Antipsychotic-induced body weight gain: Predictors and a systematic categorization of the long-term weight course

Abstract

Objective To explore the impact of premorbid and baseline body mass indices (BMIs) as well as BMI of patient’s parents and associated variables on the prediction of antipsychotic-induced body weight gain. Methods Retrospective/cross-sectional data of 65 patients receiving clozapine, olanzapine and/or risperidone were assessed according to a systematic categorization of the long-term (7.3 ± 9.2 years) weight course and evaluated using descriptive, explorative correlation and regression analyses. Results Increased values of parents’ BMI ( p = 0.041) and patients’ BMI at premorbid stage ( p = 0.039) and prior to first antipsychotic treatment ( p = 0.032) as well as female gender ( p = 0.012), younger age ( p = 0.005) and non-smoking ( p = 0.047) have the most predictive value on body weight gain under antipsychotic treatment including pre-treatment with typical antipsychotics. Weight gain under atypical antipsychotics (pre-treatment excluded) is predicted by an increased premorbid BMI ( p = 0.019). Conversely, a low BMI prior to first antipsychotic treatment predicts a higher acceleration of BMI change ( p = 0.008) in vulnerable individuals, but not total BMI change itself. Furthermore, a diagnosis of a schizophrenia spectrum disorder showed a trend towards the prediction of an increased atypical ΔBMI ( p = 0.067), possibly due to a longer treatment duration with atypical antipsychotics ( p < 0.001). Discussion The study indicates increased parents’ BMI and patients’ premorbid BMI, female gender, younger age and – as a trend – the diagnosis of a schizophrenia spectrum disorder to be predictors for antipsychotic-induced body weight gain involving atypical antipsychotics. Data contribute to the assumption of a strong impact of predispositional factors on weight gain, besides treatment-related factors.