Quetiapine augmentation for depression: dosing pattern in routine practice.

This study investigated the dosing patterns of quetiapine augmentation (QA) for major depressive disorder (MDD) in routine practice. Between 1 January 2009 and 31 May 2013, patients with a diagnosis of MDD who were receiving QA in conjunction with an ongoing antidepressant were recruited into this study. The electronic medical records and clinical data for a total of 977 patients were reviewed up to a year. Almost half the patients maintained QA treatment for more than 3 months. The mean duration of QA was ∼6 months, and the mean initial and maintenance doses were 23.6 and 40.7 mg/day, respectively (range=12.5-400 mg/day). The most frequent adverse events observed were somnolence, followed by dry mouth and lethargy. Our results indicate that the actual doses of QA for MDD in routine practice should be lower than the doses used in placebo-controlled clinical trials and those recommended by a regulatory agency. Adequately powered and well-controlled prospective studies are needed to better understand the exact role of low doses of QA in the treatment of MDD, particularly in routine practice.