Revisiting the Autism “Epidemic”

Anyone who cares about autism, and particularly the supposed spike in autism in recent years, would do well to read this very informative, cogent, and non-hysterical OpEd by Paul T. Shattuck and Maureen Durkin. It is written on the occasion of a case before the U.S. Court of Federal Claims that’s investigating whether autism is linked to childhood vaccinations, as many parents of autistic children believe.

Shattuck and Durkin’s argument, in a nutshell, is that:

1. Vaccines do not cause autism, according to the scientific consensus;

2. There surely has been an eruption of documented cases of “autism spectrum disorder,” but this does not mean that autism itself is actually on the rise, as many people believe.

3. There are a variety of reasons for the increase in documented cases of autism and related disorders, including:

a. better reporting/diagnosing;

b. more funds available for treatment, which incentivizes parents to have their children diagnosed;

c. a much broader definition in recent years of what constitutes “autism,” including the reclassification of other disorders into the autism umbrella label.

If you have an autistic child or know someone who does, you may not be satisfied with Shattuck and Durkin’s article, for it may be more comforting to have a tangible villain, like vaccines, to blame for this disorder. And a tangible villain would certainly make it easier to prevent autism in the future. But you should still read the article with an open mind.

There is one point that Shattuck and Durkin didn’t raise, which I sometimes wonder about when people discuss a link between childhood vaccines and autism. Autism usually begins to present itself at about three years of age, by which time kids have started to get a lot of vaccines. This proximity may naturally cause many parents to link the two events in their mind. But just because one event happens shortly before another does not mean that the first even caused the second — as comforting, in a warped way, as that may seem.

Here’s what we’ve written in the past about the subject.


egretman

It can be statistically proven that medical researchers are statistically inept at the use of statistics. Often coming up with vague correlations and then leaping to wild causes such as "pesticides in the environment" or "mercury in the vaccines".

And unfortunately, Dr. Levitt has given up on doing his peer review in order to take up the subject of just how stupid do you have to be to play poker for a living.

shanek

As a parent of an autistic child, I think this article is wonderful. We need to face this issue with the courage to find the truth, instead of finding some convenient bogeyman.

The experience of raising an autistic child is so frustrating--for the child as well as the parents--that we can be more easily misled by anti-vaccine people, or those hawking false hope techniques like Facilitated Communication.

On top of the stamina we need to raise our children, we also need the courage not to be taken in by easy answers and peddlers of false promises.

schadenfreude

Shattuck and Durkin never make the argument that vaccines do not cause autism. Their analyses deal with years from 1991 thru 2003. During this entire time, thermisol was present in childhood vaccines, so they can draw no conclusions regarding the alleged vaccine-autism link.

one_comment

Something should also be said about the increasing numbers of adults realizing that they've known people with autism all along, or coming in to get themselves diagnosed, as autism, especially the milder variety, gets more and more widely written about.

bertrecords

My brother is autistic. So, I have listened as my mother told me about one study after another which linked heavy metals or whatever to autism. If you are a doctor and want to get your name in the public eye, I suggest correlating something to autism like everyone else.

Simon Fodden

"incentivizes"? Aii-yi-yi! Horrible coinage. How about "encourages" or simply "gives... an incentive to" -- one more syllable, granted, but what's your hurry?

jeffstier

And along those lines, a consumer friendly review of the issues, "The Promise of Vaccines: The Science and the Controversy."
is online at http://www.acsh.org/publications/pubID.423/pub_detail.asp

frankenduf

maybe so, but would you choose a vaccine sans heavy metals for your child?

bdh

As the father of a five-year-old with autism, I may be biased, or at least overly sensitive. But I don't believe that you can accurately summarize the article as stating that the scientific consensus disputes an autism-vaccine link. The article says:

"The claims for or against an autism epidemic simply cannot be proved given the evidence available."

Note the "against." They're merely saying that there's no proof either way. It seems like you're leaping to your own conclusion to claim that the article rejects the link.

