Tuesday, July 17, 2007

Autism Truth - 1 in 100 - An Alarming Autism Number

The leaked draft report which stirred up so much controversy recently was responded to with vigor by Simon Baron-Cohen. The learned professor was one of three researchers involved with preparation of the report. He quickly trashed the 1 in 58 figure as only one of three figures mentioned in the report and made comments suggesting that the 1 in 58 figure, part of his own report, might not be that reliable. Instead Professor Baron-Cohen points to a figure of 1 in 100 as being reliable:

"In the meantime, he [Baron-Cohen] says that the best, most carefully conducted studies all show around 1 per cent of children lie on the autism spectrum (see box) and there is no reason to suspect that this has suddenly changed. There has been a gradual rise over decades, he says, but this reflects the fact that children are more routinely assessed, greater public awareness, and a wider diagnostic net.

The National Autistic Society also quotes a figure of 1 per cent for the incidence of autistic spectrum disorders. Benet Middleton, the NAS’s director of communications, says that, having spoken to Baron-Cohen, the charity had no plans to revise its figures. Middleton says: “This is an unpublished study that has not been peer-reviewed, and there are lots of reasons why studies don’t get published. The research that’s been published and peer-reviewed suggests a rate of 1 per cent.


1 in 100? The accepted UK figure of 1 in 100 is substantially greater than the 1 in 150 figure cited by the CDC in the US which until fairly recently cited an autism incidence figure of 1 in 166. Why such a huge gap between the UK and US figures? And why are education authorities in Massachusetts reporting a near doubling of autism cases in the past few years? Professor Baron-Cohen's explanation of of diagnostic criteria changes implemented in the 1994 DSM revision, with greater awareness, would seem plausible to explain some of the increase.

I am the father of an 11 year old boy with classic Autism Disorder with serious deficits. Unlike the good professor I find his assertion that 1 % of the population of the UK very alarming. I find a doubling of autism cases in the State of Massachusetts education system in the last few years alarming. I am not an autism authority but I am thankful that research is continuing into potential genetic and environmental factors in the rise in autism rates.

The world does not need another irresponsible Wakefield "vaccines cause autism" scare. But the world can also do without blithe Baron-Cohen assurances that the rise in autism numbers is solely attributable to changes in diagnostic criteria and greater awareness.

1 % of a national population is autistic? This humble "autism dad" finds that number very alarming Professor.


concerned heart said...

The numbers are rising from all reports and are very alarming and professors who do not have autistic children are not credible spokesman for what is happening in the world. Sasha Baron Cohen looks at a small percentage of the cases of autism and maybe mathmatical ability/interest ie. engineers are on the way to autism. Rising paternal age (past 31 in some cases) is the culprit and commmon denominator in many non-familial cases and often the older age of the maternal grandfather affecting the integrity of one of the mother's X chromosomes. There are many different reasons/genetic mutations responsible for cognitive deveopmental problems. The evidence for older paternal age as the culprit(in one generation or another) has been written about since the 1950s. It is time to read the old and new research and see the evidence. It is time for the public to know the risk factors for autism etc. They are consistent in Japan, in Sweden, in the UK, and in the USA.

Biological Clock Ticks for Men, Too
Genetic Defects Linked to Sperm of Older Fathers
Paul D. Thacker

JAMA. 2004;291:1683-1685. See the blogs attached to my blogger account for more info. Autism's rise is not a mystery. Sperm stem cells and sperm collect dna mutations with age and toxic exposure.)Past 31 is older in some men.

Mike said...

One thing to keep in mind about the 1% figure (or 1 in 150 for that matter) is that it includes the entire spectrum. It's estimated that "classical" autism makes up around 1 or 2 per thousand, or 0.1->0.2% of the general population, with the remainder of cases being less extreme forms like Asperger's or PDD-NOS.

Because of this, I find the hypothesis that the increasing stats are due to awareness quite reasonable. Back in the days when people had personalities rather than symptoms, most of that 1 in 150 (or 100, or whatever count you want to use) wouldn't have been diagnosed with anything.