SALT LAKE CITY — Come May 2013, Asperger's disorder will no longer be a part of the canonical diagnostic tool used by psychiatrists, psychologists and doctors. The Asperger's label has been dropped from the latest version of the Diagnostic and Statistical Manual in favor of a broader umbrella category called autism spectrum disorder.
One in 47 Utahns has some form of autism, among the highest prevalence in the nation, and about double the national average. Any changes to how those diagnoses are reached are likely to have an important effect on Utahns living with autism or caring for someone who has it.
Dr. William McMahon, Chair of the department of Psychiatry at the University of Utah, who has been an autism researcher since the early 1980s, thinks the change is long due.
"We've probably all deluded ourselves in the past to think that there's only one autism," he said. "There are many autisms and they are more like Asperger's than not." In other words, dropping Asperger's in favor of autism spectrum disorder makes sense to him.
Asperger's has long been considered a part of a wide range of disorders that fall along an autism spectrum, and in the 1990s came into its own as a specific diagnosis.Those who have it are often highly intelligent and successful, but socially awkward or lacking in social and communication skills.
It has been made more familiar though increased media coverage and mainstream portrayals in shows like "Big Bang Theory" where the protagonist Sheldon Cooper has the disorder.
The task force in charge of developing the latest version of the manual, the DSM-5, determined that the term lacked specificity and there was not data to support a differentiation between Asperger's and other similar but more severe disorders. They say the new criteria for autism spectrum disorder will be stricter and more precise, leading to better treatment.
Those with what is now called Asperger's will be under the same umbrella as those with severe autism who are unable to function in the world and need constant care. But they'll also be grouped with much milder forms of autism. The point is that it's the severity of symptoms that differentiates individuals, rather than a specific, differing diagnosis.
Utah, like the rest of the country, will likely see the prevalence of autism go down due to the DSM-5 revisions. McMahon says that studies estimate the rate will go down by ten percent, with some groups saying it could be much more. But he also emphasized that new definitions should lead to changes. "The prevalence estimates always change with definition," he said.
McMahon said he conducted a study in Utah in the 1980s that found the rate of autism was roughly 4 in 10,000 people. That rate lined up with everything they knew about autism at the time, and was in line with other studies in the U.S. and Europe.
- Studies have shown that among identical twins, if one child has an ASD, then the other will be affected about 36-95% of the time.
- Parents who have a child with an ASD have a 2%-18% chance of having a second child who is also affected.
- ASDs tend to occur more often in people who have certain genetic or chromosomal conditions.
- The majority (62%) of children the ADDM Network identified as having ASDs did not have intellectual disability.
- Children born to older parents are at a higher risk for ASDs.
- A small percentage of children who are born prematurely or with low birth weight are at greater risk for having ASDs.
- ASD commonly co-occurs with other developmental, psychiatric, neurologic, chromosomal, and genetic diagnoses.
But that was also deeply flawed due to both problems in definition and clinical issues. McMahon said that they used extremely strict criteria, and weren't yet good at diagnosing mild cases of autism.
"We probably would not have even been referred in (mild) cases to study, and if would have seen them, we may not have called the diagnosis autism," he said.
Many folks are anxious about the possibility of losing medical or educational services that they have come to rely on due to losing the Asperger's label. And some Asperger's families opposed any change, fearing their kids would lose a diagnosis and no longer be eligible for special services.
But the revision will not affect their education services, experts say.
Catherine Lord, an autism expert at Weill Cornell Medical College in New York who was on the psychiatric group's autism task force, said anyone who met criteria for Asperger's in the old manual would be included in the new diagnosis. One reason for the change is that some states and school systems don't provide services for children and adults with Asperger's, or provide fewer services than those given an autism diagnosis, she said.
Autism researcher Geraldine Dawson, chief science officer for the advocacy group Autism Speaks, said small studies have suggested the new criteria will be effective. But she said it will be crucial to monitor so that children don't lose services.
McMahon said that many insurance companies and states don't cover autism at all. So a change in definition may not have a huge impact.
"Most insurance doesn't pay for autism treatment in the first place," he said. "Here in Utah we've got a pilot program for early intervention, but it's only funded for two years."
"It's not like the diagnosis is not important, but it's just that there are so many people who once they get the diagnosis, their insurance company says, ‘Well, we don't pay for that.'"
Contributing: Lindsey Tanner, Associated Press