Researchers Ronald Glaser and Janice Kiecolt-Glaser have spent 3 decades trying to understand the role psychological stress plays in weakening the immune system. Of keen interest was the Epstein-Barr virus (EBV), which is one of 8 different herpesvirusus that can remain dormant in the body for a lifetime.

The Glasers estimate that more than 90% of American adults are infected with the EBV. EBV can cause infectious mononucleosis, also known as ‘glandular fever’ and Mono. Most people never realize that they have the virus.

The researchers were interested in what caused the virus to become active in some people and not others. What they knew was, as a body ages, the amount of protein IL-6 increases in the blood. It is IL-6 that rushes to the site of an infection. Through earlier research work they also knew that depression can also increase the levels of IL-6.

Increased stress and depression can also trigger the latent EBV virus to begin reproducing. When the EBV virus begins to increase it produces the protein dUTpase, that also increases  IL-6.

The more IL-6 level increases, so also does a person’s risk for disease. The higher levels of IL-6, as well as depression, have been associated with cardiovascular disease, osteoporosis, and type-2 diabetes.

The process of increased IL-6 (and other proteins) play an important role in the production of proinflammatory proteins. Finding that all of these factors play a significant role in the production of proinflammatory proteins was surprising to the researchers.

Their findings help explain how atherosclerotic disease may occur, or how it is exacerbated by many factors.

One key finding is the significance depression has in reactivating these viruses, thus starting the cascade that leads to inflammation,  perhaps increasing the risk of cardiovascular disease. So, treating depression is very important for a strong immune system.