I think it's been stated already, but just because "professionals" tend to diagnose AD(H)D far more often than they should doesn't mean it doesn't exist. People like to think that some pills after a quick diagnosis, sometimes even just parents assuming their child has AD(H)D, is the cure for their problems, when a disease isn't the source of the issue at all. At the same time, I'd like to think that a lot of mental "disabilities" don't actually exist, and that there's a mental disability to describe every minor sidestep for "normal" human behavior.