An Autism Anomaly, Partly Explained - New York Times
Here is a snapshot of the emergence of a new 'epidemic' in psychiatry. The question that isn't asked is whether the definition of a 'new' disease has morphed as vigilance about it increases. My guess is that states that find more autism also use a broader definition of that disorder. This certainly seems to be the case of the definition of depression over the 'prozac years.'