What Causes Autism? Is There an Autism Epidemic in the US? Advocacy group Autism Speaks says: “Autism is now officially becoming an epidemic in the United States. We are dealing with a national emergency that is in need of a national plan.”
When figures a few years ago showed that as many as one child in 110 in the United States had autism, leading autism research advocates called for health officials to declare a new “national emergency” and an “epidemic” that needed urgent attention.
Today, the situation is even more dire: One out of 88 children is believed to have autism or a related disorder, according to health officials who said on March 29 that autism appears to be on the rise, with the rate rising 23 percent in two years.
But officials admit they aren’t sure what’s causing the recorded rise — if it’s “real,” reflecting an actual rise in the disorder, or due in part to better recognition of cases, because of wider screening and better diagnosis. As the search for the cause of autism is really only beginning, officials acknowledge that the extent that factor influences the overall number is unknown — and other factors may be at play. It may be a mixture of both of both factors, and scientists are now examining environmental toxins, medications, nutrition and other factors as possible contributors.
“There is the possibility that the increase in identification is entirely the result of better detection. We don’t know whether or not that is the case but it is a possibility,” says Dr. Thomas Frieden, director of the Centers for Disease Control and Prevention, the agency that released the estimate.
“One thing the data tells us with certainty — there are many children and families who need help,” Dr. Freiden says. “What we do know for certain is autism is common and needs to be effectively served,” he told reporters.
The exact CDC figures
The new CDC analysis comes from the Autism and Developmental Disabilities Monitoring Network, which currently operates in 14 states: Alabama, Arizona, Arkansas, Colorado, Florida, Georgia, Maryland, Missouri, North Carolina, Pennsylvania, South Carolina, Utah and Wisconsin.
To find out if a child has autism or a related disorder, “clinician reviewers” examined the medical and school records of 8-year-olds in those states and also conducted screening to see which children met the criteria for autism, even if they hadn’t been formally diagnosed. They looked particularly at 8-year-old children because most autism is diagnosed by that age. Then, the researchers calculated how common autism was in each place and overall.
The CDC identified 3,820 children with some form of autism, out of a total of 337,093 in the surveillance areas. Analysis of the records showed that:
• For every 1,000 eight-year-old children, 11.3 had been identified as having an Autism spectrum disorder (ASD).
• That marks a 23 percent rise over the last data from two years earlier — and a 78 percent rise over the total number of cases presumed in 2002. At that time, the accepted estimate was that one in 150 children had some form of autism.
• The numbers are higher for boys, with one in 54 8-year-olds now considered to have autism, Asperger’s or a related condition.
• That means ASD is nearly five times more common in boys than girls, since the figures for girls show one in 252 had some form of the disorder.
• Previously, the disorder was believed to be more common in boys than girls by a factor of four to one.
• The rate for white children was 1 in 83, compared with 1 in 127 for Latinos and 1 in 98 for African Americans — but the data show those minorities have been closing the gap.
• In fact, the largest increases in autism prevalence were found among black and Hispanic children.
• ASD rates varied widely in the report — from one in 47 children in the western state of Utah to one in 210 children in the southeastern state of Alabama.
But the CDC investigators warns that the 14 sites aren’t “nationally representative” and “shouldn’t be generalized to the United States as a whole.” Still, these new findings are closely in line with what other research has shown, the CDC experts say.
In the early 1990s, based on some small studies in individual states or cities, only a few out of every 10,000 children were diagnosed with the condition. But after 2000, when Congress directed federal health officials to do more autism research and CDC started the larger study to see how common autism is, the numbers began to change dramatically.
Mark Roithmayr, president of Autism Speaks, the largest autism science and advocacy group in the U.S. says the new figures are alarming. “Autism is now officially becoming an epidemic in the United States. We are dealing with a national emergency that is in need of a national plan,” he says.
He also laments that the costs associated with autism have skyrocketed in recent years, reaching US$126 billion per year in the U.S. — or triple the figure it was six years ago.
Beside, autism costs taxpayers US$126 billion annually, according to research funded by Autism Speaks. That figure reflects the cost of healthcare, special education and other services — as well as loss of productivity, underemployment and unemployment among adults with autism.
