Jim Pfrommer said it succinctly and (as usual) well. All of the manifestations of ADD/ADHD can be explained as one or another pole of the compass of shame. I've got a chapter on this coming out in a book edited by Mel Lansky and Andy Morrison (except they are so upset that I've tackled this issue that they are trying to get away from it). When they and I are done negotiating the chapter, I'll try to get their permission to make copies available either on BOL or by snailmail.
Actually, when you sit with these children while they are trying to pay attention to something, you see all four poles of the compass whirling like a propellor on a beanie.