DD is doing very well in school since she was medicated in March of 1st grade. Before that, not so much. She basically sat there looking completely zoned out and did everything 10 times slower than everyone else (if at all). But with the meds, we have had very few problems. Her processing speed is slow and I want to get her a 504, but it's not because she is having any major problems. It would add very minor adjustments (like allowing her to wear headphones in class or give her longer time to take the SAT) which could help her out.
She just got a card in the mail from her teacher, telling her that she is a great student, so hardworking, and organized as well (yes, organized--LOL). She is one of the top 2 or 3 kids in her grade in terms of achievement scores, even after being grade accelerated. This is the kid who just wrote all over the walls with a marker when she didn't have her meds. So don't despair--ADHD doesn't necessarily have to be a major handicap if it is treated appropriately. It may take you a while to figure out what works best for him. We had to try several different meds with different doses for each med.