Efficacy of olanzapine in the treatment of bipolar mania with mixed features defined by DSM-5

Background These analyses compared efficacy of olanzapine in patients with bipolar mania with or without mixed features, as defined in the DSM-5. Methods Pooled data from 3 placebo-controlled olanzapine studies in patients having bipolar I disorder with manic/mixed episode were analyzed (N=228 olanzapine; N=219 placebo). Patients were categorized for mixed features by number of concurrent depressive symptoms at baseline (0, 1, and 2 [category A; without mixed features], and ≥3 [category B; with mixed features]), as determined by HAM-D₁₇ item score ≥1. Depressive symptoms corresponded to 6 HAM-D₁₇ items in the DSM-5 definition of manic episode with mixed features. Primary efficacy was evaluated by changes in the baseline-to-3-week YMRS total score. Results Patients were categorized into A (N=322; 72.0%) or B (N=125; 28.0%). Mean baseline YMRS total scores were 28.1 in category A and 27.8 in category B. Least-squares mean change of YMRS total scores in categories A and B (olanzapine versus placebo) were -11.78 versus -6.86 and -13.21 versus -4.72, respectively. Patients in the olanzapine- compared with placebo-group experienced a greater decrease in YMRS total score for both categories (p<0.001). An interaction between mixed features and treatment was seen in YMRS change at a 0.3 significance level (p=0.175). Limitations The results are from post-hoc analyses. Conclusions Olanzapine was efficacious in the treatment of bipolar I mania, in patients both with and without mixed features, defined by DSM-5; however, greater efficacy was observed in patients with mixed features having more severe depressive symptoms.