Okay, fellow skeptics - I've got a brain tickler for you:

[varkam]

In taking part in a recent discussion on vaccines and autism, I got involved in a discussion on whether or not there is an autism epidemic. I didn't think that there was one, and my friend thinks that there is. As evidence, I submitted the following study.

http://pediatrics.aappublications.org/cgi/content/full/117/4/1028

My friend fired back with this one:

http://pediatrics.aappublications.org/cgi/content/full/115/3/e277

They appear to essentially be saying the exact opposite thing. So, my question is why? I have a couple ideas as to what might account for the differences between the studies, but I wanted to get some more brain power in on this. If anyone has any thoughts, I'd love to hear them.

:hi:

[cosmik debris]

1. Watch out for semantics

Your study says it is not an "epidemic". His study says it is increasing. (Not a contradiction)

Your study addresses cause, his doesn't.

His study makes the statement "No concomitant decreases in categories of mental retardation or speech/language impairment were seen." To me that is easily explained by significant improvements in children's health care in recent years. Note that his study goes back to 1975.

I'll read more later, but that is my first impression.

[Warpy]

2. Don't forget that seeing autism as a spectrum disorder

that in its mildest form can be someone with a very quirky social persona but an ability to work and support himself, that's likeliest to be where we're seeing this "epidemic."

As recently as 15 years ago, they'd have been classified as oddballs, not as having the mildest form of autism.

Asperger's syndrome is part of the spectrum that has only been diagnosed as autism in the very, very recent past.

MIT was full of Aspies when I worked there. It's not all bad news.

[varkam]

3. So at least some of the cases we're seeing now...

wouldn't of been diagnosed at all? That would certainly help to explain things, but how many cases do you think that category would encompass?

[Warpy]

4. I think it would encompass a lot of "geeky, nerdy" kids

with poor social skills. I remember seeing severely autistic kids when I worked in a state mental institution in the 60s. They were classified as "deeply disturbed."

You bet the increase is because of better diagnosis!