A systematic review and meta-analysis of the efficacy of ketamine compared to electroconvulsive therapy for treatment-resistant depression

Electroconvulsive therapy (ECT) has long been considered the main method of treatment for patients with resistant major depressive disorder (MDD). Recent studies have shown that ketamine infusion can also effectively improve treatment-resistant MDD. Thus, we conducted this meta-analysis to compare the efficacy of ketamine with ECT for treating treatment-resistant depression. We systematically searched PubMed, the Cochrane Library, Scopus and Web of Science from the inception to 2 October 2024, to identify clinical trials and randomised controlled trials comparing the effect of ketamine with ECT on treatment-resistant major depression. Six studies with 353 individuals in the ketamine group and 323 individuals in the ECT group were included. No significant differences were observed between ECT and ketamine in terms of response to treatment (RR 1.03, 95% CI (0.78, 1.37), I2 = 77.14%, T2 = 0.08), MADRS score (weighted mean difference (WMD) 0.98, 95% CI (−5.04, 7.00), I2 = 94.74%, T2 = 26.52), remission (RR 0.65, 95% CI (0.16, 2.64), I2 = 89.77%, T2 = 1.19), relapse (RR 0.93, 95% CI (0.50, 1.72), I2 = 20.13%, T2 = 0.04) and the number of those experiencing adverse events (RR 0.72, 95% CI (0.47, 1.10), I2 = 0.00%, T2 = 0.00). These findings suggest that ketamine is not inferior to ECT for treating MDD; however, future studies are needed for validation. Six studies with 353 individuals in the ketamine group and 323 individuals in the ECT group were included in this study.No significant differences were observed between ECT and ketamine in terms of response to treatment, MADRS score and remission.No significant differences were observed between ECT and ketamine in terms of relapse and the number of those experiencing adverse events. Six studies with 353 individuals in the ketamine group and 323 individuals in the ECT group were included in this study. No significant differences were observed between ECT and ketamine in terms of response to treatment, MADRS score and remission. No significant differences were observed between ECT and ketamine in terms of relapse and the number of those experiencing adverse events.