"Department of Education statistics indicate that the number of students with autism rose steadily, from about 42,500 in 1997 to nearly 225,000 in 2006. Meanwhile, the number of students counted as mentally retarded declined from about 603,000 to about 523,000.
CDC scientists believe education numbers are misleading, because they reflect only how kids are categorized for services. They say there's no clear evidence doctors are substituting one diagnosis for the other.
Some parents believe environmental factors — ranging from a preservative in vaccines to contaminants in food or water — may be important contributors. (The last doses of early childhood vaccines containing the preservative thimerosal expired in 2002, although some children's flu shots still contain it.)
Dr. Gary Goldstein, scientific adviser to the national advocacy group Autism Speaks, said the explanation for the rising autism prevalence is probably complex. Labeling and diagnosing probably play a role, as do genetics, but he believes the increase surpasses those two explanations.
"I'm seeing more children with autism than I ever would have expected to see," said Goldstein, who is chief executive of the Kennedy Krieger Institute, a treatment center for pediatric developmental disabilities in Baltimore.
Autism Speaks budgets more than $4 million each year to research the causes of autism, and about 90% of that has gone to genetics research. But organization officials recently have been talking about changing that mix, and spending as much as 50% of that money on potential environmental triggers, Goldstein said."
No comments:
Post a Comment