Predictors of Electroconvulsive Therapy Outcome in Major Depressive Disorder

Background: Electroconvulsive therapy (ECT) is an effective therapy for major depressive disorder (MDD) patients. However, few clinical predictors are available to predict the treatment outcome. This study aimed to characterize the response trajectories of MDD patients undergoing ECT treatment and to identify potential clinical and demographic predictors for clinical improvement. Methods: We performed a secondary analysis on data from a multicenter, randomized, blinded, controlled trial with 3 ECT modalities (bifrontal, bitemporal, unilateral). The sample consisted of 239 patients whose demographic and clinical characteristics were investigated as predictors of ECT outcomes. Results: The results of growth mixture modeling suggested there were 3 groups of MDD patients: a non-remit group (n = 17, 7.11%), a slow-response group (n = 182, 76.15%), and a rapid-response group (n = 40, 16.74%). Significant differences in age, education years, treatment protocol, types of medication used, Hamilton Depression Scale, Hamilton Anxiety Scale score, Mini-Mental State Examination score, and Clinical Global Impression score at baseline were observed across the groups. Conclusions: MDD patients exhibited distinct and clinically relevant response trajectories to ECT. The MDD patients with more severe depression at baseline are associated with a rapid response trajectory. In contrast, MDD patients with severe symptoms and older age are related to a less response trajectory. These clinical predictors may help guide treatment selection.