Oppositional Defiant Disorder

I was reading the news today and I came across this, Oppositional Defiant Disorder.
This condition is used to refer to children who in my time (somewhere in the 17th century) might be called naughty. Maybe unruly, disruptive, difficult, recalcitrant. But Conduct Disorder and
O.D.D made me stop and think, WTF?
Is this for real?
Unfortunately a quick reference to Wikipedia told me it was.

Forgive me my ignorance but it must have been centuries ago when those who know better decided that corporal punishment was just not acceptable for children. How barbaric indeed.

I wish I could step back in time and hand a medical certificate to my teacher that would read,
Dear Sir, Lex Jnr is suffering from Oppositional Defiant Disorder and therefore must be excused for his bad behavior. Please to do not cane him, or give him any other form of corporal punishment but rather consider giving Lex counseling from a qualified psychologist.

My teacher would just look and think NO SHIT? Why didn't I realize this before?

And when I think about all those unfortunate people who have been incarcerated for torching buildings, I will think Conduct Disorder, obviously.

And when I think of all those unfortunate people doing time in prison I will think, yes, more cases of Conduct Disorder. Prison...how barbaric indeed.