I used to be a child protection social worker and I could pretty much bet that every time I removed a child from their home and placed them in foster care, I would get two calls within the first week - one from the foster parents and one from the child's teacher insisting we get the kid in for an appt with the doctor to get him or her on Ritalin for ADHD. As a psychologist, it was obvious the kid did not just spontaneously develop ADHD but instead had a perfectly normal adjustment issue due to being placed in foster care and usually in a new school.
The average GP however, talks to the foster parent hears a few sysmptoms and diagnoses the child with ADHD and places them on Ritalin, and in effect establishes them as a child with ADHD. Now, a psychiatirist or psychologist would actually know and follow the DSM-IV-TR criteria and look for the requisite number of symptoms, but also pay attention to the duration of the symptoms (at least 6 months) and rule out more likely explanations of the behaviors (such as adjustment issues due to being removed from home and placed in a foster home). You have no idea how much pressure there is to just medicate kids rather than actually deal with the issues. Pills are simple, raising kids is more complicated.
If you look at Japan, ADHD is treated as a behavioral condition. It is screened for in kindergarten and resolved with behavioral intervention. In the US on the other hand, we diagnose the hell out of it and consume 95% of the world's pruduction of Ritalin and Stratera. I doubt our lead levels are any higher in the US than in Japan nor are they causative for ADHD.
In that same vein, I see the same thing occuring with Autism diagnosis in children. Any psychiatric disorder is a matter of degree from normal to pathological. But the autism crowd has done really well as they now have an Autism spectrum disorder, where you can diagnose a child with autism spectrum disorder just for having a symptom or two that would be, and should be, considered to be within the normal range of human behavior. But it is popular and it is so much easier if I can diagnose my kid with Autism and medicate them, or just blame their unruly or sometimes just odd behavior on autism rather than poor parenting or just having a kid that is slightly different.
So please, don't give me that ADHD/Autism crap. Rates are up because it is popular to diagnose and it has some secondary gain for parents in some situations.
Again, we are a society seeking the feel good solutions while ignoring the real issues. If someone objects and points out the ineffectiveness of a law, they get shouted down with an argument along the lines of "something is better than nothing".
The thing is that this is not the case. We all "feel good" about banning lead weights, but we will continue to import chinese products that may well be coated in lead based paint and we don't think twice about living downwind from a coal fired power plant spewing lead and other heavy metals into the atmosphere in much more dangerous gaseous form. But public attention is diverted away from the tough issues as we already have an "easy" fix for the problem.
If you really want to reduce the amount of lead in the environment, that's great, but actually do something about the real causes and stop picking on insignificant things like lead wheel weights.
