In the course of my work, I've seen people who I believe had it, and I've seen people who clearly had something wrong with them but I don't believe it was ME. I've seen people desperate to get better, and people who seemed to have no interest in getting better because they liked having things done for them. And I've seen people who seemed to find it easier to believe they had ME than that they had psychological problems.
I've no doubt that some people really do have it and I hope this discovery is helpful.