HPA axis normalization, estimated by DEX/ CRH test, but less alteration on cerebral glucose metabolism in depressed patients receiving ECT after medication treatment failures Yuuki N, Ida I, Oshima A, Kumano H, Takahashi K, Fukuda M, Oriuchi N, Endo K, Matsuda H, Mikuni M. HPA axis normalization, estimated by DEX/CRH test, but less alteration on cerebral glucose metabolism in depressed patients receiving ECT after medication treatment failures. Acta Psychiatr Scand 2005: 112: 257–265. Ó 2005 Blackwell Munksgaard. 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. N. Yuuki 1 , I. Ida 1 , A. Oshima 1 , H. Kumano 1 , K. Takahashi 1 , M. Fukuda 1 , N. Oriuchi 2 , K. Endo 2 , H. Matsuda 3 , M. Mikuni 1 Departments of 1 Psychiatry and Human Behavior and 2 Diagnostic Radiology and Nuclear Medicine, Gunma University Graduate School of Medicine, Gunma, Japan and 3 Department of Nuclear Medicine, Saitama Medical School Hospital, Saitama, Japan Key words: electroconvulsive therapy; medication treatment failures; hypothalamic-pituitary- adrenocortical function; dexamethasone/ corticotrophin-releasing hormone test; 18 F-fluorodeoxyglucose positron emission tomography Itsuro Ida, Department of Psychiatry and Human Behavior, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi-shi, Gunma 371-8511, Japan. E-mail: idai@showa.gunma-u.ac.jp Accepted for publication August 3, 2005 Significant outcomes • ECT treatments were effective to depressed patients who failed trials of antidepressant medication and showed high cortisol response in the DEX/CRH test. • Cortisol response in the DEX/CRH test was normalized after a successful course of ECT. • Depressed patients with medication treatment failures presented abnormalities of rCMRGlu in the examination by 18 F-FDG PET. These abnormalities did not resolve about 1 month after ECT treatments despite clinical remission. Limitations • This study was small sample size and open design. • Depressed subjects were maintained on medication, and not drug free. • Because we failed to perform the DEX/CRH test and 18 F-FDG PET simultaneously, we could not assess the relationship between neuroendocrinological alterations and regional brain activities. Acta Psychiatr Scand 2005: 112: 257–265 All rights reserved DOI: 10.1111/j.1600-0447.2005.00625.x Copyright Ó 2005 Blackwell Munksgaard ACTA PSYCHIATRICA SCANDINAVICA 257