Autism is a complex brain disorder that inhibits a person's ability to communicate and develop social relationships and is often accompanied by extreme behavioral challenges. Autism spectrum disorders are diagnosed in 1 in 150 children in North America, affecting four times as many boys as girls. The diagnosis of autism has increased tenfold in the last decade. The Centers for Disease Control and Prevention in the United States have called autism a national public health crisis whose cause and cure remain unknown. This crisis also exists in Canada.