Weight gain over 4 months in schizophrenia patients: a comparison of olanzapine and risperidone

Weight gain frequently accompanies treatment with antipsychotics. In order to determine whether newer antipsychotic agents differ from each other with respect to weight gain, we compared two cohorts of patients with DSM-IV sc hizophrenia who had newly started treatment with either risperidone or olan zapine. After obtaining informed consent, data regarding body weight and he ight were culled from existing medical records of 100 patients (50 patients in each treatment group). Baseline body weight, close to the time of start ing the new medication, and body mass index [BMI = weight (kg)/height (m) s quared] were compared to the body weight and BMI following 4 months of trea tment. There was no significant change in mean body weight or BMI in the gr oup treated with risperidone (baseline weight = 83.1 kg +/- 20.5, follow-up = 82.8 kg +/- 19.9; matched pair t = 0.66, P = n.s.; baseline BMI = 29.6 /- 9.4, follow-up = 29.5 +/- 9.1; matched pair t = 0.79, P = n.s.). However , in the group treated with olanzapine, there was a significant increase in both mean body weight and BMI (baseline weight = 84.9 kg +/- 25.0, follow- up = 87.1 kg +/- 25.1; matched pair t = 4.62, P < 0.001; baseline BMI = 29. 5 +/- 7.4, follow-up = 30.3 +/- 7.5; matched pair t = 4.43, P < 0.001). In this naturalistic study, treatment with olanzapine was associated with a me an weight gain of about 2 kg from baseline, in patients with schizophrenia, while treatment with risperidone was associated with no mean weight change . (C) 2001 Elsevier Science B.V. All rights reserved.