Monday, December 21, 2009

Harold Doherty and Intellectual Disability

Let me address Harold Doherty's claim that the recent CDC report on autism prevalence shows that 60 – 100% of children diagnosed with Autistic Disorder also have a significant intellectual disability (IQ less than 70). To put it bluntly, that claim is a ridiculous fiction, fabricated entirely by Mr. Doherty and not supported by anything in the CDC report. It is the kind of claim made by someone who either cannot read, cannot do math, or cannot handle logic. In Mr. Doherty's case, I suspect we are witnessing a combination of all three.

What the CDC report does state is that across the reporting sites where adequate data is available, 41% of all autism spectrum disorder (ASD) cases are associated with intellectual disability (with a range across the reporting sites from 29.3% to 51.2%). Mr. Doherty then leaps to the statement that if the Asperger Disorder cases were removed from the CDC study population, then this would imply that 60 – 100% of those with Autistic Disorder must have a significant intellectual disability (with great emphasis placed by Mr. Doherty on the midrange number of 80%).

It would be interesting to examine Mr. Doherty's math on that.

To keep the numbers round, let us assume that 40 out of 100 ASD cases show intellectual disability, which is consistent with the 41% number from the CDC report. Question: how many Asperger Disorder cases (no intellectual disability) would need to be removed from the study population so that the remaining population has an 80% intellectual disability rate? The answer is that 50 out of 100 would need to be removed. Mr. Doherty's math implies that around 50% of the cases in the CDC study are Asperger Disorder cases. I wonder if he really intended that.

I myself would be willing to grant Mr. Doherty his 50% Aspergers estimate, provided that either: a) the number shows up some place in the CDC report, or b) Mr. Doherty's other posts remain logically consistent with 50% of all ASD cases being Aspergers cases. Alas, neither provision holds true.

For instance, I have looked high and low, but the CDC report does not seem to indicate how many of its identified cases fall under the Aspergers classification. Maybe Mr. Doherty has read the report more carefully than I have, but my suspicion is that Mr. Doherty has not bothered to read the report at all. Figure 5 in the report does shows a group that would include the Aspergers cases, but Aspergers by itself does not seem to be broken out. What's worse, no matter how you look at Figure 5, it clearly does not support Mr. Doherty's 50% Aspergers estimate. If anything, Figure 5 indicates an Aspergers percentage much lower than 50%, a percentage so low it cannot in any way support Mr. Doherty's feeble attempt at math.

And then there is the matter of Mr. Doherty's other posts, the ones insisting quite loudly that autism is an environmental epidemic and that people with an Aspergers diagnosis, like Ari Ne'eman, are not really autistic. But if 50% of all ASD cases are Asperger Disorder (and therefore not really autism), what remains of the epidemic? Let's go ahead and apply Mr. Doherty's methodology to the CDC report itself, where we might note that if 1 in 110 children have ASD but 50% of these are Aspergers (and therefore not really autistic), then of course only 1 in 220 children really have autism. Better yet, if we forge ahead with Mr. Doherty's brand of logic, we might next compare this 1 in 220 figure to the 1 in 150 prevalence from the previous CDC report and note that the “epidemic” is now actually reversing—the “crisis” is indeed over! (Maybe it was all those environmental toxins that provided the cure everyone was looking for.) Now if perchance the preceding analysis is making your head spin, or if you feel like you have been somehow bamboozled or that I just made things up, please do not put the blame on me; remember, I am only following Mr. Doherty's logical lead.

Listen, no one is suggesting that intellectual abilities and disabilities in autism should be swept under the rug. Clearly, a significant portion of the autistic population experiences cognitive delays and difficulties, and a better understanding of this phenomenon would be helpful for all. But to concoct “facts” for the purpose of promoting a personal agenda serves no one well. I do not expect Mr. Doherty to agree with me very often, but I do expect him to be able to read, do the math, and think logically. I do not believe that is asking too much.

Of course it is possible that it is me who is incorrect; maybe it is my math, logic and reading skills that have gone awry. If so, I invite Mr. Doherty to demonstrate the error of my ways, and if he is successful, I will gladly make acknowledgment and apologize. But note that my only requirement for this demonstration is that Mr. Doherty use information straight out of the CDC report, and not straight out of his imagination.


Autism Reality NB said...

Nice rant Mr Griswold. Lots of heat and no light.

The CDC referred to the a range of persons with Autism Spectrum Disorders having Intellectual Disability. My assumption that approximately half of those on the Autism Spectrum would be those with Aspergers was conservative if you accept the view that the increases in autism diagnoses result largely from the 93-93 changes to the DSM which expanded autism to include Aspergers. You may not be aware that an Aspergers diagnosis can not be unless there is no intellectual disability or communication delay.

