February 3, 2009

Two Causes Of Autism

Ah, finally, a post about science only, that doesn't offend anyone.

Whoops, sorry, that's my other blog.  In this blog, I write about how the parents cause autism.


First, let's get this out of the way: that was a joke, ok?  I do not think autism is caused by the parents.  Science has already disproven that link. Science shows it caused by rain.

Before any science is discussed here, take a minute and examine your prejudices, which run so deeply that I can't write a blog about narcissism without getting accused of writing too much about narcissism.

Why, when I wrote that autism was caused by the parents, did you think that was so offensively preposterous as to merit rebuttal in ALL CAPS?  Yet when I said it is rain, you were... intrigued?  

Not that you actually believed it was rain, of course, you figured that was a proxy for something else; but you did not allow that "parents" might be a proxy for something else.  Linking parenting to, well, anything, is so loaded with connotation that it is safely beyond consideration; yet a moment's reflection reveals that of course that's the best proxy.

Science in psychiatry, or in any field that pretends to examine behavior, is a false god.  It's not just the results that are biased; the way questions are asked, the questions that are asked, that can be asked-- and the ones that none dare ask-- safely protect even the sexy calf of the truth from ever being revealed.  

Take a break, Diogenes, it's going to be a long wait.


Well, what about all that rain nonsense?

In general, autism rates are higher in the norther U.S. than in the southern.

Looking at three states, Washington, California and Oregon, a study found the counties with the highest precipitation in the 1990s lead to the highest autism rates in 2005.  Additionally, kids under three who experienced higher than normal rainfall relative to other years had higher rates of autism.

What's nearly incomprehensible about this article is the next sentence:

There are a number of possibilities concerning what such an environmental trigger might be.

It goes on to list their top four explanations, but in case you don't see it, I'll spell it out: this environmental trigger is one that occurs to the child after he is born, not before, or to the parents.

They cite: rain means more TV watching; Vitamin D deficiency; household cleaners or some other indoor toxin; or the rain brings an atmospheric or ground toxin into play.

The obvious problems with the study are myriad, but

Because we do not provide direct clinical evidence of an environmental trigger for autism among genetically vulnerable children that is positively associated with precipitation, our results are clearly not definitive evidence in favor of the hypothesis. But the results are consistent with the hypothesis, and, therefore, further research focused on establishing whether such a trigger exists and on identifying it is warranted.
No one on the planet is going to misinterpret this study as actually saying rain causes autism.  What they will do, however, is hear your bias that it is something that happens to the child that leads to autism.

Which is exactly what you wanted, isn't it?


Fortunately, there's an editorial, "Do These Results Warrant Publication?"  in the same issue that critiques the study (e.g. reporting bias, etc) and then argues

that the authors' analysis and the editor's decision to publish it are to be lauded, despite the uncertain ultimate contribution of this work and the possibility (likelihood?) that nonprofessionals are going to misinterpret and misuse it.

You can say a study should be published despite misinterpretation, but why would you say it should be lauded if it is likely to be misinterpreted?

Not only was [cites numerous flaws in the study.] Nonetheless, I would argue, so what? The primary audience for the article of Waldman et al is not the practicing pediatrician, and certainly, it is not a member of the public at large. These individuals cannot take away any practical message from it.

Because people are idiots?

Of course, if a study's findings are no more than tentative ones... responsible authors will stress this, just in case members of the lay public are "eavesdropping" on the exchange of information between scientists.

He doesn't get it, at all.  Or maybe he does?  Repeatedly saying that the results are tentative, stressing the problems with the methodology, this masks and reinforces the ideological bias-- that autism is caused post-natally.

I believe that Waldman et al have indeed reported their results responsibly. They have made it clear that the message the public should take from their data regarding precipitation and autism is the same one suggested by an editorialist commenting on a recently observed modest association between prenatal exposure to cell phone use and behavior problems in childhood: "No call for alarm, stay tuned."


"Are you saying there can't be a component to autism that occurs after birth?"

How do I know?  I have no idea.  More importantly, they don't have any idea, either.  I have the very same evidence available that they do; the question is simply impossible to answer so far.

