There is no consensus regarding whether a previously prescribed, that is, failed, antidepressant should be continued or switched after a successful electroconvulsive therapy (ECT) for the maintenance of clinical remission in patients with treatment-resistant depression (TRD). In this study, we conducted a chart review to examine impacts of the antidepressant switch after the successful ECT on 1-year outcome in patients with TRD. This retrospective chart review included inpatients with TRD (ie, those who failed to respond to adequate trials of 2 distinctly different classes of antidepressants) who showed clinical remission after ECT. Readmission rate and social functioning 6 months and 1 year after the successful ECT were compared between patients who experienced an antidepressant switch and those who continued prior regimen. Twenty-eight patients (mean age, 59 years; 9 men) were followed-up for 1 year. The patients who changed antidepressants after ECT (n = 7) experienced a readmission significantly less frequent than the others (n = 21) in 1 year (0% vs 43%, P = 0.043). In addition, the former showed significantly better social contacts at 6 months (P = 0.022) and 1 year (P = 0.015). There were no significant differences in baseline characteristics between the 2 groups. The patients who experienced an antidepressant switch after ECT required a readmission less frequently in 1 year than those who were maintained with the same antidepressant. The findings of this preliminary study suggest that a switch to another antidepressant after successful ECT may be encouraged for the maintenance of clinical remission in patients with TRD.