Absolutely, I was diagnosed in 2002 when I was 20 years old. I am now 44. It is scary how tolerant I am to stimulant meds. That's just the way it is.

Not due to ageing however, I develope a tolerance extremely quickly to all meds!

I have only had med increases in the early days of treatment with adderall. I was switched from methylphenidate. I have been on the same med, same strength as long as I can remember 20+ yrs. I take 2 a day or 1-1/2 & the 2nd half in the afternoon if needed. Of course 1 or 2 naps 10- 30 min helps immensely. Periodically I take 1 pill for a few days then I can go back to my normal dose (it helps) however with out the adderall I simply do not function other than sitting & dozing off & on for the day. If I get any motivation at all it's in the evening. I have always been this way. I hate it more than anything! ( i topic jump freqently sorry if i lost ya!)