Early and long-term effects of electroconvulsive therapy and depression on memory and other cognitive functions.

Twenty-seven medication-free, depressed patients (Research Diagnostic Criteria, endogenous subtype) were administered a comprehensive battery testing memory and other cognitive functions before and after a series of bilateral, brief-pulse electroconvulsive therapy (ECT) administered according to a dosage-titration procedure (8.9 +/- 1.981 treatments). A subset of patients (N = 14) were reexamined at 1 month and 6 months after the conclusion of the treatment. Anterograde (verbal and visuospatial tasks), as well as retrograde (famous and personal events), memory function was significantly impaired at the end of the ECT series. By 1 month follow-up, performance had improved to pre-ECT (depression) levels on both anterograde and retrograde tasks and exceeded these by 6 months. The memory deficits induced by ECT were not a consequence of generalized cognitive impairment. Furthermore, depression and ECT were shown to independently affect memory, and recovery from depression was not a consequence of the amnestic action of the treatment. The results generally confirm previous reports regarding the nature of ECT-induced memory impairment, in a different language and culture. They suggest that long-term effects of the treatment on memory are even less prominent than previously observed.