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How chronic stress can shrink the brain

How chronic stress can shrink the brain

by Wellbeing Physiotherapy 31/07/2019

Life is full of excitement and possibilities. There are so many things that make us laugh and treasure. However, sometimes stress in various forms is inevitable in our daily life.

Stress may not necessarily be a bad thing, stress can help us focus and drive us to perform better. One example is when we are going for a job interview. Stress stimulates us to prepare and present our best to the panel in order to win the job.

Unfortunately, when stress is ongoing and persistent, it can produce undesirable negative effects and shrink the size of our brain.

Stress and Cortisol

When we are under stress, the body will produce a chemical called cortisol, which is the primary stress hormone. Cortisol makes us fight or flight to deal with the situation. With continual influx of cortisol in our body, it can drive a cascade of undesirable and detrimental effects on our brain.

Amygdala is the fear centre of the brain. High levels of cortisol will increase the activity level and number of neural connections in this area. Amygdala and hippocampus can become better connected, making fear respond much quicker than usual.


The hippocampus is the area of the brain associated with our learning, memory and stress control. High levels of cortisol can cause electrical signals between neurons, which deteriorate and inhibit the formation of nerve cells and decrease the size of the hippocampus. This in turn can weaken our ability to control stress.

Prefrontal Cortex

Too much cortisol can shrink the size of the brain through the loss of synaptic connection between neurons, especially in the prefrontal cortex of the brain. The prefrontal cortex regulates complex cognitive behaviour, personality expression, decision making, judgment, and social interactions.

Mental Health Impact

With ongoing stress, we lose the ability to regulate our fear and it makes us more vulnerable to develop depression, anxiety and Alzheimer’s disease later in life.

Next time, we will talk about ways to help alleviate chronic stress.