I tend to believe there is no link, but I admit to being offended by suggestions that any parent who suggests there's a link is deluded by their desire for a "villain." There's a lot of serious research, done by serious people, suggesting a link, just as there's a lot (more, to be sure) research rejecting the link. This isn't just made up by trial lawyers looking to cash in or loony parents looking for a target.

I have also seen the argument made that there are "incentives" for parents to get an autism diagnosis because of the funding available for treatment. This is absurd. My son has been in a special school getting one-on-one therapy for two years at a cost of more than $50,000 a year, all of which comes out of my pocket. We've sold our house, moved to a cheaper area, and cashed out an IRA to pay for this. Excuse me for getting a bit testy about these suggestions that autistic parents are somehow chasing all of this free funding for treatment. It's inaccurate, and offensive to those of us whose lives have been turned upside down as we do what we can to try to help our kids have normal lives.

Read more...

schadenfreude

The heavy metals are added as a preservative, so the question is would you choose more expensive or expired vaccine for your child in return for sans heavy metal?

SAMIam

> that's investigating whether autism is linked to childhood vaccinations, as many parents of autistic children believe.

Is this really true? Or is it a vocal minority? (refernces?)

kaywil

Some of the successful treatments for autism deal with these types of environmental factors; vaccines, antibiotics, GI track infections, early allergens, etc. I would rather factor in all of the possibilities than wait for industry scientists to say 10-20 years from now "oops! like with cigarettes, we were wrong!"

I do not have a child with autism. I can only try to understand. But I am very concerned about my children's health, and when I look at all the things that scientists have said were safe that turned out not to be (household cleaners, Bisphenol A in baby bottles, bottle feeding better than breast...etc.), I wouldn't take everything they say as "the truth". Science is a work in progress, even though they'd like us to believe it's 'exact'.

palmd

You mention the "proximity association" or "misattribution argument...that vaccines and autism co-incidently happen at the same time in a child's life. This is a well-known logic error in medicine, and I suppose in other fields. It is an argument that can be made for any co-incident phenomena. For instance, vaccines can be said to cause growth retardation, or perhaps to cause increases in college admissions 16 yrs later...

egretman

We don't know what causes autism. Why can't people just accept that?

This is the reason that human beings invent gods. To give credit and blame to things and events that we have no control over.

We say it's god's blessing that my child has 10 toes and 10 fingers. And we say that Thor was mad if our child had 8 fingers.

It's really not this hard. And then we learn the real reason. Stay tuned for the real reason, folks.

palmd

It IS distracting to come up with misleading hypotheses...real work has to be delayed while they are investigated. However, if we really want people to get vaccines, it is up to us as a society to prove their safety. It is unfortunate that most parents don't remember the summers in the mid 20th century when parents would keep their children inside for fear of paralytic polio.

phineasgage

The heritability of autism is >.8, which says it all, really. Source, e.g.:

Bailey, A., Le Couteur, A., Gottesman, I., Bolton, P., Simonoff, E., Yuzda, E., and Rutter, M. (1995). Autism as a strongly genetic disorder: Evidence from a British twin study. Psychological Medicine, 25, 63-77.

The vaccine scaremongers will argue that since heritability is expressed in terms of the proportion of the phenotypic (ie behavioural/expressed) variance that is attributable to genetic variance, things that don't vary won't be taken into account, such as vaccines that are given to every child.

This reasoning is specious. By this logic, any childhood universal that has emerged post-autism is equally likely to cause the increase in incidence - plastic diapers, baby gyms, TVs, you name it. And you would still have to explain why the condition runs in families. What is the vulnerability that causes the condition to be expressed so selectively?

Given what is known at present, it is more parsimonious to argue that autism is largely caused by inherited deleterious gene mutations, rather than it being caused by vaccine X that produces affects only certain inter-related people because of vulnerability Y.

Both accounts can explain the increase in incidence, so that's neither here nor there.

Read more...

egretman

The heritability of autism is >.8, which says it all, really.

