On Autism Prevalence

[HuckleB]

http://www.theness.com/neurologicablog/?p=2224#more-2224

"In order to teach science to the public it is better to tell a story about how questions are resolved in science, rather than simply to teach authoritatively the current findings of science. The process is interesting – often more so than the facts.

One such story is the true cause of the increasing autism prevalence over the last 20 years. There is no question that the number of people being diagnosed with autism is increasing. There are various theories as to why, the best, in my opinion, is that the increasing numbers are an artifact of broadening the diagnosis and increased surveillance. Meanwhile, a true increase may also be hiding in the numbers, and that would present an interesting (and important) mystery to solve.

I have written about this before (here and here on SBM, and again here on NeuroLogica). Now there is a new study which may shed some light on the question, but to quickly summarize where the evidence is: There are several ways to address the question of whether or not there is a true increase in autism numbers. One is to assess autism prevalence at various age groups. If true autism incidence is increasing, that younger age groups should have more diagnoses of autism than older age groups – when the same diagnostic criteria are applied. When this kind of analysis is done it appears that autism incidence is stable over time, which is powerful evidence against a true increase.

Another approach is to look at the same cohort today and 20 years ago (where data is available, or by comparing to historical studies) and apply a thorough survey of consistent diagnostic criteria. When this is done again we find a consistent rate of autism diagnosis.

..."

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A good piece on this issue, and on science in general. Well, worth the time taken to read it, IMO.

:hi:

[xchrom]

1. now that's interesting. nt

[d_r]

2. interesting

It makes sense that some portion of the increase is based on increased diagnosis, and some portion on other factors (e.g., paternal age). I've thought for some time there is no single "cause" of autism.

[laconicsax]

3. Well, obviously the authors of the study are in on it.

Everyone knows that the increase in diagnoses is directly caused by the interaction between morgollon-causing chemtrails, flouridated water, and an increase in thimerosal use, especially since 1999. That interaction sets the stage for the MMR vaccine to turn perfectly healthy and genetically pure children into sick, genetically corrupt autistic children.

Only when the conspiracy of PHARMA and Big Science is torn down by courageous entertainers armed with strong opinions to counter their lack of medical or scientific training/knowledge.

One day, the TRUTH will be known--no one was ever autistic before the age of chemtrails, flouridated water, and thimerosal-laced vaccines!!!1

[HuckleB]

5. Fluoride shots at my house!

[laconicsax]

6. I secretly give friends and family homeopathic thimerosal remedies to undo the damage.

No one's getting thimerosal-caused autism on my watch!

[Odin2005]

4. THANK YOU!!!

[PittsburghKid]

7. Overdiagnosis of HFA?

I think a lot of it has to do with more people actually being lumped under the HFA umbrella. I know of at least a few folks aged 30+ who have never been diagnosed but do meet today's criteria for HFA. These are your folks who are normal in almost all respects but are fascinated with unusual interests and may struggle a bit socially. Most of them go to college, get jobs, own homes and cars, and would have just been labeled "eccentric" thirty years ago.

Honestly, they need to stop lumping all ASDs together. When we hear of an increase in autism, we think of an increase in Rain Men, when really many don't fit the description of "classic autism".