Clinical characteristics associated with relapse 2 years after electroconvulsive therapy for major depression

Objective: High relapse rates are observed after electroconvulsive therapy (ECT) for major depression. Identifying patients who are at increased risk for relapse to intensify their treatment regimen post-ECT might reduce relapse rates. We aimed to determine clinical characteristics that are associated with relapse within 2 years after successful ECT. Methods: Patients who remitted to ECT in a randomised controlled trial comparing adjuvant nortriptyline and placebo during a course of bilateral ECT were followed-up prospectively for 1 year with open-label nortriptyline (Dutch Trial Register NTR5579). Second-year follow-up data were collected retrospectively. Thirty-four patients were included in this follow-up cohort. To examine the association between clinical characteristics and the risk of relapse, unadjusted hazard ratios (HRs) were calculated. Results: At 2 years post-ECT, the overall relapse rate was 50%, and the HRs for relapse in patients with psychotic features, a higher severity of depression, and medication resistance prior to ECT were 0.33 (CI 0.12–0.89; p = 0.029), 0.88 (CI 0.80–0.98; p = 0.014), and 4.48 (CI 1.28–15.73, p = 0.019), respectively. No effect was found for age, sex or episode duration on the relapse rate. Conclusions: Depressed patients with psychotic features, with higher symptom severity and without medication resistance prior to ECT have a significantly decreased risk of relapse after successful ECT. A sustained remission rate of 50% over 2 years in patients with severe major depression who were treated with nortriptyline monotherapy after successful ECT is encouraging.