I actually went to a seminar by Dr Russel Barkley less than a month ago. As I recall, people with ADHD have the same incidence rate of giftedness as the rest of the population. I could be totally wrong though. My brother and I both have above average and superior IQs respectively, for whatever that is worth. That is neither here nor there though, I believe.
The real trick is that many of the strategies that help children who are gifted also help children with ADHD and visa versa. Enriched programs, lots of structural supports that still allow for divergent thinking, a lively, fast paced program – these are all things that can benefit children with either giftedness or ADHD or both!
I am not saying your son is not gifted. It is entirely likely that he is! I will speak from my own experience involving medication and the gifted/ADHD combination though, if you’ll indulge me. While I have not yet found a combination of medications that work for me I have found that I am making great strides in my academic career since I started treatment. I developed a lot of anxiety throughout my school years as a result of my untreated ADHD and that comorbidity is what is complicating my search for the right medication. I was in karate, I had a challenging academic program, I had a supportive environment at school and (most of the time) at home and I still developed this anxiety. I think if I had the medication a lot earlier then I would have fewer problems now. There wouldn’t be this degree of academic burnout.
I don’t think you should look at medications as a last resort. They really do help. They are safe and they won’t turn your child into someone that he is not. Rather, I think you should look at medication as a COMPONENT of your child’s treatment along with a structured learning environment and enrolling him in karate. A multidimensional treatment like this would do wonders, I think. 