(HealthDay News) -- Children who are traumatized by sexual, physical or psychological abuse are more likely to develop chronic fatigue syndrome as adults, new research suggests.
The study also states that the increased risk for chronic fatigue syndrome (CFS) might be based in biology. The reason: There appears to be a connection between the nervous system and endocrine system abnormalities, called neuroendocrine dysfunction, in people with CFS who suffered childhood trauma, the researchers said.
"About 60 percent of the people who have CFS have been badly abused as children," said lead researcher Dr. William C. Reeves, chief of the U.S. Centers for Disease Control and Prevention's Chronic Viral Diseases Branch. "They also have a diminished salivary cortisol response to stress."
The same researchers found similar results in an earlier study of patients in Kansas, Reeves noted. "CFS does involve a diminished response to stress," he said.
An estimated 4 million people in the United States are thought to struggle with CFS, costing the nation some $9 billion annually, and each patient's family $20,000 a year in lost revenue, Reeves said.
The condition, which is more common in women 40 to 59 years old, is marked by a cluster of debilitating symptoms, including unexplained fatigue, problems sleeping, problems with memory and concentration, and pain.
The illness was first recognized in the late 1980s and initially dubbed the "yuppie flu," causing it to suffer from a credibility problem.
"CFS is quite common," Reeves said. "It is a real illness. If you have the symptoms of CFS, see a provider. It's not all in your head -- it's not a crock."
For the study, published in the January issue of Archives of General Psychiatry, Reeves's team collected data on 113 people with CFS and 124 people without the condition. The participants were asked whether they had experienced such childhood trauma as sexual, physical or emotional abuse or emotional and physical neglect.
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.http://www.cfids.org/about-cfids/default.asp