Maybe, but very few. Not enough to show up on radar. There were always discipline cases but they were rare....today they are the norm. You can't tell me something went undiagnosed for millenia to being prominent in the majority of our kids in a couple decades. These problems are caused by two things....parents....and a medical community looking to make a buck off their emotions.
Lower-grade cases of ADHD may potentially be solved with excessive fear of discipline, ridicule, and potentially pain. The risk of those same issues then causing an entirely DIFFERENT disorder, such as a variety of personality disorders, then increases drastically.
Most cases of the various personality disorders are thought to relate to emotional and physical abuse when growing up. If they were constantly thought of as stupid and treated as such, and weren't effectively coached, more issues crop up.
There is much to be said about effective behavioral therapy and behavior modification/coaching... so the very effective parents could get something productive.
That said, you are also ignoring the majority of cases of ADULTS who went their whole live either avoiding such a diagnosis as a kid, or doing what they could to get ahead without assistance, and then getting diagnosed with ADHD. [note: "ADD" no longer exists as a disease in of itself, it is a subtype of ADHD by modern definition. Mostly as ADHD-Inattentive Type]
Also, you are ignoring the possibility of environmental toxins. I'm not using this as a cop-out or trying to be an eco-kook or stand in the same group as the chemtrail and other conspiracy nuts.
There exists compelling evidence that environmental lead (toxic in basically every fashion a metal can be toxic, and the most minute of doses are toxic at the biological level) is directly linked to a rise in crime, mostly as a result of a rise in behavioral and mental health issues. This theory exists to explain the rise of crime that peaks in the late 80s and early 90s, and has been in a continuous slide since that peak (which continues, without fail, through today, regardless of how sensational the media may appear - all statistics across the country properly document the drop in crime rates).
All that just so happens to coincide with peak environmental lead contamination from leaded gasoline during formative years of high-crime generations.
That lead hasn't disappeared, it has merely diminished slowly. Those who may have become criminals, including those reaching maturity today, have been receiving far better mental health treatment or other behavioral modifications due to advances in treatment and therapy.
It doesn't explain ALL cases of ADHD or other mental health disorders, but it has contributed.
I know this is a wiki link, but the sources are valid and if one can access journal articles, I'm sure are terrific reads. I had read some of these before, I'm fairly sure, but cannot access them now that I am out of school and no longer have any kind of journal access.
http://en.wikipedia.org/wiki/Lead_poisoning#Nervous_system
Forever ago I had read a full journal article on this very subject, but I haven't been able to track it down, sadly. I'll make an effort to do so, but in the mean time, this is an excellent read:
http://www.motherjones.com/environment/2013/01/lead-crime-link-gasoline