Autism affects over 2 million individuals in the U.S. and tens of millions worldwide. The prevalence of autism has been increasing at an alarming rate over the past two decades, and has doubled in just the past four years. According to the U.S. Centers for Disease Control and Prevention (CDC), 1 in 88 American children is currently on the autism spectrum. Studies show that autism is 4-5 times more common among boys than girls, and an estimated 1 out of 54 boys and 1 in 252 girls in the United States has a form of autism. Some of this rise is due to improved awareness and diagnosis of the disorder, but research suggests that much of the surge in disease prevalence is real.

Many theories exist as to what is causing this rapid rise in autism prevalence, including certain foods, infectious diseases, pollutants, pesticides, vaccines and illicit drugs, however none has been substantiated and many claims have been completely disproven. Much research is underway in the attempt to identify a reversible environmental factor leading to the autism surge.