[marcusverus]

A little more on this topic. No teenager with ADHD will be interested in doing the work I've described above. If his parents aren't interested in it either, your ability to help will be severely limited.

One way to help him to do this work will be to get him out of his intellectual comfort zone. Encourage him to take on tough but fun projects (building big models, electronics kits, doing NAND to Tetris, etc) that will require foresight and planning. Make yourself available if he gets stuck, so that you can help explain that hard problems are only hard if you lack the mental framework required to parse and subdivide and organize them into simpler sub-tasks. If you can get him to sit back and think about how to solve hard problems, you'll be giving him a transferable skill which will be integral to working through life with ADHD and minimizing its impact--and you can do it without actually broaching the topic.