Depression and the brain – how stress affects the body.

After the holiday break I resume my serie about the brain and depression. The topic of today is stress. I’ll try to answer the question how stress occurs in the body and what consequences are possible when something doesn’t work out as intended. There is an interesting link to depression possible.


Stressful life events.


Life has its ways and in one form or another we all do encounter stressful events in our life. That can be all kinds of things, a divorce, an illness, the death of a loved one, losing your job, violence, abuse. Although stress plays a big role in developing a mood disorder, not everyone who is faced with life’s challenges experience one. In fact, most people don’t.


In my previous post I explained how your genes play a role in how sensitive you are to stressful life events. The combination of your genes, your brain and stressful life events can result in depression.


In this post I’m going to talk about stress and its own physiological consequences. Stress triggers a chain of chemical reactions and responses in the body. Our bodies are designed to cope with a certain intensity and amount of stress. When stress is short-lived, we recuperate ‘as normal’. When stress becomes chronic or the system gets stuck in overdrive, long lasting consequences can occur in body and brain.



How stress affects the body.


Stress is an automatic physical reaction to a stimulus that forces you to adapt to change. You notice something and you need to adapt to that. This stimulus can be internal (feeling pain for example) or external (something appears to fall on your head for instance). Every real or perceived danger triggers a cascade of stress hormones that produce physiological changes. You know when you panic! You can notice your stress response in your heartbeat going faster, your breathing becomes more shallow, your muscles tense, your focus diminishes and maybe you sweat a little or a lot.


The stress response starts in your brain, more precisely in the hypothalamus. Together with the pituitary glands and the adrenal glands the hypothalamus forms the HPA-axis. The H(ypothalamus)-P(ituitary)-A(drenal) – axis plays a role in different hormonal changes in the body and it also plays a role in depression.


What does happen in our body when a threat is perceived?


The hypothalamus will release a corticotropine releasing hormone (CRH) that stimulates your body. Hormones travel through your body to organs and groups of cells to deliver a certain message, which in turn will result in a certain response. It’s like a dance or a conversation, action reaction. So from the hypothalamus CRH travels to the pituitary gland where it stimulates the secretion of ATCH (adrenocorticotropic hormone) which goes into your bloodstream to arrive in the adrenal glands. The adrenal glands release cortisol.


Stress and the body.


Cortisol will make your body and mind ready to fight or flee, but you will react, that is for sure. What are signs that your body is the fight or flight modus?

  • your heartbeat goes up, it can be 5 times faster than normal and your blood pressure rises.
  • your breath quickens to take in more oxygen to transport to your muscles and vital organs.
  • your senses like your hearing and sight become more sharp. You focus on the threat, you get tunnel vision. And your mind also focusses on the threat, you focus.


Remember the hypothalamus that produces CRH that travel into our axis (the pituitary and adrenal glands)? CRH (corticotropine releasing hormone) does other things too. It affects the cerebral cortex, part of the amygdala and the brainstem. It is thought to play a major role in coordinating your thoughts and behaviors, emotional reactions, and involuntary responses. It influences the concentration of neurotransmitters throughout the brain. Disturbances in hormonal systems, therefore, may well affect neurotransmitters, and vice versa.


Now we know what happens to our body under stress, what can possibly go wrong?

As you read the system is quite perfect and that one action leads to another reaction. We fight or flee when necessary and therefore we can protect our life. Normally a feedback loop disables the fight or flight reaction when the threat is gone and the body can recuperate in its normal state.


In some cases the feedback loop doesn’t work as it should and the levels of cortisol (which is responsible for the fight or flight modus) rise too high or just stay too high. This can contribute to problems such as trouble staying asleep, high blood pressure, immune suppression and possibly depression.


Studies have shown that people who are depressed or have dysthymia typically have increased levels of CRH. Antidepressants and electroconvulsive therapy are both known to reduce these high CRH levels. As CRH levels return to normal, depressive symptoms recede.


Research also suggests that trauma during childhood can negatively affect the functioning of CRH and the HPA axis throughout life. Next week I’ll look deeper into the topic of trauma. I hope you enjoyed this installment and I also hope to see you again next week. Any questions, encouragements or remarks are – as always – welcome in the comments.




Full article click here.

Picture credits click here.

21 thoughts on “Depression and the brain – how stress affects the body.

      1. You’re welcome! Thanks! That’s the goal I’m focusing on now. I’m trying to speak it into existence and get this certification so I can go ahead and get started! 😊

        Liked by 4 people

  1. Hi Kacha, another great informative post. I hope you mind if I mention another Response. When fight and flight will not work, the brain elicits from the body a ‘freeze’ response. It is thought that the immobility produced by a freeze response has a number of advantages from a survival perspective, including not being detected by a predator.

    But the body is also flooded with endogenous opioids, and there is a protective numbing of the body and mind in the event of inevitable harm. Being immobile prevents further injury when wounded and allows the body the best chance to survive and recover.

    The ‘freeze’ response is exceptionally common in child sexual abuse – the brain kicks into a ‘freeze’ response and the child is literally frozen and paralysed.

    Unfortunately, many abusers take this response to mean consent, and many survivors feel terrible shame for not having fought back or tried to escape. However, they had no choice in the matter as this was literally an automatic body response.

    Liked by 1 person

    1. I love nice comments and definitely the ones I can learn from! Yes the freeze respons also exists, that would be me in a lot of situations. I usually respond to things by hiding in a corner and put my hands over my head. It’s a learned thing but weird to do as a grown up. I did not know about the opioids, that is really interesting.
      But it seems logical as many animals also ‘play dead’ to confuse the agressor.
      It is protective but like you said, it can give the impression of consent, with children, abuse or rape. And the victim feels even more guilty. I can imagine some police persons having questions about that: Why didn’t you fought back?
      Thank you for your nice comment, I feel that my post is even better now! 🙂

      Liked by 1 person

      1. In severe trauma dissociation happens which is really a protective form for mind and body. Caz, I was thinking today (that is my hobby) and I have a question for you about mental health, what is the best way to reach out to you?

        Liked by 1 person

    1. ECT is still very much used and is very effective with treatment resistent depression. I’ve seen miracles with it. Not always but sometimes it was like people coming back from the death. The treatment in itself is very very hard but sometimes the only option. Actually they should use it more and make it more accessible because not everyone can undergo it.

      Liked by 1 person

  2. Seeing the effects spelled out like this, I can appreciate how these reactions are meant to help us escape the cause of our stress. I used to wonder why stress reactions existed because we always hear about how they hurt our bodies, but that’s because we have stress we can’t just fight or flight away. I guess it’s sort of like a turbo boost. It can give you a much needed burst of speed short-term, but long-term it’ll start to break other things down.

    Liked by 1 person

    1. The right amount of stress is also needed to push us forward, to challenge us to adapt and to evolve. People who live a too protective life without any stress can get ill too. It’s all in the balance, as always. (at least, that is my experience).

      Liked by 1 person

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