New Research: 1 in 88 U.S. Children Have Autism Spectrum Disorder
Read the Centers for Disease Control Press Release about this research, and find links to other useful pages on the CDC web site: Click Here.
Watch a March 30 story on the Today Show.
Read the cover story at USA Today.
New research showing one in 88 U.S. children have autism spectrum disorders is focusing national attention on the need for earlier diagnosis and treatment, especially in rural and minority communities.
Figures released Thursday by the Centers for Disease Control and Prevention show a 23% increase in autism spectrum cases from 2006 to 2008, and 78% increase since 2002.
The largest increases in autism prevalence were found among black and Hispanic children, who have lagged behind whites in previous counts. Numbers are higher for boys, with one in 54 8-year-olds now considered to have autism, Asperger's or a related condition, though no one knows why the condition is five times more likely to affect boys than girls.
More children are being diagnosed at younger ages - average age at diagnosis has dropped from 4½ to 4. But it needs to be even earlier, says Coleen Boyle, director of the CDC's National Center on Birth Defects and Developmental Disabilities. "We heard from many parents that they were concerned long before their child was diagnosed. We are working hard to change that."
It's also not known whether increases are because of better counting or something in the environment - or a mixture of both. Researchers are examining air pollution, nutrition, medications, environmental toxins and other factors as possible contributors.
At least some of the increase is due to better awareness and diagnosis, however, "I don't believe the whole thing is diagnostic," says Peter Bearman, a Columbia University sociologist who studies autism rates in California. He says his data are consistent with the CDC's.
"What we do know for certain is autism is common and needs to be effectively served," says CDC Director Thomas Frieden. "We need to continue to increase the number of kids who are detected, detected early and enrolled in services early."
The CDC has a surveillance network around the country that has counted 8-year-olds on the autism spectrum every two years. The new numbers are based on tallies from 14 sites.
Autism Speaks, an advocacy and research funding agency, says the figures mean that the U.S. needs to take fast action to help families and children on the spectrum, and invest in the kind of research that will help better explain why the numbers are rising so rapidly.
"Clearly, we have a national emergency and clearly, we need a national plan," said Mark Roithmayr, the group's president. "It's time for us as a nation to see these numbers for what they truly are, and for us as a nation to commit to doing much more than we've done for date."
Roy Richard Grinker, an anthropology professor at The George Washington University in Washington, D.C., said he thinks the numbers still underestimate the problem. He conducted a study last year in South Korea that found an autism rate of one in 38 children there.
States including Alabama, for instance, have long lagged behind others in autism diagnoses, Grinker said, because it is a large, rural state without many services for children with autism. Rising rates may actually be a good thing, he said, because it means more children who need help are being identified.
"It doesn't mean that there's a true increase in cases," says Grinker, whose 20-year-old daughter is on the autism spectrum.
Although the CDC's 14 surveillance sites are not statistically representative of the nation, with some in large urban districts and others in rural areas, the agency is confident in the accuracy of its autism figures, Boyle says. The numbers are painstakingly collected by looking through medical and educational records, she adds, which is why it took the CDC four years to prepare them. The rates also match up with autism figures derived in other ways, she says.
Early diagnosis is considered essential because treatments are more effective when started at a young age. Most early treatment consists of one-on-one attention with the child to teach social and communication skills that do not come naturally. Occupational therapy and sensory processing therapy can also help children cope better with the sensory overload that often comes with autism, where sounds can seem louder, sights more overwhelming and the tag in a shirt can feel unbearable.
Autism-spectrum disorders include three major categories, autism, Asperger's and Pervasive Developmental Disorder-Not Otherwise Specified, or PDD-NOS. To be diagnosed with autism, a child must have deficits in three areas: communication, social skills and in the ability to shift focus - children tend to perform repetitive behaviors such as hand flapping. Those diagnosed with Asperger's learned to speak at the appropriate time but communicate awkwardly; those with PDD-NOS are considered to fall on the "higher functioning" end of the spectrum.
A professional group is now considering changing the diagnosis of autism-spectrum disorders, potentially eliminating some people on the milder end, but also adding consideration of sensory problems. Though the suggested change has met opposition from some parents and advocates, Frieden, Boyle and Susan Hyman, of the American Association of Pediatrics, said at the CDC news conference that they are not concerned about a potential change in definition. Boyle said the CDC's records are so carefully constructed that they can easily go back and reconcile a new definition with the current one.
"There's the real possibility that the new definition will actually be better for children and better for families," said Hyman, chairwoman of the pediatric society's autism subcommittee. She says autism is much better understood today than it was the last time the definition was changed in 1994.
As that change is being considered, researchers across the country are busy trying to understand what in the environment might be causing so many cases of autism.
Irva Hertz-Picciotto, a professor at the University of California-Davis' M.I.N.D. Institute, said she thinks the government and private groups haven't spent enough money researching possible environmental contributors to autism.
"So much of the funding has gone toward genetics that the environment has hardly been looked at and yet we already have several clues," she says. "We also need to think about prevention and that's where the environmental concerns are so, so critical."
In a study last year, Hertz-Picciotto found that mothers who did not take prenatal vitamins before and in the early months of pregnancy were more likely to have children on the spectrum. Anti-depressant use has also been linked to autism, as have immune problems in the mother and aging parents.
Research by Hertz-Picciotto and others suggests that air pollution, nutrition, medications and toxic chemicals might all be contributing to the rise in autism rates.
"While we're not completely sure of what is driving the rise in autism cases, it is certainly striking enough to warrant exploring in detail the possibility that environmental exposures contribute to this," said Marc Weisskopf, an epidemiologist and associate professor at the Harvard School of Public Health, who is studying a possible link between air pollution and autism. "There are plenty of other reasons to avoid chemical toxicants, but we can't yet pinpoint whether one of these is a culprit in this rise."
The CDC plans to use its autism surveillance network to examine rates of cerebral palsy, intellectual disabilities and vision problems, according to Susan Levy, a developmental pediatrician at the Children's Hospital of Philadelphia, who is involved in the research. Knowing the rates of other conditions will help put the autism in a broader context, Levy said. "If everything is increasing, it gives you perspective."
Warning signs of autism
Doctors now say that autism can be detected as early as 18 months, though some of its symptoms overlap with other conditions. Parents and pediatricians should be concerned if an older infant or toddler:
•Does not follow a pointed figure or use his or her own finger to point to objects;
•Acts as if deaf;
•Fails to respond when his or her name is called;
•Has poor eye contact;
•Rarely tries to imitate sounds and movements others make, such as smiling and laughing, during simple social exchanges;
•Infrequently seeks adult attention;
•Is delayed in motor development, including delayed rolling over, pushing up and crawling.
Sources: CDC, Susan Levy, Children's Hospital of Philadelphia; Rebecca Landa, Director of the Center for Autism and related Disorders, Kennedy Krieger Institute in Baltimore.