"We feel that, while ADHD has some symptoms in common with mental health problems, it is not appropriate for Mind, nationally, to provide detailed information on it. Our position is the same for health problems often categorised as developmental disorders, such as autism, and neurodegenerative disorders, such as dementia. Any information we wrote on ADHD would be likely to replicate other, more specialist, information provided by other organisations.
This is something Mind has considered carefully and we believe it is an area which other organisations are in a better position to lead on, as they provide excellent support and have greater expertise. For example ADHD Foundation, UKAAN or ADDISS."
Ok, so it's not a mental illness, at least not one recognised by MIND and that is good enough for me.