It is both over and under diagnosed. Teachers are likely to refer any highly disruptive kids for screenings, while ignoring less disruptive kids.
However, being disruptive isn't a particularly good proxy for "has ADHD" and someone without ADHD that is referred has a higher chance of being diagnoesd with ADHD than someone with that is not referred. This results in a lot of kids who end up being treated who shouldn't and plenty of kids who go untreated who could benefit.
However, being disruptive isn't a particularly good proxy for "has ADHD" and someone without ADHD that is referred has a higher chance of being diagnoesd with ADHD than someone with that is not referred. This results in a lot of kids who end up being treated who shouldn't and plenty of kids who go untreated who could benefit.