Here is an article that seeks to find a connection between depression and the body’s immune system. It’s short and worth a read. One particular quote stood out to me.

“When proinflammatory cytokines are administered to animals, they elicit “sickness behavior”: The animals become listless, lose interest in eating, grooming, socializing and sex, and show increased sensitivity to pain, changes strikingly similar to those in humans with major depression.

Loss of interest in food and ability to take pleasure in eating make sense as short-term response to infection — it frees up energy used for digestion and makes it available for immune defense.”

The inflammatory response is such a mixed blessing. For all that it is one of the most basic means by which our body heals itself, doctors and patients spend an exorbitant amount of time trying to counteract its effects. As a massage therapist we learned (and I often use) techniques that bring “healing inflammation” to an area, only to suggest to my client that they later put ice on the area to reduce that very response.

Thus it makes an instinctive sense to me that the inflammatory response might play an equally mixed role in mood. It makes sense that while sick we could lose interest in activities that normally bring us joy because our body must turn that energy inwards to promote healing. It makes further sense that in a society where autoimmune diseases are becoming increasingly prominent, emotional effects of our immune system might be stretching outside the realm of helpful.

I want to add a disclaimer: I have not researched the claims made in this article and simply because a rational “makes sense” does not make it true. But I am interested to see what other research is done in this area and what sort of success treatments based on this philosophy might have.