The aim of the present study was to evaluate the long-term outcome in a sample of patients with bipolar disorder with severe depression or mixed-state resistant to pharmacological treatment who have responded to electroconvulsive therapy (ECT).
The study involved 36 patients with major depression (5 patients with bipolar I depression, and 14 patients with bipolar II depression) or mixed state (17 patients) treated with bilateral ECT delivered using a brief pulse stimulator Mecta 5000 Q on a twice-a-week schedule. The patients were evaluated before ECT (baseline) and 1 week after the ECT course (final score) using the Hamilton Depression Rating Scale, Mania Rating Scale, Brief Psychiatric Rating Scale, and Clinical Global Improvement. The Longitudinal Interval Follow-up Evaluation was administered every 16 weeks to assess time to relapse (defined as LIFE scores ≥5 for at least 2 consecutive weeks or as the need for hospitalization) and periods of response and remission.
The mean duration of follow-up was 55.3 ± 30.4 weeks (range, 24–160 weeks). Thirteen patients (36.1%) showed a depressive relapse during the follow-up; the mean time (length) of depressive relapse was 20.4 ± 21.8 weeks (range, 2–60 weeks). Twenty-nine patients (80.5%) fulfilled the criteria for a full remission from depressive symptoms after 6.7 ± 7.9 weeks from the last ECT. Seventeen patients (47.2%) were in remission for more than 70% of the time. No manic episodes occurred during the follow-up, only 1 patient had a mixed episode, and 11 patients had a hypomanic episode.
Electroconvulsive therapy showed a positive impact on the clinical course of severe and treatment-resistant patients with bipolar disorders, as suggested by the high number of weeks spent in remission during the follow-up period. In our study, the duration of depressive episode was related to early relapse during follow-up period.