On my birthday, my 7 yr old son made the honor roll at his school. His first report card with straight As. What is remarkable about this feat is that as recently as Thanksgiving, his behavior problems (acting up in class, fighting) had led him to the brink of being expelled (a 7 yr old!). Took him to a kid shrink, dosed him up with ADHD meds, and now he can focus and control his impulses. Fortunately, the meds don't zone him out like a lot of kids. He actually thinks clearly and calmly for the first time in his school career.
It's not easy, but it's worth it. I wouldn't trade being a dad for anything else.