You will find that many teachers at the pre-school and elementary level will ignore written medical documentation and instead, make judgement calls about your child’s behavior. It’s worse for boys. 99% if preschool/elementary educators are women, and many if not most of them actively discourage typical and normal boy behavior.
While it’s inappropriate to diagnose a child with ADHD prior to age four, the signs are there. You will also find that few drugs are specifically recommended for childhood ADHD on label, that’s simply because the population who use them isn’t large enough to support the enormous cost of the trials necessary to get it on the label. Doctors who specialize in ADHD, real ADHD, usually make off-label recommendations based on the expertise available within that community. While there is some controversy and accusations that teachers/parents label kids and drug them to be docile, there are a lot of kids who cannot concentrate enough to make it through the day without medication.
All that said, your son could just as easily be bored out of his mind and creating mischief to pass the time. Find a group of medical professionals and educators you trust and work as a team. Each child is a puzzle, and they can’t clearly articulate what’s going on in their heads.
On free play. In some Scandinavian countries, they make no attempt to begin teaching a child to readuntil they are six or seven. Those children routinely outperform their US cousins. In fact, the academic performance difference between children who attend pre-school and those who don’t disappears by the fourth grade. Free play is critical Don’t let anyone tell you otherwise.
I do recommend “The Importance of Being Little: What Preschoolers Really Need from Grownups” by Erika Christakis, yes that Erika Christakis. She knows what’s she’s talking about.