Response trajectories in "real-world" naturalistically treated schizophrenia patients.

Background: To date, research has identified distinct antipsychotic response trajectories yet focussing on data from randomized-controlled trials (RCTs). Therefore, the heterogeneity of response in "real-world" schizophrenia patients is still unknown. Methods: Antipsychotic response was evaluated in 399 patients suffering from a schizophrenia spectrum disorder within a naturalistic multicenter study of the Competence Network on Schizophrenia using latent class regression. Baseline and illness-related variables were compared between the different trajectory classes as well as currently proposed outcome definitions (early improvement, response, remission) using univariate tests. In order to predict the trajectory group membership classification and regression tree analysis were furthermore performed. Results: Five distinct trajectories of antipsychotic response were identified: Class 1 (15%) showing an early and considerable improvement, Class 2 (14%) incorporating patients with the greatest response to treatment, Class 3 (34%) again showing an early improvement to treatment yet with a slightly lower degree of improvement, Class 4 (22%) featuring patients gradually responding to treatment, and Class 5 (15%) with the poorest antipsychotic response. Fewer depressive symptoms at admission, better functioning, a shorter duration of illness and less previous hospitalizations were found to be significant predictors of good response. No considerable differences were found comparing the present results to the previous trajectory analyses deriving from RCTs. Conclusion: Our results underline the heterogeneous course of response independent of the study or treatment design suggesting that the diversity in schizophrenia response and outcome is determined primarily by different pathophysiological underpinnings. (C) 2012 Elsevier B.V. All rights reserved.