The Autistic Brain: Thinking Across the Spectrum (3 page)

The
DSM-III,
published in 1980, listed infantile autism in a larger category called pervasive developmental disorders (PDD). To receive a diagnosis of infantile autism, a patient had to meet six criteria. One of the them was an absence of symptoms suggesting schizophrenia. The others were:

• Onset before 30 months
  
• Pervasive lack of responsiveness to other people
  
• Gross deficits in language development
  
• If speech is present, peculiar speech patterns such as immediate and delayed echolalia, metaphorical language, pronominal reversal
  
• Bizarre responses to various aspects of the environment, e.g., resistance to change, peculiar interests in or attachments to animate or inanimate objects
  

But that description was hardly precise. In fact, it became something of a moving target, changing with each new edition of the
DSM
as the APA attempted to nail down precisely what autism was—a common enough trajectory in psychiatric diagnoses that depend on observations of behavior. In 1987, the revision to the
DSM-III,
the
DSM-III-R,
not only changed the name of the diagnosis (from infantile autism to autistic disorder) but expanded the number of diagnostic criteria from six to sixteen, divided them into three categories, and specified that a subject needed to exhibit at least eight symptoms total, with at least two coming from category A, one from category B, and one from category C. This Chinese-menu sensibility led to higher rates of diagnosis. A 1996 study
compared the
DSM-III
and
DSM-III-R
criteria as they applied to a sample of 194 preschoolers “with salient social impairment.” According to the
DSM-III,
51 percent of the children were autistic. According to the
DSM-III-R,
91 percent of
the same children
were autistic.

The 1987 edition of the
DSM
also expanded an earlier diagnosis in the PDD category, atypical pervasive developmental disorder, into a catchall diagnosis that covered cases in which the symptoms of autism were milder or in which most but not all symptoms were present: pervasive developmental disorder not otherwise specified (PDD-NOS). The
DSM-IV,
which was published in 1994, further complicated the definition of autism by adding a new diagnosis altogether: Asperger syndrome.

In 1981, the British psychiatrist and physician Lorna Wing
had introduced to English-language audiences the work Austrian pediatrician Hans Asperger had done in 1943 and 1944. Even as Kanner was trying to define autism, Asperger was identifying a class of children who shared several distinct behaviors: “a lack of empathy, little ability to form friendships, one-sided conversations, intense absorption in a special interest, and clumsy movements.” He also noted that these children could talk endlessly about their favorite subjects; he dubbed them “little professors.” Asperger called the syndrome “autistic psychopathy,” but Wing felt that because of the unfortunate associations that had attached to the word
psychopathy
over the years, “the neutral term Asperger syndrome is to be preferred.”

This addition to the
DSM
is important in two ways. The obvious one is that it gave Asperger’s formal recognition by the psychiatric authorities. But when taken together with the PDD-NOS and its autistic-symptoms-but-not-quite-autism diagnostic criteria, Asperger’s was also meaningful in how it changed the way we think about autism in general.

The inclusion of autism in the
DSM-III
in 1980 was significant for formalizing autism as a diagnosis, while the creation of PDD-NOS in the
DSM-III-R
in 1987 and the inclusion of Asperger’s in the
DSM-IV
in 1994 were significant for reframing autism as a spectrum. Asperger syndrome wasn’t technically a form of autism, according to the
DSM-IV
; it was one of five disorders listed as a PDD, alongside autism disorder, PDD-NOS, Rett syndrome, and childhood disintegrative disorder. But it quickly gained a reputation as “high-functioning autism,” and by the time the revision of the
DSM-IV
appeared in 2000, diagnosticians were using
pervasive developmental disorder
and
autism spectrum disorder
(or ASD) interchangeably. At one end of the spectrum, you might find the severely disabled. At the other end, you might encounter an Einstein or a Steve Jobs.

