Systematic review and meta-analysis of the effectiveness of ECT in reducing suicidal ideation, self-harm, suicide, and mortality

Suicide and self-harm in people with depression are major public health concerns; electroconvulsive therapy (ECT) is a treatment recommended in UK clinical guidelines for severe mood disorders. We aimed to investigate published literature on the effect of ECT on the incidence of suicide, self-harm, and the recorded presence of suicidal thoughts (suicide-related outcomes). We hypothesized that ECT would be associated with a reduced incidence of suicide-related outcomes and all-cause mortality. We reviewed systematically all eligible studies as specified in our protocol (PROSPERO 293393). We included studies that compared ECT against a comparator treatment, and which included suicide-related outcomes or mortality. We searched Medline, EMBASE, and PsycINFO on January 24, 2022, updated to February 12, 2025. We identified 12,313 records and, after deduplication, screened 8,281 records on title and abstract and 212 on full-text, identifying 17 eligible studies. Studies showed significant heterogeneity in methodology, outcomes, time points chosen, and study populations. Three included studies investigated change in the suicidality domain on psychological rating scales: two showed a reduction in the ECT group; the other was underpowered for this outcome. Meta-analysis of suicide outcomes showed significant statistical heterogeneity and did not detect differences in a consistent direction. Meta-analysis of other mortality outcomes showed reductions in the risk of all-cause mortality (log relative risk [logRR]: -0.29; 95% CI: -0.53, -0.05) and non-suicide mortality (logRR: -0.21; 95% CI: -0.35, -0.07). Further high-quality studies are needed, which should seek to minimize biases (particularly confounding by indication) and report a wider range of suicide-related outcomes.