Forssmed said some of the explanations that have been floated include “increased awareness among healthcare professionals, schools and the public (and) broader diagnosis criteria”.
This seems like a likely explanation to me - ADHD awareness has exploded in recent years.
There's a real noticeable increase in different types of behavioral problems. Regardless if it's adhd, add, or other letter combination. Or just plain old bad parenting (and there's plenty of that)
I met up with a few of my old teachers and classmates last year. They all said the same. That they've seen and noticed this increase over the last 20 years.
The idea that everything is caused by more awareness is also just speculation based on anecdotal evidence. Not a bad speculation, but we shouldn't take it for a fact without a better study on that topic. Having anecdotal evidence against a hypothesis strenghtens the case for a proper study.
While kids are now more likely to be diagnosed with ADHD due to increased awareness and better diagnostic methods, this can also lead to an interesting "reverse echo" effect where their parents have a sudden realization that they're ADHD too.
Hearing about the symptoms from a doctor talking about your child can be an eye-opener that stuff we called "laziness" and "being too sensitive" back in the 80s might have a better name.