Is electroconvulsive therapy still a valid treatment for severe depression?

How well does ECT actually work for severe depression?

ECT is one of the most effective treatments available for severe depression, with response rates consistently above 50% in the studies reviewed. A large Scottish study of over 2,000 patients with moderate to severe depression found a 73% response rate and a 51% remission rate after a course of ECT [9]. An audit of 50 patients in the UK showed that average depression scores (measured by the Hamilton Depression Rating Scale) dropped from 24 out of 40 (severe depression) at the start of treatment to 7 out of 40 (mild depression) at the end, with all 50 patients showing improvement [7]. Even in patients with co-occurring eating disorders—a group that often does poorly with antidepressants—ECT still achieved a 58% response rate [5].

ECT also appears to work quickly, which is critical when depression is life-threatening. The same UK audit found that the most dramatic improvement occurred in the first 6 to 8 sessions [7]. This rapid effect is one reason ECT is often used in emergencies, such as when a patient is not eating or drinking or is at high risk of suicide.

How does ECT compare to ketamine, the newer alternative?

The evidence shows that ECT is generally more effective than ketamine for treating severe depression, though ketamine is a valid alternative in certain situations. The largest and most rigorous trial comparing the two—a randomized noninferiority trial of 403 patients—found that ketamine was 'noninferior' to ECT, meaning it was not worse than ECT by a predefined margin [1]. However, in that trial, the response rate was 55% for ketamine versus 41% for ECT [1]. This surprising result may be due to the specific way the trial was designed (it was 'open-label,' meaning patients and doctors knew which treatment was given), and other studies tell a different story.

A network meta-analysis of 17 randomized controlled trials (1,370 patients) concluded that ECT had the highest probability of being the best treatment for reducing depression severity, followed by the combination of ketamine and ECT, then ketamine alone, and finally placebo [11]. A retrospective study of 146 patients found that ECT had a 67% response rate and 60% remission rate, compared to 46% and 46% for ketamine, respectively [3]. Another review of five randomized trials noted that ECT was clearly superior in terms of response rate, remission rate, and speed of improvement, especially in older patients and those with psychotic depression [10]. However, ketamine may have advantages in specific groups, such as older adults with multiple medical problems, where one small study found a 75% remission rate with few side effects [8].

Does ECT reduce suicide risk?

Yes, the evidence strongly suggests that ECT reduces both suicidal thoughts and completed suicides. A large meta-analysis of 11 studies involving over 17,000 patients treated with ECT and over 25,000 controls found that ECT was associated with a 34% reduction in the odds of suicide and a 30% reduction in death from all causes [2]. The same analysis found a moderate reduction in suicidal ideation (the severity of suicidal thoughts) after ECT [2].

A study specifically in adolescents with major depression and suicidal thoughts found that adding ECT to medication was more effective than medication alone at reducing suicidal ideation, with fewer patients still having suicidal thoughts at discharge [4]. These findings are particularly important because depression is a leading cause of suicide, and ECT's rapid action can be life-saving.

What are the risks and side effects?

The main side effect of ECT is temporary memory loss, but the evidence shows this is usually reversible. In the large ketamine-versus-ECT trial, ECT was associated with a significant decrease in memory recall after three weeks of treatment (a drop of about 10 points on a memory test, compared to a drop of less than 1 point with ketamine), but this gradually recovered over the following months [1]. A brain imaging study found that levels of a marker of neuronal health (N-acetylaspartate) decreased by 3-6% after a course of ECT but returned to baseline six months later, suggesting the changes are temporary [6].

Other side effects include musculoskeletal pain (more common with ECT than ketamine) and dissociation (more common with ketamine) [1]. Importantly, the risk of death from ECT is very low—the meta-analysis mentioned above found that overall mortality was actually lower in the ECT group than in the control group, likely because treating the depression reduces suicide risk and other causes of death [2]. Modern ECT is performed under general anesthesia with muscle relaxants, which minimizes physical discomfort.

About These Sources

This answer is built on 11 peer-reviewed studies — published from 2022 to 2025, 6 from 2024 or later, 5 in Q1 journals, collectively cited 262 times — selected as the most relevant from 15 studies that passed quality screening, drawn from 80 papers retrieved from a database of over 500 million.

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