I agree with Mark, although I read lots of other posts after that so I don't remember his point. I just remember as I read it that I agreed.
I disagreed with some points Dysautonomia made that lots of people diagnosed with CFS don't have XMRV. Sorry, that was Dysautonomia, wasn't it?
We again might be dealing with the difference in US to UK. In the US, doctors don't like to diagnose CFS because they can't do anything. (I am talking about doctor population in general, not the specialists.) They don't think CFS (or ME) actually exists. Now I am talking about 50% of doctors, according to surveys I have seen. Someone with "it" is more likely to be misdiagnosed as depression in the US. So in the US, at least, I expect that about 70% of people diagnosed with CFS will have XMRV. And likely a good 30% of people with diagnosis of depression will actually have XMRV.
From what I am reading about UK, from you who live it, CFS has been considered psychological, so the docs there put people into that diagnosis, even if they don't have any biological abnormalities, in fact, they define CFS as people with no biological abnormalities. By contrast, docs who diagnose CFS in the US believe it exists (the other 50%) but they don't know what to do about it, they just send you to another doctor. If they don't believe it exists, they diagnose as depression.
As I have said in another post, there are main definition problems on both sides of Atlantic.
As for cortisol. My theory is that we stress, etc. and adrenal pumps it till it can't pump no more. Many who get sick have very active lives and were under stress at the time. I am one of those. Kind of like diabetes. Maybe we are the XMRV positive folks but not sick until the cortisol dries up, and then we have it all. Does virus infection generally raise cortisol levels? If it does, then that would fit also. If I remember fight, isn't low cortisol compared to high cortisol one of the ways to differentiate between CFS (or ME) and depression?
Anyway, I have low cortisol. So I am on a low dose. I understand that seems counter intuitive if I have XMRV (not tested yet, but assume I have it), but I am feeling better, so I guess I will keep on keeping on.
I think this illness is so complex and involves so many dysfunctions and interrelated systems that when you try to help one thing, you might be hurting another thing. Maybe we need more cortisol to just have normal body functions and handle stress and keep homeostasis, but the cortisol feeds the XMRV, then that causes death of NK and T Cells, which leads to autonomic dysfunction and viruses flourishing, and toxins build up. Then cytokines are elevated because of the flourishing viruses. Sex hormones are messed up because of the HPA axis mess up. And that causes more problems in immune system, and it becomes an unending loop.
Maybe the illness is when so many parts go wrong you can't crawl out because when one thing gets better, something else pushes it back down again. So anything that makes one part better, causes problem in another system.
Basically, XMRV causes a complete failure of the homeostasis such that you can't get out of the continuous loop.
Tina