Randomized, Placebo-Controlled Effectiveness Study of Quetiapine XR in Comorbid Depressive and Anxiety Disorders.

Quetiapine is approved as an adjunctive treatment for major depressive disorder (MDD) and as monotherapy for bipolar depression. It is often used off-label for treating anxiety conditions and as an augmentation agent for treatment-resistant depression. However, its benefit in depression with comorbid anxiety disorders has not been systematically evaluated. The current study evaluated the benefit and tolerability of quetiapine as augmentation to first-line antidepressants for MDD comorbid with anxiety disorders. In this multicenter trial (June 2008-June 2013), 76 adults (aged 18-65 years) with a primary diagnosis of unipolar depression comorbid with at least 1 anxiety disorder (per criteria) received flexible-dose quetiapine extended-release (XR) 50-300 mg/d or placebo as add-on for 12 weeks in a 2:1 ratio. Depression, anxiety, life satisfaction, and adverse events were assessed. Depression, anxiety, and function improved significantly in both groups. On primary outcome measures, quetiapine was superior to placebo in improving depression (17-item Hamilton Depression Rating Scale score: mean difference = -3.64; 95% CI, -7.01 to -0.27) and anxiety symptoms (Hamilton Anxiety Rating Scale score: mean difference = -4.02; 95% CI, -7.41 to -0.64), as well as Clinical Global Impressions-Severity of Illness scale score (mean difference = -0.64; 95% CI, -1.13 to -0.15). On secondary measures including the Montgomery-Asberg Depression Rating Scale, Beck Depression Inventory, Penn State Worry Questionnaire, and Quality of Life Satisfaction and Enjoyment Questionnaire, quetiapine produced a greater degree of improvement compared to placebo, but group differences were not statistically significant. Quetiapine was well tolerated, with mostly minor and no serious adverse effects. Quetiapine augmentation may be a useful intervention for MDD with comorbid anxiety. ClinicalTrials.gov Identifier: NCT00688818.