The researchers also screened the participants for depression, anxiety and post-traumatic stress disorder. They were also tested for saliva levels of the hormone cortisol; low cortisol levels can indicate reduced function of the body's neuroendocrine stress response system.
The researchers found that people who had experienced a childhood trauma were six times more likely to develop chronic fatigue syndrome, compared with non-traumatized individuals.
Among people with CFS who'd suffered childhood trauma, cortisol levels were lower. That was not the case among those with CFS who had not had a childhood trauma. The researchers said this finding indicates that stress early in life might cause a biological susceptibility to CFS.
Reeves's group hopes to extend the findings to new treatments for the condition.
Dr. Anthony L. Komaroff, a professor of medicine at Harvard Medical School and an expert on CFS, doesn't think childhood trauma causes CFS but, rather, might contribute to its development.
"Since a substantial fraction of people with CFS report no childhood abuse, and since none of the control subjects [in the new study] with childhood abuse had CFS, childhood abuse is not the cause of CFS," Komaroff said. "However, childhood abuse may alter brain chemistry in such a way that people are subsequently more vulnerable to developing CFS."
To learn more about chronic fatigue syndrome, visit the CFIDS Association of America.
SOURCES: William C. Reeves, M.D., chief, Chronic Viral Diseases Branch, U.S. Centers for Disease Control and Prevention, Atlanta; Anthony L. Komaroff, M.D
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