Depression can lead to permanent changes in the structure of the brain. In a study conducted at the University of Edinburgh, researchers found alterations in parts of the brain known as white matter – the key component of the brain and spinal cord consisting mainly of nerve fibres.  White matter is critical for normal functioning of the brain, and its disruption has been linked to problems with emotion processing and thinking skills.

For the study, researchers used Diffusion Tensor Imaging (DTI) to map the structure of white matter in 3461 participants. They found that the quality of the matter – known as white matter integrity – was reduced in participants who reported symptoms indicative of depression while in non-depressed participants, the changes were not seen.

Diffusion Tensor Imaging (DTI) is an advanced Magnetic Resonance Imaging (MRI) technique that provides a description of the diffusion of water through tissue, and it can be used to identify micro-structural changes in the brain’s white matter. It also provides an overall view of brain anatomy, including the degree of connectivity between the different areas of the brain.

According to World Health Organisation, depression affects more than 300 million people annually. It’s the world’s leading cause of suicide and disability. Researchers say since the large numbers of people were included in the study, their findings are very robust, and they shed light on the biology of depression and could help in the search for better diagnosis and treatment.

“This study uses data from the largest single sample published to date and shows that people with depression have changes in the white matter wiring of their brain,” says Dr Heather Whalley, Senior Research Fellow, Division of Psychiatry, University of Edinburgh in a statement.

“There is an urgent need to provide treatment for depression and an improved understanding of its mechanisms will give us a better chance of developing new and more effective methods of treatment. Our next steps will be to look at how the absence of changes in the brain relates to better protection from distress and low mood.”

The study, entitled “Subcortical volume and white matter integrity abnormalities in major depressive disorder” has been published in Scientific Reports and it was done in collaboration with the University of Glasgow.

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