Pioglitazone for the Treatment of Bipolar Depression

The study is a double-blind, placebo-controlled 8-week trial of pioglitazone, either as monotherapy or adjunctive to a mood stabilizer, for the acute relief of bipolar depression. The enrollment goal is 80 subjects (40 patients each in the pioglitazone treatment group and the placebo treatment group). Screening Phase: Patients who have been prescribed a mood stabilizer for \> 4 weeks and are on a therapeutic dose will proceed directly to the Screening Visit. For situations in which the patient prefers to be taking a mood stabilizer or where the treating psychiatrist feels it is clinically necessary, a mood stabilizer (lithium, divalproex, carbamazepine, lamotrigine, olanzapine, quetiapine, risperidone, aripiprazole, ziprasidone or lurasidone) will be initiated (see Mood Stabilizer Initiation section below). For this set of patients who do begin a mood stabilizer, the Screening Phase may last up to 8 weeks. Otherwise, subjects who do not come in on a mood stabilizer will proceed directly to screening. Double-Blind, Placebo-Controlled Study Period (Week 1 to Week 8): Patients who meet inclusion/exclusion criteria will be randomized to study treatment at the baseline/randomization visit within 30 days of the screening visit. The efficacy and safety assessments will be carried out at baseline/randomization and then weekly or every two weeks for a total of 8 weeks.