How Chronic Stress Affects the Brain

When we experience a stressful situation or thought, the Hypothalamus Pituitary and Adrenals are triggered, and this is referred to as the HPA Axis.  This is where the endocrine glands in the brain and the adrenals that sit on top of the kidneys interact to control your body’s reaction to stress.

Cortisol and adrenaline are then released to prepare your body to act quickly.  This is known as sympathetic mode and the fight or flight response is activated.  This is typically considered a good thing as that response can keep us safe from a dangerous situation.  It also reduces the function of what the brain considers non-essential systems in that moment such as immune system responses, reproductive systems, and the digestive system.  However, it is not a space we need to be in long-term.

How chronic stress affects the brain long-term

Whilst the right production of cortisol can be favourable, when we experience ongoing cortisol release long-term, it can have damaging effects on the brain and the body.

As cortisol levels increase, the electrical signals in the hippocampus (responsible for creating memories, learning and controlling stress) begin to deteriorate.  The hippocampus is also responsible for inhibiting the HPA Axis.  This means that by being continually stressed, the brain becomes less able to control stress.

Cortisol also increases the size of the amygdala by increasing the number of neural connections.  This may seem like a good thing, but the amygdala is strongly responsible for emotions, and is considered the fear centre of the brain.  An enlarged amygdala means increased levels of fear and anxiety which increases your stress levels even more.

In addition to increasing the size of the amygdala, cortisol can also cause the brain to experience what is known as “brain fog”.  As the brain is busy putting its attention on the fight or flight response, synaptic connections between neurons are lost.  When the prefrontal cortex shuts down, this affects social interaction, concentration, judgement, and decision-making.  It also means less brain cells are being created in the hippocampus making it more difficult to remember or learn.

What are some of the problems caused by chronic stress?

We can become so used to experiencing stress that we don’t even realise we are stressed anymore.  Here are some symptoms that may indicate that your cortisol levels are affecting you:

• Forgetfulness/memory loss
• Difficulty making decisions
• Anxiety
• Depression
• Headaches
• Weight Gain/Loss
• Digestive Issues
• Difficulty maintaining concentration
• Insomnia
• Higher alcohol or drug intake
• Avoiding social activities
• Low energy levels
• Overly emotional
• Lack of sex drive
• Teeth grinding/Jaw pain
• Racing mind
• Decreased immunity/Increased colds and flus

If chronic stress continues, more severe health problems such as Alzheimer’s disease, cardiovascular disease, infertility, obesity and more can be experienced.

What mice have shown us about how chronic stress affects the brain

In 2004, a group of scientists published an article with their findings from a study entitled “Epigenetic Programming by Maternal Behaviour”.  The study showed that the offspring of nurturing mother mice had more cortisol receptors than those who had less-nurturing mothers.  As a result, those mice with increased cortisol receptors were less sensitive to stress.

The study also showed that the changes were epigenetic meaning the genes were affected without changing the genetic code.  These epigenetic changes then proved to be passed on through many generations of mice.

Many of the epigenetic changes are also reversible.  This means that if you had a less than ideal start to life, you can still increase your cortisol receptors and become less sensitive to stress.

How to reduce your stress

It may sound easier said than done, but reducing your cortisol levels doesn’t need to be difficult.  Starting with mini “cortisol breaks” to allow your body to enter parasympathetic mode which is healing and restorative to your body and brain.

Here are a few ways to give yourself a break from increased cortisol levels:

• Gentle exercise –a short walk around the block or some stretching
• Deep breathing – it can stimulate the parasympathetic functioning
• Meditation – a 5-10 minute one can work wonders
• Mindfulness – be aware of your thoughts and emotions (see my article on attentional intelligence)
• Journalling – especially great before bed or first thing in the morning
• Quality Sleep – at least 7-8 hours a night
• Nature – if you can’t be out in nature, bring the outdoors in with plants
• Avoid CATS – caffeine, alcohol and tobacco
• Eat nutritious food – just like using premium fuel in your car
• Laugh – it’s very hard to have a good belly laugh and be tense at the same time
• Connect – spend time with friends and loved ones
• Hobbies – spend some time doing what you love

Summary

So many of the leaders I encounter believe that stress is just part of the territory in business.  The problem is that if left to become chronic, stress can have extreme detrimental effects on the brain and the body.  Stress can be a silent killer.  When you understand how the brain works, you can work with it to unlock your full potential.

If you’d like to know more about how to unlock your brain potential, sign up for my free “Brain Basics” e-book below.