What does depression do to your brain?

This is Article 1 in a series on depression and the brain. Next article coming soon.

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I affect 3.8% of the population wide,

With 280 million voices struggling inside.

In women, my reach is 6%, 

And 5.7% of those over 60 feel me.

Among new mothers, I reach 10%,

With over 700,000 lost to my torment each year.

What am I?

Depression. The most prevalent psychiatric disorder that costs both money and lives.

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Also known as Major Depressive Disorder (MDD), depression is a heterogenous disease, which means the manifestation of the disorder is influenced by multiple genes. It is commonly known that consistent low mood, loss of interest in hobbies you used to enjoy, lethargy, feeling of hopelessness etc. are physical symptoms of depression. However, have you ever wondered what happens in the brain in a depression sufferer, from the neuroscience aspect?

Structurally, research into the neuroscience of depression reveals significant structural abnormalities in the brains of affected individuals. Studies using structural magnetic resonance imaging (MRI) have shown that those with MDD show reductions in gray matter volume in regions responsible for emotion regulation. The limbic system of the brain is responsible for producing and regulating emotions. In depressed individuals, the hippocampus—a key component of the limbic system—shows reduced gray matter volume, which is linked to abnormalities in the associated white matter tracts.

White matter consists of myelinated axons that facilitate communication between different brain regions, while grey matter contains the neuronal cell bodies responsible for processing information. The presence of abnormalities in white matter suggests a disconnection between regions within the limbic system, potentially impairing their ability to communicate effectively. This disconnection may contribute to the emotional dysregulation observed in depression, highlighting the intricate relationship between grey and white matter in the pathology of this disorder. 

Depression is a complex disorder that not only affects mood but changes the structure and function of the brain. By understanding the neurobiological changes—including reductions in grey matter and white matter disconnections—we can better grasp the pathogenesis of this condition. Continued research in the neuroscience behind depression is essential for developing more effective treatments. There is still much more to explore and understand in depression research; with each new discovery, we realise how much more there is to learn.

Written by Chloe Kam

Related article: Depression in children