A 52-Week Study of Olanzapine with a Randomized Behavioral Weight Counseling Intervention in Adolescents with Schizophrenia or Bipolar I Disorder.

OBJECTIVES: To evaluate the 52-week safety/tolerability of oral olanzapine for adolescents with schizophrenia or bipolar mania and compare effectiveness of a standard versus intense behavioral weight intervention in mitigating risk of weight gain.

METHODS: Patients 13-17 years old with schizophrenia (Brief Psychiatric Rating Scale for Children [BPRS-C] total score >30; item score ≥3 for hallucinations, delusions, or peculiar fantasies) or bipolar I disorder (manic or mixed episode; Young Mania Rating Scale [YMRS] total score ≥15) received open-label olanzapine (2.5-20 mg/day) and were randomized to standard (n = 102; a single weight counseling session) or intense (n = 101; weight counseling at each study visit) weight intervention. The primary outcome measure was mean change in body mass index (BMI) from baseline to 52 weeks using mixed-model repeated measures. Symptomatology was also assessed.

RESULTS: No statistically significant differences between groups were observed in mean baseline-to-52-week change in BMI (standard: +3.6 kg/m2 ; intense: +2.8 kg/m2 ; p = 0.150) or weight (standard: +12.1 kg; intense: +9.6 kg; p = 0.148). Percentage of patients at endpoint who had gained ≥15% of their baseline weight was 40% for the standard group and 31% for the intense group (p = 0.187). Safety/tolerability results were generally consistent with those of previous olanzapine studies in adolescents, with the most notable exception being the finding of a mean decrease in prolactin. On symptomatology measures, patients with schizophrenia had a mean baseline-to-52-week change in BPRS-C of -32.5 (standard deviation [SD] = 10.8), and patients with bipolar disorder had a mean change in YMRS of -16.7 (SD = 8.9), with clinically and statistically significant improvement starting at 3-4 days for each.

CONCLUSIONS: Long-term weight gain was high in both groups, with no statistically significant differences between the standard or intense behavioral weight interventions in BMI or weight. Safety, tolerability, and effectiveness findings were generally consistent with the known profile of olanzapine in adolescents.