..."researchers find." Link is here, and really the biggest thing I want to say about this, is thank goodness. Thank goodness that researchers are bothering to find out this fact, which may seem obvious to some of us. The fact they are finding is not so much that high IQ doesn't "help" but that high IQ doesn't mean someone doesn't have ADHD.
I sometimes find it surprising that we have to be told this. Maybe that's because in my training as an ADHD coach, at some point I learned that one characteristic of ADHD can be a mismatch between achievement and potential for achievement, where IQ might be one measure of such potential.
I have been personally fortunate never to have anyone tell me that I couldn't possibly have ADHD because I was too smart, or had gotten through too much school, despite having made it through a Master's degree, and through some doctoral research, before even knowing what ADHD is. But I have gotten to know people who have, including some of my clients. This has included the particularly nasty cases where a previous diagnosis was dismissed simply because of some success in academics.
I think this notion that IQ or book smarts or whatnot could exclude ADHD is particularly insidious for people who also don't have the obvious target written all over their faces of obvious hyperactivity. The same holds for other with very quiet disabilities (such as learning disabilities). If you are one of these people, take heart that not everyone writes off your struggle. Luckily, there are people, including doctors, who get it, or who even have ADHD themselves and are open about it. And three cheers for folks like those at Yale who use their credentials to make things easier for us.