Predicting the final response and remission of electroconvulsive therapy in treating major depressive disorder: exploring the earliest predictive factors for early improvement

BACKGROUND: To date, no study has investigated the earliest predictors of early improvement during electroconvulsive therapy (ECT) in patients with major depressive disorder (MDD). The primary objective of this study was to compare the predictive ability of the improvement rate in the 17-item Hamilton Depression Rating Scale (HAMD-17) scores after each ECT session for final treatment response and remission, thereby identifying the earliest early improvement predictors for ECT efficacy in MDD. METHODS: HAMD-17 scores were collected from 143 patients with MDD after each ECT session. Treatment response was defined as a ≥ 50% reduction in HAMD-17 scores from baseline, and remission was defined as a HAMD-17 score ≤ 7. Predictive factors identified as significant in univariate analyses (p < 0.05) were further evaluated using receiver operating characteristic (ROC) curve analysis. An area under the ROC curve (AUC) value > 0.8 was considered to indicate good discriminative ability. The earliest time point at which the AUC first exceeded 0.8 was determined as the earliest early improvement predictor for treatment outcomes. The optimal threshold of early improvement for predicting response and remission was determined using the Youden index. RESULTS: Of the 143 patients who received ECT, 76.92% achieved treatment response and 58.04% achieved remission. An improvement rate of ≥ 42.21% in HAMD-17 scores after three ECT sessions optimally predicted final response, while an improvement rate of ≥ 47.05% after four sessions optimally predicted final remission. CONCLUSION: Early improvement during the course of ECT has predictive value for treatment outcomes. Close monitoring of treatment efficacy in the early stages of ECT may facilitate timely adjustment of treatment strategies and improve overall outcomes.