I can explain it easily enough. DISCIPLINE and the KNOWLEDGE the student is responsible and accountable for all their behavior.
It worked before and it will work again. Get the F’n lawyers, hand wringers and bed wetters OUT of the classroom and make these children (and their parents) understand from day ONE in the school systems that bad behavior will NOT be tolerated.
Once again ... it’s not just about bad behavior. I was not a behavior problem in my youth ... just couldn’t focus. And I see that same thing in today’s classrooms too ... and in my own kids. My wife is a teacher and has some really good kids in her class. Some focus fine, others don’t. She does not push parents to have them checked for ADHD, in fact that is against the law. And my kids are good kids ... never any behavior issues at school. High marks in that category even. But their inability to stay focused does cause them some problems.
Bad behavior is bad behavior ... not ADHD.