I don't know the answer, but I can lay out the logical possibilities.
The Stanton Peele Addiction Website, May 25, 2009. This blog post also appeared on Stanton's Addiction in Society blog at PsychologyToday.com.
Why We Can't Solve Autism
Writing in the Sunday New York Times in reference to a disease he knows well (his autistic brother, Noah, is now in his forties), Karl Greenfeld makes an eye-opening statement: autism "is now among the most financially successful and mediagenic diseases ever, with hundreds of millions of dollars a year going to research, and regular press coverage." And this has been true for a number of years.
Yet autism shows no signs of abating, and many signs of increasing. There were around 15000 cases of autism among Americans ages 6-22 in 1992; today there are over 250,000 cases (over 300,000 among those 3-22) - a 1500 percent increase. To say the least, we do not have a handle on what causes autism. And, as in the Middle Ages - when Jews were blamed (and burned) across Europe for causing the black plague - when there is an unexplained epidemic, people get ornery.
The biggest fight is among those promoting and opposing the idea that mercury-based vaccines cause autism. Although by now vitrtually every concerned government (e.g., World Health Organization, European Medicines Agency, Centers for Disease Control) and independent private (Institute of Medicine, American Academy of Pediatrics) medical and health body has rejected the thimerosal (the mercury-based medium for inoculations) link to autism, it continues to be promoted avidly by such media stars as Robert Kennedy Jr., Deirdre Imus, and Jenny McCarthy and boyfriend Jim Carrey (here is one critique of Kennedy's work).
If you Google "thimerosal-autism," your first hit will be: "What Causes Autism," from the National Autism Association, which headlines: "Recent studies have confirmed the association between the use of thimerosal and autism has moved from ‘biologically plausible' to a ‘biological certainty.'" The second link will be to the Maryland Court of Appeals decision rejecting the validity of scientific claims that thimerosal causes autism. The third will be to the Vaccine Education Center which enumerates the evidence against such a link.
Go ahead - read all you want and make your own decision. But the most convincing piece of evidence that eliminating thimerosal in childhood vaccines won't solve the autism surge is - it's already been done, between 1997-1999. Childhood vaccines have for a decade not contained mercury, and the incidence of autism has still not declined, and continues to rise. This is scary on a number of grounds. But why is autism rising? Here are the logically possible explanations for the autism epidemic, and the problems with each:
1. Autism isn't really exploding. Can the rise in the prevalence of autism from 1 in 10,000 infants to 1 in 150 in a few decades really be due simply to our greater awareness of and readiness to diagnose the disease? Boy, that's as hard to swallow as the thimerosal linkage. Maybe greater sensitivity to - and a broadening of the definition and criteria for - autism account for some of the increase since 1992, but all of the 1500% increase? Autism often causes a major - sometimes near-total - failure at functioning (as it did with Noah Greenfeld). Did we really miss all of these until recently? Not likely.
2. Genetic causes. Although it is not strictly accurate to state that diseases with large genetic components cannot increase in their incidence, genetics are not an easy, efficient explanation for dramatic rises like that we have observed with autism.
3. Environmental pollutants. Would some rapidly growing environmental pollutant cause such a dramatic rise in a disease without a clear-cut biological basis (there are no reliable brain or other medical markers for autism)? It is far more likely that such a pollutant - were one to exist - would impact some malady with a clearly identified biological source in the body. This doesn't make it impossible that such an environmental-medical link will be found, but it is increasingly unlikely.
4. Child-rearing style. Explanations for childhood diseases in parental behavior are now frowned on as being guilt-inducing and victim-blaming. And it is certainly hard to believe that parents are doing something so radically different from parents just a few decades ago as to explain this accelerating epidemic.
5. Society. Is something modern society as a whole is doing, something that we don't recognize or acknowledge, causing a major developmental failure in many of our children? This suggestion is (a) vague and nearly meaningless, (b) anxiety and panic provoking, (c) something that, by definition, we cannot act on. If this "explanation" were true, then autism might continue to grow without end (although it might also suddenly reverse itself). What a frightening prospect!
But many people are beginning to feel this way.
Note (May 26):
Please see the responses to this post: the confusion, antagonism, warring skeptics and true believers that I outlined in my post are present as well in the responses to it.