The CDC has been rapidly increasing its estimate of children with autism for years. It's tripled in the past 15 years.
This has lead to a lot of speculation, including dramatic claims like vaccines causing autism.
My physiology-major wife tells me that the enormous increase is likely simply increased awareness and alterations to its definition.
But I never hear anything definitive. Even with changes to awareness, definition, etc., given that autism is a common, incurable, lifelong condition, isn't this is really easy to answer?
- Take a population sample.
- Test for autism using chosen, fixed criteria.
- Analyze how age correlates to the measured autism rate.
Okay, maybe not "really easy", but as easy as other physiological population studies.
Has anyone done this and found the answer? Is actual autism prevalence increasing?