I haven't been formally diagnosed with ADHD, but based on what I've been reading, I suspect I will be. I have been using David Allen's Getting Things Done approach for productivity. As I learn more about ADHD, I realize that my following GTD is sort of a self-treatment that helps me cope. The things a like about it are that it's a flexible system and focuses on getting things off my mind and on to paper. There's much more to it than that, but these are the key things that make it work for me.