Twenty-two patients suffering from intractable recurrent unipolar or bipolar mood disorders were enrolled in a maintenance-ECT protocol (ECT-M) for more than 18 months, with a treatment at approximately monthly intervals. Eleven have continued treatment for > 2 years. Whereas 44% of the year had been spent in the hospital with at least three episodes a year prior to ECT-M, only 7% of the year was spent in the hospital during ECT-M with only one relapse every 16 months requiring admission (p < 0.001). Forty-five percent of the patients were in full remission and 27% in partial remission according to DSM-III-R criteria. ECT-M responsiveness of rapid-cyclers and delusional depressed patients usually drug refractory has been very encouraging with full or partial remission for 100% of rapid-cyclers and 80% of delusional depressed patients.