There is a lot of doubt and controversy behind ADD/ADHD actually being a disease. Before you start taking this drug, do a search on google to read what opponents of ADD's existence have to say.
Methylphenidate, the active ingredient of Ritalin and Concerta, is very similar to cocaine, and is addictive.
see here for a long but interesting article.
Ask yourself: WHAT WOULD YOU DO IF A PSYCHIATRIST PRESCRIBED YOU COCAINE TO USE DAILY!
Bob