" I wonder how many of these children just need more attention and discipline."
Unfortunately, those who don't know often think it's just a matter of parental attention/discipline, but it's not. It only makes it harder for struggling parents to be judged by other parents. FYI.
Also, EandCmom, a diagnosis of ADHD does not necessarily mean medication. There are other alternatives. And a diagnosis may allow your friend's son to get the help/accommodations he needs in class. Maybe his desk just needs to be closer to the teacher, or maybe he has to take a test in a room by himself. Unfortunately, those on the other end of the labeling are often labeling in their own way. If your friend suspects a problem, she should get the best evaluation she can find and then figure out what to do about it. And a thorough evaluation considers all the possibilities, including, maybe he's just bored in school...
