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Ketamine Comparable to ECT for Many Patients With Refractory Depression

Nick Zagorski

Psychiatric News July 24, 2023 DOI: 10.1176/appi.pn.2023.08.7.47 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Randomized, open-label, non-inferiority clinical trial Peer reviewed
Sample size 403
Population Adults aged 21 to 75 with DSM-5 major depressive disorder without psychotic features, referred for ECT, with a Montgomery-Åsberg Depression Rating Scale score greater than 20 and failure to respond to at least two adequate antidepressant trials
Interventions Ketamine Electroconvulsive therapy (ECT)
Dose Ketamine 0.5 mg per kilogram of body weight over 40 minutes; ECT initially right unilateral ultrabrief, could be switched to bilateral delivery
Duration Three weeks of treatment; one-month follow-up
Measures Montgomery–Åsberg Depression Rating Scale (MADRS), 16-item Quick Inventory of Depressive Symptomatology–Self-Report (QIDS-SR)
Topics Depression Esketamine Ketamine
Key findings Ketamine was about as effective as ECT for treatment-resistant depression without psychosis: 55.4% of ketamine recipients responded versus 41.2% of ECT recipients, and remission rates were 32.3% versus 20%, respectively. The trial was designed as a non-inferiority comparison, and the presenter stated that future trials are needed to determine whether ketamine could be superior to ECT for some patients.

Abstract

Back to table of contents Previous article Next article Annual MeetingFull AccessKetamine Comparable to ECT for Many Patients With Refractory DepressionNick ZagorskiNick ZagorskiSearch for more papers by this authorPublished Online:24 Jul 2023https://doi.org/10.1176/appi.pn.2023.08.7.47AbstractFollowing a presentation of new clinical trial data at the Annual Meeting, some questioned why patients were limited to only nine doses of ECT instead of the typical 12 to 16 sessions.Ketamine is about as effective as electroconvulsive therapy (ECT) for patients with treatment-resistant depression without psychosis, a study published in the New England Journal of Medicine has found. Amit Anand, M.D., a professor of psychiatry at Harvard Medical School and principal investigator of the ELEKT-D clinical trial, presented these findings during APA’s Annual Meeting in May.“The reason ECT has been around 80 years is because it is an effective and fast-acting treatment,” Anand told the audience. However, some patients are worried about cognitive side effects, he continued, so it is worth examining how alternative options for treatment-resistant depression compare, he continued.To compare ketamine with ECT, Anand and colleagues recruited adults aged 21 to 75 who had been referred by their clinical providers for ECT. The participants met the criteria for a DSM-5 diagnosis for major depressive disorders without psychotic features. All participants were required to have a score greater than 20 on the 60-point Montgomery–Åsberg Depression Rating Scale (MADRS), indicating moderate to severe depression, and to have failed to respond to at least two adequate trials of antidepressant treatment.The study was designed to mimic real-world outpatient clinical care as much as possible, Anand noted. The trial was open label, participants could continue all their existing medications, and clinicians could adjust treatment as needed.The 403 enrolled participants were randomly assigned to three weeks of ECT (initially right unilateral ultrabrief but could be switched to bilateral delivery) three times a week or ketamine (initially 0.5 mg per kilogram of body weight over 40 minutes) two times a week.The primary outcome was patient-reported treatment response, defined as at least a 50% decrease on the 16-item Quick Inventory of Depressive Symptomatology–Self-Report (QIDS-SR).After three weeks, 55.4% of participants in the ketamine group and 41.2% in the ECT group reported a response to treatment. Ketamine was also associated with a higher remission rate on QIDS-SR (score of less than 5) than ECT: –32.3% versus 20%, respectively. Anand noted that ketamine outperformed ECT in other outcomes as well, but since the trial was designed as a non-inferiority comparison, future trials are needed to determine whether ketamine could be superior to ECT for some patients.The participants receiving ECT reported greater memory declines at the end of treatment compared with those who received ketamine, though at the one-month follow-up there was little difference between the two groups. Among other side effects, ECT participants reported more musculoskeletal adverse effects, whereas ketamine participants reported more dissociation symptoms.Anand noted that these latest findings seem to contradict those of a 2021 study, which concluded that ketamine was not as effective as ECT. There were several differences between the populations of patients included in the two trials, Anand said; for instance, the 2021 trial included hospitalized adults and those with psychotic depression—a population known to respond to ECT.During a spirited Q&A session at APA’s Annual Meeting, multiple people in the audience questioned whether the authors’ decision to limit ECT to nine sessions across three weeks skewed the study to favor ketamine; they pointed out that previous ECT trials have indicated that 12 to 16 sessions are optimal for treating acute symptoms. Anand countered that as a pragmatic trial, ELEKT-D reflected routine practice, which has found most patients receive six to nine ECT sessions before stopping for whatever reason.“I agree that with three more sessions, the response rate for ECT would have gone up,” Anand said. But another week of ketamine therapy would increase the response of those patients as well, he said. In addition, more ECT sessions would increase the number of reported memory problems. “I don’t see any scenario of treatment length where ketamine becomes inferior to ECT,” he said.The study was supported by the Patient-Centered Outcomes Research Institute. ■Resources“Ketamine Versus ECT for Nonpsychotic Treatment-Resistant Major Depression”“Racemic Ketamine as an Alternative to Electroconvulsive Therapy for Unipolar Depression: A Randomized, Open-Label, Non-Inferiority Trial (KetECT)” ISSUES New Archived

Comparable studies

Other randomized controlled trials on ketamine for depression, most cited first.

Study Year Design Participants
Antidepressant Efficacy of Ketamine in Treatment-Resistant Major Depression: A Two-Site Randomized Controlled Trial Patients with treatment-resistant major depression experiencing a major depressive episode 2013 Randomized controlled trial n = 73
Efficacy and Safety of Flexibly Dosed Esketamine Nasal Spray Combined With a Newly Initiated Oral Antidepressant in Treatment-Resistant Depression: A Randomized Double-Blind Active-Controlled Study Adults with moderate to severe nonpsychotic depression and a history of nonresponse to... 2019 Phase 3, double-blind, active-controlled, multicenter randomized controlled trial n = 227
Efficacy of Esketamine Nasal Spray Plus Oral Antidepressant Treatment for Relapse Prevention in Patients With Treatment-Resistant Depression Adults with treatment-resistant depression who achieved stable remission or stable... 2019 Phase 3, multicenter, double-blind, randomized withdrawal study n = 297
Efficacy and Safety of Intranasal Esketamine Adjunctive to Oral Antidepressant Therapy in Treatment-Resistant Depression Adults with DSM-IV-TR diagnosis of major depressive disorder and history of inadequate... 2017 Phase 2, double-blind, doubly randomized, delayed-start, placebo-controlled study n = 67
Efficacy and Safety of Intranasal Esketamine for the Rapid Reduction of Symptoms of Depression and Suicidality in Patients at Imminent Risk for Suicide: Results of a Double-Blind, Randomized, Placebo-Controlled Study Depressed patients at imminent risk for suicide 2018 Randomized controlled trial n = 68

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