Nov. 9, 1999 (Atlanta) -- Chronic fatigue syndrome -- a debilitating illness that over the last decade has been called Epstein-Barr virus, chronic mononucleosis, and yuppie flu -- may be an illness caused by one or more infections, according to a paper appearing in the current issue of Annals of Behavioral Medicine.
Stress and depression may act to perpetuate the condition by disrupting immune, neurological, and hormone functions necessary to fight the infection, Susan K. Johnson, PhD, a psychologist with the University of North Carolina at Charlotte, tells WebMD. "There very much is a mind-body connection," she says.
Studies conducted at a Chronic Fatigue Research Center at the New Jersey Medical School have looked at the role psychiatric disease plays in CFS. They have identified two types of CFS patients. One group had a gradual onset of physical symptoms, accompanied by psychiatric problems, such as depression and anxiety. The other group had a sudden onset of physical symptoms with no psychiatric problems. Studies have shown that when CFS is accompanied with depression or anxiety, the chance for cure is dramatically reduced, Johnson says.
Several additional studies have shown CFS patients have a tendency to minimize the psychological implications of their illness. Other studies show many people with CFS tend to regard the disease as the sole problem in their lives, and believe that it has a biological origin. They are resistant to implications that the disease has a psychological rather than biological basis, says Johnson.
Chronic fatigue is an illness that impairs daily function and involves numerous arthritis-related, infectious, neurological, and psychiatric symptoms. Criteria for diagnosis once focused on infectious symptoms, but in 1992 it was modified to include depression and anxiety. Symptoms may include mild fever, muscle weakness, sore throat, severe fatigue after mild exercise, headaches, body aches, sleep problems, depression, and anxiety.
Fewer doctors today consider chronic fatigue to be a trivial complaint. "It's taken much more seriously than it once was," Johnson tells WebMD.
The illness is difficult to diagnose, in part because fatigue is a very common, subjective symptom found in many illnesses. "Fatigue can denote problems with muscle weakness, exhaustion ... mental tiredness ... or lack of motivation," says Johnson. Most doctors today establish a diagnosis by ruling out all the other diseases, she adds.
While chronic fatigue primarily affects middle-aged women, it seems to be most prevalent among black and Native American women with incomes under $40,000. "The image of chronic fatigue syndrome as an illness of the white professional class is inaccurate," says Johnson.
Because researchers have been unable to pinpoint any physical cause, a true explanation of the illness' cause has eluded researchers. There is an unresolved debate whether chronic fatigue is an emotional disorder or an organic disease, says Johnson. Also, the type of depression found in chronic fatigue patients can be quite different from classical depression, with significantly lower evidence of sadness in CFS patients.
Research to date has failed to provide convincing evidence that a single infectious agent causes the illness. "It is likely that more than one infectious agent is involved in producing CFS," says Johnson.
Laboratory researchers are investigating cellular activity to better understand how viral infection affects cell functions and the immune function. As with all studies of CFS, findings have not proven consistent, says Johnson. "To date, there are still no useful viral or immune diagnostic markers for CFS, although there is promising work being done."
With the diverse symptoms shown by chronic fatigue sufferers, it is hardly surprising that there is no firmly established treatment, says Johnson. While many physicians recommend low-dosage antidepressant therapy, at least one study showed that it had no effect. A few drug treatments have been identified as important sources of symptom relief and symptom management. But the vast majority of antiviral medications, immune modifiers, antifungal agents, vitamins, and minerals that chronic fatigue patients try have not been tested.
While exercise and psychological counseling have been suggested to increase activity levels and interrupt cycles of depression, studies indicate that they are promising but high dropout rates show that they do not fit all cases of chronic fatigue.
Researchers still don't understand why many who suffer from chronic fatigue never are cured. But studies consistently show that those who are less likely to have complete recovery tend to be older and suffer from depression or anxiety disorder. "There's been some pretty good physiological research, but it's been frustrating, too," says Johnson. "Findings look promising but tend not to be replicated [in subsequent studies]. There's something there, but we're having lot of trouble grasping it, pinning it down."
CFS is a multidimensional illness and challenges traditional perspectives on illness, Johnson tells WebMD. "There's been progress, but it's been incremental. There are still many unanswered questions."