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Autism debate: Does an epidemic continue?
lack and white picture of man with glasses, shadow on right side of the face
Photo from alainelorza
A portrait of a French man with autism.

Counting autism, confronting panic

On December 18, the federal government published a new estimate of how many children have autism or related disorders. After a detailed examination of records on more than 300,000 children living in 11 states, the researchers reported that in 2006 one eight-year-old in 110 had an autism spectrum disorder, or ASD.

Autism spectrum disorders can involve dramatic limitations on communication, social behavior and intelligence. Autistic children typically require educational accomodations and in many cases place severe burdens on their families.

The new numbers, from the Autism and Developmental Disabilities Monitoring Network, show that autism spectrum disorders, which include three diagnoses (see box) affect one in 70 boys and one in 315 girls.

Alarmingly, the new study (see #1 in the bibliography) showed a 57 percent rise in the incidence of ASD from 2002 to 2006. Because that increase followed a decades-long rise in reports of autism, the new study brought another set of anxious headlines.

The three types of Autism Spectrum Disorders which affect social, communication and behavioral abilities:

half  brainAutism disorder ("classic" autism): characterized by significant delays in language development, challenges with social interactions and communication, intellectual disability, and unusual behaviors and interests.

half  brainAsperger syndrome: displays milder symptoms of autistic disorder, with diagnosed individuals also showing unusual behaviors and interests, but less significant language or intellectual disabilities.

half  brainPervasive Developmental Disorder - Not Otherwise Specified: usually have fewer and milder symptoms, which might cause only social and communication challenges.


If the increasing rate of autism reflects a genuine rise in the percentage of children with this severe diganosis, we'd best get to work finding the cause of such an explosion of serious behavioral and intellectual impairments. But the rising rate could be less reflective of actual disability than of other changes, such as a broadening definition or a desire to obtain services to treat autism. In that case, finding and prevnting the cause would still be important, although it might deserve a different share of resources than what would be appropriate for confronting a tidal wave of developmental disease.

Graph showing dramatic rise in autism diagnosis, from 1 in 5000 in 1975 to 1 in 110 in 2009
The prevalence of autism has soared since 1975. In 1980, psychologists wrote a standard definition of autism. In 1994, the idea of a broader "autism spectrum disorder" was codified. Experts still debate how much of this increase reflects a real change in the population, and how much results from better reporting.

A lot rides on the distinction. Parents want both a label for their child's problems, and some want something to blame (witness the common, but widely discredited, notion that vaccines cause autism). To some parents and advocates, these questions are visceral, not academic: Experts who dispute the supposed link between vaccines and the "autism epidemic" have received hate mail and death threats.

Here's food for thought: Though many bemoan the rising rate of autism, it could be a good thing if it reflects better diagnosis and results in more kids getting needed services.

Still, it ought to be possible to answer a simple question: Is autism increasing, or are the soaring numbers due to an expanded definition of autism, better diagnosis and changing social conditions?

Terry Devitt, editor; Steve Furay, project assistant; S.V. Medaris, designer/illustrator; David Tenenbaum, feature writer; Amy Toburen, content development executive

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