I am aware, however, that there are plenty of possibilities, both post-natally and pre-natally. This study doesn't test the existence of "environmental triggers" because it could easily be explained by completely genetic factors: for example, that parents who are predisposed to having autistic kids choose to live in Oregon.  (What, is that so insane?)

If his concern is misinterpretation and misapplication of a single study, then he should be aware enough to spot how it will be misinterpreted.

So it isn't misinterpretation that rain causes autism, but that this study has anything to tell us about environmental triggers at all.

The worry about the eavesdropping public isn't that they will read this study and hear, "rain might be involved somehow" but that they become convinced that there is an environmental trigger.

The study will adds to the study pool labeled "Evidence For Environmental Causes" and it simply isn't that.  But when those studies are stacked up on top of each other, it looks like that.


We can now reverse this discussion entirely.

There is considerable evidence that advanced paternal age, but not maternal age, increases the risk for certain psychiatric conditions but not others (e.g. schizophrenia yes, depression no) and increases massively the risk of autism.

I want you to take three seconds and come up with a plausible explanation for why that is.

You picked: defective sperm.  Me, too.

However-- and this is the point-- you must recognize that there is nothing in the epidemiological evidence that allows you to jump to that conclusion.  It is your bias that older father= defective sperm, i.e. that the older father is actually a proxy for a pre-conception risk factor, and NOT that he's too tired to play with the kid; or that any man who had to wait until later to have kids is semi-autistic himself, etc.  All of those are prejudices, biases, unfounded in science, but they are exactly the same as believing it has to do with defective sperm.

There is circumstantial evidence, e.g. with mice, that older fathers produce progeny with various "problems": decreased exploratory activity, worse performance on avoidance tasks, etc, but nothing that would hold up in court.

Advanced paternal age could just as well be a post-natal risk factor as it could a pre-natal one; just as rain could just as well be a pre-natal risk factor as it could a post-natal one.

However, both camps have chosen a side and fail to consider the other side.  They're already firm about when the problem started, or what kind of problem to look for.  Dialogue is therefore impossible.


There is an additional twist to this story: the kind of autism (or schizophrenia) that is associated with advanced paternal age may be a different kind of autism or schizophrenia then the heritable kind.

To illustrate this, consider the happy discovery that in monozygotic twins (identical) have a 50% concordance for schizophrenia.  Dizygotic twins (fraternal, non identical) have much less-- 10%-- the same as any other first degree relative. (For autism it's 60% MZ, 0% DZ.) This can easily be taken to mean, "it's genetic."  End of debate.

Well, it really depends on what "genetic" means.  You're going to want to sit down for this:

When MZ twins are divided between monochorionic (one placenta for both fetuses) vs. dichorionic (each MZ twin gets it's own placenta) you find slightly different concordances: 60% for the same placenta twins, and 10% for the separate placenta twins.

Remember, even though they have different placentas, their DNA is still completely identical.  If schizophrenia was really mostly about DNA, then the placenta shouldn't matter.  But it appears that placenta matters more than DNA.

The average reader will find this quite fascinating, but for me, the truly fascinating, jaw dropping part of it all is this: the article cited, above, was written in 1995.  Since that time, no one has furthered this line of inquiry.

Not because the study was debunked-- no one tried to debunk it.  It's simply too hard to study twins in this way, and since it is to hard, we pretend that it isn't important.  The only analogy that comes to mind is a political one: it's way too hard to track down loose Russian nukes, so instead we'll continue to work on disarming ours.

 Autism is a spectrum; schizophrenia is a spectrum, and not only are multiple factors involved, but likely specific factors are involved in specific subtypes only that we currently lump all together.

Add to that everyone's camping out in different corners of the nature/nurture octagon, and if you're wondering why over 40 years of research into the causes of both disorders we're still at the level of "rain," well, that's why.


It is my personal bias (emphasis mine and bold and underlined) that advanced paternal age is a proxy for both/either "defective sperm" or some diathesis of... developmental disorder... in the father.  Either or both may be relevant for different cases.  If someone wanted to do a second study, take the rain study and cross it against paternal age.  Do older fathers live in Oregon?

