Pioglitazone for the Treatment of Major Depressive Disorder Comorbid With Metabolic Syndrome

Inclusion Criteria: * Be male or female between the ages of 18 and 70 * DSM-IV diagnosis of major depressive disorder * Currently depressed as confirmed by the MINI-Plus at the screening visit * Quick Inventory of Depressive Symptomatology-Self-Report(QIDS-SR) score \> 11 at study baseline * Meets criteria for the metabolic syndrome as defined by the NCEP ATP III criteria Exclusion Criteria: * Pregnancy or breast feeding * Unstable or inadequately treated medical illness as judged by the investigator * Severe personality disorder * Serious suicidal risk as judged by the investigator or having a score \> 2 on item 18 of the Inventory of Depressive Symptomatology-Clinician Rated (IDS-CR) scale * Known history of intolerance or hypersensitivity to pioglitazone * Treatment with pioglitazone in the 3 months prior to randomization * Currently taking an antidiabetic/glucose-lowering agent. Antidiabetic agents that are prohibited include insulin, rosiglitazone, metformin, sitagliptin, sulfonylureas (e.g. glyburide, glipizide, glimepiride), non-sulfonylurea secretagogues (e.g. repaglinide, nateglinide), incretins (e.g. exenatide), and α-glucosidase inhibitors (e.g. acarbose, miglitol). * Diagnosed with dementia * Diagnosed with heart failure * Transaminase elevation \>2.5 times the upper limit of normal * Presence of renal impairment