Electroconvulsive therapy was superior, but outcomes with ketamine were better than expected for this difficult-to-treat population.

Electroconvulsive therapy (ECT) is the gold standard for patients with treatment-resistant depression; however, ketamine infusion can confer rapid improvement (within hours to days). Repeat ketamine infusions will often sustain improvement for at least one month. In this meta-analysis, researchers examined six studies in which ketamine infusion (three per week for two weeks) was compared with ECT (three per week for four weeks).

At one month, ECT was moderately but significantly more effective than ketamine, with remission rates of 63% versus 43% in the largest study. Effects of ECT and ketamine were similar for reducing suicidal thinking; ECT was associated with more cognitive side effects and ketamine was associated with more depersonalisation, vertigo and visual disturbance. Two studies showed waning of effects over time for both ECT and ketamine, with comparable outcomes at three and 12 months. 

Comment: Popular press sites and social media have lauded the benefits of rapidly acting ketamine treatment for depression and even for acute suicidality, despite limited information on the inevitable waning of it effects over time. In contrast, we have evidence for long-term maintenance of ECT benefits (with specific medication combinations and, in some cases, monthly ECT). In contrast to ECT, intravenous ketamine is not reimbursed by insurers; US FDA-approved nasal esketamine is generally reimbursed by insurers but has lower bioavailability and is thought to be less effective. Although ECT appears to be superior, ketamine might be preferred by patients looking for more-rapid effects and wanting to avoid ECT’s short-term cognitive side effects.
PETER ROY-BYRNE, MD
Professor, Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle; USA.

Rhee TG, et al. Efficacy and safety of ketamine vs electroconvulsive therapy among patients with major depressive episode: a systematic review and meta-analysis. JAMA Psychiatry 2022 Oct 19; e-pub (https://doi.org/10.1001/jamapsychiatry.2022.3352).

This summary is taken from the following Journal Watch title: Psychiatry.