Hyporeactivity and Gulf War Illness

This research project is a follow-up to the prior VA-funded study that found that chronic fatigue reported by many Gulf War veterans may be a symptom of dysfunctional cardiovascular stress response regulation. Specifically, ill veterans had diminished autonomic responses during demanding psychosocial tasks involving high level cognitive processing and emotional stress. There was a close relationship between clinical status of ill veterans and their inability to mount an appropriate physiological response under stress. The main objective of the present investigation is to determine the specific mechanism through which this abnormality may contribute to Gulf War-related chronic fatigue. We also observed that Gulf veterans with posttraumatic stress disorder (PTSD) had the most dampened autonomic activation to stressors involving higher brain activities. The second major focus of this study is to explore the role of a psychiatric disorder, specifically PTSD, as a factor in abnormalities in stress response regulation. This aspect of the study may also provide pertinent information as to the role of stress of military deployment as a contributing factor in post-Gulf War illnesses.