When an subject is controversial, one cannot hope to tell the truth. One can only show how one came to hold whatever opinion one does hold. One can only give one's audience the the chance of drawing their own conclusions as they observe the limitations, the predjudices, the idiosyncracies of the speaker.

- Virginia Woolf

Tuesday, July 11, 2006

Opinion : Causes of Autism

not quite finished but here it is anyway:

Untill much further scientific research is conducted, autism causes will unfortunately continue to fall under the category of opinion. It is important to remember however, that opinions on matters of science can be (and should be) tested. This is why I will not only disagree with this author's recently published (and widely rumored) belief that mercury poisoning causes autism, I will point out why he is wrong and how it can be proved.

Before we get to the science, I want to point out that the author in this case is an anti-corporate activist who is trying to raise politicised donations for a politically motivated not-for-profit group. That by itself pretty much should pretty much suggest the "evil corpratations plus complacent goverment hurts children" theme that is the whole article. Yet it is well written and well argued and makes some seemingly good points, so I will give it its due.


First, the author tries to draw the correlation between increases in autism and the increases in vaccinations to suggest the source of the mercury poisoning. While it is true that both increased in the late 80's to early 90's that doesn't imply a direct correlation. Several other things also increased with the same pattern, computers and cell phones come to mind. But my intention is not to start wild speculation about what causes autism, it is to show that mercury containing vaccines do not.
There are two clear ways to disprove the mercury hypothesis. One is that, as the article points out, we stopped using those vaccines in 2003. If a direct correlation were present, the number of new autism cases should have plummeted in the last two years. Sorry, not the case. Second, mercury exposure by vaccine is a post-natal event. It cannot be an explanation if there are prenatal signs of autism. And yet there are (I know of elevated testosterone levels, and avoidance of infant-mother eye contact) These are not used to diagnose autism because the symptoms and tests are not nearly as clear or accuarate as for other forms of developmental disability, yet if they are present they imply similar causation (genetic, maternal exposure).

Second, the article makes several claims about scientific articles supporting his conclusion (without citations, of course). Some are serious, but some are just funny. The most eggregious: "Scientists have been able to induce autism-like symptoms in mice by exposing them to Thimerosal." Sorry, disorders that only effect cognition can't be induced in species that don't have cognition (did the animals start counting match sticks and become fixated on certain TV shows? no wonder these scientists remained unamed). This was also a major problem when I researched schizophrenia. Another example: "there have been reports of significant improvements in some brain-injured children by removing mercury from their brains." Since when is autism considered an injury? The article also claims that only a crappy european study has exonerated the thermisol additive. Actually the largest study on the topic was conducted at the Univ. of Rochester and also exonerated the vaccines. No comment on that, of course.

Finally, there is the all important issue of medical cost/benefit anaylsis. Let's say for a minute that it was proven without a doubt that the vaccines cause autism. Should we keep giving them anyways? Probably yes (assuming no other equally effectife adjuvant was available). Don't forget that these vaccines are also proven to prevent deadly infectious diseases. How many people have died of Autism? (none) Your odds are much higher that your children will get the diseases without the vaccines than the odds they will get autism with it. A clever person might argue that there is enormous cost in the lifetime treatment of an autistic individual, and therefore on a pure economic basis, we should throw away those vaccines and let the unlucky children live tragically short lives for the sake of reducing healthcare costs. I will concede that argument if that clever personcan explain it to a dying child's parents. The fact is that turning down vaccinations based on fears of the side effects is playing dice with your children's lives, and it is not justified by an unproven side effect correlation.


Disclosure: I recieved a thermisol containing vaccine on thursday. Its toxic effects on my brain may have caused me to write this piece.

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