Past research has demonstrated that the antidepressant effect of high-dose quetiapine (150-300 mg/day) is independent of its sleep-inducing properties (Trivedi et al., 2013), although to the researchers knowledge no study has adequately addressed this question using only low-dose (50 mg/day) quetiapine. To test this hypothesis the researchers are using data from 366 participants in D1448C00001 (50 mg/day arm [n = 182] and placebo arm [n = 184] only; Weisler et al., 2009) because as far as the researchers know it is the only quetiapine XR monotherapy trial for major depression that used doses of 50 mg/day.