Chronic fatigue syndrome: a clinical and laboratory study with a well matched control group.
Swanink, C M, Vercoulen, J H, Bleijenberg, G et al.·Journal of internal medicine·1995
This study compared 88 people with ME/CFS to 77 healthy controls matched by age, sex, and location. Researchers tested blood work, checked for infections, and used questionnaires to measure fatigue, depression, and how much the illness affected daily life. Standard blood tests came back normal in ME/CFS patients, but they reported significantly more fatigue, depression, and difficulty with daily activities than healthy controls.