Psychotropic drug-induced weight gain and other metabolic complications in a Swiss psychiatric population.

Purpose: To describe the weight gain-related side-effects of psychotropic drugs and their consequences on metabolic complications (hypercholesterolemia, obesity) in a Swiss cohort of psychiatric patients.

Method: This cross-sectional observational study was performed in an out-patient psychiatric division with patients having received for more than 3 months the following drugs: clozapine, olanzapine, quetiapine, risperidone, lithium, and/or valproate. Clinical measures and lifestyle information (smoking behaviour, physical activity) were recorded.

Results: 196 inclusions were completed. Weight gain (≥10% of initial weight) following drug treatment was reported in 47% of these patients. Prevalence of obesity (BMI ≥ 30), hypercholesterolemia (≥6.2 mmol/L) and low HDL-cholesterol (<1.0 mmol/L in men, <1.3 mmol/L in women) were present in 38%, 21%, and 27% of patients, respectively. A higher standardised dose, an increase of appetite following medication introduction, the type of medication (clozapine or olanzapine > quetiapine or risperidone > lithium or valproate), and the gender were shown to be significantly associated with evolution of BMI.

Conclusion: High prevalence of obesity and hypercholesterolemia was found in an out-patient psychiatric population and confirms drug-induced weight gain complications during long-term treatment. The results support the recently published recommendations of monitoring of metabolic side-effects during treatment with atypical antipsychotics. Moreover, the weight gain predictors found in the present study could help to highlight patients with special health care management requirement.