A comparison of some retrograde and anterograde effects of electroconvulsive shock in patients with severe depression.

Seventy severely depressed patients were randomly assigned to receive either a standard course of bilateral electroconvulsive therapy (ECT) or a course of simulated ECT (muscle relaxant and anaesthesia) identical to the real course except that the shock was omitted. Anterograde amnesia due to the shock was demonstrated in recognition memory for word lists and in recall of labels for faces, but this was eliminated by priming. Retrograde amnesia was also present for labels for faces learned the day before a treatment, but this was not eliminated by priming. Recognition memory for material learned in the remote past was better in the patients who had received shock than in those who had received only anaesthetic.