The Impact of Ketamine-Based Versus Non-Ketamine-Based ECT Anesthesia Regimens on the Severity of Patients’ Depression and Occurrence of Adverse Events: A Systematic Review with Meta-Analysis

Objective: To compare efficacy and safety outcomes for ketamine anesthesia + electroconvulsive therapy (ECT) versus nonketamine anesthesia + ECT in treatment-resistant depression (TRD) patients. Data Sources: PubMed and Embase were searched from the earliest date through November 27, 2023. Study Selection and Data Extraction: Relevant randomized controlled trials (RCTs) of ketamine + ECT versus nonketamine anesthesia + ECT that reported data on remission (odds ratio [OR]), defined as a Hamilton Depression Rating Scale (HAM-D) and Montgomery-Asburg Depression Rating Scale (MADRS) score <8-10) and mean differences (MDs) in HAM-D scores after several ECT sessions were compared using inverse variance methods. The risk of bias (RoB) was assessed using the Cochrane RoB tool. Data Synthesis: Seventeen RCTs (RoB: Low N = 12, Moderate N = 2, High N = 3) with 1181 total patients met inclusion criteria. Patients receiving ECT experienced greater clinical remission (OR: 1.78, [95% confidence interval (CI): 1.08-2.93], I² = 11%, N = 9) and lower HAM-D scores after the third through sixth ECT sessions as well as the eighth ECT session when ketamine versus nonketamine anesthesia was used. Ketamine use with ECT significantly increased fear with hallucinations (OR: 1.99, [95% CI: 1.11-3.58], I² = 0%, N = 7) than with nonketamine anesthesia. Relevance to Patient Care and Clinical Practice: Selecting ketamine-based anesthesia could more quickly and profoundly enhance the beneficial effects of ECT for patients with severe TRD, but the balance of benefits to harm is unclear as there may be additional adverse events. Conclusion: Ketamine is a promising anesthesia adjunct to ECT that may enhance antidepressant effects in exchange for more adverse events.