Ketamine and Electroconvulsive Therapy: Better Together?

A narrative review examined whether ketamine, a dissociative anesthetic, could improve the antidepressant effects of electroconvulsive therapy (ECT) for treatment-resistant depression. ECT is a standard end-line therapy but can cause memory impairment, possibly from overstimulation of glutamate receptors in the hippocampus. Ketamine blocks NMDA receptors and stimulates glutamate release, so it was proposed as an ECT adjuvant to reduce cognitive side effects and speed response. However, response and remission rates with ketamine in ECT showed no significant difference from comparator groups, and it was linked to more psychiatric and cardiovascular adverse events. The findings do not support combining ketamine and propofol as anesthetics for ECT in major depressive disorder.

Study at a glance

Abstract

Introduction Major depressive disorder (MDD) is a highly prevalent clinical condition with a leading cause of disability worldwide. The currently available therapeutic agents have important limitations regarding side effects, partial or non-responsiveness. Patients are considered to have treatment-resistant depression (TRD) if there is no effect or minimal effectiveness after receiving adequate dose-duration use of antidepressants from two different categories. For this patients, electroconvulsive therapy (ECT) can be a treatment option and new therapies appear to tackle TRD like ketamine, a dissociative anesthetic and analgesic. Objectives The authors elaborate a narrative literature review to understand if ketamine might enhance the antidepressant efficacy of ECT. Methods PubMed database searched using the terms “Electroconvulsive therapy”, “ketamine” and “treatment-resistant depression”. Results ECT is currently recommended as an end-line therapy for TRD. Memory impairment after ECT could be a consequence of indiscriminate activation or saturation of glutamate receptors during the treatment, disrupting hippocampal plasticity involved in memory. Ketamine inhibits N-methyl-d-aspartate (NMDA) receptors, while stimulating glutamate release and was proposed as an ECT adjuvant, might reduce cognitive adverse effects, time until response/ remission and inclusively improve response rates to ECT. However, response and remission rates of ketamine in ECT showed no significant difference from the comparator groups and was associated with higher rates of psychiatric and cardiovascular adverse events. Conclusions The results did not support the use the combination of ketamine and propofol as anesthetic agents for ECT in patients with MDD. However, further studies are needed to investigate the beneficial clinical and cognitive effects of ketamine alone in ECT settings. Disclosure No significant relationships.