TED日本語 - スティーヴ・シルバーマン: 忘れられていた自閉症の歴史

Just after Christmas last year,132 kids in California got the measles by either visiting Disneyland or being exposed to someone who'd been there. The virus then hopped the Canadian border, infecting more than 100 children in Quebec. One of the tragic things about this outbreak is that measles, which can be fatal to a child with a weakened immune system, is one of the most easily preventable diseases in the world. An effective vaccine against it has been available for more than half a century, but many of the kids involved in the Disneyland outbreak had not been vaccinated because their parents were afraid of something allegedly even worse: autism.

But wait -- wasn't the paper that sparked the controversy about autism and vaccines debunked, retracted, and branded a deliberate fraud by the British Medical Journal? Don't most science-savvy people know that the theory that vaccines cause autism is B.S.? I think most of you do, but millions of parents worldwide continue to fear that vaccines put their kids at risk for autism.

Why? Here's why. This is a graph of autism prevalence estimates rising over time. For most of the 20th century, autism was considered an incredibly rare condition. The few psychologists and pediatricians who'd even heard of it figured they would get through their entire careers without seeing a single case. For decades, the prevalence estimates remained stable at just three or four children in 10,000. But then, in the 1990s, the numbers started to skyrocket. Fundraising organizations like Autism Speaks routinely refer to autism as an epidemic, as if you could catch it from another kid at Disneyland.

So what's going on? If it isn't vaccines, what is it? If you ask the folks down at the Centers for Disease Control in Atlanta what's going on, they tend to rely on phrases like "broadened diagnostic criteria" and "better case finding" to explain these rising numbers. But that kind of language doesn't do much to allay the fears of a young mother who is searching her two-year-old's face for eye contact. If the diagnostic criteria had to be broadened, why were they so narrow in the first place? Why were cases of autism so hard to find before the 1990s?

Five years ago, I decided to try to uncover the answers to these questions. I learned that what happened has less to do with the slow and cautious progress of science than it does with the seductive power of storytelling. For most of the 20th century, clinicians told one story about what autism is and how it was discovered, but that story turned out to be wrong, and the consequences of it are having a devastating impact on global public health. There was a second, more accurate story of autism which had been lost and forgotten in obscure corners of the clinical literature. This second story tells us everything about how we got here and where we need to go next.

The first story starts with a child psychiatrist at Johns Hopkins Hospital named Leo Kanner. In 1943, Kanner published a paper describing 11 young patients who seemed to inhabit private worlds, ignoring the people around them, even their own parents. They could amuse themselves for hours by flapping their hands in front of their faces, but they were panicked by little things like their favorite toy being moved from its usual place without their knowledge. Based on the patients who were brought to his clinic, Kanner speculated that autism is very rare. By the 1950s, as the world's leading authority on the subject, he declared that he had seen less than 150 true cases of his syndrome while fielding referrals from as far away as South Africa. That's actually not surprising, because Kanner's criteria for diagnosing autism were incredibly selective. For example, he discouraged giving the diagnosis to children who had seizures but now we know that epilepsy is very common in autism. He once bragged that he had turned nine out of 10 kids referred to his office as autistic by other clinicians without giving them an autism diagnosis.

Kanner was a smart guy, but a number of his theories didn't pan out. He classified autism as a form of infantile psychosis caused by cold and unaffectionate parents. These children, he said, had been kept neatly in a refrigerator that didn't defrost. At the same time, however, Kanner noticed that some of his young patients had special abilities that clustered in certain areas like music, math and memory. One boy in his clinic could distinguish between 18 symphonies before he turned two. When his mother put on one of his favorite records, he would correctly declare, "Beethoven!" But Kanner took a dim view of these abilities, claiming that the kids were just regurgitating things they'd heard their pompous parents say, desperate to earn their approval. As a result, autism became a source of shame and stigma for families, and two generations of autistic children were shipped off to institutions for their own good, becoming invisible to the world at large.

