Using standard self-evaluation questionnaires, numerous studies have found that subjective memory improves shortly after electroconvulsive therapy (ECT). This change covaries strongly with depression severity and is not associated with objective amnestic effects or treatment parameters. We examined subjective evaluations of ECT's cognitive effects using a novel interview that directly inquired about global impact, in contrast to the standard method of inquiring about specific aspects of cognition.
We conducted a prospective, randomized, double-masked trial comparing the effects of pulse width (0.3 vs 1.5 milliseconds) and electrode placement (right unilateral vs bilateral) on cognitive outcomes. Subjective evaluations were obtained before and during the week after the randomized ECT course, using the Cognitive Failures Questionnaire, the Squire Memory Complaint Questionnaire, and the novel Global Self-Evaluation of Memory. An extensive neuropsychological battery was administered at these time points.
Cognitive Failures Questionnaire and Squire Memory Complaint Questionnaire scores improved at post-ECT relative to pre-ECT, strongly covaried with depression severity (24-item Hamilton Depression Rating Scale scores) but not with objective amnestic deficits or treatment parameters. In contrast, the treatment conditions differed in post-ECT Global Self-Evaluation of Memory scores, and these scores were associated with objective amnestic effects.
In contrast to standard methods, direct questioning about global impact resulted in more negative views about ECT's cognitive effects, concordance with objective cognitive measures, and differences among treatment conditions. Patients may be more accurate in their assessment of ECT's adverse effects than had previously been suggested.