According to Australian researchers, chronic stress can contribute to the development of Alzheimer’s disease. The authors identified key genetic stress factors that affect neurodegeneration. The results are published in the journal Biological Reviews.
Chronic psychosocial stress is increasingly cited as one of the causes of Alzheimer’s disease. Australian scientists led by David Groth of Curtin University’s Institute for Medical Innovation looked at environmental and genetic factors that can affect the hypothalamic-pituitary-adrenal axis (HPA axis) — the main neuroendocrine system that regulates many processes in the body, including digestion, the immune system, mood and emotions, sexuality, energy storage and expenditure, and manages responses to stress.
The hypothalamic-pituitary system determines the interactions between glands, hormones, and parts of the brain. Under stress, it regulates the production of the glucocorticoid hormone cortisol, produced by the adrenal cortex. Patients with Alzheimer’s disease often report a malfunction in the system and, as a result, an increased level of cortisol.
According to the authors, genetic stress factors within the HPA axis and other pathways can affect the functioning of the brain’s immune system. When the disorders are regular, such as in the case of chronic stress, it increases the risk of dementia and contributes to the development of Alzheimer’s disease.
“We know that chronic stress affects many biological pathways in the body. There is a close relationship between the effects of chronic stress and the pathways that affect the body’s response to such stress,” David Groth said in a press release. “Genetic variations within these pathways can affect the behavior of the brain’s immune system, leading to a dysfunctional response. In the brain, this leads to chronic disruption of normal brain processes, increasing the risk of subsequent neurodegeneration and, ultimately, dementia.”
The authors described the mechanisms by which genetic factors of chronic stress affect the HPA axis, causing inflammation in the brain — the main cause of neurodegeneration. According to scientists, genetic factors change the immune response of brain cells and microglia, which contributes to the emergence of a neurotoxic environment.
Scientists believe that their discovery will contribute to the development of new recommendations for taking glucocorticoids for stress management, based on the individual characteristics of patients, which are due to a combination of genetic and environmental factors, which will ultimately help reduce the risk of developing Alzheimer’s disease in the population.