Ketamine Alcohol (in Treatment-Resistant Depression)

Objective: Glutamate-based medications including the glutamate modulator ketamine result in rapid, robust and sustained (typically up to one week) antidepressant effects in randomized controlled trials in treatment-refractory unipolar and bipolar depression. Previous work by the investigators' group has demonstrated that a family history of alcohol dependence predicts a more robust antidepressant response to ketamine in both treatment-resistant unipolar and bipolar depression. Recently-detoxified alcoholics and affected first-degree relatives display blunted psychotomimetic, cognitive and other neuropsychiatric effects when administered a subanesthetic dose of ketamine. Based on the prior post hoc results, the investigators seek to prospectively demonstrate that a family history of an alcohol use disorder predicts a more robust antidepressant response to ketamine. Study Population: 18-55 year old TRD without psychotic features patients in a current major depressive episode of at least moderate severity will be recruited and enrolled in this study. All subjects must not have a current substance use disorder (except nicotine or caffeine). All subjects must be psychotropic medication-free for at least two weeks prior to the ketamine infusion. The targeted number of completers is 50 depressed subjects (60 signing consent to account for attrition): 25 FHP subjects \[as defined by either one first degree relative or two second-degree relatives with an alcohol user disorder on the Family Interview for Genetics Studies (FIGS) and Family Tree Questionnaire (FTQ)\] and 25 FHN negative subjects. Design: This study is currently a single site, open-label protocol in psychotropic medication-free depressed subjects. This protocol consists of two phases. Phase I consists of a medication taper (if needed) and at least two week drug-free period. Phase II includes a subanesthetic/antidepressant dose ketamine infusion during 7T-MRI. Outcome Measures: The primary hypothesis/outcome measure will be mean change in MADRS total score from the pre-ketamine infusion (baseline) to 7 days post-infusion between the FHP and FHN groups. Other exploratory measures include glutamate alterations during intravenous ketamine infusions and rs-fMRI as a function of family history status.