Self-Harm and Suicide Attempts Preceding and Following Electroconvulsive Therapy: A Population-Based Study.

OBJECTIVE The beneficial effect of electroconvulsive therapy (ECT) on suicidality has been documented in clinical trials, whereas naturalistic studies on the topic are scarce and restricted to individuals with mood disorders. Here, based on population-based data from Danish registers, we aimed to investigate the course of self-harm and suicide attempts preceding and following ECT across 4 major mental disorders. This was done to examine whether data from the real-world clinical setting are compatible with the positive results from clinical trials. METHODS We identified all patients diagnosed with unipolar depression (n = 8843), bipolar disorder (n = 2713), psychotic disorder (n = 2692), or personality disorder (n = 2085) who received ECT for the first time in the period from 2008 to 2019, as well as age-, sex-, diagnosis-, illness duration-, and admission-matched comparison groups not receiving ECT. A mirror-image model was used to examine whether the number of incidents of self-harm/suicide attempts changed following ECT (paired t test). RESULTS There were substantial and statistically significant reductions in the number of incidents of self-harm/suicide attempts when comparing the month leading up to and the month following initiation of ECT for all diagnostic groups (unipolar depression: reduction, 83% [P < 0.001]; bipolar disorder: reduction, 72% [P < 0.001]; psychotic disorder: reduction, 82% [P < 0.001]; personality disorder: reduction, 83% [P < 0.001]). The analog results for the comparison groups not receiving ECT suggested that these reductions in self-harm/suicide attempts were partly mediated by a protective effect of admission. CONCLUSIONS Data from the real-world clinical setting are compatible with results from clinical trials with regard to the protective effect of ECT on suicidality.