"Autism Study Shifts Focus From Nature to Nurture"

Post Reply New Topic

Article at San Francisco Chronicle, 5 July 2011, from a Stanford study:

http://www.sfgate.com/cgi-bin/article.c ... z1RDTQAF93

? ? ?

This is rather unexpected after the last 20-30 years of intense investigation into genetic factors. Interesting. Although it appears that what they are referring to as "new factors" are not exactly "nurture" so much as environmental, eg. mothers taking anti-depressants before and/or during pregnancy.
.

Flashback to the 60s when autism was caused by Refrigerator Mothers. My mum wasn't like that. She played Spiderman and Barbies with me. Her and I hugged each other a lot. We watched MASH together and my mum would sing to me and rub my back whenever I had a nightmare.

That's where the article and/or study conclusions seem somewhat illogical, because they are apparently *not* talking about "fridge mum-nuture" factors, so much as "environmental" ones ...

I don't understand how a mother taking anti-depressants before and/or during pregnancy could have a different effect on twins ( of the same pregnancy, ( which they say was one of the factors that they detected ), nor how drugs taken before a baby is even conceived can count as "nurture", seeing as the effect must be partly or totally on the way the genes are expressed in the growing foetus ... ie. nothing to do with what most people usually think of as "nurture" ...

It seems that the main point of the study-results is simply that the "purely genetic", *hard-wired" autism approach of the last 20 years or more is being challenged ... ... ... ?
.

Basically, they're saying that autism is epigenetic. Environmental factors influence gene expression.

But, these environmental factors are not about 'nurture'. Nurture is how you raise your child. These environmental factors can be things that the unborn baby is exposed to in the womb. They could be things that the mother has little control over.

Also, genetics are still relevant. If the baby does not have a genetic predisposition for autism, the environmental factors won't make any difference.

They're not saying that it is not genetics. They are saying that it is not only genetics. It's not really controversial that environmental effects increase the likelihood of being autistic. What they're talking about in this study is epigenetics. That is, some infants have a genetic vulnerability to autism, but environmental factors make it much more likely to occur.

My totally unscientific feeling is that this idea is nonsense.

192 pairs of twins is a very small sample. Also, 'identical' twins are not always genetically identical nor do they develop exactly the same.

As for anti-depressants having a role - what about before anti-depressants became available? They certainly weren't available when my father was in the womb (and he almost certainly has AS) and nor did my mother ever take them. Nor did my partner take them before my eldest child (who likely has AS) was born.

Sounds like this half-baked theory hasn't been thought through.

The same study also looked at "womb conditions" as a potential cause in addition to genetics. This would explain the higher incidence of both fraternal twins being diagnosed as well as the higher incidence of 2 children being born close together in a time frame both being diagnosed.

My mom was more a fount of caustic acidity ...

FASD kids are more likely to be autistic, as are kids with Fetal Rubella Syndrome (ironically, refusing the MMR could cause autism in some kids!).

So clearly it can be affected by environmental factors in some cases.

Well, currently neither the article nor the headline say anything about "nurture". I assume the subject heading on this post was the headline on the article. It's now "UCSF, Stanford autism study shows surprises". And the article itself uses the word environmental.

As far as the word "nurture" where it's been used in reporting this (and I can see via Google that it as), that's simply bad reporting and/or bad headline writing. Science reporting tends to be not so good.

The article is not saying that anti-depressants are the one and only pre-natal cause of autism. Just that it's possible that it's one thing in the prenatal environment that contributes to autism.

Here is the link the full report of the study:

http://archpsyc.ama-assn.org/cgi/content/full/archgenpsychiatry.2011.76

I may not be clearly understanding some of the posts, but it sounds like some are under the impression that the study on Anti-Depressants was part of the twins study. In case anyone is under that impression, that was an entirely different study.

If studies continue to provide this result it proves that genetics alone is not destiny for someone to develop autism. If that is the case, it will be next to impossible for a prenatal test for autism to gain any credibility. Considering so many loose genetic associations have been found but no definitive ones have been identified, it's not too surprising that the environment would play a role this large in determining if one develops symptoms of Autism.

I think both factors are important. As far as I know autism is more biological but environmental factors could influence the severity or how it effects an individual.

That's a good point, a diagnosis requires the symptoms to impair one's life. A person could have a genetic pre-disposition to autism and end up having symptoms that are not serious enough to warrant a diagnosis, whereas another individual exposed to different environmental variables might experience symptoms that are impairing enough to warrant a diagnoses.

In the recent study that showed 30% of the population has at least one trait of Autism, some may possess genetic markers for Autism, but they may not have been exposed to the same environmental factors that may increase the number and severity of symptoms that lead to a diagnosis.

Well, there's something to the epigenetics thing. Heritability for autism is not 100%; it's only in the low 90% range, so you can really only say that the average case of autism is 90% genetic. Something has to account for the other 10% of the cause, and epigenetics is the only thing left once you dump the obviously false, firmly disproven conspiracy theories.

Also, while identical twins will both have ASD almost all the time, it's not that uncommon for them to have different traits.

So what I'd say would be the next question to ask is not "What causes autism?" Because we know that already: It's almost entirely genetic. We should be asking, "What changes how autistic children develop, before and after birth?"

Yeah that is definatly possible......I think compared to some other disorders there is evidence suggesting autism is not something one develops but is born with. But yeah I think environment probably does play a role in how severe it is I know there are things in my environment that probably added to things. I mean I have always had social interaction issues when I was a child I knew there was something different about me and a lot of people treated me like crap so I kind of started isolating myself by getting lost in whatever book I was reading or otherwise occupying myself...so yeah I would say my environment did not help me develop better social skills.