Effects of stress on the brain (A complete guide)

We have all read or heard about stress, a natural response that if given in excess can affect our health, however, do we know what happens in our brain when we suffer from stress?

In this post we will talk about stress and how it can affect the well-being of the body and mind.

Effects of stress on the brain

Changes in the brain can be responsible for the development of numerous neuropsychiatric disorders, such as post-traumatic stress disorder, anxiety and, above all, depression.

Is stress harmful? Although the answer may seem obvious, it is not that simple. In fact, the most correct answer would be “it depends”.

Let’s assume that stress is a normal component of our life. The stress response has been evolutionarily selected to deal with environmental threats that endanger our survival. For our ancestors, stress was a clear advantage, since it was necessary to get food, reproduce, find a place to shelter…

But things have changed. In our society, most of these needs are covered, and now the sources of stress are mainly social. We live in a world with high work and family demands and a fast pace of life, which is a constant challenge. This “frenzied” lifestyle encourages stress.

To this we must add that the moment we are currently living, as a result of the covid-19 pandemic, has increased social stress. An exceptional situation that generates uncertainties about the future, health, the economic situation…

In addition to the harsh social isolation due to confinement, the workload has increased (teleworking, family conciliation, children’s school support…). Without forgetting that, for young people, the pandemic has threatened their life projects and altered their lifestyle.

These circumstances can generate negative stress responses. And while the human being has mechanisms to cope with it, the impact of stress will depend on individual perception. Faced with the same stress situation, each person can react in very different ways depending on multiple factors (personality, social support, previous experiences…).

How this perception is determines what the neurobiological response to stress will be. If we are subjected to very intense or repeated stress, or if it is simply perceived as unpredictable and uncontrollable, it can have significant consequences for our health, especially for the brain.

Stress hormones

Cortisol is the main stress hormone. When we are in a stressful situation, a signal is sent to the pituitary gland that hormonally activates the adrenal glands (small glands located in the upper part of each kidney).

These are the ones that release cortisol, which when rising in the blood increases glucose levels for the whole organism, thus the organs work more efficiently, being appropriate for short times, but in no case for long ones. In addition, there are the following.

• Glucagon (in a stressful situation, the pancreas releases large doses of glucagon into the bloodstream).
• Prolactin.
• Sex hormones (such as testosterone and estrogens).
• Progesterone whose production decreases in stressful situations.

Changes that stress causes in brain structures

Suffering from chronic stress can cause various reactions in the following areas of our brain:

1. Hippocampus

One of them is the death of neurons in the hippocampus (neurotoxicity). The hippocampus located in the medial part of the temporal lobe of the brain is a structure linked to memory and learning, it belongs on the one hand to the limbic system and on the other to the archicortex, composing together with the subiculum and the dentate gyrus the so-called hippocampal formation.

It contains high levels of mineralocorticoid receptors making it more vulnerable to long-term biological stress than other brain areas.

Stress-related steroids reduce the activity of some hippocampal neurons, inhibit the genesis of new neurons in the dentate gyrus, and atrophy the dendrites of the pyramidal cells of the CEA3 region.

There is evidence of cases in which post-traumatic stress disorders can contribute to hippocampal atrophy.

In principle, some effects may be reversible if stress is interrupted, although there are studies with rats subjected to stress shortly after birth whose damage to hippocampal function persists throughout life.

2. Amygdala

The amygdala is part of the limbic system and is responsible for the processing and storage of emotional reactions. Recent research suggests that when a person is under stress, this region of the brain sends signals to the spinal cord indicating that it should increase the production of white blood cells.

The problem is that an excess of white blood cells can cause arterial inflammation, which can lead to the development of cardiovascular diseases such as strokes, angina pectoris and heart attacks. 

3. Gray and white matter

Another long-term effect of stress is the imbalance between gray matter and white matter in the brain.

Gray matter is mainly made up of cells (neurons that store and process information, and supporting cells called glia) while white matter is made up of axons, which create a network of fibers that interconnect neurons. White matter gets its name from the white, fatty myelin sheath that surrounds the axons and accelerates the flow of electrical signals from one cell to another.

Chronic stress was found to generate more myelin-producing cells and fewer neurons than normal. This produces an excess of myelin and, therefore, white matter in some areas of the brain, which changes the balance and internal communication within the brain.

How stress damages our brain?

Stress is not a disease, but a natural reaction. Therefore, it is not bad by nature. What can harm health are its consequences. One thing is also for sure: no one can escape stress because we are genetically programmed to stress.

