My assumption would be that it's not so much a desire to hide things that they know, but a tendency to make assumptions in favour of big business/capital when the evidence is still not clear. Then as the evidence becomes more overwhelming, to emphasise how no-one could have possibly known what was true previously. That's not to say the researchers themselves are intentionally corrupt (although the recent spin around PACE, and Crawleys claims that PACE showed a 30-40% recovery rate for CBT/GET have left me feeling that CFS researchers are more likely to be corrupt than I'd previously assumed). When the evidence surrounding a matter is not clear, and one group of researchers hold beliefs which will benefit those in power, while another hold beliefs which will be costly to those in power, who do you think is most likely to get funding/promotions/influence? The researchers themselves could be entirely sincere in their beliefs, and believe that their rise was the result of meritocracy in action. I'd be amazed if CFS was caused by any one thing, never mind something which was already known. Fatigue is such a universal symptom, that I wouldn't be surprised if the majority of currently undiagnosed/discovered medical problems have it as a feature. edit: I've said very similar things to Mark, despite having not read his post when I was typing and coming at things from a quite different angle. I've never really looked in to the government's classified files on CFS. I wonder if any of the big organisations are keen to get them open.