Impact of switching or initiating antipsychotic treatment on body weight during a 6-month follow-up in a cohort of patients with schizophrenia.

OBJECTIVE: Although weight gain is one of the most widely studied adverse effects of second-generation antipsychotics, only relatively few studies have specifically evaluated the long-term effect of switching antipsychotic medication on body weight. We aimed to evaluate the impact of switching antipsychotics on body mass index (BMI) during a 6-month follow-up period in a large cohort of patients with schizophrenia. METHOD: Data came from a 6-month prospective naturalistic survey in 6007 patients with schizophrenia. RESULTS: We prospectively studied the effect on BMI of initiating or switching antipsychotic medication after 6 months of treatment among 3801 patients with schizophrenia in a real-life setting. Patients who were being treated with clozapine or olanzapine at baseline were more likely to experience a decrease in BMI during the follow-up period than the patients who were being treated with a conventional antipsychotic (odds ratio, 2.25 and 1.68, respectively). Patients treated with aripiprazole and, to a lesser extent, those treated with risperidone were more likely to experience a decrease in BMI during follow-up than patients treated with conventional antipsychotics (odds ratio, 2.96 and 2.06, respectively). CONCLUSIONS: Our findings suggest that switching antipsychotics could be an effective strategy for reducing or preventing weight gain.