Maintenance Treatment for Patients With Bipolar I Disorder: Results From a North American Study of Quetiapine in Combination With Lithium or Divalproex (Trial 127)

Objective: The authors evaluated the efficacy and safety of quetiapine plus lithium or divalproex in the prevention of recurrent mood events in patients with stabilized bipolar I disorder. Method: A total of 1,953 patients received open-label quetiapine (400–800 mg/day in flexible, divided doses) with either lithium or divalproex (target serum concentrations 0.5–1.2 meq/liter and 50–125 μg/ml, respectively) for up to 36 weeks. After at least 12 weeks of clinical stability, 628 patients were randomly assigned to double-blind treatment with quetiapine or placebo, in combination with lithium or divalproex, for up to 104 weeks. The primary efficacy measure was time to recurrence of any mood event (mania, depression, or a mixed episode). Results: Fewer patients in the quetiapine group experienced a mood event compared with the placebo group (20.3% versus 52.1%). The hazard ratio for time to recurrence of a mood event was 0.32. Hazard ratios were similar for mania and depression events (0.30 and 0.33, respectiv...