That range, though, is part of the problem. It was almost certainly no coincidence that just as the idea of an autism spectrum was entering the mainstream of both popular and medical thinking, so was the concept of an autism “epidemic.” If the medical community is given a new diagnosis to assign to a range of familiar behaviors, then of course the incidence of that diagnosis is going to go up.

Did it? If so, wouldn’t we see a drop in some other diagnoses—the diagnoses that these new cases of autism or Asperger’s would have previously received?

Yes—and in fact, we do see evidence of that drop. In the United Kingdom, some of the symptoms of autism would have previously been identified as symptoms of speech/language disorders, and those diagnoses in the 1990s did go down in roughly the same proportion that autism diagnoses went up. In the United States, those same symptoms would have received a diagnosis such as mental retardation, and, again, the number of those diagnoses went down as autism diagnoses went up. A Columbia University study
of 7,003 children in California diagnosed with autism between 1992 and 2005 found that 631, or approximately one in eleven, had had their diagnoses changed from mental retardation to autism. When the researchers factored in those subjects who hadn’t previously been diagnosed with anything, they found that the proportion of children who would have been diagnosed with mental retardation using older diagnostic criteria but who were now diagnosed with autism was
one in four.

A later Columbia University analysis
of the same sample population found that children living near autistic children had a greater chance of receiving the diagnosis themselves, possibly because their parents were more familiar with the symptoms. Is the kid talking on schedule? Does the child stiffen up and not want to be held? Can she play patty-cake right? Does he make eye contact? Not only were children who would once have been diagnosed with mental retardation now more likely to receive a diagnosis of autism, but more children were likely to receive a diagnosis of autism, period—enough to account for 16 percent of the increase in prevalence among that sample population.

I can see the effects of a heightened awareness of autism and Asperger’s just by looking at the audiences who come to my talks. When I started giving lectures on autism in the 1980s, most of the audience members with autism were on the severe, nonverbal end of the spectrum. And those people do still show up. But far more common now are kids who are extremely shy and have sweaty hands, and I think,
Okay, they’re sort of like me—on the spectrum but at the high-functioning end.
Would their parents have thought to have them tested for autism in the 1980s? Probably not. And then there are the geeky, nerdy kids I call Steve Jobs Juniors. I think back on kids I went to school with who were just like these kids but who didn’t get a label. Now they would.

I recently spoke at a school for autistic students, to a hundred little kids sitting on the floor in a gymnasium. They weren’t fidgeting much, so they were probably on the high-functioning end of the autism spectrum. But you never know. They looked to me just like the kids I had seen several months earlier at the Minnesota State Science Fair. Did the kids at the autism school get the diagnosis just so they could go to a school where they’d be left alone to do what they did best—science, history, whatever their fixations might be? Then again, did some of the kids at the science fair fit the diagnosis for autism or Asperger’s?

The number of diagnoses of autism spectrum disorder almost certainly went up dramatically for another reason,
one that hasn’t gotten as much attention as it should: a typographical error. Shocking but true. In the
DSM-IV,
the description of pervasive developmental disorder not otherwise specified that was supposed to appear in print was “a severe and pervasive impairment in social interaction
and
in verbal or nonverbal communication skills” (emphasis added). What actually appeared, however, was “a severe and pervasive impairment of reciprocal social interaction
or
verbal and nonverbal communication skills” (emphasis added). Instead of needing to meet
both
criteria to merit the diagnosis of PDD-NOS, a patient needed to meet
either.

We can’t know how many doctors made an incorrect diagnosis of PDD-NOS based on this error. The language was corrected in 2000, in the
DSM-IV-TR.
Even so, we can’t know how many doctors continued to make the incorrect diagnosis, if only because by then the incorrect diagnosis had become the standard diagnosis.

Put all these factors together—the loosened standards, the addition of Asperger’s and PDD-NOS and ASD, the heightened awareness, the typographical error—and I would be surprised if there
hadn’t
been an “epidemic.”

