Comment by jessriedel

Is there evidence of a well-defined physiological mechanism rather than merely being a symptom cluster that might be purely psychological? Some brief Googling suggests that CFS is sometimes precipitated by various viral or bacterial infections, which is a step in the right direction, but I haven't read anything yet that rules out the alternative hypothesis that this is a (cluster of related) psychological disorders that is sometimes prompted by a life event. The dozen patient organizations campaigning for recognition is a bit of a red flag.