Antidepressant and cognitive effects of twice- versus three-times-weekly ECT

The purpose of this study was to determine which of the two commonly used schedules of ECT administration, twice or three times weekly, is clinically optimal in terms of antidepressant efficacy and cognitive effects.

In this double-blind study, 52 consenting, medication-free patients with major depressive disorder, endogenous subtype (Research Diagnostic Criteria), were randomly assigned to bilateral, brief-pulse, constant-current ECT administered over 4 weeks at a rate of three times weekly or twice weekly with the addition of one simulated ECT (anesthesia and muscle relaxant only) per week. Outcome measures were the Hamilton Depression Rating Scale, Acute Cognitive Effects Battery, and Chronic Cognitive Effects Battery.

Hamilton depression scale scores were significantly improved by both schedules, with no difference in outcome either 1 week or 1 month after the end of the ECT series. However, the rate of response to ECT three times a week was significantly faster and was related to the rate of real ECT administration. Cognitive effects were more prominent with ECT three times a week.

ECT twice a week is an effective schedule for clinical practice and is potentially advantageous in view of a therapeutic outcome identical to that of ECT three times a week and less severe cognitive effects. ECT three times a week may be specifically indicated when early onset of clinical effect is of primary importance.