Monday, June 01, 2009

Autism Rising in the UK: Kevin Leitch Fumbles the Ball, Demolishes Non-existent Argument

Congratulations to Kevin Leitch at lbrb who reports that he has corresponded by email with Professor Simon Baron-Cohen about his recently published study of UK autism rates. As reported by the BBC in Many autism cases 'undiagnosed' the official UK autism rates of approximately 1 in 100 may not reflect the undiagnosed cases of autism disorder that probably exist:

The researchers say that, if these findings were extrapolated to the wider population, for every three known cases of autism spectrum, there may be a further two cases that are undiagnosed.

The BBC article talks about these findings in terms of the impact on various services and the need to prepare for that impact. Mr. Leitch, to his credit, also went directly to the source and asked Professor Baron-Cohen about the implications of the increase for the alleged existence of an autism epidemic as set out in the following email exchange between Baron Cohen and Kevin Leitch in which Professor Baron-Cohen stated that the numbers do reflect a real increase in autism:

Professor Baron-Cohen and I had the following exchange about the autism ‘epidemic’:

KL: What would you say to someone who says that your paper is strong evidence of an ‘autism epidemic’ (because you know they will)?

SBC: I think the term ‘epidemic’ of most value in relation to contagious diseases, which autism is not.

KL: Can I rephrase my question? Would you say your findings support the idea that there has been a true rise in prevalence? As oppose to the seven items you say have caused a seeming rise in autism earlier in your paper?

SBC: There has been a real rise in prevalence but what is at issue are the causes of this rise. In the paper we summarize the quite ordinary factors that might have driven the rise, such as better recognition, growth of services, and widening diagnostic criteria.

The quote above does not appear to be the entire email exchange between Professor Baron-Cohen and Kevin Leitch in so far as the Professor refers only to the various diagnostic and social changes that have contributed to the rise in autism diagnoses. It also makes clear the non-contentious point that he was not referring to autism as a contagious disease. I don't know anyone who argues that autism is a contagious disease but I suppose Kevin Leitch does deserve credit for helping to demolish a non-existent argument.

What appears to be missing in this exchange is any reference by Professor Simon Baron-Cohen to the environmental factors contributing to autism even though he himself has acknowledged the role of environmental factors in the past. In an exchange with a parent published on the One Click Group site Professor Baron-Cohen stated:

The One-Click Group seems to be a website for those who want to see more research into environmental risk factors in autism, and to me this seems to be a very worthy agenda. We know that autism is not 100% genetic in origin, since in the case of identical twins (who share 100% of their genes), there are instances of one twin having autism and the other not having it. In fact, the likelihood of the co-twin also having autism where one of them has it (in monozygotic (MZ) pairs) is about 60%. This means that there must be some non-genetic (i.e., environmental) factors that are part of the cause of autism. ...... I hope the above statement shows clearly and unambiguously that I regard autism as most likely the result of a gene-environment interaction.

Professor Baron-Cohen made the same point in a December 2007 interview piece published on TimesOnLine, Freedom of Expression:

Studies of twins have established that it is not 100 per cent genetic, since even among identical twins, when one has autism, the likelihood of both twins having autism is only about 60 per cent. This means there must also be an environmental component, but what it is remains unknown.

It is not clear whether (1) Baron-Cohen went on to comment in his email exchange with Kevin Leitch about the environmental factors and those comments were not included in the excerpt published at LB/RB or whether (2) Kevin Leitch did not bother to ask about such environmental factors.

Either way I know of no one who assumes that autism disorders are contagious. It is a pity that Mr. Leitch avoided asking publishing comment about or asking about the role of environmental factors contributing to what Professor Baron-Cohen described in his email exchange as a "real rise in [autism] prevalence". Of course it is possible Neurodiversity club member Mr. Leitch did not want to hear anything about environmental factors. It is difficult to promote a "posautive" view of a neurological disorder caused or triggered by environmental toxins whether those toxins are inhaled in our air, consumed in food or drink, or injected. Better not to ask the question if you know the answer will not help your case.

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Stephanie said...

Isn't Baron-Cohen the one who came up with all of those "Aspie" quizzes?

These tests are widely circulated and used to diagnose even though they have never been empirically validated.

I sometimes wonder if the "Autism Epidemic" is really nothing more than a few psychiatrists tricking suspecting people into believing something is wrong with them to further some strange agenda and for profit.

1 in 100 people in the UK now have an ASD? I don't buy that at all.

farmwifetwo said...

My nickel's worth is to include current prenatal care practices.

I think the environmental triggers are many and you'll never pick just one. But, it has to be more than genes.

M.J. said...

You haven't heard of the contagious form of autism before? I have run into a number of people who have had this disorder.

I am not sure where it came from but it seems to spread like wild fire in certain internet message boards. First one person diagnoses themselves as having autism, then a second, and a third, and before you know it the entire board has it.

Anonymous said...

"I am not sure where it came from but it seems to spread like wild fire in certain internet message boards. First one person diagnoses themselves as having autism, then a second, and a third, and before you know it the entire board has it."