The role of extended-release quetiapine fumarate monotherapy in the treatment of patients with major depressive disorder.

Pharmacotherapy, psychotherapy and other nonpharmacological interventions are used in patients with major depressive disorder (MDD). However, 50% of the patients with MDD fail to achieve a response to first-line antidepressant treatment. In four of five acute monotherapy studies, once-daily extended-release quetiapine fumarate (quetiapine XR) significantly improved depressive symptoms compared with placebo in patients with MDD. One acute monotherapy study demonstrated that neither quetiapine XR nor escitalopram had a statistically significant separation from placebo on the primary endpoint. Quetiapine XR maintenance therapy also significantly reduced the risk of recurrence of a depressive event. No significant improvement in overall quality of life was observed versus placebo except in the acute elderly study. Tolerability findings were consistent with the known pharmacological profile of quetiapine; the most common adverse events were dry mouth, sedation, somnolence and dizziness. Quetiapine XR monotherapy has been approved as a treatment for MDD in a limited number of countries.