Subjective memory complaints: a review of patient self-assessment of memory after electroconvulsive therapy

Interest in patients' subjective complaints about the adverse cognitive effects of electroconvulsive therapy (ECT) spans several decades. This article reviews the major areas that have been examined in relation to patients' subjective assessment of memory function: 1) technical aspects in the administration of ECT; 2) objective tests of cognitive function; and 3) clinical state. For the most part, subjective assessments of memory following ECT have relied on a single instrument, the Squire Subjective Memory Questionnaire (SSMQ). While older reports of the impact of the technical aspects of ECT on subjective memory assessment following ECT suggest a detectable negative influence with certain forms of treatment, most recent studies indicate that subjective memory improves following ECT. This shift in findings may be due to the change in practice from sine wave to brief-pulse ECT. While the impact of ECT on objective tests of memory is clear and reproducible, the relationship of objective findings to subjective memory assessment appears to be weak. Instead, subjective reports of cognitive function are strongly influenced by mood state. Current batteries of objective tests of memory may not include components that are most affected in reports about subjective memory. In addition, the literature mainly reports group effects, and sample sizes have been small. We lack data on the number of individuals who believe ECT has had a markedly negative effect on memory functioning, and on the characteristics of memory function in this subgroup of patients who complain of severe impairment. Furthermore, there is a paucity of information relating patient characteristics to subjective memory outcomes with ECT.