It is understandable that many people are sceptical though.
I do believe that ADHD is a real condition, and some people do have it, but in some cases, it's a product of their environment and parenting that causes certain behaviours in children/people, and not necessarily an actual chemical or biological problem. Some people are too quick to label them with ADHD. Some people even self diagnose! As the above poster @ThisNattyTurtle said, it is over diagnosed. It is certainly not UNDER diagnosed. (as @swimsong suggested!) How can that be? So many children/young people you meet these days seem to have it/say they have it!)
One of my neighbours was overjoyed when her 7 y.o. was diagnosed with ADHD, (a very shouty, angry child who kicks, and spits on people, and breaks things, and bullies other children at school...) But when the mother took him for his diagnosis, I bet she neglected to mention that she screams blue murder at him half the time, she is always angry, she's always shouting/never talks properly, and she boots him outside most of the day, to find someone to play with as she CBA with him.
She has no job, and very little to do, but CBA to lift a finger to play with him, read to him, take him out for picnics or to the park, and generally be a mum. IMO his upbringing has resulted in his bad behaviour. There is no actual chemical or biological reason for it. IMO. I reckon with better parenting he would have been a different person, and would very likely never have been diagnosed with ADHD. That is JMO of course.
Oh, she was overjoyed, when he was diagnosed with ADHD, because she now had a reason for his behaviour, and it was nothing to do with her. 🙄
!