Electroconvulsive Therapy (ECT) for Moderate-Severity Major Depression among the Elderly: Data from the PRIDE Study

Abstract Background : Electroconvulsive therapy (ECT) is usually reserved for treatment of severe major depressive disorder (MDD), but may be equally effective in the treatment of moderate-severity MDD. This possibility, however, has only been studied to a very limited extent. We therefore investigated the efficacy of ECT after stratifying patients into severe MDD and moderate-severity MDD. Methods : We used data from the Prolonging Remission in Depressed Elderly (PRIDE) study, in which 240 patients (≥60 years) with MDD were treated with right unilateral ultrabrief pulse ECT, combined with venlafaxine. We used the six-item core depression subscale (HAM-D6) of the Hamilton Depression Rating Scale to define depression severity. Participants with baseline total scores ≥12 on the HAM-D6 were considered to have severe MDD, while those with HAM-D6 total scores ≤11 were considered to have moderate-severity MDD. Results : Among the participants with severe MDD and moderate-severity MDD, the mean change in the HAM-D6 total score from baseline to endpoint was -8.2 (95% confidence interval (95%CI) = -7.5; -9.0, paired t-test: p Limitations : The PRIDE study was not designed to address this research question. Conclusions : ECT combined with venlafaxine appears to be an effective treatment for moderate-severity MDD. It may be appropriate to expand the indications for ECT to include patients with moderate-severity MDD.