Lurasidone in the treatment of bipolar depression with mixed (subsyndromal hypomanic) features: post hoc analysis of a randomized placebo-controlled trial.

OBJECTIVE: Mixed (subsyndromal hypomanic) features are prevalent in patients with bipolar depression and are associated with more severe and complex illness, including increased risk for suicide attempts, higher switch to mania during antidepressant therapy, and a higher rate of recurrence. The aim of this post hoc analysis was to evaluate the efficacy and safety of lurasidone in the treatment of patients with bipolar depression presenting with mixed features.

METHOD: Patients with a DSM-IV-TR diagnosis of major depressive episode associated with bipolar I disorder, with or without rapid cycling, and with a Montgomery-Asberg Depression Rating Scale (MADRS) score ≥ 20 and a Young Mania Rating Scale (YMRS) score ≤ 12 were randomly assigned to 6 weeks of double-blind, once-daily treatment with lurasidone 20-60 mg, lurasidone 80-120 mg, or placebo. The presence of mixed features was defined as a YMRS score ≥ 4 at study baseline. Efficacy analyses included change in MADRS total score from baseline to week 6 (the primary outcome in the original study, conducted between April 2009 and February 2012).

RESULTS: At baseline, mixed features were present in 56% of patients (lurasidone, n = 182/323; placebo, n = 90/162). Treatment with lurasidone (vs placebo) was associated with significantly greater reductions in MADRS scores in the mixed features group (-15.7 vs -10.9; P = .001; week 6; mixed model for repeated measures [MMRM]; effect size, 0.48) and in the group without mixed features (-15.2 vs -10.8; P = .002; week 6; MMRM; effect size, 0.48). Rates of protocol-defined treatment-emergent hypomania or mania were similar for patients with mixed features (lurasidone, 2.2%; placebo, 3.2%) and without mixed features (lurasidone, 3.4%; placebo, 0.0%).

CONCLUSIONS: Lurasidone was found in this post hoc analysis to be efficacious in the treatment of patients with bipolar depression who present with mixed features (assessed cross-sectionally at study baseline). No increased risk of treatment-emergent mania was observed in either group.

TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00868699.