In addition to the suggestions above, I highly recommend Dr. Russell Barkley's Youtube videos about ADHD (on Youtube). Maybe your parents can look into the "B Mod" technique he talks about for organizing the environment (and creating an appropriate system of consequences/rewards) for kids (and young adults) with ADHD. Folks with ADHD start with a smaller mental "energy tank" than others, but can do very well with careful adjustments in habit/routine/life structure.