Behind the Rise In Autism

The rise in the number of reported cases of autism is due to more diagnoses, not because there is an epidemic as some have repeatedly claimed.

Children classified by school special education programs as mentally retarded or learning disabled have declined in tandem with the rise in autism cases between 1994 and 2003, the author of the study said, suggesting a switch of diagnoses.

Government health authorities have been trying to allay widely publicized concerns that vaccines containing the mercury-containing preservative therimerosal, which is no longer used, were behind an autism epidemic.

There may be as yet unknown environmental triggers behind autism, study author Paul Shattuck of the University of Wisconsin at Madison said, but his research suggested the past decade's rise in autism cases was more of a labeling issue.

Autism was fully recognized in 1994 by all states as a behavioral classification for schoolchildren, who receive individualized attention whatever their diagnosis, he wrote in the journal Pediatrics.

Subsequent increases in the number of autism cases have varied widely by state but the average prevalence among 6- to 11-year-olds enrolled in special education programs increased from 0.6 per 1,000 pupils in 1994 to 3.1 per 1,000 in 2003.

During the same period, diagnoses of mental retardation fell by 2.8 per 1,000 students and diagnoses of learning disabilities dropped by 8.3 per 1,000 students.

It would appear that instead of being classified as mentally retarded or learning disabled, these children would be diagnosed with autism or an autism spectrum disorder. I hope that further study is done to evaluate whether the new classifications are helping these children receive focused treatment that improves their cognitive and social skills. Otherwise, we're playing a shell game and throwing money at a problem that has always persisted, just under different names.