I believe the common drug for ADD/ADHD is Ritalin, is it not? Regardless, being that ADD deals with the brain and any drug taken does also I'm going to bet the answer is no. Any type of psycho-altering drug, ie anti-depressants, ritalin, and the such, are not allowed per the FAA. Call AOPA or even the FAA Aero-Medical office in OKC for the final word.