I'll start by saying that I'm not trying to be provocative, or insulting. I'm really not. But this is a really complicated subject and bad faith actors really aren't helping your cause.
I worked as a medical claims assessor for around 17 years. The vast, vast majority of our incapacity claims were for CFS or fibromylagia. In the early years CFS dominated and then over time, we saw a shift to fibromyalgia and the CFS claims dropping off.
I have two very close friends who have CFS. And they are genuinely and legitimately disabled by it. So I come from a place of believing that it's a real condition, just like fibromylagia.
But the problem you have is complex.
Firstly, if someone is going to fake an illness, they're going to pick something like CFS or fibromyalgia. We caught many, many claimants faking their CFS or fibro - but it required private investigators and video evidence to prove it. That wouldn't have been cost-effective so the smaller claims just got accepted and never investigated, even if they looked dubious.
Secondly, we saw quite a lot of claimants who had a history of anxiety and depression. Some of them absolutely refused to accept that there could even be a smidgeon of anxiety/depression etc influencing how they felt. As PP have said, there seems to be a steadfast insistence that it must be a physical cause even when there is evidence to suggest MH may be a factor. There shouldn't be any shame in acknowledging that MH is contributing to physical conditions but people seem to think that admitting that means they are making things up.
Just to reiterate what I said upthread. CFS is undoubtedly real and causes horrible disability. I remember going to a seminar years ago where a consultant talked about studies that showed an increase in lactic acid.
But:
Some people who claim to have CFS are perfectly well. They either never had it or else recovered and have lied about it.
Some people with a diagnosis of CFS clearly have mental health difficulties too. No idea which came first, but there's typically a history of anxiety/depression. Refusing to acknowledge this really doesn't help with credibility.
Not everyone with CFS will fall into the above groups, but some will - and therein lies the problem.
I've assessed literally thousands of claims over the years, and CFS and fibro made up a large bulk of these. They are both debilitating and awful conditions, and anyone who is suffering from either has my absolute sympathy. It's so hard when you don't know how, when, or if, you'll get better. And being caught in a vicious circle makes it harder - no energy to exercise but by not exercising, muscles atrophy and it's harder/more exhausting. Absolute bastard.
If you genuinely have CFS/fibro, one of your biggest problems is that you probably don't realise how many scammers there are out there. And your debilitating condition is the thing they often claim to have. It makes people suspicious of anyone with CFS/fibro, even though that's not fair.
I understand the desire to grasp onto any shred of "proof" but I don't think this study is what you're hoping it is. Maybe with further research it will be, but I don't think it's at that point yet.