The Claim of the Autism Epidemic

It’s April 15th, halfway through Autism Awareness Month 2008, and you’ve surely heard more than a few mentions about the supposed “autism epidemic” that we’re currently facing, and musings about what is causing the recent rise in the prevalence rate of autism: In the 1960s, autism was considered a rare disorder that occurred in only about 3 in every 10,000 children; now the prevalence rate for autism is, according to the most recent figures released on February 8, 2007, by the Centers for Disease Control and Prevention, 1 in 150 among children in the United States. And in New Jersey, where I live, the prevalence rate is 1 in 94.

A recently published study in the Developmental Medicine and Child Neurology by Dorothy Bishop, et al., found that some adults who received a diagnosis of language disorder during childhood might now have been diagnosed with autism. 38 adults (age 15 to 31) were included in the study, which has rekindled discussion about two hypotheses for the recent rise in the autism rate: Is there truly some epidemic of autism caused by some external, environmental agent? Or, can the change be accounted for by diagnostic substitution, by our being better able and equipped to identify, diagnose, and understand autism?

The answer to this question is not simply academic. To say that there is currently an epidemic of autism means that, until recently, there just were not a lot of autistic people, and that most of the increase in the autism rate is because there are more children with autism. According to this argument, there are a lot more autistic children than there are autistic adults. Prof. Bishop’s recent study disputes such a notion, as she suggests that if today’s diagnostic criteria for autism and autism spectrum disorder were to be applied to many adults who were diagnosed with various language disabilities, mental retardation, and other conditions in the past, the autism rate among today’s adults might well be similar to what it is in today’s children.

The April 10th Economist state that it’s not that there is more autism, but that how we define autism is different:

Fashion is a strange thing, and many fields are susceptible to it—not least, medicine. There has, for example, been a vogue (among commentators, if not among doctors) to ascribe the rising number of cases of autism diagnosed over the past couple of decades to childhood vaccinations against measles, mumps and rubella. That this is fashion rather than reality is suggested by the fact that the explanation proffered in Britain has been that such vaccines provoke an immune response that damages the nervous system, whereas Americans have blamed residual mercury in the same vaccines.

It’s not that autism is some new “trendy” diagnosis to apply to a child who might have been termed “quirky” or a sort of “funny-looking kid” (”FLK”) in times past. The diagnostic criteria have changed, as you can see if you examine the evoluation of the DSM criteria for autism through the years. The Economist rather suggests that what’s in “vogue” is ascribing the “rising number of cases of autism” to “childhood vaccinations”; to some external, environmental agent. Vaccinations have been also linked to ADHD and asthma, to Alzheimers, to juvenile diabetes, et alia. Alternative treatments for autism such as chelation—which some claim has “cured” their child from autism—-are also used to treat Lou Gehrig’s Disease, heart disease, and cancer. People talk about detoxifying autistic children of heavy metals; people talk about detoxification as a cancer treatment and as a treatment for obesity.

Might it be the case that it is (per the Economist) the “fashion”—that it is how we intuit and understand the world, to say there is an “epidemic” of certain childhood conditions, that something in the “environment” can be pointed to, and that removal of certain “toxic” elements can “cure” a child?

These aren’t easy questions to respond to as, in order to accurately answer them, one has to consider the changing definitions and cultural understandings of words like “epidemic” and “normal” and “mental retardation.” One has to keep in mind that it is only fairly recently in the history of the world that we look at disease from a psychiatric and psychological perspective. In a review of Prof. Bishop’s study, blogger Kev at Left Brain/Right Brain referenced Unstrange Minds: Remapping the World of Autism by anthropologist Roy Richard Grinker. Published in January of last year, Unstrange Minds makes a cogent case for how the changing diagnostic criteria for autism and rising understanding have contributed to a sort of “epidemic of discovery” of autism, and hence to the notable increase in diagnoses. From Unstrange Minds:

Doctors now have a more heightened awareness of autism and are diagnosing it with more frequency, and public schools….which first started using the category of autism during the 1991 – 1992 school year are reporting it more often….Epidemiologists are also counting it better. (p. 4)

…the newer, higher, more accurate statistics on autism are a sign that we are finally seeing and appreciating a kind of human difference that we once turned away from and that many other cultures still hide away in homes or institutions or denigrate as bizarre. (p. 5)

Prof. Grinker, who is the father of a child with autism, will be speaking at New York University this Thursday, April 17th, 3-5pm, about “What in the World is Autism?: How Culture Shapes an Illness. He’ll be discussing how the shift in how we view and count autism is part of a set of “broader shifts taking place in societies throughout the world”: Autism and neurological and mental health disorders are understood differently in different cultures around the world. (This is topic that I’ve long been sensitive to as I’m a third-generation Chinese American and I still don’t know exactly know how my parents explained about Charlie’s autism to my grandparents, one of whom does not speak English).

As for epidemics: If you want to read about a real epidemic, see today’s New York Times about cholera and how it “shaped the modern metropolis,” and spread throughout Five Points and lower Manhattan—another favorite, and a fashionable, site for us to wander and walk with Charlie.