“Stress is a physiological reaction of the organism in response to an external, physical, psychic or sensory stimulation that we interpret as threatening. And it is very good that it is like this: this reflex allows the organism to adapt quickly to various disturbing situations and, with often unforeseen “, as stated by French doctor Michel Cymes, otolaryngologist and surgeon in his latest publication ‘Pamper your brain’.

Nowadays, in addition, sources of stress are multiplying and in front of them it is not possible to flee in the opposite direction. In the end, everything is synonymous with stress, even when it is not justified.

“Specifically, it responds to a scientifically proven and defined physiological mechanism. And, although we all do not react in the same way to it, it is the same for everyone,” says the specialist.

But how does it work? To explain it, Cymes indicates that the brain detects a threat and orders the organism to prepare to face it.

“The heart and respiratory rates accelerate, the muscles are tense and certain glands secrete hormones, such as adrenaline and cortisol, among others, which help to prolong the fight in the longer term. The longer the stress lasts, the more demands are placed on it, the organism, which goes to its reserves and then runs out, “he warns.

The first characteristic symptoms of stress in the body are: tension in the neck, back and other muscles, digestive problems, fatigue, nausea, vomiting, among others.

“These can lead to cardiovascular problems and psychological disorders, as well as increase the risk of contracting diseases. Hence the importance of knowing how to manage it, something that depends largely on ourselves. How we react to stress and how we interpret the stressful stimulus can be trained up to a point”, he adds.

Stress can transform the size of the brain, its function and its structure and “not exactly for the better.” At the same time, it highlights that the reaction to stress between men and women is different.

“In general, men tend to irritability, anger, alcoholism and aggressiveness, while women take refuge in anxiety or depression. That said, there is nothing fixed. There are men who get depressed and women who they drink excessively, ” he adds.

This is how the stressed brain suffers

Although stress can cause heart, digestive, and immunological problems …, without a doubt our brain is usually the worst offended. Changes in the brain can be responsible for the development of numerous neuropsychiatric disorders, such as post-traumatic stress disorder, anxiety and, above all, depression.

The depression will be in the coming years another of the pandemics with which we will have to live. It is believed to be the most diagnosed disease in the coming decades. Possibly one in six people will experience at least one episode of depression in their lifetime.

If, as we have explained, their nervous plasticity decreases due to stress, the person would have less capacity to face the challenges of life and fewer resources to face the problems of day to day. For this reason, it could fall into a state that is known by the term of hopelessness.

On the other hand, let’s think about how we feel when we have an infection. We are more tired, without energy, without wanting to do anything … Do any of these symptoms remind us of depression? It is logical to think, therefore, that stress can cause depression.

Furthermore, exposure to stress also modifies the onset and course of many neurodegenerative diseases, including Alzheimer’s disease, which among other things is related to inflammatory and nerve plasticity alterations. Just the same ones that induce stress.

In principle, this does not seem very encouraging. But do not fall into despair. There are strategies we can use to reduce the consequences of stress.

Physical exercise, a balanced diet, social support and meditation are some examples of strategies that reduce its effects. Strategies to take into account to face the situation generated by the current pandemic.

FAQS: Effects of stress on the brain

How can you reverse the effects of stress on the brain?

• Learn to refuse to do things. 
• Disconnect. 
• Neutralize toxic people. 
• Do not hold a grudge. 
• Practice mindfulness. 
• Put things in perspective. 
• Use a support system.

How does stress affect the mind and body?

Stress weakens our body and is related as a trigger for diseases of different kinds, such as heart disease or tumors. What’s more, it also favors accidents and the appearance of mental illnesses that can lead to suicide.

What stress can do to your body?

Body stress may lead to serious health issues such as heart disease, high blood pressure, diabetes and other diseases such as depression or anxiety, including mental disorders.

Can stress cause neurological symptoms?

Symptoms of functional neurological disorders can appear suddenly after a stressful episode, or with physical trauma or emotional trauma.

Can a chemical imbalance in the brain be cured?

Medicines or pills can temporarily modify the chemistry of your brain, but they have little power to alter neuronal pathways or connections. There is a transient chemical alteration in the brain triggered by the drug.

In this post we talked about stress and how it can affect the well-being of the body and mind.

If you have any questions or comments please let us know!

References

de Kloet, E. R. (2003). Hormones, brain and stress. Endocrine regulations, 37(2), 51-68.

Yaribeygi, H., Panahi, Y., Sahraei, H., Johnston, T. P., & Sahebkar, A. (2017). The impact of stress on body function: A review. EXCLI Journal, 16, 1057–1072. https://doi.org/10.17179/excli2017-480

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Harvard Health Publishing. (2020). Protect your brain from stress – Harvard Health. Retrieved November 23, 2020, from Harvard Health website

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