Randomised, double-blind, placebo-controlled study of olanzapine in patients with bipolar I depression

Atypical antipsychotics are widely used in bipolar mania. However, the efficacy of atypical antipsychotics in bipolar depression has not been comprehensively explored.

To evaluate olanzapine monotherapy in patients with bipolar depression.

Patients with bipolar depression received olanzapine (5-20 mg/day, n = 343) or placebo (n = 171) for 6 weeks. The primary outcome was change from baseline to end-point in Montgomery-Åsberg Depression Rating Scale (MADRS) total score. Secondary outcomes included: Clinical Global Impression - Bipolar Version (CGI-BP) scale, 17-item Hamilton Rating Scale for Depression (HRSD-17) and Young Mania Rating Scale (YMRS) scores, and the rate of response (≥50% reduction in MADRS at end-point), recovery (MADRS ≤12 for ≥4 weeks plus treatment completion) and remission (MADRS ≤8). The trial was registered with ClinicalTrials.gov (NCT00510146).

Olanzapine demonstrated: significantly greater (P<0.04) improvements on MADRS (least-squares mean change -13.82 v. -11.67), HRSD-17 and YMRS total scores and all CGI-BP subscale scores v. placebo; significantly (P≤0.05) more response and remission, but not recovery; significantly (P<0.01) greater mean increases in weight, fasting cholesterol and triglycerides; and significantly more (P<0.001) patients gained ≥7% body weight.

Olanzapine monotherapy appears to be efficacious in bipolar depression. Additional long-term studies are warranted to confirm these results. Safety findings were consistent with the known safety profile of olanzapine.