Credentials: ADD from back when it was hyperactivity. Been on the Feingold Diet (worked for me, not for everybody), various drugs (works for me, not for everybody), and a lot of forced practice courtesy of mom (would probably work on everybody, since she's a force of nature).
I"ve heard various things about this, over the years, and the question that occurs to me: what happens when they've re-trained the brain this way, to the *good* aspects of ADHD?
I can zip through solving problems in a way that a lot of other people can't. I can 'see' the solution when working at fixing something mechanical. I can also spot discrepancies - visual, aural, logical - much quicker than my friends.
How much of this goes away? That would be a very interesting followup research project, IMHO.