Cognitive Side-effects of Electroconvulsive Therapy in Elderly Depressed Patients

Abstract

Knowledge about cognitive side-effects induced by electroconvulsive therapy (ECT) in depressed elderly patients is sparse. In this study we investigated changes in the cognitive functioning of non-demented elderly depressed patients receiving ECT (n = 62) compared with healthy elderly people (n = 17). Neuropsychological tests were administered at the start of treatment and again within 1 week after treatment. We computed reliable change indices (RCIs) using simple regression methods. RCIs are statistical methods for analyzing change in individuals that have not yet been used in studies of the acute cognitive side-effects of ECT. At the group level, only letter fluency performance was found to be significantly reduced in the ECT group compared with the controls, whereas both groups demonstrated stable or improved performance on all other measures. At the individual level, however, 11% of patients showed retrograde amnesia for public facts post-ECT and 40% of the patients showed a significant decline in neuropsychological functioning. Decline on a measure of delayed verbal anterograde memory was most common. Our findings indicate that there are mild neurocognitive impairments in the acute phase for a substantial minority of elderly patients receiving ECT. Analysis of reliable change facilitated the illumination of cognitive side-effects in our sample.

Keywords:

• Adverse cognitive effects
• Amnesia
• ECT
• Executive function
• Reliable change.

ACKNOWLEDGMENTS

This work was supported by the Norwegian ExtraFoundation for Health and Rehabilitation through the Norwegian Council for Mental Health under Grant number 2011/2/0009; and Diakonhjemmet Hospital. We would like to thank the participants for their essential contribution to the study. Registered nurse Marianne Larsen offered extensive and skillful assistance with neuropsychological testing. We would also like to thank the staff in the Department of Geriatric Psychiatry for their support and engagement in the study. We are thankful for valuable supervision by Ivar Reinvang, Professor in Neuropsychology, in planning the study and creating the Media Questionnaire. No conflicts of interest exist.