Why there's no autism epidemic.

Health and medicine explained.
Jan. 15 2007 2:30 PM

The Autism Numbers

Why there's no epidemic.

Unstrange Minds; Remapping the World of Autism

For a decade or more, parents of autistic children, including public figures ranging from quarterback Doug Flutie to Rep. Dan Burton to NBC Chairman Bob Wright, have argued that an epidemic of autism is sweeping the country. The claim usually comes in the context of advocating more funding for autism research and treatment, which the advocates justify by pointing to the increase in reporting of autism cases. The numbers of autistic children on the rolls of the California Department of Developmental Services, for example, swelled 634 percent from 1987 to 2003. Similar increases have been reported in other states. Thirty years ago, autism was thought to occur in one in 2,000 children; prevalence rates put it at about one in 200. Various environmental factors have been held to blame, and autism has entered public consciousness in a new way, which makes it feel like a new disease, at least in its current dimensions.

But is there, in fact, an autism epidemic? Most of the scientists who study the disease—though not all—believe that any increase in recent decades in autism incidence, as opposed to diagnosis, has been modest. In his new book Unstrange Minds; Remapping the World of Autism, George Washington University anthropologist Roy Richard Grinker, who has an autistic 15-year-old daughter, makes the case that the rise in autism diagnosis is nothing more than an epidemic of discovery.

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For parents who are convinced that vaccines cause autism, it is significant that autism did not exist as a diagnosis until the Johns Hopkins University psychiatrist Leo Kanner first described the disorder in a 1943 journal paper—several years after children started receiving vaccines that contained minuscule amounts of a mercury preservative. But Kanner merely gave a name to a condition that probably always existed. Children with behaviors that would be called autistic today are scattered through the literature of past centuries. William of Newburgh in 12th-century England described "green children" who could not communicate or follow social customs. Sixteenth-century Russia had "blessed fools," seizure-plagued mutes preoccupied with repetitive behaviors. In 1887 England, Dr. Landon Down—after whom the chromosomal condition Down syndrome was named—coined the phrase "idiot savants" to describe some of the autistic children he saw. Down described the "self-contained and self-absorbed" child who was not "entertained other than in his own dream-land, and by automatic movements of his fingers or rhythmical movements of his body." Even Sigmund Freud saw patients whom he described in terms that match the current definition of autistic—"satisfaction of the instincts is partially or totally withdrawn from the influence of other people." In other cultures, autistics continue to exist behind other categories: "eternal children," among the Navajo, "marvelous children" in Senegal.

Grinker (whose grandfather Roy Grinker Sr. was an early American psychiatrist) covers all this early history while writing of his daughter's autism and the manner in which cultures from South Africa to Korea have dealt with autistic children. He points out that Kanner's father and grandfather, as well as Kanner himself, had clearly autistic traits. This sensitivity allowed him to bundle the symptoms of autism—social isolation, obsession with maintenance of sameness, muteness or repetitive language—into an identifiable syndrome. "Other doctors completely missed autism," writes Grinker, "because they weren't looking for it." About one in 300 Americans were in mental asylums in the mid-20th century, and case reports show that a good portion of them would be called autistic, if diagnosed today.

Psychiatrists made no real effort to systematically diagnose childhood mental illness, Grinker writes, until 1980, when the American Psychiatric Association published the third edition of its diagnostic manual. Further revisions of the manual in 1987 and 1994 expanded the number of children whose problems could be described as lying on the "autistic spectrum." The most important cause of the increase in autism diagnoses was the Individuals With Disabilities Education Act, a federal law that required states to provide suitable education to autistics and to create registries for them. Autism has become a trendy diagnosis, and at times a useful one to stretch. "I am incredibly disciplined in the diagnostic classifications in my research," Judy Rapoport, a senior child psychiatrist at the National Institutes of Health, tells Grinker, "but in my private practice, I'll call a kid a zebra if it will get him the educational services I think he needs."

As reporting of autism expanded and improved, the numbers of autistics recorded in research studies also increased. In the 1960s and 1970s, when autism was thought to be rare, the few surveys of autistics were simple tallies from administrative records in hospitals and clinics. In more recent surveys, investigators have used expanded diagnostic criteria, registries, and screening techniques to find children with disorders on the autism spectrum, which ranges from full-blown autism to Asperger's syndrome. Many more children with high IQs are now given diagnoses on the spectrum as the new techniques turn up many more cases than the previous, more passive approach. Indeed, the number of autism diagnoses may continue to grow. When California reported 18,000 children under 19 in autism programs in 2002, out of a population of 11 million kids, the prevalence rate of one in 550 was still considerably smaller than the number to be expected from the most careful epidemiological research.

A good side of the refined techniques of autism diagnosis is that many children get earlier treatment, in the form of behavioral therapies that enable them to reduce their symptoms, and sometimes shed their diagnoses by adulthood. Hundreds of thousands of adult autistics, by contrast, struggle with some degree of disability without ever having been diagnosed.  (The same is true, Grinker points out, of the estimated one in 500 children born with Fetal Alcohol Syndrome, many of whom were never diagnosed at birth, and may not get the help they need for learning disabilities and problems with impulse control.)

"I am not sure why people are so resistant to the idea that true autism rates may have remained stable," Grinker writes.  "Perhaps they don't want to give up on the hope that, if only we could find the cause of the 'epidemic' we could help these children. We could eliminate the toxins, hold big corporations accountable, do something to reverse the trend. If there is no real epidemic, we might just have to admit that no one is to blame." There's one more thing to be said for the cries of "epidemic"—they get the research money flowing.

Arthur Allen is the author of The Fantastic Laboratory of Dr. Weigl, Ripe, and Vaccine. He is a health writer and editor at Politico.