So where is the real money in genetic research in autism and schizophrenia?  More generally: where are we most likely to find "genetic" explanations for complex behavioral traits that defy simple "gene model" explanations?

Start by looking at the possible explanations for the genetic effects of advanced paternal age:

There are three main lines of thought.

1.  Older sperm has longer time to suffer point mutations.  Men's sperm is constantly (24 times a year) undergoing cell division, each time brings opportunity for mutation.

2.  Expanding trinucleotide repeats. 

3.  Imprinting.

I believe with no hesitation that the money is in imprinting.  Let me explain.

Part 3 In one week


This type of study is becom... (Below threshold)

February 3, 2009 1:22 PM | Posted by Jim: | Reply

This type of study is becoming common, and annoying. Seemingly interesting, or emotionally-charged results are written up and the authors stand back, hold their hands in the air and say "Don't draw any conclusions, we're just saying the results support the hypothesis. We've no idea why." (I'm assuming this is the case here, since I can't read the actual article, only your quotes). What led them form the hypothesis in the first place? And yeah, hypotheses are supposed to just be viewpoint-neutral statistical tools. Only they're not.

for example, that parents who are predisposed to having autistic kids choose to live in Oregon. (What, is that so insane?)
Not insane, completely reasonable. These three states have a ton of tech companies, who employ a whole lot of geeks systemizers like me. These folks tend to make higher than average wages and can afford property near the coast, where there is more rain. Growing evidence (or at least media reports) exists that children who have two systemizers for parents have higher rates of autism. But, Alone, you already knew that.

BTW, what is your other blog? I looked here, but there are no entries posted.

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I laughed. I guess that me... (Below threshold)

February 3, 2009 1:26 PM | Posted by Lexi: | Reply

I laughed. I guess that means I have a sense of humor biased in favor of you?

A lot of tech people are in those cities too (well San francisco/silicon valley) . . . there was once a rumor that it's because uber geeky already lacking in social skills possibly already on the autistic spectrum techies were breeding together . . .

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"there was once a rumor tha... (Below threshold)

February 3, 2009 1:58 PM | Posted, in reply to Lexi's comment, by Dorn im Dunklen: | Reply

"there was once a rumor that it's because uber geeky already lacking in social skills possibly already on the autistic spectrum techies were breeding together . . ."

Sorry, can you say that again in English please?

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I always heard the higher r... (Below threshold)

February 3, 2009 2:30 PM | Posted by ItsTheWooo: | Reply

I always heard the higher rates of autism in the pacific northwest had to do with the fact this area was the heart of the late 90s early 2000 internet / tech boom.

I did not find it offensive when it was suggested parents might play a role in autism. We go from one extreme to the other; we shift away from this "refridgerator mother" nonsense to the complete opposite extreme, that ONLY biology determines autistic behaviors.
I personally have a great deal of autistic traits, and I can see both a genetic and parenting basis for them. It is genetic in the sense that autistic traits are present in all of my family members, especially my maternal grandfather (which I take after a lot). I clearly would not have these traits if I did not have genes from a more extroverted, less nerdish family.
It is parental in the sense that my parents did not put a lot of effort into "getting me out of my shell", they didn't stress the importance of people and learning social skills... furthermore, they supported and encouraged my obsessive focus on a few topics of interest (buying me building blocks, things to take apart/build, art supplies and never encouraging me to diversify my activities). This is probably because my parents, especially my mother, are also this way and they see nothing wrong with being an antisocial savant.

In adulthood I have made attempts to learn how to socialize and be less obsessive with my activities... I have had some success. I am still not normal and people treat me like I'm a weirdo, but the fact that I have had SOME success suggests to me that some degree of autistic traits are encouraged by the parents. If parents focus a great deal on integrating the child who tends to isolate, shows disinterest in others, and fixates on a few hobbies, I think it is likely that autistic traits in adulthood can be reduced.

Of course, I'm mostly talking about aspbergers syndrome and people with autistic traits. If we're talking about severe autism where the child is non-verbal, that is a more biological situation (as opposed to a biologically-driven tendency like the aspbergers syndrome and possessing autistic traits).

