Stress, hormones and disease.

My postdoctoral training under Dr. Gerard Smith began me on a lifetime of investigation on the role of stress, hormones, and disease. The first set of experiments asked what hormone, if any, best reflected the range of aroused behaviors. We found that catecholamines performed substantially better than glucocorticoids did, despite the belief that glucocorticoids were sensitive indices of stress. But we also learned that hormones themselves were nowhere near as good in monitoring stress than motor behaviors were. In a second set of experiments, we tried to understand how stress affected medical disease. We learned that stress can produce disease in a healthy organism but has its most profound effects when disease already exists. Finally, in the early 1990s, I shifted my focus on stress and disease to a broader problem in behavioral medicine, namely, medically unexplained fatigue and pain. Among the studies we have done investigating these disorders, we looked specifically at veterans of the first Gulf War--many of whom developed problems with severe fatigue. A critical question in the literature asked if unexplained fatigue was simply a physical component of concurrent posttraumatic stress disorder (PTSD). In a large epidemiological study, we found that PTSD tracked stressor intensity in a stepwise fashion, while fatiguing illness increased with stressor intensity only on the milder side of the intensity spectrum. This result indicated that the two ailments are both stress sensitive but dissimilar.