The long-term effects of electroconvulsive therapy (ECT) on the risk of stroke are unknown. We examined the association between ECT and risk of incident or recurrent stroke. A cohort of 174 534 patients diagnosed with affective disorder between 2005 and 2016 in the Danish National Patient Registry were followed for stroke until November 2016. The association between ECT and stroke was analysed using Cox regression with multiple adjustment and propensity-score matching on sociodemographic and clinical variables. In 162 595 patients without previous stroke, 5781 (3.6%) were treated with ECT. The total number of patients developing stroke during follow-up was 3665, of whom 165 had been treated with ECT. In patients <50 years, ECT was not associated with stroke (adjusted hazard ratio (HR) = 1.29, 95% CI 0.87–1.93). In patients ≥50, ECT was associated with a lower risk of stroke (adjusted HR = 0.69, 95% CI 0.57–0.89), but this estimate was likely influenced by competing mortality risk. Of 11 939 patients with a history of stroke, 228 (1.9%) were treated with ECT. During follow-up, 2330 (19.5%) patients had a recurrence, of which 26 were patients treated with ECT. ECT was not associated with risk of a new event (HR = 0.69, 95% CI 0.46–1.00; P = 0.05). ECT is not associated with an elevated risk of incident or recurrent stroke.
Declaration of interest