According to a new study the rise in autism cases is not evidence of an epidemic but reflects that schools are diagnosing autism more frequently.
Study author Dr. Paul Shattuck, says in reality autism rates have not increased over the last two decades, and children classified by U.S. school special education programs as mentally retarded or learning disabled have declined in tandem with the rise in autism cases between 1994 and 2003, which suggests a switch of diagnoses.
Shattuck says there may be unknown environmental triggers behind autism, and his research suggests the past decade's rise in autism cases was more of a labeling issue.
Shattuck used U.S. Department of Education data to support his hypothesis but his theory has been rejected in a number of scientific studies.
Autism organizations believe this latest article is just a part of a phenomenon of denial that inhibits open scientific investigation of autism's causes and blocks allocation of needed resources into autism.
They say that the prevalence of autism now far exceeds other high profile disorders such as cerebral palsy, cystic fibrosis, and juvenile diabetes and want autism be recognized as a national emergency in order that unbiased epidemiological studies can be conducted that count both older and younger people with autism to see if the increases are real.
Government health authorities have for years 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.
According to the Autism Society of America, Autism is a spectrum of disorders caused by abnormal brain development that can lead to diminished social skills, as well as unusual ways of learning and reactions to sensations.
As many as 6 in 1,000 children are ultimately diagnosed with it to some degree.
Autism was fully recognized in 1994 by all U.S. states as a behavioral classification for schoolchildren, who receive individualized attention whatever their diagnosis.
The paper's use of Department of Education data to conclude no epidemic exists is of concern and troubling and the author himself agrees the data set is inconsistent and is subject to administrative and policy changes by the states.
He notes that 28 of the 48 states included in the analysis do not support his theory of reclassification as a reason for autism increases.
A commentary by Dr. Craig Newschaffer that accompanies the Shattuck article in the journal is supported by Autism Groups.
The commentary makes a number of valid points regarding Dr. Shattuck's approach and conclusions.
The hypothesis of reclassification, or "diagnostic substitution", has been examined and rejected in several scientific papers as a likely major factor in reported autism increases.
One study was in fact authored by Dr. Newschaffer.
Studies by Robert Byrd and Blaxill, Baskin and Spitzer have also ruled out diagnostic substitution.
More information about the Shattuck study and autism prevalence may be found at http://www.safeminds.org or by calling Jamie Shor at 202-628-7772.
The study and Newschaffer's comments are published in Pediatrics.
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