Ketamine for treatment-resistant major depressive disorder: Double-blind active-controlled crossover study

Abstract

Background<br/>The N-methyl-D-aspartate antagonist ketamine has rapid onset antidepressant activity in treatment-resistant depression (TRD).<br/>Aims<br/>To evaluate mood rating, safety and tolerability data from patients with TRD treated with ketamine and the psychoactive control fentanyl, as part of a larger study to explore EEG biomarkers associated with mood response.<br/>Methods<br/>We evaluated the efficacy and safety of intramuscular racemic ketamine in 25 patients with TRD, using a double-blind active-controlled randomized crossover design. Ketamine doses were 0.5 and 1 mg/kg, and the psychoactive control was fentanyl 50 mcg, given at weekly intervals.<br/>Results/outcomes<br/>Within 1 h of ketamine dosing, patients reported reduced depression and anxiety ratings, which persisted for up to 7 days. A dose–response profile for ketamine was noted for dissociative side effects, adverse events and changes in blood.