The aim of the present study was to explore any heterogeneity in the 6-month clinical response in antipsychotic drug-naive schizophrenia patients, and to determine predictors of that outcome.

467 antipsychotic drug-naive schizophrenia patients were included in France nationwide and followed up over 6 months. In order to identify trajectories of clinical response, a latent class growth analysis was performed using the Clinical Global Impression-Severity (CGI-S) scores at baseline, 1, 3 and 6 months. Regression models were used to identify predictors of trajectory membership.

Five trajectory groups were identified: a rapid response group (n=45), a gradual response group (n=204), patients remaining mildly ill (n=133), patients remaining very ill (n=23) and a group with unsustained clinical response (n=62). Predictors of the 6-month clinical response were baseline CGI-S score (odds ratio 3.1; 95% confidence interval, 2.1-4.4) and negative symptoms (OR 1.5; 95%CI, 1.2-1.9). The sole predictor of rapid response as compared to gradual response was employment (OR 2.5; 95%CI, 1.2-4.9).

Clinical response in schizophrenia patients 6 months after a first-ever antipsychotic drug initiation is heterogeneous. Therapeutic strategies in first episode should take account of symptoms severity and of early clinical response, in order to maximize the chances of recovery.