A Comparison of the Efficacy and Adverse Effects of Ketamine and Electroconvulsive Therapy in the Management of Treatment-Resistant Depression: A Systematic Review

Ketamine has been repeatedly demonstrated to be an effective treatment in the management of patients with treatment-resistant depression (TRD). An important question is whether it is equally or more effective than the current gold standard of electroconvulsive therapy (ECT), as the adverse effects of ECT can lead to memory loss and neurocognitive deficits. A literature search was conducted for trials that directly compared the efficacy and adverse effects of ketamine and ECT via PubMed and Google Scholar. A total of 56 articles were identified with six included in this review. The studies included differed significantly in their quality and with differing levels of potential for bias. Ketamine has a more immediate effect when compared to ECT, but the antidepressant effects are shorter-lasting. Cognitive deficits were less pronounced in patients undergoing ketamine therapy. Many studies had a small number of participants and varied widely in the type of ECT used. Allocation bias seems likely in nonrandomized studies. Follow-up times were also short in some studies. The existing literature does not provide sufficient evidence to support the usage of ketamine over that of ECT for TRD, as remission rates were significantly higher over extended periods in ECT groups. Cognitive adverse effects were more pronounced in patients undergoing ECT. More high-quality randomized controlled trials (RCTs) directly comparing these two treatment modalities are required before drawing any firm conclusions.