The Effects of Topiramate on Weight Gain in Patients with Schizophrenia: A Double-Blind Randomized Placebo-Controlled Clinical Trial

BACKGROUND: Weight gain among patients with schizophrenia is challenging. To evaluate the effects of topiramate on treatment of schizophrenia and weight gain management. METHODS: For this double-blind randomized placebo-controlled clinical trial; 59 patients at Arak University Hospital were recruited. In the control group (n=29) atypical antipsychotic agent equivalent to 20 mg of olanzapine was given while the intervention group (n=30) was treated with atypical antipsychotic equivalent to 20 mg of olanzapine and topiramate at dose of up to 200 mg for 12 weeks. The Positive And Negative Syndrome Scale (PANSS) and Body Mass Index (BMI) of patients were measured at baseline and during the study. RESULTS: 59 patients, 31 males (52.5%) and 28 females (47.5%) with mean age of 29.9 +/- 7.67 years (ranged 16.7-47.3 years) were randomized. In the two groups, total PANSS significantly decreased after 12week therapy (P=0.001). BMI in the control group decreased by only 0.25% from baseline to week 12 and was not significant (p=0.69). In topiramate group, the reduction of BMI from baseline to week 12 was 8.3% and was statistically significant (26.67 +/- 3.51 to 24.47 +/- 3.55, P=0.001). The difference between the treatment and control groups regarding BMI in weeks 8 and 12 and PANSS in weeks 4, 8 and 12 was significant (P<0.05). CONCLUSION: Our results indicated that topiramate at a dose of 200 mg/day is a safe agent and induces weight loss and significantly decreases PANSS score in patients with schizophrenia.