Environmental risk score as a predictor for 25-year symptom and functional trajectories in first episode psychosis.

Background and Hypothesis: Environmental exposures linked to schizophrenia may play a role in shaping long-term clinical outcomes among individuals with psychotic disorders. This study examined whether the Maudsley Environmental Risk Score (ERS), a cumulative measure of five established environmental risk factors, predicts trajectories of symptoms, cognition, and psychosocial functioning over 25 years following first hospitalization for psychosis. Study Design: Participants were drawn from the Suffolk County Mental Health Project, a longitudinal cohort of individuals with first-admission psychosis assessed six times over two decades. A total of 516 participants had sufficient ERS data and repeated assessments of symptoms (SAPS, SANS), cognitive ability, and functioning (GAF). Study Results: Linear mixed-effects models showed that higher ERS was significantly associated with lower global functioning (β = -0.104, p = 0.008), an effect that remained consistent over time. ERS also predicted more severe and worsening reality distortion (β = 0.082, p = 0.023 for intercept; β = 0.005, p = 0.032 for slope of time). No significant associations were observed between ERS and cognitive ability, disorganization, or negative symptoms. Conclusions: These findings highlight the contribution of environmental risk to functional impairment and persistent positive symptoms across the course of psychotic illness. Incorporating ERS into clinical risk models may aid the identification of individuals likely to experience a more severe illness trajectory, and inform long-term treatment planning.