An overview of chronic fatigue syndrome.
Krupp, L B, Mendelson, W B, Friedman, R·The Journal of clinical psychiatry·1991
This review examined research on ME/CFS to understand whether the illness is caused by psychological factors, immune system problems, or both. Researchers found that ME/CFS patients experience more disabling fatigue than people with other chronic illnesses, and some have immune system abnormalities. However, many ME/CFS patients have no psychiatric illness, suggesting ME/CFS is a real medical condition separate from depression.