration [B = -1.51 (-2.78 to -0.24), p = .022]. This final model explained 8.6 % of the variance (R²) in the GAF score, with ES-SCZ being the primary contributor, accounting for 35.5 % of this explained variance.

This study independently replicated the finding that ES-SCZ predicts general functioning in FEP, showing its potential for forecasting functioning in remitted FEP patients.