A common theme on this website (and the reason for the domain name, “dontbeasalmon.net”) is the link between stress and illness.
Here’s a brief article on ScienceDaily.com: Starve A Fever, Feed A Cold, Don’t Be Stressed. There are notes about the field of “psychoneuroimmunology” (which is a new one for me) and the study of the effects of stress upon our immune systems.
There are some interesting comments about cross-training psychology students in biology and physiology to aid future cross-discipline development. I’m surprised this doesn’t already happen.