The purpose of this study is to evaluate the rapid and sustained antidepressant effects of repeated doses of ketamine in the brain. We want to learn how ketamine affects areas of the brain important in regulating mood and if there are unique signatures that could help predict who may respond to the drug. Also, we want to see if repeated doses of ketamine are safe and effective in treating the symptoms of depression.
We are enrolling eligible adults, ages 18 to 65 with major depressive disorder. This inpatient study lasts 14-20 weeks and procedures include a medication taper and drug-free period, taking repeated doses of the research drug, two infusions of placebo, multiple brain imaging scans, transcranial magnetic stimulation, and psychological testing. After completing the study, participants can receive short-term care at the NIH while transitioning back to a provider.