Objective: The purpose of this study was to evaluate the efficacy of continuation ECT in depression.
Method: The authors used retrospective chart review to identify 29 patients who received continuation ECT plus long-term antidepressant treatment after a positive response to acute treatment with ECT for a depressive episode (continuation ECT group). A retrospective case-controlled approach was used to ascertain a matching group of 29 patients who received long-term antidepressant treatment alone after responding positively to acute ECT (antidepressant-alone group). All 58 patients (46 with unipolar depression, 12 with bipolar disorder) had been chronically depressed before receiving acute ECT. Data from medical records were analyzed by using survival analysis and proportional hazards regression to determine outcome and risk factors.
Results: The mean duration of the follow-up period for all patients was 3.9 years (5.4 years for the continuation ECT patients and 2.4 years for the antidepressant-alone patients). Outcome was significantly better in the continuation ECT group. The cumulative probability of surviving without relapse or recurrence at 2 years was 93% for continuation ECT patients and 52% for antidepressant-alone patients. At 5 years, survival declined to 73% for continuation ECT patients, but fell to 18% for antidepressant-alone patients. Mean survival times were 6.9 years for the continuation ECT patients and 2.7 years for the antidepressant-alone patients.
Conclusions: The findings provide strong support for the efficacy of continuation ECT plus long-term antidepressant treatment in preventing relapse and recurrence in chronically depressed patients who have responded to acute treatment with ECT.