I've speculated about this for years. It's cool to see scientific studies in the subject. I like this quote:

Intelligent individuals who are bombarded by ideas seek to make sense of them by organizing them into new perceptual relationships. Thus the creative, original idea is born

I wish ADD/ADHD was understood when I was a student. Most teachers back then wrote you off as some sort of immature day-dreamer. My oldest son has ADHD that he inherited from me, but is doing way better than I ever did in school because there is knowledge and support. And as far as the creative connection goes, I think my son goes far beyond where I was at his age in terms of his creative conceptual ability. I remember him drawing a picture of his baby brother when he was in first grade, and he draw everything in a rudimentary one-point perspective.