>The main problem with this data is that the definition of autism has expanded over time.
How do we know this is the case and not that it was under-diagnosed in the past? I also see this logic with ADHD. Yet in the past, a lot of these children would be shoved off to group homes or labeled 'slow' and such. At least with diagnosis they have a chance for recovery. I don't think past diagnosis stats are unquestionable. We actually don't know what the real rate should be. At least not yet.
Some cases are ambiguous, as fuzzy definitions change over time. In this case, however, a name that once applied only to relatively severe cases has been intentionally expanded:
The term "Asperger's disorder" will not appear in the
DSM-5, the latest revision of the manual, and instead
its symptoms will come under the newly added "autism
spectrum disorder", which is already used widely. That
umbrella diagnosis will include children with severe
autism, who often do not talk or interact, as well as
those with milder forms.
It's certainly both. The definition has literally expanded (now including Asperger's), but with more awareness it's more likely people who are borderline autistic will be able to get diagnosed.
This all makes it very hard to answer the question "are more people today autistic than 50 years ago?"
How do we know this is the case and not that it was under-diagnosed in the past? I also see this logic with ADHD. Yet in the past, a lot of these children would be shoved off to group homes or labeled 'slow' and such. At least with diagnosis they have a chance for recovery. I don't think past diagnosis stats are unquestionable. We actually don't know what the real rate should be. At least not yet.