Depression and Disease

Science Suggests Loneliness and Illness Have a Positive Correlation

 Angus Chen released a health article earlier today on NPR, " Loneliness May Warp Our Genes, And Our Immune Systems". Previous studies have found loneliness is linked inflammation, which increases the likelihood of developing cancer or other illnesses. The human body is not built for prolonged inflammation, and experiencing depression for several years puts a person at risk to develop illnesses. But why does this happen, and what is the connection between the two?

The Study

Steve Cole, a genomics researcher at the University of California, wanted to determine how loneliness changes the human body. It has been determined that depressed people have an elevated white blood cell count, which causes inflammation, and they have lower levels of antiviral compounds. Cole conducted a study where he monitored 141 people over 5 years, regularly asking them how lonely they felt and taking blood samples to monitor inflammation. They also checked levels norepinephrine, which is released during periods of extreme stress.

The Link

All of the participants who reported symptoms of depression and/or loneliness had elevated norepinephrine levels. When norepinephrine is released in the body, immune functions shut down that would normally protect against disease. White blood cell production increases, which normally help protect the body when there is a wound. However, this constant increased production diminishes the overall white blood cell count. This makes a person more susceptible to other diseases. Furthermore, it seems as though people with depression make genes which prevent them from absorbing cortisol which counters inflammation.

Conclusions

Cole claims " At this point, my best guess was that loneliness really is one of the most threatening experiences we can have" (2015). An elevated white blood cell count and the production of norepinephrine stem from our ancestors survival mechanisms. Humans who lived alone were in constant threat of being attacked by animals, and therefore had a highly stressed immune system (creating norepinephrine and white blood cells to protect the body from open wounds). This, however, leaves the body with less resources to fight diseases from other human beings, or to fight against other ailments.

Perhaps the most disturbing take away from this study is that loneliness and increased production of norepinephrine work in-conjunction in a cycle. If a person reported they felt lonely, it was indicative they would have increased gene activity around inflammation (and vice versa). Essentially, being lonely could contribute to isolationist behaviors (avoiding social situations). This is a complicated issue which is dependent on several factors; there is no simple way to combat depression.