Hyperactivity in the hypothalamic-pituitary-adrenal axis in demented patients with delirium

Occurrence of delirium is known to be related to, among other things, organ ic brain disorder, somatic disease and old age. It has been hypothesized th at delirium is also associated with stress. Disturbances of the hypothalami c-pituitary-adrenal (HPA) system have been found in delirious patients in v arious studies. The aim of the present study was to determine the activity in the HPA axis in demented patients to ascertain whether the stress regula ting system was more disturbed in patients with delirium than in those with out delirium. Demented inpatients with no acute medical illness were includ ed in the study, Basal cortisol levels in serum were measured and dexametha sone suppression test (DST) was performed, The most important finding of th e study was a strong relationship between delirium and DST pathology irresp ective of age and severity of dementia, It is suggested that certain dement ed individuals have an impaired HPA system and a low delirium threshold and respond to stress with delirium. Int Clin Psychopharmacol 16:39-47 (C) 200 1 Lippincott Williams & Wilkins.