I don't believe they are really up. I believe it is just being more diagnosed now. They also include the multiple different types of autism in stats. My son has Aspergers. Years ago it was usually misdiagnosed as adhd (still is a lot of the time). Since Aspergers is a form of autism it is included with the statistics. So an increase in proper diagnosis incrases the numbers. It would be even higher if teachers, parents, and therapist didn't jump on the adhd trip when their child seems to have issues. Nearly 1,000,000 children are misdiagnosed with adhd yearly. I'm sure at least some have a form of autism.