Many thanks for that book reference.
Then the other thing I always think, my son is blessed actually. He is very intelligent and if I think of all those famous people with ADD/ADHD
That's an interesting list of people - though I'm not entirely sure how it's possible to say that Socrates (for example) would be diagnosed with ADHD if he were alive today, unless that website's saying something similar to what I was saying in my original post - that a collection of disparate symptoms is being labelled as ADHD without reference to an underlying chemical or genetic cause.
I'll explore the site some more, and hope to increase my understanding as a result.