[my bold]
As always, obfuscating and playing down the grim fact hidden within those words "some patients do not benefit from these therapies". It is a sleight of words designed (yes I do mean 'designed') to give the impression that those who do not benefit, simply remain unchanged, and are no worse off. That is the generally accepted interpretation of such language.
But the use of such language here is intentionally different I'm sure. It is intended to convey exactly that impression, whilst it also embraces a more sinister, but equally valid interpretation: That within the group of patients who do not benefit, there will be a subgroup who deteriorate.
So when these folk very ambiguously state that not everyone benefits from GET/CBT for ME/CFS, they really should be challenged to be more specific regarding those who do not benefit - what about those whose mode of "not benefitting" is to in fact deteriorate?
Ambiguity is second nature to these people, knowing that people will assume the most obvious interpretation, and thereby completely miss the more incisive interpretation they want people to miss.