Daily Mail article : Are you tired all the time? You could be ill

[Snow Leopard]

However, I understand that the questionnaires asked not about how people felt in terms of being stressed, but asked about major objective events like marriage, divorce or bereavement (events that are known to cause stress).

But those might not be the factors that led to the association - unless they publish the individual factors, it's merely speculation on your part.

I think it is very relevant that for example ME/CFS is usually kicked off by viral infection.

I also find it very relevant that in the historical ME/CFS infectious outbreaks, the ME/CFS epidemic was always confined to a specific area, and never travelled further outside that area (thankfully). That to me suggests that a virus alone does not usually cause ME/CFS; it requires the virus in combination with some other second factor local to the outbreak area — a second factor that allowed the virus to trigger ME/CFS. In the case of Lake Tahoe, the proposed second factor was the toxic cyanobacteria that had grown on the Lake that year.

But infection, not necessarily viral does seem to be associated as a precipitating factor of a majority of ME cases (as opposed to stressful events only being a precipitating factor in a small minority of ME cases). I don't think the infection itself is that important. I don't think it is worth examining the minutiae of EBV for example, just because it seems to be a common trigger.

The stressful events could simply increase the risk of someone developing an infection in the first place - it might have a measurable impact, but isn't terribly interesting in the big picture. This risk could also be behavioural in terms of exposure, rather than requiring any sort of hypothesis of immune system suppression.

As to your latter comment, that is certainly interesting, but it is wildly speculative and well, I don't think it can really explain so many similar cases worldwide.