Monday, July 23, 2007
Autism Surging but Why? The Jury is Still Out
Lost in the hoopla over the Wakefield hearing in the UK and the "Vaccine trials" in the US are the increases in reported cases of autism in various parts of the world. The US reports have increased to 1 in 150 and the UK reports, by no less an authority than Simon Baron-Cohen himself, a 1 in 100 incidence of autism. Obviously some of those numbers are attributable to the changes in the DSM and in better awareness, diagnosis and reporting. But while everyone is aware of those factors no serious study or report actually attributes the entire increases in the incidence in autism to these factors alone, Baron-Cohen's opinion, and that of Neurodiversity bloggers notwithstanding.
The graph from the California Department of Developmental Services shows that reported incidence of autism increased by five times in the ten year period from 94 to 04. Undoubtedly the DSM change would be a substantial factor in that startling increase along with better awareness, diagnosis and reporting. But do environmental factors contribute to the increasing incidence of autism and if so to what extent? This is a serious question which is not answered by self assured opinions from Baron-Cohen. The medical tribunal will soon report its verdict on Mr. Wakefield and the US "Vaccine Court" may offer some insight on vaccines and thimerosal but as to environmental factors generally the jury may well be out for some time to come.