ADHD is SOOO overdiagnosed.
Generally with high IQ you get some of the symptoms of ADHD regarding focus, but never hyper. It is rare that somebody with ADHD is only at a focus loss or is only hyper, it is most always a combination of the two.
Almost every single extremely intelligent person I've met was diagnosed for ADHD including myself.
however, I won't say I can easily focus on brain intensive tasks (I'm usually last to turn in my algebra tests)
But I'm really, really not hyper.
I'm sure some of you here might have ADHD, but seriously go read up on the side effects of higher IQ versus the symptoms of ADHD. You might be surprised.