Do patients with paranoid and disorganized schizophrenia respond differently to antipsychotic drugs?

Abstract

The aim of this study was to compare the differential response to amisulpride in patients with paranoid versus disorganized schizophrenia. We reanalyzed the original data from five different randomized drug trials comparing Brief Psychiatric Rating Scale (BPRS) scores in a database containing 427 paranoid and 296 disorganized patients with schizophrenia. Both the disorganized and the paranoid group showed a substantial improvement of the BPRS total score within the first 4 weeks. In the paranoid group, mean (±SD) BPRS reduction was 16.9 (±14.6) (t = 24.06, df = 426, P < 0.001) and in the disorganized group 17.0 (±15.9) (t = 18.49, df = 295, P < 0.001). An analysis of covariance (ancova) controlling for BPRS at baseline and the influence of different trial protocols showed significant differences between diagnostic groups (F = 13.47, df = 1, P < 0.001), Cohen's D 0.31 (CI = 0.16-0.46). Paranoid patients improved by 4.8 BPRS points more than disorganized patients (adjusted means 18.90 (CI = 17.33-20.37) for the paranoid and 14.1 (CI = 12.04 - 16.11) for the disorganized group. We conclude that amisulpride is effective in disorganized as well as in paranoid schizophrenia, but that symptom reduction in the disorganized subtype is less pronounced.