Increased cerebrospinal fluid cortisol level in Alzheimer's disease is not related to depression

Hypothalamo-pituitary-adrenal (HPA)-axis hyperactivity is well established in a large proportion of both Alzheimer's disease (AD) patients and idiopathic depression patients, resulting in, e. g. increased cerebrospinal fluid (CSF) cortisol levels. We hypothesized that HPA-axis activity in depressed AD patients is even more increased than in non-depressed AD patients, resulting in higher CSF cortisol levels. Cortisol levels were measured in post mortem CSF of depressed and non-depressed AD patients and in controls. Cortisol levels in AD patients were more than double those of controls, while no significant differences were found between depressed and non-depressed AD patients. These results suggest a different pathogenetic mechanism in depression in AD than in idiopathic depression. (C) 2005 Elsevier Inc. All rights reserved.