Saturday, March 15, 2014
New Study: Autism, Environmental Factors and Intellectual Disability
There is a new study published last Monday that connects autism with environmental influences. The particular environmental influences are not teased out, but this county-by-county study points to the environment as a contributing factor to autism and what the authors call "Intellectual Disability". Here is a quote from the Science Daily report:
The team found that every one percent increase in malformations in a county was associated with a 283 percent increase in autism and 94 percent increase in ID in that same county. Almost all areas with higher rates of autism also had higher rates of ID, which the researchers believe corroborates the presence of environmental factors. In addition, they found that male children with autism are almost six times more likely to have congenital genital malformations. Female incidence was linked with increased malformation rates, but weakly so. A county-by-county map of autism and ID incidence above or below the predicted baseline for the entire US is included in the study.
The report on the study can be found here:
I've always thought the autism 'epidemic' (not my word; theirs) would have as a contributing factor environmental toxins. However, in my experience, some of the students identified as having autism whom I see now would not have had that diagnosis in the 70's when I first started in this field. But I also think the fact that more families have multiple children on the spectrum rests on environmental issues. We didn't see families with more than one child on the spectrum in the 1970's. If they had one, their other children were neurotypical, except in extreme situations.
What do you think? Toxins or changes in diagnostic categories?