I have ADHD and I havn't had any problems of it getting worse. I also havn't heard of it getting any worse either.
I can only speak for myself, of course, but as I have gotten older my own ADD has indeed gotten more severe, but not a lot because I finally found a treatment for it. I'm on a rather large dose of Adderall and it has had an unbelievable impact on my life. I wish I'd had it when I was a child or in high school.
I feel I must qualify this by saying that I also suffer from depression and anxiety and am also being treated for these.
However, before my psychiatrist and I found the right combo of meds, we went through more drugs and drug combos than I can accurately recall. I'd start a new treatment, it would help for a short while then I would 'crash.' Each time this happened I would feel worse.
With my Adderall I can concentrate, finish projects, and my self esteem has even improved because I know that I /can/ achieve goals and finish things now, where in the past I wouldn't even try because I was sure I'd just give up or lose interest.
For me, I was diagnosed with ADHD when I was 6. I am 19 now. Going into adulthood my ADHD did increase in severity, but I am in my second week of treatment with adderall. I am currently taking 15mg a day (10mg when I wake up, 5mg at 4:00). The dosage is completely too low, but it's helping a bit.
there's a couple of ways of looking at this, too. my ADD seems to be getting much worse as I get older, (I'm being treated and am taking Dexadrine, which helps a lot) and yes, it could be that my ADD is actually getting worse, but it couls also be that as I get older I am having to deal with a lot more problems and responsibilities, and it may be that because of this it is simply becoming more obvious, which would appear (and feel)exactly the same.