RODALE NEWS, http://www.rodale.com/causes-autism-0
BY LEAH ZERBE —A large study released this week found that environmental factors are more responsible for autism than previously believed.The largest and most rigorous twin study of its kind finds environmental exposures among the leading causes of autism.
Autism experts not involved in this particular study say the research is well done, and could help further turn the tide of autism research toward recognizing that environmental chemicals and certain drugs could be causes of autism. “It’s very credible stuff,” says pediatrician and epidemiologist Phil Landrigan, MD, professor and chair of the department of community and preventive medicine at Mount Sinai School of Medicine in New York City. “As new information comes in, it’s becoming very clear that there’s environmental contribution.”
THE DETAILS: The study, published in Archives of General Psychiatry, studied nearly 200 sets of twins, some identical and some fraternal. At least one child in each set of twins had been diagnosed with autism. The researchers determined that fewer than 40 percent of the cases were caused strictly by genetics. Shared environmental factors, including exposures in the womb, were implicated in nearly 60 percent of the cases. A separate study published in the same journal issue found a doubled risk of autism in children whose mothers took SSRI antidepressants a year before giving birth.