I don't doubt there are people in this world for who ADHD is a real thing. But I think we are too quick in the modern age to drug without thinking. Parents demand antibiotics for illnesses which are just small bugs... guess what, now we are having problems with drug resistant bacteria. Lawmakers, administrators, and teachers (in that order) want to turn classrooms in to machines which churn out educated people like clockwork. Turns out, humans are animals, not machines, so we load everybody with some stimulants to make children just sit still.
I'm not anti-medicine in any way. I have personally seen Ritalin work on a friend who actually had ADHD growing up. And I have also seen another friend buy Vyvanse illegally so he could study for 15 hours a day. I believe in prescription drugs. I just don't always believe in the prescription.