I was recently diagnosed with ADHD, and started taking Ritalin, and it's helped tremendously. In the past I took that, and sometimes Vicadin, to help. They both helped me focus and get much more done. Obviously the Vicadin wasn't prescribed for that, I just found out by accident that it worked.

I just tried this test and scored a 99% for ADD (ADHD was recently changed to be all encompassing - you can have either inattentive or hyperactive or both).