Continuation electroconvulsive therapy vs pharmacotherapy for relapse prevention in major depression: a multisite study from the Consortium for Research in Electroconvulsive Therapy (CORE).

Background: Although electroconvulsive therapy (ECT) has been shown to be extremely effective for the acute treatment of major depression, it has never been systematically assessed as a strategy for relapse prevention.
Objective: To evaluate the comparative efficacy of continuation ECT (C-ECT) and the combination of lithium carbonate plus nortriptyline hydrochloride (C-Pharm) in the prevention of depressive relapse.
Design: Multisite, randomized, parallel design, 6-month trial performed from 1997 to 2004.
Setting: Five academic medical centers and their outpatient psychiatry clinics.
Patients: Two hundred one patients with Structured Clinical Interview for DSM-IV-diagnosed unipolar depression who had remitted with a course of bilateral ECT.
Interventions: Random assignment to 2 treatment groups receiving either C-ECT (10 treatments) or C-Pharm for 6 months.
Main Outcome Measure: Relapse of depression, compared between the C-ECT and C-Pharm groups.
Results: In the C-ECT group, 37.1% experienced disease relapse, 46.1% continued to have disease remission at the study end, and 16.8% dropped out of the study. In the C-Pharm group, 31.6% experienced disease relapse, 46.3% continued to have disease remission, and 22.1% dropped out of the study. Both Kaplan-Meier and Cox proportional hazards regression analyses indicated no statistically significant differences in overall survival curves and time to relapse for the groups. Mean +/- SD time to relapse for the C-ECT group was 9.1 +/- 7.0 weeks compared with 6.7 +/- 4.6 weeks for the C-Pharm group (P = .13). Both groups had relapse proportions significantly lower than a historical placebo control from a similarly designed study.
Conclusions: Both C-ECT and C-Pharm were shown to be superior to a historical placebo control, but both had limited efficacy, with more than half of patients either experiencing disease relapse or dropping out of the study. Even more effective strategies for relapse prevention in mood disorders are urgently needed.