Wednesday, March 3, 2010

Michelle Dawson writes a letter

Evidence-based medicine is the idea that all medical decisions should be based on the best scientific evidence that is available.  The concept is really very straightforward. You take the results that research has provided, rank them according to the quality of the information, and use that ranked evidence to decide what the best course of treatment is.

The important thing to note here is that a treatment doesn't have to be proven beyond all possible doubts in every possible scenario before it can be used - it just has to be shown to be applicable to the case at hand and have enough evidence that says it is more likely than not to work.

In a way, the name says it all. You base your medical decision on what has been shown to work, in other words evidence-based.

As easy as that concept is, some people seem not to understand it, especially when it comes to autism. As it stands now, there are very few treatments that have been shown to be effective in helping people with autism. There are many different things that are used in and attempt to help people (especially children) with autism  but most of these things do not have a solid evidence base behind them. I am not saying that these treatments can't or don't work but rather that they fall outside what is considered evidence-based medicine - they would be considered alternative medicine.

One of the few treatments for autism that does have a solid evidence base is ABA (Applied Behavior Analysis).   While it is not guaranteed to work for everyone, the available evidence shows that it can be an effective tool to help teach children with autism and is almost universally recommended.

That is, with the exception of the universe of Michelle Dawson.  As I have pointed out before, Ms Dawson has a real problem with ABA. She seems to have an almost irrational obsession with proving that ABA is somehow unethical or immoral to use on children with autism. She would tell you that she has ethical concerns and that there is very little evidence that ABA works.  However, Ms Dawson is almost universally alone in her opinion.

With that in mind, consider a letter that Ms Dawson wrote to The Lancet in rebuttal to a study1 published late last year. In this letter2, Ms Dawson attacks the evidence cited in the study to support the assertion that ABA is "highly effective". She dismisses three of the cited works as not studying ABA and says that another didn't study what it says it did.  This leaves, in her opinion, only one small study as the entire evidence base for ABA which leads to the conclusion that -
"the claims made by Levy and colleagues, with respect to intensive ABA-based programmes for autistic children, have no basis—either in the review they cite or in any other published study."
Open and shut case - ABA isn't evidence based - so says Michelle Dawson. We should all stop using it now and rejoice that we have seen the error of our ways, right?


The authors of the study responded3 to the letter. They say that Ms Dawson is correct about the one cited reference - it did not do what it said it did. However, they "respectfully disagree" with her assertions about the other three studies and point out that they did in-fact study ABA. They go out to point out that there were five additional studies that they did not cite directly because of space limitations and that brings the total to "only" nine randomized trials that support the effectiveness of ABA.

Remember when I mentioned above the quality of the information? Randomized trials (when done correctly) are considered some of the best evidence available. To put this into perspective, most issues are considered "proven" when they have two or three good randomized trials.  Here there are nine supporting the conclusion that ABA is effective. And, as the authors go on to point out -
In addition to these trials, a host of other studies that used rigorous and sometimes not-so-rigorous quasi-experimental designs point to the efficacy of ABA-based methods, such as discrete trial training, pivotal response training, and teaching in functional routines, either alone or in combination, in improving adaptive behaviour, language, and in some cases socialisation of children with autism.
In other words, the response to Michelle Dawson's letter was an unequivocal "what do you mean there is no evidence?"  Kinda makes you wonder what Ms Dawson is talking about. Perhaps she should reconsider the evidence.

But don't take my word for it, the text of the letters are freely available on The Lancet's site (free registration required), go read them for yourself.


1: Levy SE, Mandell DS, Schultz RT. Autism. Lancet. 2009 Nov 7;374(9701):1627-38.
Epub 2009 Oct 12. Review. PubMed PMID: 19819542.

2: Dawson M, Gernsbacher MA. Effectiveness of intensive autism programmes.
Lancet. 2010 Feb 27;375(9716):722-3. PubMed PMID: 20189018.

3: Mandell DS, Levy SE, Schultz RT. Effectiveness of intensive autism programmes
- Authors' reply. Lancet. 2010 Feb 27;375(9716):723. PubMed PMID: 20189020.


  1. MJ Michelle Dawson did not write this letter alone. You also note Morton Gernsbacher's name on the letter with michelle Dawson's.

