Methods: Participants were randomly assigned to a 52-minute intravenous administration of ketamine (0.71 mg/kg, N=17) or the active control midazolam (0.025 mg/kg, N=23), provided during the second week of a 5-week outpatient regimen of motivational enhancement therapy.

Results: Ketamine significantly increased the likelihood of abstinence, delayed the time to relapse, and reduced the likelihood of heavy drinking days compared with midazolam. Infusions were well tolerated, with no participants removed from the study as a result of adverse events.

Conclusions: A single ketamine infusion was found to improve measures of drinking in persons with alcohol dependence engaged in motivational enhancement therapy. These preliminary data suggest new directions in integrated pharmacotherapy-behavioral treatments for alcohol use disorder.