I agree with the conclusion, at least with all the evidence and experience I have taken into account. ME/CFS is a physical disease.
Where the proponents of psychogenic disease can hide, and have with MS on occasion, is the claim its not only a physical disease.
The argument shows that whatever ME/CFS is it prevents gaining substantive fitness from the types of exercise used. Most people would have major gains in the time frame used. We nearly always do not. Now my opinion is that this is because of a spectrum of physiological impairments we are still trying to understand. However there is still that lurking potential claim that some as yet not understood psychological process is causing it. What the paper's argument does suggest is that such claims of psychogenic processes would be tenuous given current data, and indeed their own data. That suggests this would be an extraordinary claim, and I would want to see substantive evidence of that claim. I am still waiting. I have yet to see such evidence.
Once we have a replicable biomarker that highlights specific mechanisms there will be much less need of making these arguments. We are not there yet. So this paper serves a useful purpose, even if its not perfect. Its pretty good.
