A syndrome in which various combinations of extreme fatigue, muscle pain, lack of concentration, panic attacks, memory loss and depression occur. Its existence and causes has been the subject of a controversy that is reflected in the variety of names given to the syndrome: CHRONIC FATIGUE SYNDROME (CFS), post-viral fatigue syndrome and (in the past) epidemic neuromyasthenia. ME often follows virus infections of the upper respiratory tract or gut, MONONUCLEOSIS or LYME DISEASE but it is not clear whether this is a coincidental event or cause-and-effect. Physical examination shows no evidence of diagnosable disease and there is no definitive test – diagnosis usually being made by excluding other possible disorders. The sufferer usually recovers in time, although sometimes recovery may take many months or even years. The most severely affected may be bedridden and may need tube-feeding. There is no specific curative treatment, but symptomatic treatment such as resting in the early stages may help. Some experts believe that the illness has a psychological element, and sufferers have been treated with COGNITIVE BEHAVIOUR THERAPY.