Few systematic evaluations have been performed of the efficacy of electroconvulsive therapy (ECT) as a relapse prevention strategy in major depressive disorder (MDD). This is a single-blind, multicenter, randomized controlled trial to compare the efficacy and tolerability of pharmacotherapy plus maintenance ECT (M-Pharm/ECT) versus pharmacotherapy alone (M-Pharm) in the prevention of MDD relapse. Subjects with MDD who had remitted with bilateral acute ECT (n = 37) were randomly assigned to receive M-Pharm/ECT (n = 19, 14 treatments) or M-Pharm (n = 18) for nine months. The subjects were followed up for 15 months. The main outcome was relapse of depression, defined as a score of 18 or more on the Hamilton Depression Rating Scale. At nine months, 35% of the subjects treated with M-Pharm/ECT relapsed as compared with 61% of the patients treated with M-Pharm. No statistically significant differences between groups were indicated by either Kaplan-Meier or Cox proportional hazards regression analyses. The subjects without psychotic features were at higher risk of relapse. There were no statistically significant differences in the MMSE scores of the two groups at the end of the study. Further studies are needed to better define the indications for M-ECT in order to improve its efficacy as a relapse prevention strategy.
Keywords: electroconvulsive therapy; maintenance; major depressive disorder; prevention; recurrence; relapse.