I may be wrong again, I often am, but I only left school 18 years ago. All these syndromes you hear about today simply didn't exist when I was at school, yet were "discovered" many years ago.
Tourettes, Autism, Aspbergers (Sp), ADHD, Cognitive Behavioural Deficit, blah blah blah.
The only thing that made kids odd was the revelation that certain "E" numbers, especially in KiaOra and what not.
I recall the movie Rainman was in fact the platform for such symptoms to come to light.
I doubt the whole psychiatric world and need for parents to label their wayward kids with something scientific. Some kids are just bad, some good, some mad and some just sad.
That is how it was not that long ago.