A 3-year retrospective cohort study of predictors of relapse in first-episode psychosis in Hong Kong

Objective: Relapses in psychosis are costly and may have irreversible consequences. Relapse prevention is thus critical in the treatment of schizophrenia. Apart from medication discontinuation, a consistent relapse predictor has not been identified due to limitations in previous studies. We aim to investigate relapse predictors in a large cohort of patients with first-episode psychosis. Method: This is a retrospective cohort study designed to evaluate relapses in first-episode psychosis patients in 3 years. A total of 1400 patients' case records were retrieved from a hospital database. Potential relapse predictors including demographic variables, baseline clinical measures, medication adherence, and residual positive symptoms upon clinical stabilization were collected. Results: The cumulative relapse rates were 19.3% by year 1, 38.4% by year 2, and 48.1% by year 3. Multivariate Cox-proportional hazards regression analysis revealed that medication non-adherence, smoking, schizophrenia diagnosis, younger age, and shorter baseline hospitalization were associated with an increased risk of relapse in 3 years. Conclusions: Nearly half of patients relapsed after 3 years following their first-episode psychosis. Smoking as a predictor of relapse is an intriguing new finding supportive of a link between nicotinic receptors and the dopamine system. Their relationship deserves further investigations with potential clinical implications for relapse prevention.