Medical Correlates of Chronic Multisymptom Illness in Gulf War Veterans.

Background: Chronic multisymptom illness (CMI) is more prevalent among deployed than nondeployed veterans from the first Gulf War. Objective physiologic markers of CMI are lacking. The purpose of this study is to determine whether measurable abnormalities in the autonomic nervous system or hypothalamic-pituitary adrenal axis would distinguish CMI cases (CMI+) from controls (CMI-) among deployed veterans of the 1990-1991 Gulf War.