Hey foggy, As a kid i too was tested with a slight case of add, and i was in slower classes till high school because of it. My parents decided that they didn't want me on medication cause there is nothing wrong with me, thats just how i am. To improve on it i had to really really push myself to focus. I had to figure out and test the best ways for me to tune my focus.
These were the things that really helped me
1. I got an adequate amount of sleep each night
2. Eating breakfast
3. Drinking caffeine when needed (Sparingly)
4. While studying, i had to literally shut my door, turn off all distractions and listen to some music. The music helped me get motivated and also helped block out all outside noise!
5. I took breaks whenever i got frustrated
6. I also had some friends help me along the way
There is nothing worse than treating the symptoms rather than attacking the source first. Dont look at ADD as a disadvantage, look at it as a special talent, there are many advantages. I also noticed that the things i didn't focus good in were the subjects i simply hated, it may be like this for you too! Read this inspirational article i found through Google, it is really neat!
Top 10 Advantages of ADD in a High Tech Career | Adult ADD Strengths