The EFFECT-Dep Trial - A randomised trial of bitemporal and high-dose unilateral ECT for depression (ISRCTN23577151)

Introduction: Electroconvulsive therapy (ECT) is the most effective treatment for severe depression. Previous efficacy studies, using thrice-weekly brief-pulse ECT, reported that high-dose (6x seizure threshold) right unilateral (RUL) ECT is similar to standard bitemporal ECT but has less cognitive side-effects. We assessed effectiveness and cognitive side-effects of twice-weekly moderate dose (1.5x seizure threshold) bitemporal ECT compared with high-dose RUL ECT. Methods: We conducted a pragmatic, patient- and raterblinded, non-inferiority trial of 138 patients with major depression (DSM-IV) in a national ECT service. Participants were remotely randomised online to bitemporal or high-dose RUL ECT with sixmonth follow-up. Primary outcome was change in 24-item Hamilton Depression Rating Scale (HDRS-24) after the ECT course; pre-specified non-inferiority margin was 4.0 points. Secondary outcomes included cognition. Analyses were by intention-to-treat. Results: We randomised 69 patients to bitemporal ECT and 69 to RUL ECT. High-dose RUL ECT was non-inferior to bitemporal ECT with respect to the HDRS-24 at end of ECT course (mean difference 1.2 points in favour of RUL ECT [95% CI, -1.510 to 3.995]). There was no significant difference for six-month relapse status. Recovery of orientation was quicker following RUL ECT (median 19.1 vs 26.4 mins, p<0.001). RUL ECT was associated with better % recall of autobiographical information (OR = 0.66, p = 0.001) that persisted for six-months. Conclusion: Twice-weekly high-dose RUL ECT is not inferior to bitemporal ECT for depression, and may be more acceptable to patients because of its better cognitive side-effect profile.