I have a lot of medical monographs at hand including descriptions of such studies. I'm still reading them. But the summaries I've seen so far in my reading are quite ambiguous as to claimed benefits of taking ADHD drugs (for anyone), especially for the inattentive subtype of ADD. Subjectively reported "this drug really helps me" or third-party observation of "this kid doesn't wiggle around so much in class" is not the same as carefully verified gains in learning from using the drug versus not using the drug.