Weight Management Program for Treatment-Emergent Weight Gain in Olanzapine-Treated Patients With Schizophrenia or Schizoaffective Disorder: A 12-Week Randomized Controlled Clinical Trial

Background: The main objective was to assess the efficacy of a weight management program designed for outpatients taking olanzapine for schizophrenia or schizoaffective disorder and to compare these patients with a randomized control group. The effects of the weight management program were also assessed with regard to safety and quality of life.

Method: Forty-eight patients were enrolled in a 12-week, randomized, multicenter weight management study. Thirty-three patients were randomly allocated to an intervention group in which they received olanzapine within a weight management program. Fifteen patients were allocated to a control group in which they were given olanzapine treatment as usual outpatients. Weight, body mass index (BMI), and measurements of safety and quality of life were evaluated. The study was conducted from January 7, 2003, to September 16, 2003.

Results: Thirty-six patients (75%) completed this study. We found significant differences in weight (-3.94 ± 3.63 kg vs. -1.48 ± 1.88 kg, p = .006) and BMI (-1.50 ± 1.34 vs. -0.59 ± 0.73, p = .007) change from baseline to endpoint between the intervention and control groups, respectively. Significant differences in weight reduction were initially observed at week 8 (p = .040). No significant differences were found with regard to the safety outcomes. When the ratio of low-density lipoproteins to high-density lipoproteins was calculated, change from baseline was greater in the intervention group than the control group (-0.19 vs. -0.04), but the difference was not statistically significant (p = .556). After the completion of the weight management program, there was a trend toward statistical difference in the physical health score changes between the weight management and control groups (1.12 in the intervention group vs. -0.93 in the control group, p = .067).

Conclusion: The weight management program was effective in terms of weight reduction in patients with schizophrenia or schizoaffective disorder taking olanzapine and was also found to be safe in terms of psychiatric symptoms, vital signs, and laboratory data. In addition, such a weight management program might improve quality of life in patients with schizophrenia or schizoaffective disorder with respect to their physical well-being.

J Clin Psychiatry 2006;67(4):547-553