Well there you go. God works in mysterious ways. Only 2 hours and 31 minutes after I spoke, we have our answer.

God is banished from this subject. Science moves on to the next mystery. Life gets better.

qestia

For me, investigating the autism link was the tip of the iceberg in questioning the safety of the childhood vaccination program. I'd love to see the Freakonomics authors address other concerns, such as whether it makes sense to vaccinate five times by age five for diptheria when there are barely a handful of cases each year--but the reporting of "adverse events" from the vaccine number in the thousands. Or, what is the wisdom of vaccinating day-old infants for Hepatitis B, which is spread through intravenous drug use or sexual contact--when, again, their likelihood of contracting the disease (unless the mother was a carrier) is miniscule compared to the rate of "adverse events".

mandala oblongata

As a parent of a child with an autism spectrum disorder, I was annoyed by both the NYT OpEd and Dubner's blog post about it.

First, much time has been spent discussing whether there is an "epidemic" of autism spectrum disorders, with the focus being whether there is an increase in the number of kids getting ASDs or whether there is an increase in statistical reporting. This is often the lead point of stories. Who cares? Isn't the main issue that we now realize that there are many more kids on the autism spectrum than we did 15 years ago?

Second, neither the article nor Dubner try to tackle the issue of what the prevalence of kids with ASDs really is. Prevalence rates vary from state to state but are much higher in states such as New Jersey that have more sophisticated methods of identifying and tracking kids, more educators and therapists who are adept at identifying kids, and more awareness among parents (and other family and friends) who can point out the red flags. However, even in states like NJ where reporting rates are approaching 1 in 100, not all kids are diagnosed. Therefore, my guess is that the CDC estimate of 1 in 150 is significantly below the actual prevalence.

Third, the OpEd and Dubner spend nearly no time analyzing what the right amount of funding for treatment and research for kids on the spectrum would be. Since this is an area of diagnosis, treatment and study that is relatively nascent, my guess is that funding lags in all important areas. For example, even a minimal amount of research would show that the number of schools and placements for kids on the spectrum lags prevalence even in the more "innovative" geographies.

Fourth, people in the media seem to write a lot of articles about speculation about what causes autism spectrum disorders. Since the issue has only really been studied for a decade or so, there hasn't been enough research over a significant enough period of time to determine correlation let alone causation definitively. The early evidence suggests a strong family link that is hereditary, and genetics may end up being proven to be the only cause. But the short answer right now seems to be that there isn't enough evidence about cause and we need much more research.

Fifth, Dubner's wrote, "it may be more comforting to have a tangible villain, like vaccines, to blame for this disorder." Perhaps there are people out there who feel this way. But I've never met a parent of a child on the spectrum who spends much time on finding someone or something to blame. The vast majority of us have little time or energy for this, as it won't help our kids. Instead, to help our children as best we can, many of us completely upend our lives: some quit or change jobs to be more involved, some move closer to decent services, and most invest countless hours educating ourselves (and our families, friends, teachers and therapists) on how best interact with our kids to speed their development whenever possible.

Sixth, Dubner wrote, "you should still read the article with an open mind." Yes, and I should use my fingers rather than my elbows to type on a keyboard. Let me counter some pedantic commentary with some of my own. If you are a journalist and are going to write multiple posts on the topic on an internationally-read blog, you should interview some parents, psychologists or therapists to become better educated on autism spectrum disorders.

Read more...

browndog319

The issue with the general public hearing a sound bite of an entire body of scientific research is that it creates baseless fear. This fear leads to parents choosing to not vaccinate their children. Whether you want to believe it or not, vaccines have improved quality of life for the general public. Was it as recently as the 1940s and 1950s that children were crippled by polio? My own aunt was born deaf because while her mother was pregnant, she developed German measles. So, clearly the benefits of vaccinating your children far outweighs the risk of autism.

Additionally, thimerasol hasn't been in vaccines since the early 1990s and autism prevalence has continued to increase. Therefore, there is clearly not a link between the two.