For years, many medical officials have suspected that the trend is artificial--due to changes in diagnoses or migration patterns rather than a real rise in the disorder.Much though I would like to believe that we are finally turning a corner relative to understanding autism, I find that I'm skeptical. Of course, it may well be that autism - as it's presently understood - is caused, at least in part, by environmental factors. But I have many questions about the recent MIND study's ability to tell us definitively one way or the other. I just don't see how the numbers they've used allow us to draw the conclusions they've drawn.
But the new study concludes that those factors cannot explain most of the increase in autism....The culprits, Hertz-Picciotto said, could be "in the microbial world and in the chemical world."
Hertz-Picciotto and Lora Delwiche of the UC Davis Department of Public Health Sciences analyzed 17 years of state data that tracks developmental disabilities, and used birth records and Census Bureau data to calculate the rate of autism and age of diagnosis.
The results: Migration to the state had no effect. And changes in how and when doctors diagnose the disorder and when state officials report it can explain less than half of the increase.
The existing diagnoses that fall within the autism spectrum include only one - Asperger syndrome - which clearly defines whether a patient is "high" or "low" functioning. The large category of Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS) includes children of all levels of functioning - and certainly some doctors use the term "autism" as a general catch-all diagnosis. Without further investigation into the functioning level of individual children with "PDD," "PDD-NOS," and "Autism Spectrum" diagnoses, there's no way to know whether those children would or would not have received autism diagnoses prior to 1990. If there's no way to know, based on statistics, how many children with "higher functioning" symptoms would have been diagnosed with autism prior to 1990, how is it possible to make a useful statistical comparison?
In addition, autism has become an increasingly well-known and well-funded disorder. In the last three years, celebrities have appeared on Oprah, Larry King and numerous other talk shows to discuss their children with autism. Sanjay Gupta hosted day-long specials on autism, featuring family after family coping with the disorder. Autism Speaks is covering the nation with public service ads, star-studded events, and even Starbucks coffee cups - all intended to raise awareness of autism. Twenty years ago, autism was a blip on the medical horizon. Today it's front and center, discussed on every TV, radio, and computer monitor. Is it really possible that such media saturation has no impact on rates of diagnosis? And assuming there has been an impact, is it really possible to measure that impact?
Schools are overwhelmed with children diagnosed on the autism spectrum. In part, that's because a new category CALLED "autism" was created by the Department of Education during the 1990's. Before that time, there was no category for autism - so no children with autism were recorded as attending public school. As a result, there is no useful way to actually compare autism rates in schools today with those in, say, the late 1980's. In fact, the only way to make that comparison would be to literally review the records of individual children who might have been described as trouble-makers, mildly mentally retarded, speech delayed, behavior problems, and so forth - and compare their actual symptoms to today's autism spectrum criteria.
Lastly, MIND researchers have gone on record as saying their new study suggests that environmental (as opposed to genetic) factors are to blame for autism. Of course, it's perfectly possible that environmental factors are behind at least some cases of autism. But it's hard to see that this particular study has anything to say about the possible impact of, for example, antibacterial soap (a potential causative factor which Hertz-Picciotto mentioned in an interview).
Autism, today, impacts an enormous range of individuals. My guess is that the very wide range of symptoms we now call autism have many causes... many effective treatments... and probably some cures. The researchers behind the MIND study feel that their findings support more robust research into environmental factors - and such research certainly would be a good thing. But I am not at all sure that the recent MIND study can tell us a great deal about causes, treatments or cures. In fact, I'm not completely certain what it does tell us.