Ketamine vs. electroconvulsive therapy for severe depression with suicidal thoughts

The question

For people with severe depression and active suicidal thoughts, how does intravenous ketamine compare with electroconvulsive therapy (ECT) in terms of speed of improvement, overall benefit and side effects?

What they did

Researchers at a tertiary care psychiatry department in India enrolled 64 patients aged 18 to 60 with severe depression (a score of 19 or more on the Hamilton Depression Rating Scale) and suicidal ideation (a score of 4 or more on the Scale for Suicide Ideation). Participants were randomly assigned to intravenous ketamine (31 people) or ECT, a procedure that uses a brief electrical stimulus to trigger a seizure under anaesthesia (33 people). Both groups had six sessions over two weeks while continuing their oral antidepressants. Depression and suicidal thinking were measured at the start, right after treatment, and four weeks later.

What they found

Both treatments significantly reduced depression and suicidal thinking (p < 0.001). By the four-week follow-up, Hamilton depression scores fell from 27 to 1 in the ECT group and from 26 to 2 in the ketamine group. Suicidal ideation scores fell from 12.1 to 1.2 with ECT and from 12.6 to 2.0 with ketamine. The authors report that ketamine acted faster, while ECT showed slightly more durable results. Side effects were described as mild in both groups: temporary thinking and memory problems with ECT, and minor dissociation (feeling detached from oneself or surroundings) and urinary symptoms with ketamine.

The fine print

With 64 people at a single centre, the study is small, and neither patients nor raters could realistically be blinded to whether someone received ketamine infusions or ECT. Follow-up ended four weeks after treatment, so longer-term durability and relapse rates are unknown. The abstract reports the claims about faster onset and greater durability without supporting statistics, and gives no confidence intervals or between-group comparison numbers. This summary is based on the abstract alone.

What it means

In this trial, ketamine and ECT both produced large reductions in depression and suicidal thinking over two weeks, with ketamine appearing to work sooner and ECT appearing to hold slightly longer; the two had different side effect patterns.

Evidence grade: Moderate. A randomized controlled trial, but small, at a single centre, with a short follow-up and no placebo or blinding of the two very different treatments.

This summary is based on the study’s published abstract.