    Morton Gernsbacher is someone who has also written a piece claiming autism is not harmful entitled autism:common heritable but not harmful which was coauthored with michelle dawson and Laurent Mottron.

    Gernsbacher has also written that severely autistic persons have made great contributions to arts and sciences in her essay entitled autistics need acceptance not cure.

  2. This comment has been removed by a blog administrator.

  3. Excellent post. Michelle Dawson has actively opposed Canadian parents seeking government funded ABA services for their own autistic children for many years. As you point out Ms Dawson does not appear to understand the "evidence based" concept or the negative implications of rejecting the most evidence based intervention available to help autistic children.

    The Gernsbacher connection mentioned by Jonathan is also interesting in respect of the ABA issue. Professor Edward K. Morris of the University of Kansas has published a scathing critque of Professor Gernsbacher's anti-ABA ideology and the harm it has caused in "A Case Study in the Misrepresentation of Applied Behavior Analysis in Autism: The Gernsbacher Lecture" which can be accessed at:

  4. Brett,

    I am deleting your comments because they don't seem to be related to the post and seem to be more like spam.

  5. Jonathan, you are indeed correct that Michelle Dawson didn't write this letter alone. I am not as familiar with Morton Gernsbacher's work so I refrained from commenting about her involvement.

    But from what you and Harold pointed out, it seems that Gernsbacher hold very similar view's to Michelle Dawson.

    I wish I could understand why people like this feel the need to bash treatments like ABA - is isn't perfect but it does help.

  6. This comment has been removed by a blog administrator.

  7. Clay,

    You are more than welcome to leave relevant comments (or even slightly irrelevant ones). However, I will remove comments that are purely derogatory - especially when they are set to song lyrics.

  8. Well, I hope you and Jonboy enjoyed it. I know I did! ;-)

    It'll be on my blog, soon enough.

  9. Are there any studies that have followed graduates of ABA into adulthood? Do they have meaningful work? Can they have a conversation that is not scripted and meanders from one thread to another? Do they have friends? Are they able to live independent lives?

    My autie daughter is 20yo and she is not severely autistic (but was severely aphasiac for many years). She is not high functioning enough to attend college. But, we do see her ability to interact with people blooming thanks to RDI. There are not enough studies to back RDI yet because it is an emerging therapy. I can see with my own eyes (biased, yes, but observant) how much she has grown in the past three years!

  10. I don't think there have been many studies that have looked at the outcomes for any treatment in adulthood, let alone ABA.

    I am glad that you had a good experience with RDI with your daughter. As you say, RDI doesn't have as much evidence behind it but that doesn't mean it can't work.

    There isn't a single type of therapy that will work for every person, you have to find what works for your particular circumstances.

  11. Thanks MJ.

    There is a lot of studies of adults with autism, some of whom would have been ABA kids and some not. The long term is not good (12 to 15 percent are employed, and much less are independent or have relationships and friendships). ABA has been around much longer than any other therapy, and I was hoping somebody would have checked into the long-term outcomes by now.

    RDI had been awesome for my daughter, especially considering we only started it 3 years ago when she was turning 18 yo! The whole neural plasticity bug-a-boo is not the end of the world . . .


  12. Hi again, Glasers, friendly greetings to you.

    I think the reason why no long-term studies of the results of ABA don't exist is because - they know the results would be dismal. It doesn't work very well for most autistic kids. Any program that involves parents or adults getting down on the floor (so to speak) with their children, and attempting to experience what the child experiences, is bound to be more efficacious.

  13. I would like to ask a question to all the people bashing Michelle Dawson for speaking out against ABA. You say it is evidence based but that can only mean,in this case that on the surface it produces. a more 'normal' child. How do you know that there is any soulful substance to their more socially acceptable behavior? All ABA does is train the Autistic child to copy and pastse 'normal' behavior despite their lack of understanding of it's significance. ABA trains the Autistic child to hide their pain. ABA advocates may say that they are teaching the child to express their pain and discomfort in a more appropriate way but that may be difficult for someone who is a rigid mono thinker. It is not by choice that they think in mono. It is how their brains are wired. 'Holding therapy ' or 'electric shock therapy' is evidence based on the surface. The child is forced to give the desired responses and be more compliant but at what cost? The irony of all this is that it is Autistics who are believed to lack empathy.