Alzheimer’s Deterioration: The Hidden Danger of Chronic Stress

Around the world, 44 million people experience Alzheimer's disease, which is the most common form of dementia, and it is the 6^th leading cause of death in America alone. Alzheimer’s is a serious disease that does not only affect the person that has it but also everyone surrounding them. Many of those who have this type of disease are expected to live only up to 4-8 years. It is a disease that kills brain cells, which results in a lack of long-term memory. However, the first signs of Alzheimer's disease usually involve short-term memory loss.

There is still no definitive answer on what causes Alzheimer’s disease as it is still a puzzle to many experts. However, many studies show that chronic stress might be one of the factors that can affect the development of Alzheimer’s.

The link between chronic stress and Alzheimer’s

Stress is defined as the body’s response to challenging situations. Everyone experiences stress in short-term, such as in fight-or-flight situations. Stress alerts the body that it needs an immediate response to what is happening. Some of the symptoms of stress are sweating and heavy pounding of the heart, but it will stop once the situation has passed. However, once it gets too frequent, it might become chronic. While it is a completely natural response of the body, chronic stress affects the physical and mental well-being of a person by releasing a hormone called cortisol.

Chronic stress can affect the brain through the release of cortisol which can cause depression and memory problems. While the release of cortisol might be benign in small amounts, research shows that a large amount of this hormone can cause further memory problems such as Alzheimer’s disease.

In a study published in The Journal of the Alzheimer’s Association, the researchers found out through neuroimaging that chronic stress can cause a decrease in the gray matter volume of the hippocampus, the part of the brain that is in charge of long-term memory.  This can cause the degeneration of memory due to the hippocampus’ impaired function.

Another study also uses mice to show that mice with Alzheimer’s have a count of stress hormones than those without. There are also significant damages to the brain as compared to those not affected by Alzheimer’s.

Rats injected with cortisol are also known to have memory impairments while lowering cortisol levels improve memory even in already old rats. This shows that high levels of cortisol affect the regulation of HPA axis, a neuroendocrine system that controls how the body will react to stress.  This results in a lower volume in the hippocampus and leads to memory deficits.