Hype or hope? High placebo response in major depression treatment with ketamine and esketamine: a systematic review and meta-analysis.
Frontiers in psychiatry January 1, 2024 Alexandros Matsingos, Marcel Wilhelm, Laila Noor et al. 18 citations
In double-blind randomized trials of ketamine and esketamine for major depressive disorder, the placebo response accounts for up to 72% of the overall treatment response. Across 14 studies with 1100 participants, the pooled effect size for placebo was -1.85, while the treatment effect was -2.57. Seven days after treatment, the placebo response accounted for 66% of the treatment response. Ketamine and esketamine show large antidepressant effects, but the placebo response plays a significant role and should be leveraged in clinical practice.