Researchers studying chronic fatigue rates in the United States saw a dip in the syndrome immediately after the terrorist attacks of September 11, 2001, suggesting a possible “fight or flight” effect may have put some people's fatigue into remission, a new study finds. Study author Christine Heim, Ph.D. and colleagues screened more than 7,000 U.S. adults for fatigue and interviewed roughly 900 adults in detail, about half of whom were not considered fatigued, while the other half suffered from prolonged, chronic or CFS-like fatigue. Half of the interviews were conducted before the attacks as part of a Centers for Disease Control and Prevention pilot study, and the rest were conducted after the attacks.
“The terrorist attacks of September 11, 2001, represented a major national trauma and may serve as a model to evaluate the effect of stress on public health,” notes Heim of the Department of Psychiatry and Behavioral Sciences at Emory University School of Medicine in Atlanta. The exact cause of CFS, which involves at least six months of extreme fatigue and other symptoms including sleep disturbances, poor concentration and pain, remains unknown. But stress — with its complex effects on the central nervous, neuroendocrine and immune systems — probably plays a major role, according to the study.
Other studies have found that CFS is often associated with severe stressors, such as experiences of childhood abuse or combat-related trauma, but “little is known about the immediate effects of an acute trauma like September 11th,” according to the study. Heim and colleagues found rates of fatiguing illnesses to be significantly lower in the two months after the attacks than in the two months before. A number of potential explanations exist for their findings, which are published in the current issue of the journal Psychosomatic Medicine.
One possibility is that the terrorist attacks may have distracted the attention of those suffering from their fatigue or altered their perceptions of fatigue. It is also possible the attacks led to bodily changes associated with the fight-or-flight response that improved fatigue symptoms. But Heim notes that such a reprieve could be temporary. “With chronic or repeated stress, or after cessation of the threat, such psychobiological adaptations might evolve into an exhausted system and relapse of fatigue,” she says.
Heim says the study results may be skewed, if fatigued individuals represented a disproportionate number of people who dropped out of the project after the attacks. “It is possible that subjects who were fatigued were less willing to participate in the interviews after the attacks,” Heim suggests. Heim and colleagues call for more research to determine potential psychological or biological mechanisms for their findings. They also note that their study was designed only to note an association between Sept. 11 and CFS rates; more research is needed to prove whether the terrorist attacks affected CFS rates. Also, since their study ended only three months after the attacks, it wasn't long enough to detect new cases of CFS that may have been related to the attacks. “It is possible that increases in cases of fatigue related to the attacks of September 11, 2001, would have affected prevalence rates at a later time,” Heim says. This study was funded by the Chronic Fatigue Syndrome Program of the Centers for Disease Control and Prevention. By Ann Quigley, Contributing Writer
Health Behavior News Service