Wednesday, September 23, 2009

The end of the idea of an autism epidemic?

NHS (National Health Service in the UK) Statistics released a study Autism Spectrum Disorders in adults living in households throughout England – report from the Adult Psychiatric Morbidity Survey 2007 detailing the results of a very intensive survey on psychiatric health of 7500 adults in the UK. They give as key facts:

1. Using the recommended threshold of a score of 10 or more on the Autism Diagnostic Observation Schedule, 1.0 per cent of the adult population had ASD. Published childhood population studies show the prevalence rate among children is also approximately 1.0 per cent.
2. The ASD prevalence rate was higher in men (1.8 per cent) than women (0.2 per cent). This fits with the gender profile found in childhood population studies.
3. There is no indication of any increased use of treatment or services for mental or emotional problems among adults with ASD. This is borne out by the recent National Audit Office publication “Supporting People with Autism Through Adulthood”.
4. A greater proportion of single people were assessed with ASD than people of other marital statuses combined. This was particularly evident among men.
5. Prevalence of ASD was associated with educational qualification, particularly among men. The rate for men was lowest among those with a degree level qualification and highest among those with no qualifications.

This means three things:

1. These data do not support the notion of an "autism epidemic" or more precisely, there appears to be an administrative increase in prevalence, not an actual increase of cases, since they found just as many autistic adults per 100 as there are kids. This is not necessarily surprising. While anti-vaccine organisations, like Generation Rescue, liked to exaggerate the increase of autism, claiming an increase of 6000% in rather bold adverts, more thorough research in Europe and the US has shown that the prevalence of autism had been systematically underestimated. A hat tip is due to blogger Joseph, who had predicted the 1% rate in adults some years ago, using prevalence studies of adults (see here). There is no indication that the prevalence of autism in the UK would be any different from the prevalence in the United States. While this survey is not conclusive for a steady prevalence of ASDs, taken with other data, is strong evidence that ASD prevalences have not actually increased.

2. There is a huge gap in services for autistic adults, which is one of the main reasons the NHS commissioned the study in the first place and also the main point that the NAS (National Autistic Society in the UK) stresses in their press release in response to the study:

… The NAS has long campaigned to raise awareness of the fact that services and support for adults with autism are woefully inadequate. Nearly two thirds (63%) of adults with autism told us they do not have enough support to meet their needs. Many thousands feel isolated and ignored and are often completely dependent on their families. This study gives us further evidence to demand that more vital support is put in place….

And, as the BBC and Guardian immediately clued in on:

3. It seems that the MMR is completely off the hook here, since the MMR was not introduced in the UK until the birth year of the youngest adult in this cohort, therefore is unlikely to have contributed to their autism.

Bad news for the "vaccine caused your child's autism but I can cure her" peddlers. Good news for many parents who suffered from the idea that it could have been the vaccines they 'allowed' to be given that caused their child's autism, and hopefully for the autistic adults, whose needs might get more attention now.

Most interestingly, a well known pediatrician, who calls this study "bogus" without having read it, gave an impromptu explanation for the apparent rise in autism diagnosis in comparison to official autism numbers in previous decades. He writes (intended to support the notion of an "autism epidemic"):

I see a NEW child with autism that I diagnose or suspect myself at least once or twice a month. NOT kids who come to me because of their child's problems - I've talking kids that the parents had no idea.

How wonderfully this supports the current finding. Reasonably young doctors with training in current DSM criteria will find autism even in cases in which not even the parents were aware of any developmental issues. That alone would explain a large percentage of autism diagnoses made today, compared to 20 or 30 years ago, when DSM criteria for autism were more narrow and doctors not as aware as they are today. It should not surprise anyone that if today’s doctors take a second look at “yesterday’s children” that they will find a lot of cases of ASD who went undiagnosed.

Preliminary reaction to the results of this survey by some have been perplexing. We have seen comments such as, “Claiming there's no autism epidemic is an insensitive slap in the face to all families affected by autism.” and “Anyone who is around young children can see there is an alarming increase in ASD - along with allergies.” Identifying the autism prevalence amongst adults and enacting services will undoubtedly benefit today's autistic children, hardly a "slap in the face". In fact, we would hope that the NHS will expand this survey to produce results that would more accurately reflect adult autism prevalence and gaps in services and that other countries will follow suit.

Research objectives such as those in the NHS survey are relatively inexpensive to conduct and will profoundly benefit everyone in the autistic community. The farther reaching implications being that if autism prevalence has remained steady for several decades then not only does that severely weaken the vaccine-autism claims but limited research funding can be directed towards studies that will also positively impact the autism community such as genetics and therapies research. The only ones benefiting from an "autism epidemic" are those making money from perpetuating the myth of "vaccine-damaged" children. So who really has the autistic community's best interest in hand?


  1. Nicely done, as usual. I hope folks pay particular attention to your final paragraph.

  2. Predictably, Age of Autism is trashing this study. I'm not scientifically literate enough to assess their critique. Can you? That would be much appreciated.

  3. Thanks Squillo, it's always nice to hear from you.

    Anonymous, there is a discussion of that going on here:
    If this doesn't help and you have some specific questions about their methodology, I'm sure one of us can help.

  4. Thanks for pointing me to LB/RB. A dear friend is in thrall of Age of Autism and I'm hoping to help her gradually pull away. It will take some doing, but this might be a good opening salvo. I just need to be able to explain to her why AoA's criticisms are weak, because she's surely read them.

  5. Anon

    what I find remarkable is the following:
    The NHS conducted this study to get better data about the prevalence of autism amongst adults and the need for specific services for this population. A higher prevalance and "underusage" of services that the NHS researchers found presumably means that they will now invest in better services for adults with autism. I can absolutely not comprehend how this should be a bad thing and why parents of autistic children most of whom will grow up to be autistic adults would argue against findings that will improve services for their children.

  6. I see that Handley has now weighed in over at AoA. I hope the discussion at LB/RB will address his comments too.

  7. Sullivan over at LB/RB weighs in and addresses some of the criticism:

    1 in 100 adults are autistic

  8. In my view, a valid criticism of a study should mention at least one obvious thing the authors overlooked that would explain away the results.

    If you notice, the AoA criticisms don't do that. They simply try to poke holes on the screening tools like the AQ-20 (which I've explained is irrelevant, since the methology is designed to work with imperfect tools), plus they put forth other spurious critiques about study limitations which are not convincing at all.

  9. "In my view, a valid criticism of a study should mention at least one obvious thing the authors overlooked that would explain away the results.

    If you notice, the AoA criticisms don't do that. "

    AoA's comments remind me of this joke "Your honor, I object on the grounds that this evidence totally devastates my case"