Autism is a spectrum of disorders caused by abnormal brain development that can lead to diminished social skills, as well as unusual ways of learning and reactions to sensations. A spectrum disorder, meaning people with autism can have a range of symptoms. Mildly affected, children develop life skills at an early age. Severely afflicted children may be unable to function in almost any setting.

As many as six in 1,000 children are ultimately diagnosed with autism to some degree, according to the Autism Society of America. The number of school-age children getting treatment soared by 600 percent, in recent years. Autism cases are on the rise nationwide, experts say the disorder affects as many as one in 166 children. Autism is the fastest growing population of special -needs students in the US, according to data from the United States Department of Education.

The number of diagnoses seems to be increasing, but some argue this is simply because of a greater awareness of the condition. They also claim that the rise in new cases may be attributed to increased screening, better recognition, pediatricians diagnosing it more often, and schools being apprehensive in treatment. The prevalence, number of children diagnosed with autism may have increased significantly in recent years, raising the question of whether foreign factors might be involved. As well as the incidence, the cause is unclear. Many have speculated that genetic causes, pollution, food additives, or childhood vaccinations may play roles.

Autism was fully recognized in 1994 by all states as a behavioral classification for school children, who receive
individualized attention whatever their diagnosis. Children classified by school special education programs as mentally retarded or learning disabled have declined, with the rise in autism cases between 1994 and 2003. Before the 1980s, only one in 10,000 children was diagnosed as autistic. Two decades later it’s diagnosed one in every 175 American children. As many as 1.5 million Americans may have some form of autism, including milder variants, and the number is rising. Research estimates the number of autistic children in the US could reach four million in the next decade.