HPA axis normalization, estimated by DEX/CRH test, but less alteration on cerebral glucose metabolism in depressed patients receiving ECT after medication treatment failures

Abstract

OBJECTIVE: To examine the clinical effects of electroconvulsive therapy (ECT) on depressed patients with medication treatment failures, we investigated the alterations in hypothalamic-pituitary-adrenocortical (HPA) function and regional cerebral metabolism rate of glucose (rCMRGlu) after ECT in these patients. METHOD: Before and after ECT, the combined dexamethasone/corticotrophin-releasing hormone (DEX/CRH) test was administered to seven patients who were referred for ECT. In the same patients, (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) was also assessed. RESULTS: Cortisol response in the DEX/CRH test significantly decreased after a successful ECT. A significant hypometabolism in various frontal regions and hypermetabolism in the parietal regions of these patients when compared with controls remained after ECT. CONCLUSION: Depressed patients who failed trials of antidepressant medication showed a remission with ECT that was accompanied by resolution of HPA dysregulation. However, measures of cerebral brain metabolism did not resolve.