Objective: To investigate the efficacy and tolerability of quetiapine monotherapy for the treatment of major depressive episodes in patients with bipolar I disorder, as a post hoc analysis of data from 2 large studies, the BipOLar DEpRession (BOLDER) I and II studies, which investigated the overall efficacy of quetiapine in both bipolar I and II disorder.
Method: A combined cohort of patients with depressive episodes in bipolar I disorder (DSM-IV criteria) (N = 694) from 2 nearly identical double-blind, randomized, placebo-controlled studies that each randomly assigned patients with bipolar I and II disorder to 8 weeks of treatment with quetiapine 300 or 600 mg/day or placebo was analyzed. The primary efficacy measure was change from baseline to end of treatment (week 8) in the Montgomery-Asberg Depression Rating Scale (MADRS) total scores.