Antidepressant Efficacy of Ketamine in Treatment-Resistant Major Depression: A Two-Site Randomized Controlled Trial

Intravenous ketamine demonstrated rapid antidepressant effects in an optimized study design, improving depression severity in 64% of treatment-resistant patients 24 hours after a single dose. The double-blind trial provides evidence for the role of the N-methyl-d-aspartate glutamate receptor in depression, a receptor not currently activated by existing antidepressant drugs.