How depression can affect your brain

How depression can affect your brain

Depression is a debilitating illness which can affect everything we do.

It’s not simply a feeling of sadness. Its symptoms can range from a feeling of hopelessness or despair to irritability and anger, and the inability to perform normal daily activities.

Depression can range from milder mood disorders which last weeks or months, to major depressive disorders which can last years.

Its causes are not fully known, though research has pointed to stressful life events, genetics, hormone imbalances particularly after pregnancy and during menopause, and biochemical reactions as potential triggers.

Recent scientific research has found that inflammation in the brain, a lack of Vitamin D, or an imbalance in the flora in the gut can also adversely impact on mental health.

Depression, particularly major depressive disorders, are seen to have profound effects in certain areas of the brain.

The hippocampus, the amygdala, and the prefrontal cortex play key roles in depression.


The hippocampus

This part of the brain is near the centre. It stores memories and produces the stress hormone cortisol.

This is released when the body or mind are under stress – including during depression. When excess cortisol is released over a lengthy period, this can lead to changes in the brain.

People with long-term, major depression find that their cortisol levels do not fall during the day, unlike those without depression.

Long-term exposure to increased cortisol levels can slow the production of new neurons (brain cells) and it can cause existing neurons within the hippocampus to shrink.

A magnetic resonance imaging (MRI) study of more than 8,000 people with recurring bouts of depression found they had a smaller hippocampus.

The research by Professor Ian Hickie found that the more depressive episodes a person had, the more the effect was seen on the size of their hippocampus.

Those changes  in the hippocampus can lead to problems with memory.

The prefrontal cortex

This regulates emotions, helps form memories, and helps in making decisions.

Found at the front of the brain, it has been found to shrink when there is too much cortisol in the brain.

The amygdala

The fear and pleasure centre of the brain, the amygdala governs emotional responses.

Prolonged exposure to cortisol, such as during depression, leads to the amygdala becoming enlarged.

This can also lead to problems with activities like sleeping and the release of other hormones and body chemicals which can cause more problems.

There is some good news, though.

The profound effects of depression on the brain can often be reversed, doctors say.

There are various treatments including medication, psychotherapy, and lifestyle changes.

In my next blog, I’ll look at how exercise can help combat these brain changes – and, sometimes, reverse them.


I specialise in helping people who have been suffering from depression – helping them combat the condition with exercise and a healthy lifestyle.

If I could help you, please call me on 02920 676 623.

Leave a Comment


Email* (never published)