Amazingly, it wasn't until the 1970s that researchers began to test Kanner's theory that autism was rare. Lorna Wing was a cognitive psychologist in London who thought that Kanner's theory of refrigerator parenting were "bloody stupid," as she told me. She and her husband John were warm and affectionate people, and they had a profoundly autistic daughter named Susie. Lorna and John knew how hard it was to raise a child like Susie without support services, special education, and the other resources that are out of reach without a diagnosis. To make the case to the National Health Service that more resources were needed for autistic children and their families,

Lorna and her colleague Judith Gould decided to do something that should have been done 30 years earlier. They undertook a study of autism prevalence in the general population. They pounded the pavement in a London suburb called Camberwell to try to find autistic children in the community. What they saw made clear that Kanner's model was way too narrow, while the reality of autism was much more colorful and diverse. Some kids couldn't talk at all, while others waxed on at length about their fascination with astrophysics, dinosaurs or the genealogy of royalty. In other words, these children didn't fit into nice, neat boxes, as Judith put it, and they saw lots of them, way more than Kanner's monolithic model would have predicted.

At first, they were at a loss to make sense of their data. How had no one noticed these children before? But then Lorna came upon a reference to a paper that had been published in German in 1944, the year after Kanner's paper, and then forgotten, buried with the ashes of a terrible time that no one wanted to remember or think about. Kanner knew about this competing paper, but scrupulously avoided mentioning it in his own work. It had never even been translated into English, but luckily, Lorna's husband spoke German, and he translated it for her.

The paper offered an alternate story of autism. Its author was a man named Hans Asperger, who ran a combination clinic and residential school in Vienna in the 1930s. Asperger's ideas about teaching children with learning differences were progressive even by contemporary standards. Mornings at his clinic began with exercise classes set to music, and the children put on plays on Sunday afternoons. Instead of blaming parents for causing autism, Asperger framed it as a lifelong, polygenetic disability that requires compassionate forms of support and accommodations over the course of one's whole life. Rather than treating the kids in his clinic like patients, Asperger called them his little professors, and enlisted their help in developing methods of education that were particularly suited to them. Crucially, Asperger viewed autism as a diverse continuum that spans an astonishing range of giftedness and disability. He believed that autism and autistic traits are common and always have been, seeing aspects of this continuum in familiar archetypes from pop culture like the socially awkward scientist and the absent-minded professor. He went so far as to say, it seems that for success in science and art, a dash of autism is essential.

Lorna and Judith realized that Kanner had been as wrong about autism being rare as he had been about parents causing it. Over the next several years, they quietly worked with the American Psychiatric Association to broaden the criteria for diagnosis to reflect the diversity of what they called "the autism spectrum." In the late '80s and early 1990s, their changes went into effect, swapping out Kanner's narrow model for Asperger's broad and inclusive one.

These changes weren't happening in a vacuum. By coincidence, as Lorna and Judith worked behind the scenes to reform the criteria, people all over the world were seeing an autistic adult for the first time. Before "Rain Man" came out in 1988, only a tiny, ingrown circle of experts knew what autism looked like, but after Dustin Hoffman's unforgettable performance as Raymond Babbitt earned "Rain Man" four Academy Awards, pediatricians, psychologists, teachers and parents all over the world knew what autism looked like.

Coincidentally, at the same time, the first easy-to-use clinical tests for diagnosing autism were introduced. You no longer had to have a connection to that tiny circle of experts to get your child evaluated.

The combination of "Rain Man," the changes to the criteria, and the introduction of these tests created a network effect, a perfect storm of autism awareness. The number of diagnoses started to soar, just as Lorna and Judith predicted, indeed hoped, that it would, enabling autistic people and their families to finally get the support and services they deserved.

Then Andrew Wakefield came along to blame the spike in diagnoses on vaccines, a simple, powerful, and seductively believable story that was as wrong as Kanner's theory that autism was rare.

If the CDC's current estimate, that one in 68 kids in America are on the spectrum, is correct, autistics are one of the largest minority groups in the world. In recent years, autistic people have come together on the Internet to reject the notion that they are puzzles to be solved by the next medical breakthrough, coining the term "neurodiversity" to celebrate the varieties of human cognition.

One way to understand neurodiversity is to think in terms of human operating systems. Just because a P.C. is not running Windows doesn't mean that it's broken. By autistic standards, the normal human brain is easily distractable, obsessively social, and suffers from a deficit of attention to detail. To be sure, autistic people have a hard time living in a world not built for them. [ Seventy ] years later, we're still catching up to Asperger, who believed that the "cure" for the most disabling aspects of autism is to be found in understanding teachers, accommodating employers, supportive communities, and parents who have faith in their children's potential.

An autistic woman named Zosia Zaks once said, "We need all hands on deck to right the ship of humanity." As we sail into an uncertain future, we need every form of human intelligence on the planet working together to tackle the challenges that we face as a society. We can't afford to waste a brain.

Thank you.

(Applause)