It is good to see research challenging the sleep police.
There is some evidence that aspects at least of our sleep patterns are cultural, for example there is the suggestion that in Europe at least the previous norm was not 'go to bed, fall asleep for eight hours, then get up' but rather 'sleep for several hours, be active for several hours, then have a second sleep'.
See
https://www.sciencealert.com/humans-used-to-sleep-in-two-shifts-maybe-we-should-again
https://www.bbc.co.uk/news/magazine-16964783
However this does not stop people such as Prof Crawley seeking to present a dogma that people with ME must correct their aberrant sleep patterns, must not sleep during the day and must sleep in one eight hour block at night. She even seems to go as far as to suggest establishing 'correct' sleep patterns will change our brain neurophysiology in such a way that is the equivalent of a drug treating the underlying biomedical deficit in ME/CFS.
To quote the Guardian quoting Crawley (
https://www.theguardian.com/society...-syndrome-treatment-trial-success-netherlands ):
The approach regularly receives criticism from some activists who argue it treats chronic fatigue syndrome as a disease of the mind.
Prof Crawley said: "A teenager might say, 'You are just trying to change my sleep', but do you know how much biology you actually change?
"Children who come to my clinic have low cortisol [stress hormone] levels in the morning, that is why they feel so terrible; by changing their sleep, we reverse that.
"The stuff we are doing is not a pill, but it might as well be."
There is obviously issues around us not fully understand the implications of artificial light and/or overuse of screen based technology in relation to healthy or restorative sleep, and we can not rule out the possibility there is a group of people who suffer fatigue because of unhelpful sleep habits such as overuse of IT devices before attempting to sleep, who may be helped by good sleep hygiene practices. It may even be probable that Crawley with her over broad definition of CFS misdiagnoses such teenagers as having CFS.
Presumably, if Crawley had data demonstrating ME is invariably linked to low morning levels of cortisol and that changing sleep patterns reverses this which in turn is associated with curing ME, she would have published it. Without such evidence we are dealing with her personal beliefs not evidence based medicine.
There is no evidence that trying to force people with ME into a perceived 'normal' sleeping pattern, is helpful. We do not understand the relationship between ME and sleep, especially as the same individual can shift between sleeping twenty or so hours a day and total insomnia or a complete reversal of the normal diurnal rhythms over the course of their disease.
Anecdotally people report that sleeping when the body demands it is helpful, that day time sleeps can help improve functioning. Until we have evidence that not sleeping when our bodies demands it and trying to force sleep when our bodies reject it is actually helpful, surely the rational response is to listen to our bodies.