THE EPIDEMIOLOGY OF FATIGUE - IMPLICATIONS FOR THE DEFINITION OF CHRONIC FATIGUE SYNDROME

Fatigue is an extremely common psychosomatic symptom, for which medical assistance is not always sought. Fatigue is rarely the only manifestation of organic disease but is associated with increased psychopathology, with the most common disorders being depression and anxiety. Among subjects with fatigue, those who attend fatigue clinics are considerably more likely to have psychiatric disorders than those who consult primary care physicians or abstain from seeking medical help. Fatigue is distributed as a continuous variable in the general population. Chronic fatigue syndrome can be considered to be at one end of the continuum. Chronic fatigue syndrome patients have persistent incapacitating fatigue, multiple unexplained symptoms, nonspecific psychiatric disturbances, and a tendency to ascribe symptoms to organic causes.