Causes

• Researchers have discovered 88 different genes in patients with chronic fatigue syndrome (CFS) related to blood disease, immune system function, and infection. Within this group of genes, the researchers identified seven subtypes, which could relate to infection response, and which might be used as part of a diagnostic test. They also honed in on five genes that could be possible targets for treatment.
• Researchers have discovered further evidence that a faulty stress response contributes to CFS. Women with CFS have significantly lower levels of the stress hormone, cortisol when they wake up in the morning compared with women who don't have the condition. Men with CFS do not have a similar drop in cortisol level, suggesting that a difference in the cortisol response may contribute to the increased risk of CFS only in women.

Diagnosis

• Depression is a common symptom of CFS. In one study, 36% of CFS patients were depressed. Depression in these patients was associated with lower self-esteem and an increased likelihood of suicidal thoughts.

Prognosis

• CFS patients appear to have slower motor speed and reduced working memory than those without the condition, and these changes don't seem to be related to any psychological conditions or medication use.
• Children with CFS have more difficulty than usual paying attention and remembering, which may explain why kids with this condition have more trouble in school than their peers.

Treatment

• Cognitive behavioral therapy (CBT) is effective at reducing the symptoms of fatigue compared with usual care. This treatment appears to be more effective than other psychological therapies.

Chronic fatigue syndrome (CFS), sometimes called immune dysfunction syndrome or myalgic encephalomyelitis (in Europe), is not a new disorder. In the 19th century the term neurasthenia, or nervous exhaustion, was applied to symptoms resembling CFS. In the 1930s through the 1950s, outbreaks of disease marked by prolonged fatigue were reported in the United States and many other countries. Beginning in the early- to mid-1980s, interest in chronic fatigue syndrome was revived by reports in America and other countries of various outbreaks of long-term debilitating fatigue.

Unexplained chronic fatigue describes fatigue that lasts for more than 6 months, impairs normal activities, and has no identifiable medical or psychological problems to account for it. In addition to fatigue, people may complain of other problems, such as difficulty with memory or concentration, headaches, or sore muscles or joints.

The symptoms of CFS may be categorized as follows:

• Chronic fatigue syndrome (CFS). A number of criteria must be met in order for a patient's symptoms to be described as CFS. Six million patient visits are made each year because of fatigue, although only a very small percentage of these visits can be attributed to actual chronic fatigue syndrome.
• Idiopathic chronic fatigue. If the symptoms do not meet the criteria for CFS, the condition is referred to as idiopathic chronic fatigue, meaning the cause is unknown.

Although the exact causes of CFS are not known, researchers think infection, genetics, hormonal imbalances, and chemical toxins play roles in different patients.