Effectiveness of antipsychotics in schizophrenia and related disorders. Results of a naturalistic study

Introduction. The present study aims to evaluate effectiveness of antipsychotics in a cohort of chronic outpatients affected by schizophrenia and related disorders. Materials and Methods. Three hundred chronic patients affected by schizophrenia (n=173), schizoaffective (n=117) and delusional (n=60) disorder who were in treament with antipsychotics on 1.3.2008 were considered in the study; effectiveness of antipsychotic treatment was evaluated by means of rates of all cause discontinuation in a 12 months period (31.3.2008 - 31.3.2009) and of "overall duration of treatment" (DT) (duration of treatment retrospectively evaluated on the basis of clinical records+duration of treatment prospectively evaluated during the 12-months follow up). Results. Discontinuation of treatment was registered in 25% of patients (29% due to side effects, 14% due to scarce adherence, 11% due to lack of efficacy, 22% due to more causes). Clozapine (7%), Risperidon Long-acting (10%), Typical Antipsychotics depot (11%) and Olanzapine were associated to lower rates of all causes discontinuation. Overall mean duration of antipsychotic treatment was 18 32 months, with statistically significant differences between drugs (F=4.65, p=0.000). Clozapine (65 mo), Olanzapine (50 mo), buthyrrophenons (49 mo), typical antipsychotics depot (48 mo), and risperidone (47.5 mo) were the antipsychotics with a longer duration of treatment. Only Clozapine showed a significantly longer DT than any other antipsychotic medication excluding buthyrrohenones. Conclusions. Rates of all cause discontinuation of antipsychotics appear to be somewhat lower than expected on the basis of pragmatic studied published in the last years; similarly overall duration of treatment seems to be longer. Clozapine is associated to a higher overall effectiveness respect to any other atypical antipsychotic. Clin Ter 2011; 162(4):331-341