I'm a neuroscientist who published on central sensitization and chronic pain. Unfortunately, I was forced into retirement by chronic fatigue syndrome.

The linked article and others have convinced me that CFS can be caused by viruses.

There's one important and tricky question: is a viral infection necessary to trigger CFS in humans (such as long COVID or in this linked article), or is an extremely stressful series of events (which could include the physical stress of a severe viral infection) sufficient?

Giving a certain interpretation of their comment, I think the physician could be stating that they've seen patients with CFS that has been triggered by stressful events alone. I think this can coexist with the linked research if CFS can be triggered by stress OR a virus.

When chronic stress is mentioned as a factor, that should not be interpreted as being a psychological predisposition ("it is all in their head"). Instead, it is a predisposition on a cellular level.

The brain regions involved in central sensitization are tightly linked with those involved in chronic stress. Animal models of chronic stress lead to central sensitization of pain, as do animal models of chronic illness. Chronic stress causes an immense amount of remodeling in the brain and the rest of the body.

Proving or disproving that CFS can be triggered by chronic stress alone is difficult because CFS is a diagnosis of exclusion. Diagnosis can take a long time. We humans are always getting viruses and occasionally enduring stressful life events, so it is difficult to untangle the two.

If we look at my personal history, my diagnosis took several years (above average for CFS patients). I can point to 3 stressful life events and 2 viral illnesses that might have preceded CFS onset. The cause for my CFS remains a mystery.

Without a mechanism and diagnostic test for CFS, I think this question will remain unanswered.

I think it is contentious to say that CFS is an endpoint of central sensitization. It might be, but it also might be related to mitochondrial dysfunction or another mechanism-- too soon to tell, in my opinion. Central sensitization is certainly a component, but I do not think it is proven to be the only component. I should say that I'm extremely biased towards believing in central sensitization as the cause of many things because that was the primary focus of my research.

Again, without a mechanism and a diagnostic test for CFS, much is murky. Viral infection can at least be a cause. I think we're far away from having a tidy answer like the story of H. pylori and ulcers though.