Effectiveness of maintenance electroconvulsive therapy in rapid-cycling bipolar disorder.

Objectives: : To evaluate the effectiveness of maintenance electroconvulsive therapy (m-ECT) in rapid-cycling (RC) bipolar disorder (BPD) patients.

Methods: : A population sample of 14 patients with BPD (type I or II) and an RC course were treated with m-ECT. Patients had not responded to previous treatments. Sessions of m-ECT were administered monthly and then gradually decreased in frequency upon amelioration of the course. Response to treatment was evaluated as the difference between days of illness before and after the treatment for the same 2 periods in a 2-year time frame.

Results: : We treated 14 patients with RC BPD (mean age, 46 years; 71% women; 64% with BPD type I). Mean treatment duration was 21 months. All patients improved during treatment. Eight (58%) did not relapse during the 2-year follow-up period, and 6 (42%) relapsed one time each year. Illness duration decreased 13-fold from 304 to 24 days of illness per year, and illness-free intervals increased from 52 to 334 d/yr (all P < 0.0001). A multivariate analysis showed that the factors independently associated with improvement were male sex, diagnosis of type II BPD, hyperthymic temperament, and younger age.

Conclusions: : Despite patients' clinical severity, we recorded a highly significant reduction of illness morbidity. The m-ECT had a real, long-term prophylactic effect in treating a severe clinical course such as that with rapid cycles. Notwithstanding, our study has to be considered preliminary and carries some limitations, such as its naturalistic design and relatively low number of patients recruited.