Efficacy of quetiapine monotherapy in bipolar I and II depression: a double-blind, placebo-controlled study (the BOLDER II study)

This study evaluated the efficacy and tolerability of quetiapine monotherapy for depressive episodes in patients with bipolar I or II disorder (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) who were randomized to 8 weeks of double-blind treatment with quetiapine (300 or 600 mg/d; once daily, evening dosing) or placebo. Patients were assessed weekly using the Montgomery-Asberg Depression Rating Scale (MADRS) and Hamilton Depression Rating Scale (HAM-D). The primary end point was change in MADRS total score from baseline to Week 8 (analysis of covariance/last-observation-carried-forward analysis). Of 509 patients randomized, 59% completed the study. Improvements from baseline in mean MADRS total scores were significantly greater with quetiapine 300 and 600 mg/d than with placebo from first evaluation (Week 1) through Week 8 (both P