Weight change from 3-year observational data: findings from the worldwide schizophrenia outpatient health outcomes...

Weight change data from randomized clinical trials are often of limited duration and trials do not always report a full range of clinically relevant categorical end points.

We conducted a post hoc analysis of data from the observational Worldwide Schizophrenia Outpatient Health Outcomes database (2000-2005) on weight change in 4,626 patients completing 3 years of antipsychotic monotherapy with amisulpride, clozapine, olanzapine, quetiapine, risperidone, and oral and depot first-generation antipsychotics (FGAs). Reported outcomes included mean and categorical weight changes and the trajectories of different measures of weight change.

Mean weight gain was lowest with amisulpride (1.8 kg; 95% CI, 0.2-3.3) and highest with olanzapine (4.2 kg; 95% CI, 3.9-4.5). Weight change for all antipsychotics was most rapid during the first 6 months; subsequent weight change was slower but did not plateau. All drugs showed considerable individual variation in weight change. The proportion losing ≥7% of their baseline bodyweight was highest with quetiapine (10%; 95% CI, 7%-16%) and lowest with depot FGAs (5%; 95% CI, 3%-10%). Between 7% and 15% of patients moved into an overweight or obese body mass index (kg/m2)category (≥25).

The degree of weight gain varied between antipsychotics. All antipsychotics were associated with significant (≥7%) weight loss and gain from baseline. The mean rate of weight gain was maximal during the first 6 months but continued over 3 years without a plateau in this specific cohort. Patients should receive regular monitoring of weight throughout treatment.