Randomized trial of ketamine masked by surgical anesthesia in patients with depression
Nature Mental Health October 19, 2023 Theresa R. Lii, Ashleigh Smith, Josephine R. Flohr et al. 94 citations
A single dose of intravenous ketamine given during surgical anesthesia was no more effective than placebo at reducing depressive symptoms in adults with major depressive disorder. The trial randomized 40 patients to receive either ketamine or saline while under anesthesia for routine surgery, ensuring that neither participants, investigators, nor staff knew which treatment was given. Depression severity was measured over three days after infusion. Only about 37% of participants correctly guessed their treatment, indicating successful masking. The results suggest that ketamine's antidepressant effect may be influenced by its psychoactive effects, which complicate placebo-controlled testing.