RSS feed for
News Items

Twenty years ago, people diagnosed with autism were relatively rare, and the public’s awareness of the disorder was chiefly limited to Hollywood depictions such as that in the 1988 Academy Award-winning movie Rain Man. Today, many people know a neighbor, friend or classmate who is dealing with autism—prevalence has risen about twenty-fold since 1990. But what’s behind this startling increase? Scientists agree that some of it is due to changes in diagnosis and awareness, but just how much is hotly debated.

“The best papers I’ve seen suggest that there is a genuine increase,” Ricardo Dolmetsch says. “But it’s not as big as it seems. A big, big contribution is societal awareness and changes in diagnostic criteria.”

There have been at least two shifts in diagnosis, says Dolmetsch, an assistant professor of neurobiology at Stanford University. First, some kids who might have once been diagnosed as mentally retarded now are recognized as autistic. Second, children with autism display some of the same characteristics as those who have attention-deficit hyperactivity disorder (ADHD). When the diagnosis is ambiguous, doctors in California tend to diagnose autism rather than ADHD, because the state pays for services (such as behavioral therapy) for autism but not ADHD, Dolmetsch says.

Moreover, the medical establishment’s thinking about what constitutes abnormal behavior has shifted, says Joachim Hallmayer, associate professor of psychiatry and behavioral sciences at Stanford. “There’s no doubt that what we diagnose as autism is different than what we diagnosed 20 years ago.” Autism has been on the rise globally, but the explosion of cases occurs at different times in different countries, which points to a large role for societal awareness, Hallmayer says.

Some of the increase is definitely real, though, according to Antonio Hardan. He cites two contributors. More premature babies are surviving, and preemies are at high risk of autism (about 10 percent will develop it), and more couples are having babies when they’re older, which increases the risk of genetic errors that can lead to autism.

Could something in the environment also be a factor? Maybe, the researchers say, but there is little scientific evidence to back any such claim. Despite widespread concerns about a link between pediatric vaccinations and autism, vaccines have been soundly exonerated, they say.

Paula Gani, says her 4-year-old son Marcus, who has a milder form of autism, “is one of those kids who would not have been diagnosed 20 years ago.” But the diagnosis and early intervention he’s received are likely rewriting his future. He made limited eye contact and didn’t engage socially when he was diagnosed two years ago, but “yesterday, we were going out to pizza with another mom and her kid. And he took the other little boy’s hand and started singing ‘The more we get together, together, together . . . ‘,” she recounts. “It’s a huge difference.”

Share, Email or Print:
  • Print
  • del.icio.us
  • Facebook
  • Google Bookmarks
  • email
  • LinkedIn
  • MySpace
  • Twitter
  • Yahoo! Bookmarks

Also on Stanford Knowledgebase:

  1. Malpractice Reforms Increase the Supply of Physicians
  2. New Model Could Increase Transplants
  3. Research: High PTSD Rates for Iraq War Veterans

2 Responses to “Why the Increase in Diagnoses of Autism?”

  1. mhirzel says:

    Is this an article from a few years ago? If not, you seem to be totally unaware that this explanation for increase in diagnosis has been completely discredited.

    Changes in diagnosis criteria and “better awareness” account for a small proportion of the increase. Environmental factors have now been acknowledged, though reluctantly, by our public health “authorities.”

    Please try to come up to speed before posting this misinformation again.

  2. Stan says:

    I would have wished for a more comprehensive report from my old alma mater on this important matter. Even a cursory examination of ALL of the material on the subject would have led an open-minded investigator to look more deeply into the matter, than just to say:

    “Could something in the environment also be a factor? Maybe, the researchers say, but there is little scientific evidence to back any such claim. Despite widespread concerns about a link between pediatric vaccinations and autism, vaccines have been soundly exonerated, they say.”

    “Soundly exonerated, they say”? And you just take their word for it, and leave your report at that? Why not just print a press release of theirs, and call it a day…wasted?

    The Stanford Knowledgebase leaves rather much to be desired, in this day and age, if this is a typical example. Whatever happened to good old open-minded investigation of facts? When did Stanford become merely a talking dummy for the Establishment? What happened to its independence and critical thinking, that it used to pride itself in?

    Nest time, let’s have some meat; and leave your milquetoast at home.