Chronic fatigue syndrome in male Gulf war veterans and civilians: a further test of the single syndrome hypothesis.
Ciccone, Donald S, Weissman, Lois, Natelson, Benjamin H·Journal of health psychology·2008
This study looked at whether ME/CFS is the same disease in everyone or if it might be different depending on how it starts. Researchers compared 45 male veterans with ME/CFS to 84 male civilians with ME/CFS and found some interesting differences: civilians were more likely to get ME/CFS suddenly (like after the flu), while veterans developed it differently. Civilians also had more fibromyalgia alongside their ME/CFS. These differences suggest that ME/CFS might not be one single disease affecting everyone the same way.