Does modern life exacerbate adhd?

I've been thinking about this a lot lately - does modern life, parenting and education styles exacerbate adhd? I have come to think that in the past the application of higher levels of external structure on people tended to mask their adhd to a certain extent. If you think about it people with adhd have a low internal locus of control, that is very likely physiological in origin. This means that if parents, school and society impose an external locus of control then many individuals with adhd will pass for 'normal'. Hmmmm, interesting to think about!