Randomised, placebo-controlled trial on topiramate add-on therapy for weight reduction and symptomatology in overweight/obese persons with schizophrenia.

INTRODUCTION: Higher cardiovascular mortality is seen with schizophrenia due to the disorder itself and antipsychotic use. South Asians are more vulnerable to developing metabolic disorders than others. Resource-limited settings in South Asia have only a few mental health professionals, and individualised case management is mostly unavailable. Therefore, there is less monitoring and personalised support for diet and physical exercise programmes. Topiramate is useful for weight reduction and improvement of psychopathology in schizophrenia. However, there has been only one previous randomised controlled trial (RCT) done in South Asia, which possesses a quarter of the world's population.

METHODS: We conducted a double-blind RCT in an outpatient setting in Sri Lanka. We compared topiramate 100 mg/day with a placebo in overweight/obese adults with schizophrenia who have been on antipsychotics for at least a year. We obtained monthly anthropometric measurements and assessed the symptomatology using the brief psychiatric rating scale (BPRS).

RESULTS: Fifty patients each in the topiramate and placebo arms completed the study. Topiramate add-on therapy led to significant weight/Body Mass Index reduction and improved symptomatology as measured by the BPRS compared to the placebo. The topiramate group had significantly more reporting of loss of appetite.

DISCUSSION: According to available data, this is the RCT with most participants assessing the use of topiramate in schizophrenia and only the second in South Asia. Topiramate was shown to be useful for weight reduction and symptomatic improvement in persons with schizophrenia in a resource-limited setting in South Asia.