IntroductionDisrupted sleep is common in depression.ObjectivesInvestigate effects of adjunct extended release quetiapine fumarate (QTP-XR) on sleep disturbance and quality in patients with MDD and inadequate response to antidepressant (AD) therapy.MethodsData were pooled from two (D1448C00006/D1448C00007) 6-week, double-blind, randomised, placebo (placebo+AD)-controlled studies of adjunct QTP-XR (15 0 mg/day and 300 mg/day). Primary endpoint: MADRS total score change versus placebo+AD. Secondary endpoints (post hoc): change from randomisation in MADRS item 4 (reduced sleep), HAM-D items 4, 5 and 6 (early-, middle- and late-insomnia), sleep disturbance factor (HAM-D items 4+5+6) and sleep quality (PSQI global score). MADRS total score change in patients with baseline HAM-D sleep disturbance factor score > = 4 or < 4 (high and low sleep disturbance, respectively) was evaluated.Results919 patients received adjunct QTP-XR: 150 mg/day (n = 309), 300 mg/day (n = 307), placebo+AD (n = 303). At Week 6, adjunct QTP-XR (both doses) reduced MADRS item 4, HAM-D sleep disturbance factor, HAM-D items 4, 5 and 6 and PSQI global scores from baseline versus placebo+AD (p < 0.001). In patients with baseline HAM-D>=4 (n = 226, 215 and 210, respectively) adjunct QTP-XR (both doses) improved (p< 0.01) MADRS total score versus placebo+AD from Week 1 onward. In patients with baseline HAM-D< 4 (n = 83, 92, 93, respectively) adjunct QTP-XR (both doses) improved (not statistically significantly) MADRS total score versus placebo+AD at Week 6.ConclusionsAdjunct QTP-XR significantly restored sleep and improved sleep quality in patients with MDD and inadequate response to AD. Significant improvement in depressive symptoms was demonstrated with adjunct QTP-XR in patients with MDD and high baseline sleep disturbance. AstraZeneca funded.