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I actually had the opposite... (Below threshold)

February 3, 2009 5:54 PM | Posted by jmp: | Reply

I actually had the opposite reaction to the parent comment. My first instinct was, "I knew it was the parents all along..."

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As someone that lives in Or... (Below threshold)

February 3, 2009 6:09 PM | Posted by Fargo: | Reply

As someone that lives in Oregon, I can't really say anything to autism rates here, but whatever genes/upbringing factors assist people in learning to drive well are almost totally absent here. This was also true of San Jose when I lived there. Phoenix, where I'm from, there you just had to watch out for the insanely old.

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The research was conducted ... (Below threshold)

February 3, 2009 6:39 PM | Posted by Dr X: | Reply

The research was conducted by Michael Waldman, an economist. His hypothesis was that higher levels of television watching during childhood could trigger autism. Obviously, there are lots of problems with the study, but he was looking at rainfall because higher rates of rainfall are associated with higher rates of television viewing. Here is the abstract:


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Two comments:1. U... (Below threshold)

February 3, 2009 7:18 PM | Posted by Common Reader: | Reply

Two comments:

1. Unlike everyone else in the world who theorizes on the internet on the subject, I am aware of the existence of non-middle class, non-white autistic children. The rise in autism is not explicable by geeks breeding with geeks because it has taken place in all classes and all races. If the cause were geeks breeding with geeks it would be very very clear, because there wouldn't be a proportionate number of nonwhite and nonwhite Asian autistic children. But 1) there are and 2) there is a disproportionately low number of Asian autistic children. So, bzz, sorry, try again.

2. I have never had such a drive to get the fuck out of dodge as I have to get the fuck out of Seattle. I moved here a year ago and I want OUT. Perhaps it is some kind of deep instinctual warning system trying to prevent me from reproducing away from healthful sunshine.

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Wow, so many Oregonians in ... (Below threshold)

February 4, 2009 9:01 AM | Posted by fraise: | Reply

Wow, so many Oregonians in just 8 comments -- I too was born and raised in Oregon. And I have quite a few autistic traits as well. (Next article: "Oregonians with autistic traits read The Last Psychiatrist", heh.)

I was actually looking forward to reading about how it was attributable to parents too, since like ItsTheWooo I can see genetic and parental influences for my own autistic traits. Basically, I could write nearly the same post as ItsTheWooo, with a key difference being that my parents never (as in, never) allowed me to see friends outside of school and church. They'd moved to the Oregonian countryside precisely to make it as difficult as possible for their kids to go out as teens. Doesn't exactly help develop social skills. But like ItsTheWooo, adulthood has been a much richer experience.

Common Reader, some of the cleanest air in the world can be found in the Pacific Northwest! While sunshine is nice, with it come larger populations, less cleansing rain and thus more pollution. (Yeah, you can tell I'm a native Oregonian... wait, I think I see some moss growing on the soles of my feet again, darnit, and I just cleaned them last month...)

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Gosh, I wonder how my steps... (Below threshold)

February 4, 2009 12:00 PM | Posted by spriteless: | Reply

Gosh, I wonder how my stepsister who needed a tube down her throat managed to watch so much TV en utero. O_O

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Who needed a tube down her ... (Below threshold)

February 4, 2009 12:01 PM | Posted, in reply to spriteless's comment, by spriteless: | Reply

Who needed a tube down her throat because she did not suckle or respond to the outside world. Sorry, I should read these before I post them.

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Fraise, it's totally mold. ... (Below threshold)

February 4, 2009 3:05 PM | Posted by Common Reader: | Reply

Fraise, it's totally mold. MOLD CAUSES AUTISM. YOU READ IT HERE FIRST.

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thx for the tip on the plac... (Below threshold)

February 5, 2009 8:53 AM | Posted by MedsVsTherapy: | Reply

thx for the tip on the placenta dimension. i am gonna get that article. i read a lot of health research literature, and have never heard this mentioned. can't wait for the follow-up.

