Here is my take on ADHD (and variations thereof) as someone diagnosed and being treated for AADD.
ADHD is over diagnosed, specifically in young children (K-5 specifically, but 6-8 still problematic as well). This is also more towards young boys, and for reasons that aren't difficult to understand; boys are rambunctious.
I was first "diagnosed" around 4th grade (apx. 9 or 10 years old). I put this diagnosis in parenthesis as this was made by a school counselor, whom later recommended my mother that she take me to a doctor (of the counselors recommendation) and put me on Ritalin. My mother did not, and I did not protest (as I just wanted to be "normal"). Many of my friends were also "diagnosed," and to my recollection most, if not all, refused Rx. I was still placed in an ESE (Exceptional Student Education) class, which deals with learning disabilities (mild to extreme) to gifted (130+ IQ, which I was also placed in as such was a requirement for the school I attended, Pine View; which only exacerbated my embarrassment of being labeled "ADD").
I was properly diagnosed a few years later (I believe 8th grade) by a psychiatrist, but I still protested any medication, and did not take any. I denied not only the prescription, but also the disease itself. After the embarrassing (both by oversensitivity to the situation on my part, and the extremely condescending nature that many of the faculty held towards said situation) treatment I received at Pine View. So the problem went untreated throughout high school (which was a different school). Many of my teachers noticed, and lectured me to no end about slacking, missing assignments and the like, but I was long used to these speeches. Fortunately I was smart enough, and a good enough schmoozer/liar, that I pulled away with an 'A' average (mind you, this was no longer a school for "the gifted" and the curriculum was not particularly taxing).
Unfortunately, for me, such was not the case for college and "real life" in general. It took me over a year to finally look back and accept that ADD was a real disease and I really did have it. I made an appointment, received treatment (Adderall), and things began to improve drastically.
My problem was the way ADD/ADHD was over diagnosed, and the misunderstanding the general public seems to regard it with. These factors stopped me from receiving treatment much earlier, when it would have been much more beneficial (full disclosure: my own personal hangups also stood as a hurdle, though I can't accurately determine how much those were affected by the aforementioned treatment and stigmas). People were to willing to try and solve the problem of young boys being young boys, by giving them medication. This created a view of ADD/ADHD as an illegitimate disease, and just a new way to not deal with difficult children. Frankly, I'm against giving an Rx of this type to all but the most clear cut, and extreme, cases for pre-teens. This reluctance is not just a response to the over diagnosis and to curb the misinformation, or even to ensure they do have the disease (though this is a close secondary), but because giving amphetamines or analogous medications to young children is something that should be last resort, not first response.
That is something I hate. The over diagnosis of ADD/ADHD.