Conditions: Major Depressive Disorder
Keywords: patients FK949E
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 172
Healthy volunteers: no

Brief summary:
In this study, quetiapine XR or placebo will be administered orally for 6 weeks to major depressive disorder patients with lack of response to existing antidepressants, with the aim of evaluating the efficacy of quetiapine XR and dose-response in three quetiapine XR dose groups based on changes in Montgomery-Asberg Depression Rating Scale (MADRS) scores.

Detailed description:

Arms:
arm 1: Participants received matching placebo tablets once daily before bedtime for 7 weeks. arm 2: Participants received quetiapine extended release (XR) 50 mg tablets once daily before bedtime for 7 weeks. arm 3: After 2 days of up-titration, participants received quetiapine XR 150 mg tablets once daily before bedtime for 6 weeks followed by quetiapine XR 50 mg tablets once daily for 1 week. arm 4: After 4 days of up-titration, participants received quetiapine XR 300 mg tablets once daily before bedtime for 6 weeks followed by quetiapine XR 150 mg tablets once daily for 1 week.

Interventions: intervention 1: quetiapine extended release (XR) intervention 2: Placebo
Intervention descriptions: intervention 1: Extended release tablets intervention 2: matching tablets

Protocol document: