Cognitive and behavioural responses to symptoms in adolescents with CFS: A case-control study nested within a cohort, 2019, Loades et al

Yup. https://www.ncbi.nlm.nih.gov/pubmed/20663256

Seems to basically report that sicker people describe themselves as sicker than people who are less sick. Groundbreaking stuff.

I'm not even sure what is meant by "standardized". They are used exclusively by people within a closely-knit circle of like-minded ideologues and are not valid by any measure.

 

Sadly this is potentially evidence base for NICE. Similarly the n=1 account of intensive therapy for a teenage boy with severe ME which reads like torture.
There is very little biomedical research for paediatric/ adolescents. A muscle study which Tymes Trust were involved with ( Dundee uni) , but can't really think of (m)any others.
Worrying.