ADHD is something that I find very curious. I fully accept that it is a genuine condition, as I've known a couple of people who were diagnosed and medicated and I could see a huge difference in how they lived. On the other hand I've also known people who seemed to be little more than teenage boys being teenage boys with parents who insisted they were "hyper" and needed medication. The kind of things that were expected of me when I was a teenage boy have, in some parents' minds at least, become grounds for drugging their children into compliance.
Likewise Oppositional Defiant Disorder sounds like little more than children testing the boundaries. At what point is a child who has never been required to obey instructions - usually it would appear by parents who are more interested in being their child's friend than their child's parent - considered to have a diagnosable condition that can and should be medicated? The reason I ask is to get your specific insight into it, rather than much of what is online that seems like little more than propaganda from one side or the other paired with the inevitable slanging match between supporters and detractors.
Obviously my experience is limited and not a substitute for scientific research but my personal observations are that children who are never required to sit down and be quiet have trouble sitting down and being quiet, children who are never expected to obey instructions have trouble obeying instructions, children who are never taught boundaries and the consequences of crossing them have trouble with boundaries, children whose parents allow them to use baby-talk long past the time other children are starting to talk more normally have trouble talking more normally, and so on. Part of this is caused by a curiosity as to why diagnoses like ADHD have rocketed in recent years.