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

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.

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.

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.

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.