Having trouble absorbing this, even though I started this. I guess we would have to read Jason's study to answer some of these questions. But from what we see now, is he saying that ICC is catching a subset.
Jason has published an enormous amount of work, and I think it might be necessary to read some of it to find out where he is coming from. This particular paper is quite a small exploratory study, and all he seems to be saying is that ICC patients have a higher incidence of comorbid psychiatric issues than Fukuda patients. He doesn't state which psychiatric issues, as far as I understand, and he doesn't discuss why it is an issue, and he doesn't discuss neurological issues. And he doesn't come to any other conclusions about the ICC. It's simply a case of reporting the facts, in terms of his findings, using the SCID (As far as I understand it, the SCID is a very long and comprehensive questionnaire that thoroughly investigates a large variety of psychiatric possibilities).
Jason says that he has read the comments after Cort's article, so hopefully they have given him some food for thought, in terms of the relationship between neurological problems and psychiatric symptoms.
I haven't read a great deal of Jason's work in detail, so I really don't understand why he considers psychiatric comorbidity to be a problem, if indeed he does consider it a problem.
I think it is helpful to investigate to see if the ICC can distinguish between primary ME and primary psychiatric disorders. Perhaps that is what Jason's intention is. He's simply doing thorough exploratory research, in terms of understanding how the ICC works in practise.
It always seemed obvious to me (an assumption) that PENE would distinguish between ME and psychiatric disorders, and that severe neurological symptoms can have a similarity to some psychiatric symptoms, and that neurological issues can cause psychiatric symptoms. So Jason's study came as a surprise to me. But perhaps it's not all as obvious as I thought it was, and perhaps I haven't thought it through properly.
It can only be helpful to explore these issues, as long as it is done properly and thoroughly. The ICC needs to be thoroughly explored and validated if it is to be widely used. Jason does an excellent job of investigating diagnostic criteria, and seems to be widely respected.
There are reasons as to why many researchers might consider comorbidity a problem.
It can complicate research, for a start. And secondary psychiatric disorders need to be distinguished from primary psychiatric disorders.
Anyway, I think that Jason is a top quality researcher, and this is simply part of his rigorous research.
Many people have a problem with Fukuda because it isn't able to fully exclude psychiatric patients. Jason has published work, previously, that has highlighted this problem.
Jason (or perhaps it was someone else - my memory fails me) has demonstrated that Fukuda isn't able to distinguish between CFS and primary major depression. So, obviously, that
is a problem.