I’m not saying that the incidence of autism hasn’t actually increased over the years. Environmental factors seem to play a role in autism—
environmental
not only in the sense of toxins in the air or drugs in the mother’s bloodstream, but other factors, like the father’s age at the child’s conception, which seems to affect the number of gene mutations in sperm, or the mother’s weight during pregnancy. (See chapter 3.) If an environment changes for the worse—if a new drug comes on the market that we later discover causes autistic symptoms, or if a shift in the national work force leads more couples to wait to have children—the number of cases might rise. If an environment changes for the better—if services for children diagnosed with ASD become available in a community, prompting parents to doctor-shop until their kid gets the “right” diagnosis—well, the number of cases might rise then too.

For whatever combination of reasons, the reported incidence of autism diagnoses has only continued to increase. In 2000, the Centers for Disease Control and Prevention established the Autism and Developmental Disabilities Monitoring (ADDM) Network
to collect data from eight-year-olds to provide estimates of autism and other developmental disabilities in the United States. The data from 2002 indicated that 1 in 150 children had an ASD. The data from 2006 raised the incidence to 1 in 110 children. The data from 2008—the most recent data available as I write this, and the basis for the most recent report, in March 2012—raised the incidence even further, to 1 in 88 children. That’s a 70 percent increase in a six-year period.

The sample was 337,093 subjects in fourteen communities in as many states, or more than 8 percent of the nation’s eight-year-olds that year. Given the size and breadth of that sample, the lack of geographical consistency was striking. The number of children identified with an ASD ranged erratically from one community to the next, from a low of 1 in 210 to a high of 1 in 47. In one community, 1 in 33 boys was identified as having an ASD. The rate of ASD incidence among black children was up by 91 percent from 2002. Among Hispanic children, the rise was even steeper—110 percent.

What’s going on here? “At this point, it’s not clear,” Catherine Lord, the director of the Center for Autism and the Developing Brain in New York, wrote on
CNN.com
after the release of the 2012 report. And unfortunately, the
DSM-5,
²
issued in 2013, doesn’t clarify matters. (See chapter 5.)

You know how when you’re cleaning out a closet, the mess reaches a point where it’s even greater than when you started? We’re at that point in the history of autism now. In some ways, our knowledge of autism has increased tremendously since the 1940s. But in other ways, we’re just as confused as ever.

Fortunately, I think we’re ready to pass that point of maximum confusion. As Jeffrey S. Anderson,
the director of functional neuroimaging at the University of Utah School of Medicine, says, “There’s a long tradition in medicine where the diseases start out in psychiatry and eventually they move into neurology”—epilepsy, for example. And now autism is joining that tradition. At long last, autism is yielding its secrets to the scrutiny of hard science, thanks to two new avenues of investigation that we’ll explore in the next two chapters.

Over here, on the closet shelf corresponding to chapter 2, we’ll put neuroimaging. Over there, on the shelf corresponding to chapter 3, we’ll put genetics. We can begin to reorganize the closet with confidence, because now we have a new way of thinking about autism.

It’s in your mind?

No.

It’s in your brain.

2

O
VER THE YEARS
, I’ve discovered I have a hidden talent. I’m very good at lying completely still for long periods of time.

The first time I realized I had this ability was in 1987, at the University of California, Santa Barbara, when I became one of the first autistic subjects to undergo magnetic resonance imaging, or MRI. The technicians warned me that the experience would be loud, which it was. They said the headrest would be uncomfortable, which it was. They said I had to lie very, very still, which, with some effort, I did.

None of these physical hardships, however, bothered me in the least. I was too excited. I was laying myself down on the altar of science! Slowly, my body slid into the big metal cylinder.

Not bad,
I thought.
Sort of like the squeeze machine. Or something out of
Star Trek.

Over the following half an hour, everything I had been warned about happened: the sound of hammers on anvils; the crick in the neck; the self-conscious monotony of monitoring my every nonmovement.
Don’t move, don’t move, don’t move—
thirty minutes’ worth of telling myself to lie absolutely still.

And then it was over. I hopped off the gurney and headed straight for the technician’s room, and there I received my reward: I got to see my brain.