Hi joesy,
I too have a son with ADD. Although he is only 9 your question ways heavily on my own mind. My son is at a wonderful school. they have a program set up for him that allows for un- timed tests, pre- teaching, and one on one help in the class room for additional support. He seems to be doing well but as I'm sure with your son if the topic is not interesting enough to listen to he day dreams instead. I don't know if you are trying any medication. My family has decided against it. We have been going with the  natural approach with vitamins, omega 3, vitamin B and trace minerals like zinc and magnesium. Also a clean diet, meaning NO processed foods or synthetic dyes. I'm not sure if home schooling is the answer. If he's anything like my son, he gets aggravated with homework and he yells and fights me about the work. He has good days and then some are just awful. But recently sense we started the vitamins I've seen SOME improvements.   I think the structure of a classroom  routine is comforting for him. I think their would be more distractions at home. I have heard that meditation is helpful for some. We haven't tried that yet.
My best to you and your son.
Katama

Hello joesy!
Listen to Katama about dietng!! Homeschooling may be very good for your son it opens up many new opertunites for learning and it is also very flexible if he ever needs help understanding something there is allways time to go over what he needs untill he gets it! I would do some reaserch on homeschooling and see if is right for you.

oh and do not put him on medication no matter what others say. it may cause matters to worsen or become more complicated