File under “Stress is bad for you, Reason #6508.” Chronic stress increases the expression of the amyloid precursor protein (APP); the abnormal processing of this protein is a key event in the development of Alzheimer’s disease (AD).

Of course that’s not the whole story: Numerous factors contribute to the pathologenesis of AD, including inflammatory factors secreted by glial cells; this is likely exacerbated by glial senescence, which accumulates with age.