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), butyrophenones (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.