Second, why do some people have overactive immune systems? Well, because of personality type, stress or trauma, of course.
As
@Simon M points out, the researchers "measured psychosocial factors including childhood trauma before the interferon-alpha treatment started. And these factors did not predict subsequent fatigue."
Previously, psychosocial researchers have used weak evidence, such as that of pre-illness child trauma, as evidence that their psychosocial model was correct. It’s harder to argue that some people develop/maintain CFS after infection because of psychosocial issues (compared with those that don’t develop the illness) when there is no difference in psychosocial factors before the infection (Or immune activation). Why did these people who got CFS suddenly have psychosocial problems after an infection??
I think people are being too nitpicking. I agree with Simon. The basic study here is useful in documenting the fact that a known immunological stimulus can cause a long term and severe illness characterised by fatigue. That may not be the same as CFS or ME but it shows that you do not need to postulate any psychological factors in the causation of an illness at least similar to ME in some respects. A small step but an important one.
To put it another way: this is useful because it shows that illness can persist despite the absence of obvious markers. It's a major nail in the coffin of the 'no abnormalities = no problem' narrative.
I mostly agree with what Simon, Jonathan and Adam say above but I'm not sure that it necessarily contradicts the CBT model of CFS. The model suggests that it is patients' unhelpful beliefs, rather than any underlying abnormal pathology, which perpetuate the illness. These unhelpful beliefs are often assumed to be caused by pre-illness psychosocial factors but is there any reason why they could not be argued to be a consequence of what Sharpe refers to as "an abnormal or excessive immune response"?
Is there anything in the Pariante study which directly refutes the notion that those whose immune systems predispose them to having an abnormal or excessive immune response to interferon-alpha are more likely to develop unhelpful beliefs
as a consequence of the severity of the symptoms caused by the immune response - just as the probability of suffering from psychological problems after being involved in a road accident may be directly proportional the scale of the accident?
As much as I'd like to, I can't see anything in the paper which necessarily contradicts Wessely's idea that an illness like ME/CFS can be
triggered by a virus (or some other event which causes an immune response) but is then perpetuated by unhelpful beliefs - and this seems to be what Sharpe is still desperately clinging on to.
Presumably, the next stage will be to test whether CBT/GET can help reverse persistent fatigue (PF) and/or prevent it if it is given to those whose immune systems suggest they may be susceptible to developing PF following interferon treatment. And I have a sneaky feeling I know what the results may be! Perhaps this is why the SMC are hyping it so much.
Ironically, the best evidence we have that unhelpful beliefs do not perpetuate ME/CFS is the PACE trial, because it suggests that changing the way that patients think about their symptoms has no effect on levels of activity/disability. When one combines that with the evidence from Pariante, that pre-illness psychosocial factors are not predictive of persistent fatigue following interferon treatment, it makes the BPS ideas about ME/CFS look about useful as a creationist view of the universe.
[edit - typo]
