The number of children diagnosed with autism has ballooned in recent years, but the reason for the increase is hotly debated. Some argue autism results when rare gene mutations are triggered by environmental factors like pollution, certain chemicals or even parental age. Others say it’s due to the fact that we’ve simply gotten much better at diagnosing it. Now, a large new study published in the journal JAMA Pediatrics suggests the primary cause of the increase of autism spectrum disorder is actually due to changes in how the disease is diagnosed.
“This study is important because it shows a large part of the increase has nothing to do with the environment, but rather administrative decisions,” says study author Stefan Hansen of Aarhus University in Denmark.