Efficacy and Cognitive Side Effects of Electroconvulsive Therapy (ECT) in Depressed Elderly Inpatients With Coexisting Mild Cognitive Impairment or Dementia

Objective: To study cognitive performance in depressed geriatric inpatients with or without preexisting cognitive impairment who received a first course of electroconvulsive therapy (ECT). Method: Forty-four elderly inpatients with major depressive disorder (ICD-10 criteria) were included in a prospective consecutive case series of a university hospital. The patients were divided into 3 groups (no cognitive impairment [NCI], mild cognitive impairment [MCI], dementia) and rated for cognitive performance with the MMSE before first ECT, after sixth ECT, and 6 weeks and 6 months after ECT termination. Affective symptoms were rated by 21-tem Hamilton Depression Rating Scale (HDRS-21) before and 6 weeks after ECT. Analysis of variance or Kruskal-Wallis tests on ECT-induced MMSE and HDRS-21 score changes were compared to baseline. Binary logistic regression was used for predictor analysis. The study was conducted from April 2004 to April 2008. Results: After initial nonsignificant cognitive deterioration in all 3 groups, the NCI group improved cognitively 6 weeks (P=.018) and 6 months (P=.027) after ECT. The MCI group improved in cognition 6 months (P=.036) after ECT. In the dementia group, mean MMSE scores also improved numerically over the course of ECT without significance. Dementia patients with antidementia treatment improved in cognition to a clinically relevant extent after the sixth ECT. Dementia subjects without antidementia treatment deteriorated. After the sixth ECT, 70.0% of dementia patients (P=.004) presented a cognitive decline, and 68.8% of MCI patients (P<.001) presented a decline 6 weeks after ECT. Six months after ECT, one-third of the dementia patients (P<.036) still had a cognitive decline. Affective symptoms remitted after ECT in all 3 groups (P<.001). Pre-ECT cognitive deficits were the best predictor of MMSE decline (6 weeks after ECT, P=.007; 6 months after ECT, P=.055). Conclusions: ECT is effective and well tolerated in geriatric depressed inpatients regardless of preexisting cognitive impairment. Cognitive deficits were transient. J Clin Psychiatry 2011;72(1):91-97 (C) Copyright 2010 Physicians Postgraduate Press, Inc.