As in most diseases involving mental function, the origin of Alzheimer's Disease is probably a complex interaction between heredity, early development and environmental influences . The focus of this web piece concerns how chronic stress might play a part in the onset of the disease. Damage to the hippocampus results in overactivity of the HPA axis, progressively higher levels of cortisol given off by the adrenal cortex, which leads to increasing destruction to the hippocampus.
Chronic stress leads to overproduction of cortisol which has a damaging effect on the hippocampus.
As more nerve cells in the hippocampus are lost, there is over-secretion of cortisol. There is speculation that this type of disregulation plays a role in the onset of Alzheimer's disease. There appears to be elevated basal cortisol levels in Alzheimer patients. Alzheimer patients seem to show excess cortisol responses to stress. Cortisol reduces hippocampal glucose metabolism in normal elderly, but not in Alzheimer's Disease.