What does Stress do to our brain?

What really is stress, and how do we measure it?

We’ve all had moments where we were stressed. Stress is a complicated thing and affects everyone differently. With the current events going on many of us are stressed. Have you ever stopped and wondered what stress does to our brain?

When we encounter stressful moments it activates a system in the brain called the autonomic nervous system. The autonomic nervous system controls a lot of our body physically and mentally. It can change our heart rate, breathing rate, and even our body temperature. This system in our brain has three parts to it, one part is called the sympathetic nervous system. Most people know this system as the one that controls the “Fight or Flight response”. This part of the nervous system is helpful and can prepare the body and mind for stressful situations and it lets us react very quickly.

The main stress hormone is a hormone called cortisol. Cortisol has good effects and bad effects. I had the opportunity to interview the Chair and Professor of Psychological & Brain Sciences at Washington University, Dr. Deanna Barch. She offered the following when I asked about Cortisol.
“We need it to be able to cope with threats and stressors, it’s just that when it’s released in either too large amounts, over too long of a period of time, and we can’t shut off that response then it can end up having toxic effects. So by itself, in normal amounts, normal situations, it’s not a bad thing… We need it, we need cortisol secretion, we need that whole system to be active, to appropriately cope with stressors. It’s just that when stressors…end up being really chronic, much greater than usual or something interferes with our ability to cope with those stressors, then it might become more problematic.”
Some bad effects that link back to “too much stress” include increased risk of depression. So in times of Covid being more stressed is completely normal and makes a lot of sense logically and probably involves too much cortisol. Talking to Dr Barch, she said,
“Think about what things we normally do to reduce our stress, there’s a lot of things we normally do, social Interactions, exercise, fun things…We’ve been cut off from a lot of things we would normally do to mitigate our stress, or to reduce our stress. So it’s both that we’re…under increased stress and we can’t engage in some of the things that would allow us to sort of reduce our stress and to manage our stress response.”

So we know that stress is a thing and we know that there are stress hormones and that they have good and bad effects, but how do we measure all of it? Dr. Barch said that we can measure hormones in several different ways, including in blood, saliva and hair.
“… In the context of Covid, hair might actually be a really interesting way of looking at it because hair cortisol is a better measure of long term accumulation over months…”
Stress levels have definitely changed over the past couple of months mainly because of current events. I asked her about how we could measure cortisol levels in hair and she said that,
“We could take locks of your hair…. and grind them up and extract the cortisol, that would give me an average measure of the cortisol secretion over the past month(s). If we were to have measures of that from a year ago when we didn’t have Covid and measures now when we have Covid and compare them across a bunch of different people we would be able to see if people in different circumstances are experiencing greater levels of stress and greater levels of cortisol secretion”.

Stress affects everyone differently, some people might find it as an opportunity to do distractions or something to cope with stress, like working out or doing something that they enjoy. Other people curl up and become quiet and sometimes even procrastinate. So why does stress affect people in different ways? Dr Barch was talking about an “HPA Axis”. The HPA Axis is a system in the body that controls many important functions including cortisol secretion.
“So there are individual differences in our biology, where some people may have a more responsive HPA Axis then others, and that’s just due to genetics. I think it probably does also interact with what other experiences people have had in their life.”
She went on to say that your HPA axis can be altered and because of that people can have different responses to different types of stressors. She also explained that the type of environment you are in and what support you have can have a large impact on how you deal and respond to different situations involving stress.

Many things are reversible and many things aren’t. Does stress fall into the reversible category? Asking Dr Barch, she commented,
“Its certainly the case that we can mitigate the effects of stress and depression. I think we don’t know how reversible really long lasting, very chronic severe stress is.”

So what did we learn here? Well we learned stress can affect people in many different ways because of genetics and previous experiences. So, how you respond to stress is very personal, so from now and in the future I hope this article helped you understand how we respond to stress.