HYPOTHALAMUS-HYPOPHYSIS DYSREGULATION OF DEPRESSIVE PSEUDODEMENTIA AND DEMENTIA IN AGED POPULATION

The aim of this study is to elucidate the difference of hypothalamus- hypophysis dysregulation between depressive pseudodementia and dementia in aged popula- tion. Eight patients with pseudodementia due to major depression and eight patients with dementia of Alzheimer type or cerebral vascular dementia were investigated with the thyrotropin releasing hormone (TRH) stimulation test and the dexamethason supression test (DST). Plasma TSH level following injection of TRH and serum cortisol level after administration of dexamethason were measured. In the demented patients, both ΔTSH and serum cortisol level after administration of dexamethason were lower than those in the depressed patients. Since these differences were not significant, further investigation of the utility of TRH stimulation test and DST is necessary to improve our armamentarium for diagnosis and treatment of demented states