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This is starting to remind ... (Below threshold)

February 5, 2009 9:19 AM | Posted by iwdw: | Reply

This is starting to remind me alot of Gabor Maté's books, especially Scattered Minds which was regarding ADHD. In the course of the three books he's written, he has been exploring similar ideas -- one of the thing he mentions is that even something as "insignificant" as the amount that the mother's eyes dilate when interacting with her baby can have huge cognitive impacts down the line.

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Interesting about the place... (Below threshold)

February 5, 2009 11:53 AM | Posted by anoreader: | Reply

Interesting about the placenta.

There are some newer studies pointing out the higher incidence of autism among preemies.

How much is related to the factors that caused the prematurity, how much to the immediate post-natal issues, how much to a combination of other factors, has yet to be determined.

I also, from my years of work with autism and ASD, think that there are different types of autism.

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i literally cheer while rea... (Below threshold)

February 5, 2009 1:56 PM | Posted by mel g: | Reply

i literally cheer while reading this blog more than i did when the steelers won last sunday.

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Who even knows how valid... (Below threshold)

February 5, 2009 5:47 PM | Posted, in reply to MedsVsTherapy's comment, by Alone: | Reply

Who even knows how valid it is? My point in citing it is a) isn't that wild? and b) um, does no one else want to follow this up?

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I also, from my years of... (Below threshold)

February 6, 2009 2:16 AM | Posted by Common Reader: | Reply

I also, from my years of work with autism and ASD, think that there are different types of autism.

There totally are. And people who have worked with the kids all know it. And nobody listens to us.

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why can't we face the 'real... (Below threshold)

February 6, 2009 12:46 PM | Posted by Trei: | Reply

why can't we face the 'real' truth? 'society' has become something so horrible and fake that some children are allergic to it and don't want to be a part of it. I totally get it.

Pay attention to your own lives for one day – really pay attention. You’ll see what I mean.

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In Pubmed, I crossed these ... (Below threshold)

February 6, 2009 3:04 PM | Posted by MedsVsTherapy: | Reply

In Pubmed, I crossed these two searches: (monochorial monochorionic dichoronial dichorionic) with (autism autistic aspergers asperger's) and the result was one article: pubmed number 10511337. Not relevant to autism etiology. Thus it is true: no one has gotten any pubs out about this.

on a related topic, as posted by iwdw:
I seriously doubt that pupil dilation can have an impact on newborn cognitive development. Please give a citation for such a remarkable claim. More likely is detection of a chance relation, due to multiple testing.

When exploring mother-infant dynamics, a prominent methodology is to observe videotapes of mother-infant interaction, and have trained raters rate various aspects. Typically, a researcher in this does many similar studies, with variants on relational hypotheses, and so could re-run pupil dilation as a predictor in several study samples. Several aspects are measured in each (pupil dilation, eye contact time and frequency, smiles, etc.). So, there is a good opportunity to go 'fishing' for a significant relation between all these measures. With p at .05, one out of twenty zero-order analyses will be positive. I did similar video coding rating, with maybe 20 independent subjective ratings to provide per adult interviewee (on defense mechanism profile). We obviously had to watch out for spurious relations.

on a related topic, as posted by trei:
a two-year-old realizes how fake society is, and goes autistic? Wow, that is a new one for me. My two-year old would not even take the fake-fruit grape out of his mouth last week, after discovering it was fake. The music box has come out of Barney, so now he knows Barney is not really singing. He (my son, not Barney) has not yet gone autistic.

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Gah you got to the best par... (Below threshold)

February 6, 2009 9:17 PM | Posted by Anonymous: | Reply

Gah you got to the best part of the entry and then you ended it with a "Too be continued..."


Great post though so far

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Ah, finally, a post abou... (Below threshold)

February 6, 2009 10:27 PM | Posted by Anonymous: | Reply

Ah, finally, a post about science only, that doesn't offend anyone.

Whoops, sorry, that's my other blog.

Ah, yes, where you write about the same things, but so inoffensively it's hard to stay awake. Seen that one. [It needs a better photo. I'm just saying.] This one's better.

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VI.There is an add... (Below threshold)