Written by Sara Bozyel
We all experience stress at some point in our lives. It is such a condition that can come as a huge reflection of emotions, like a panic attack, or an inconspicuous reaction of thoughts, like a tremble in the legs. Well, as it turns out, we can define stress as a good thing since it helps our body and brain stay sharp and on alert, but chronic stress can cause many diseases such as anxiety, depression, or even heart diseases caused by high blood pressure.
Stress is the fight or flight response to a perceived threat (1). When we are stressed, the “fear center” of the brain, called the amygdala, activates our central stress response system and regulates the stress hormone cortisol (1). It causes an increase in glucose levels, a speed at the heart rate, and an increased blood flow to the muscles in our arms and legs. After the threat passes, the body eventually turns back to normal.
When the stress becomes chronic, the fear system of the brain stays active nonstop which means that the body is in a constant state of stress. Cortisol levels are constantly elevated, which, over time, starts to cause problems with digestion, sleeping, and the immune system (1). When one part of the brain is constantly engaged, the other parts start to lose the ability to carry out their functions properly, and it's just a little flaw besides the other impacts that stress causes in our brain.
Chronic stress impairs memory, and the high level of cortisol causes short-term memory declines (1). The research shows that people who are stressed are more likely to be forgetful and less likely to remember specific details. For instance, being late for school can cause us to forget the simple things we need, like where our books are.
Chronic stress causes changes in the brain’s structure, our brain is composed of both gray and white matter. The gray matter serves to process information in the brain, it's used for problem-solving and decision-making. The white matter refers to the parts of the brain and spinal cord that provide communication between the gray matter regions and between the gray matter and the rest of the body. In essence, gray matter is where the processing finalizes, and the white matter is on the channel of communication. It appears that during times of chronic stress, the myelin sheaths that make up white matter become overproduced, while the gray matter is less produced. When this happens, an imbalance between the gray and white matter appears. In some cases, this situation ends up with permanent changes to the brain’s structure.
Chronic stress makes us more susceptible to mental illness, an imbalance between the matters of the brain can affect the development of mental illness (1). Having an excessive level of myelin in certain areas of the brain interferes with the timing and the balance of communication. Chronic stress can negatively alter hippocampal function; the hippocampus is a brain structure that has a major role in learning and memory (1).
Stress kills brain cells; it appears that stress can kill even the new neurons in the brain’s hippocampus, one of the two places where neurons are produced (1). According to studies, neurons produced during stress are more likely to die within a week.
Stress shrinks the brain; it has been found that chronic stress causes the parts of the brain which are related to emotions, metabolism, and memories to shrink (1). Chronic stress also makes people more available to experience brain shrinkage when they are exposed to intense stressors (1). This means that people who are under constant stress may find it harder to handle in the future.
Stress is not all bad for our brain; in fact, moderate stress can develop brain performance by consolidating the connection between our neurons in the brain. It is what keeps us going, as long as we won’t let it consume us.
References
Alyssa. (2021, September 20). 6 ways stress affects your brain. Premier Neurology & Wellness Center. https://premierneurologycenter.com/blog/6-ways-stress-affects-your-brain/.
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