Large study finds key link between depression and inflammation

By Brittany Roston/May 17, 2021 3:16 pm EST

Depression and inflammation are tightly linked, according to a large new study involving data on more than 86,000 people. The research comes from King's College London, which found that even after accounting for other factors that may fuel inflammation, the link between it and the mental health disorder remained.

The study pulled data from the UK Biobank database on 86,000 people, including answers to questionnaires about mental and physical health, blood samples, and genetic data. Of these participants, 31-percent suffered from major depressive disorder (MDD), a chronic form of depression that can cause significant issues in one's life.

Among other things, the study found that people who have depression also have higher levels of C-reactive protein (CRP) in their blood, an inflammation marker, compared to people who don't suffer from depression. Though accounting for potential factors that could influence inflammation, including BMI and smoking, reduced the levels somewhat, depressed participants were still found to have greater levels overall.

Likewise, the researchers found that the greater one's genetic risk of depression, the more inflammation they were likely to have, highlighting evidence that there may be a direct biological link between greater inflammation in the body and experiencing clinical depression.

One of the study's senior authors, Professor Carmine Pariante, explained:

Our large-scale analysis of data removed socioeconomic background, ill health, unhealthy habits as well as genetic predisposition to immune dysfunction as the only explanations for the relationship between depression and inflammation. By this process of elimination, we show that there may be a core biological process that is behind the association between depression and increased inflammation. If we can identify this process and uncover more detail about its role in the development of depression, we can pave the way for trialing new treatments for this widespread mental health disorder.