Scientists are still learning about the connection between mind and body because they are not as separate as people tend to think. The connection between the immune system and the mind may not be as obvious, but a recent study indicated that IL-17, a molecule produced by the immune system, may affect the mind. The purpose of the IL-17 is to act as an defender against outside elements, causing inflammation. The outer area of brain tissue has a lot of gamma-delta T cells which make IL-17 molecules. Researchers removed gamma-delta T cells from the brains of mice, with most of their behavior remaining nearly the same. However, the mice were more anxious, or acted more anxious than before the gamma-delta cells were removed.
This shows a potential link between the molecule and regulation of anxiety. It is known that people tend to withdraw when they are sick, which is likely as a result of signals from the immune system. This study suggests that there is a lot of interaction between the brain and immune system, so researchers are interested in trying a study with humans to see how IL-17 may affect anxiety. If a stronger link is determined this could help improve treatment for problems like anxiety and depression.
To learn more about the link between the immune system and the mind, check out A Molecule Links the Immune System to Mental Health.