JB Handley noted that the 62-99 caseload is still rather small, however, and he's right of course. Rick Rollens wrote a rant along the same lines, which follows.
I for one am really sick and tired of the current stock of "the world is flat" thinkers who continue to spew the notion that there has been no real increase in autism, that the prevalence and incidence of autism has remained the same all these years, and in years past we simply over looked thousands of persons with autism, and today we finally found them. Bottom line: they have always been here. I believe that applying a little common sense and facts provided by our California Department of Developmental Services (DDS) we can once and for all drive the spike of fact and truth into the heart of these modern day flat earth society members who may be living in our world, but seem to be far removed from it's obvious realities.
Premise : If there has not been a true, dramatic increase in the incidence of autism creating an autism epidemic, then we should have among us a proportional and sizeable number of adults with autism. Since DDS's data only includes those persons with autism who have a professional diagnoses of full syndrome (i.e. worst form) of autism, we can assume that hiding, misplacing, loosing or not recognizing thousands of adults with moderate to severe behavioral issues, extremely apparent bazaar social behaviors, and moderate to severe language deficits would be impossible. We are not talking about a person here who melds into society and is not noticed and/or is not in need of major supports and assistance. They would have to be somewhere, and somewhere for adults likes these in California would either be in the community or in an institution. Now I guess it is possible that some could be homeless, but as far as I know there has never been reports of large numbers of persons with moderate to severe autism running amok through homeless shelters and soup kitchens, if they were there, I am sure we would have heard about it by now. California's developmental services system has been in place since 1969...38 years for adults with autism and their families to find their way into the system.
Facts: According to the latest data from DDS, there are 2,809 persons with autism in California's DD system...16% or 5125 are adults over 22 years old. That means for the autism population that 84% are under the age of 22, with 78% under the age of 18. It is a remarkable fact that adults with autism make up only 16% of the autism population, while in the same DD system 55% of the cerebral palsy population, 61% of the mental retardation population, and 63% of the epilepsy population are adults over the age of 22 years old. Using an average of the CP, MR, and epilepsy populations, it is safe to assume that adults over the age of 22 with moderate to severe autism should constitute roughly 60% of the total autism population, not 16% as they do and have for many years.
So, rather then having just 5125 adults currently in our system with full syndrome autism, we should have somewhere around 19,685 adults with full syndrome autism if you believe the flat earth folks that there has been no real change in the incidence of autism. We do know that there are a very small number of adults with autism in California's five remaining state institutions... 358 to be precise. So doing the math leads me to these conclusions:
Based on the fact that roughly 60% of adults with the three other conditions served by California's DD system (MR, CP, and Epilepsy) are over the age of 22 years old, and recognizing that we have only 5125 (16%) of the autism population over the age 22, add in the 358 who currently reside in state run institutions, we are short 14,202 adults with autism in our system that should be there! That number represents 43% of the entire current autism population in California's DD system.
43% of the population missing? Over 14,000 adults in California suffering with full syndrome autism and no one has seen or heard from them? Is this possible, or is it that they simply do not or ever existed. Is it also a fact that DDS has documented, in two separate Reports, that California's autism epidemic began roughly 22 plus years
Believe me when I say....The world is round.
I think the flaw in Rick Rollens' argument is obvious: He assumes that CDDS autism counts are a good approximation of the number of autistic persons in the state of California for any age group. This is an incorrect assumption, and not just probably incorrect or a little bit incorrect. I will now provide a numerical argument as to why.
The DSM-IV-TR prevalence of PDD in the population with mental retardation is about 16% (source). This estimate appears to be conservatively valid in adults, going back at least 24 years (source).
Let's now take the mental retardation caseload in the 52-61 cohort as of Q4 2006, which is 10,632. We should thus expect that 1,701 CDDS clients have PDD with mental retardation. It seems to me that these 1,701 autistics in the 52-61 cohort could easily have an "autism" classification in their records. Instead, we find that only 325 do. CDDS has missed at least 80.9% of all autistics in that cohort. I emphasize "at least" because among young autistic clients, mental retardation is relatively rare.
This all comes to show that CDDS ascertainment is nowhere close to accurate, and it is least accurate in older cohorts. In reality all the California DDS report can give us is an approximate lower bound on ASD (not even autistic disorder).
Rick Rollens admits his argument is based on the following premise:
Since DDS's data only includes those persons with autism who have a professional diagnoses of full syndrome (i.e. worst form) of autism, we can assume that hiding, misplacing, loosing or not recognizing thousands of adults with moderate to severe behavioral issues, extremely apparent bazaar social behaviors, and moderate to severe language deficits would be impossible.
He is clearly assuming that (1) if an autistic person is not registered with CDDS, then they were "missed"; and that (2) all autistic persons registered with CDDS have "autism" in their records. Neither of these assumptions have ever been determined to be factual, which is a fatal flaw in this type of argument.
Also, Autism Diva discussed the "full syndrome" characterization. It's not really the way Rick Rollens would have us believe.
So, yeah, the world is not flat; but neither is CDDS autism ascertainment, obviously.