Early improvement predicts outcome of major depressive patients treated with electroconvulsive therapy.

The aim of this study was to test whether early symptom improvement predicts final response and remission for patients with major depressive disorder (MDD) receiving electroconvulsive therapy (ECT). MDD inpatients (N=130) requiring ECT were recruited. ECT was generally performed for a maximum of 12 sessions. Symptom severity was assessed using the 17-item Hamilton Depression Rating Scale (HAMD-17) before ECT, after every 3 ECT sessions, and after the last ECT. Early improvement was defined as a reduction in the HAMD-17 score by at least 20%, 25%, or 30% after 3 and 6 ECT sessions. Response was defined as 60% HAMD-17 score reduction, while remission was defined as an end point HAMD-17 score of ≦7. Receiver operating characteristic (ROC) curves were used to determine whether 3 or 6 ECT sessions had better discriminative capacity. Sensitivity, specificity and predictive values were calculated for the different definitions of early improvement. Of the 105 patients entering the analysis, 85.7% (n=90) and 70.5% (n=74) were classified as responders and remitters, respectively. Early improvement after 6 ECT sessions showed better discriminative capacity, with areas under the ROC curve at least 0.8. It had high sensitivity and high negative predictive value for all cutoffs in predicting response and remission. High response and remission rates were observed. Final response and remission could be predicted by early improvement after 6 ECT sessions. Patients without early improvement were unlikely to reach response and remission.