Autism May Be More Common Than Thought
Survey Shows 1 in 91 Children May Have Autism Spectrum Disorder
WebMD News Archive
Interpreting the New Autism Data
Experts are not certain what to make of the findings but urged caution in
interpreting them. "In ASD, we don't know if the change in the numbers over
time is a change in the actual condition," Arias says, or to other factors.
Among the other factors are that awareness of the condition is more
widespread, she says, and the condition is now thought about on a continuum, so
what is now considered a mild case may not have been diagnosed in past
"We also know from other studies that there has been a decreasing average
age of diagnosis, which would lead to increasing prevalence at any one point in
time," Kogan says.
In recent years, experts have also realized that ASD often coexists with
other disorders, such as attention deficit hyperactivity disorder, and a child
who previously was only diagnosed with ADHD may now have a diagnosis of both
ADHD and ASD, for instance.
And what of the 38% of children who seemed to have shed their diagnosis? "We
know that some children diagnosed at young ages won't meet the criteria as they
age," Kogan says. Some parents surveyed may have been reporting a health care
provider telling them they suspected ASD, rather than the actual diagnosis, he
In addition, some research has suggested that some children do have
resolution from the condition and lose the diagnosis with age.
Experts who reviewed the survey for WebMD say it is a carefully done report.
They, too, are uncertain about what to make of the dramatic rise. "What it may
be is that the numbers are the same but we are capturing a milder form [in the
survey]," says Susan Hyman, MD, associate professor of pediatrics and division
chief of neurodevelopmental and behavioral pediatrics at the University of
Rochester and chairwoman of the American Academy of Pediatrics' autism
''The big take-home message is that autism spectrum disorders are more
common than we thought 50 or 60 years ago," says Susan Levy, MD, a member of
the autism subcommittee of the American Academy of Pediatrics and an autism
expert at Children's Hospital of Philadelphia. The newer surveys, such as the
one published in Pediatrics, suggest the disorders are more common, she
says, than people thought even 10 years ago. Like all surveys, however, Levy
says, it may not be completely accurate.
For parents, the message is clear, whether the increase in numbers turns out
to be totally representative of the population or not, experts say. It's
important to know potential signs of ASD and to consult a pediatrician as soon
as possible to check out the child, experts stress. Among the potential signs
are social interaction problems, language difficulties, or behavior problems
such as repetitive behavior.