Ketamine for the Rapid Treatment of Major Depressive Disorder and Alcohol Use Disorder

The investigators will compare 3 treatment groups (ketamine plus naltrexone vs. ketamine alone vs. placebo) for treating major depressive disorder (MDD) and alcohol use disorder (AUD) in an 8-week randomized, double-blind, placebo-controlled, between-subjects trial. First, prior to the double-blind trial, the investigators will conduct an open-label trial that will include 5 patients with comorbid MDD and AUD to test safety and efficacy of repeated ketamine treatment (0.5 mg/kg; once a week for 4 weeks; a total of 4 ketamine infusions) with a follow-up of 4 weeks. Second, after reviewing the safety and efficacy of repeated ketamine treatment from the open-label trial, the investigators will conduct an 8-week, randomized, double-blind, placebo-controlled trial that will include 60 patients with comorbid MDD and AUD to test safety and efficacy of repeated ketamine treatment (0.5 mg/kg; once a week for 4 weeks; a total of 4 ketamine infusions) plus naltrexone with a follow-up of 4 weeks. The 4-month follow-up session will also occur.