I think ADHD is real and that gifted kids can be ADHD - however, I think ADHD is overdiagnosed in gifted kids.
When ADHD is diagnosed by the behavior rating and the gifted child is not in an appropriate educational setting, it isn't a valid way to diagnose ADHD.
We went to a pediatric neuropsychologist who tested my son and verified that he doesn't have an attention span problem. It seemed to be a much better way to do the diagnosing than measuring behavior that is so easily influenced and so easily confused with normal gifted behavior.
The book 'Misdiagnosis and Dual Diagnosis of Gifted Children' is a great reference on this topic.