You seemed to have skipped over the fact that my estimate of 80% of persons with Autistic Disorder having an ID is also consistent with the 2006 brief of the Canadian Psychological Association.

As for environmental factors as causes of autism you really should read the transcript of David Kirby's interview with Dr. Thomas Insel who acknowledges the role of environmental factors in causing autism. In case you are unaware Dr. Insel is the current head of the IACC, the Interagency Autism Coordinating Committee.

Your Neurodiversity, autism is beautiful ideology, is getting the better of you. Your knowledge of and understanding of autism spectrum disorders is woefully out of date. You should take advantage of the holiday season to read something other than ND blogs.

Merry Christmas.

Autism Reality NB said...

Oh, here is another reference which indicates that 80% of persons with autism have intellectual disability. Since it is from 1999 I assume that it was referring to actual Autistic Disorder since it was not as common than to lump autism together with Aspergers Disorder:

1.1j. 80% of individuals with autism have significant intellectual disability. Conversely, autistic ‘traits’ are very common amongst people with intellectual disability: the full syndrome occurs in 17% overall and 27% of those with an IQ < 50i,ii. i. Berney TP. Autism – an evolving concept. British Journal of Psychiatry 2000; 176: 20-6
(Type IV evidence – wide ranging review of 93 recent papers)

ii. Deb S, Prasad KBG. The prevalence of DSM3-R autistic disorder among the children with a learning disability in the north-east of Scotland. British Journal of Psychiatry 1994; 165: 395-399
(Type IV evidence – cross sectional study)

There is no need to apologize for the insults in your blog comment. I am happy to assist you in your continuing education about autism disorders.

Alan Griswold said...

I notice that neither of Mr. Doherty's rambling replies includes the data he used or the math calculations he made in arriving at his 60 – 100% claim. I wonder if he just forgot.

He did, however, include another splendid example of Mr. Doherty's brand of logic. Mr. Doherty says that his “estimate of 80% of persons with Autistic Disorder having an [intellectual disability] is also consistent with the 2006 brief of the Canadian Psychological Association.”

So let me see if I have this straight. Mr. Doherty starts by relying on the CDC report to establish that 60 – 100% of children with Autistic Disorder have a significant intellectual disability (IQ less than 70). He then uses this “fact” as evidence in support of claims such as those made in the 2006 brief of the Canadian Psychological Association. Then when someone points out that neither the CDC data nor the laws of mathematics support Mr. Doherty's original “fact,” he then trots out the 2006 brief of the Canadian Psychological Association as evidence for his original claim. As far as I can tell, the only difference between Mr. Doherty and a cat chasing its own tail, is that the cat does no harm.

Alan Griswold said...

I notice that T.P. Berney's 80% figure also comes without supporting data and calculations. Perhaps T.P. Berney learned his craft from Mr. Doherty.

dionnes said...

Hello Alan -
As reliable as the sunrise, Mr. Doherty will fit the facts he hand-selects from each study and interview to his worldview that autism is an "environmental epidemic" .... without actually claiming a position, and therefore having to defend his view. Perhaps his index finger is simply too exhausted after years of clicking the "moderate comment" button on his blog when faced with polite, constructively critical comments to soldier on and allow for alternative points of view.
His comments here well illustrate his lack of propensity to actually dealing with the facts at hand, and provide a bright spotlight on why he avoids actual, honest discussion in his own little corner of the internet.

Socrates said...

Mr D's figures suggest there are between 162000, and 285,000 Autisic children in the US, with ID. The question is Harold, where are they?

2) The CDC estimated that between about 1 in 80 and 1 in 240, with an average of 1 in 110, children in the United States have an Autism Spectrum Disorder.

3) The CDC estimated that 29.3 to 51.2% of children with Autism Spectrum Disorders also had an Intellectual Disability. (That estimate itself misleads by including Aspergers with Autistic Disorder in estimating ID prevalence "on the spectrum"). The percentage of persons wih Autistic Disorder and Intellectual Disability is approximately 75-80%.

764,375 with Autism at 1 in 80
254, 792 with Autism at 1 in 240
555,909 wwith Autism at 1 in 110

Using 1 in 110 - with ID

29.3% of 555,909 = 162,881
51.2% of 555,909 = 284,625

Socrates said...


I forgot the payoff:

Therefore with D's figure of 75% there should be

416,931 Autistic children with ID in the USA

So the question, again is

Where are they?

Alan Griswold said...

Hi dionnes and Socrates. Thanks for stopping by.

Although I appreciate the attempts to analyze Mr. Doherty and his fabrications, I think you are going to find that deconstructed gibberish still qualifies as gibberish.