For decades, a diagnosis of autism was given only to kids with severe language, intellectual and social impairments and unusual, repetitious behaviors like hand-flapping. But the definition of the disorder has gradually expanded, so that today a group of milder, related conditions, including Asperger’s syndrome is also considered “autism.”
Today, autism includes a wide spectrum of developmental differences. It may range from complete inability to communicate, sensitivity to certain lights and sounds, behavioral problems, repetitive movements, to mild social awkwardness.
Autism-spectrum disorders include three major categories: autism, Asperger’s and Pervasive Developmental Disorder-Not Otherwise Specified or PDD-NOS. People 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.
To be diagnosed with autism, a child must have deficits in three areas: communication, social skills and in the ability to shift focus. But the diagnosed is made by making judgments about a child’s behavior; there are no blood or biologic tests — so diagnosis isn’t an exact science.
Many people misunderstand the disorder, says Melissa Miller, a St. Petersburg, Florida, mom whose daughter, Chelsea, was diagnosed last year at age 2. “I think many people hear ‘autism’ and think ‘Rain Man,”‘ she tells the Associated Press, referring to the 1988 movie featuring Dustin Hoffman as an extremely socially impaired autistic man.
“The autism spectrum is so vast and all of our children are different. Many of them don’t rock back and forth or have savant skills. They are sweet, affectionate, intelligent, goofy — and exhausting — kids,” Miller explains.
Meanwhile, doctors working to update the Diagnostic and Statistical Manual of Mental Disorders have proposed considerable changes to the definition of autism. According to a New York Times report, some experts think that if the changes are carried out, they could reduce the number of children being given a diagnosis. These changes are due to take effect in 2013.
Searching for autism’s cause
Sadly, autism’s cause remains a mystery — and CDC is also studying the cause of autism. “To understand more, we need to keep accelerating our research into risk factors and causes,” says Dr. Coleen Boyle, director of the CDC’s National Center on Birth Defects and Developmental Disabilities.
Scientists say genetics play a role. For a long time, they estimated that genes were responsible for 90 percent of the autism risk and environmental factors caused the remaining 10 percent. But a 2011 study of twins by Stanford University researchers found that environmental factors accounted for 62 percent of the autism risk — and genes only 38 percent.
Some parents and religious groups have believed childhood vaccines trigger autism — but many studies haven’t found a connection.
Right now, CDC is conducting a study to identify possible factors that cause autism: antidepressants and other medications that either the pregnant women or the children took, illnesses that mothers had while they were pregnant with children who later were diagnosed as autistic. The first results of that study are expected next year.
Another large study, also funded by the National Institutes of Health, also examines everything from what the mother of a child with autism ate during her pregnancy to what pollutants were in the dust, to what cleaners were in the house.
Still, “there isn’t a clear frontrunner” among possible environmental causes of autism, says Dr. Craig Newshaffer, lead investigator of one of the NIH-sponsored studies and chairman of Drexel University School of Public Health’s Department of Epidemiology and Biostatistics.
Newshaffer’s team has also focused on factors that have changed in the last two decades — increasing parental age, the rise in pre-term births and low-birth weight babies and pregnant women’s use of certain antidepressants.
And, there is what he called “good evidence” that any environmental culprit present during the second or third trimester — at the peak of synapse formation — will raise the risk for autism. Scientists believe that faulty brain wiring underlies autism.
All these has prompted Ken Cook of Environmental Working Group to call for “upending the federal government’s approach to regulating toxic chemicals and putting tough emissions standards in place at power plants are two good places to start.”
“These stunning new figures are a call to action among our elected leaders to minimize our children’s exposures to mercury and other toxic chemicals,” he says.
Reminder to parents: earlier is better
“When it comes to treating children with autism, the research suggests earlier is better,” Andrew Adesman, chief of developmental and behavioral pediatrics at New York’s Steven and Alexandra Cohen Children’s Medical Center tells the Agence France Presse.
Early diagnosis is essential because treatments are more effective when started at a young age. These include teaching social and communication skills that don’t come naturally to a child in a one-on-one setting, sensory processing therapy can also help children cope better with the sensory overload that often comes with autism and occupational therapy.
Currently, 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, urges Dr. Boyle 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,” Dr. Boyle tells the USA Today.
What Causes Autism? Is There an Autism Epidemic in the US? Posted 16 April 2012.