They also agree, in somewhat general terms, on the various behavioral affects this disorder has on individuals. But when it comes to trying to determine what causes autism, a long laundry list of possibilities are often discussed.
Autism spectrum disorders (ASDs) are a group of developmental disabilities defined by significant impairments in social interaction and communication and the presence of unusual behaviors and interests.
Many people with ASDs also have unusual ways of learning, paying attention, or reacting to different sensations, according to the Centers for Disease Control and Prevention.
The thinking and learning abilities of people with ASDs can vary – from gifted to severely challenged. ASD begins before the age of three and lasts throughout a person's life. It occurs in all racial, ethnic, and socioeconomic groups and is four times more likely to occur in boys than girls.
Psychologists, physicians, and researchers are focusing on science. Theories are being examined that a single gene causes autism. Multiple genes, possibly ranging in number from five to 15, or gene networks, are now thought responsible.
The fact that the global climate has been undergoing a change at about the same time that autism cases have been on the rise has some experts believing that environmental factors could be responsible.
Plus, there is a mysterious minority among children diagnosed with the disorder. Only one out of four of them are girls. The fact that most autistic children are boys leads some to believe that perhaps imbalances in hormones could be a factor.
Data from several studies that diagnose autism and autism spectrum disorders (ASD), such as Asperger's disorder, found it prevalent in between two and six per 1,000 individuals. In other words, one in 500 (2/1,000) to 1 in 166 children (6/1,000) have an ASD, according to the CDC.
There is not a full population count of all individuals with an ASD in the United States. However, it is estimated that if 4 million children are born in the United States every year, approximately 24,000 of these children will eventually be diagnosed with an ASD.
And autism and ASD can no longer be thought of as childhood maladies.
According to the CDC, assuming the prevalence rate has been constant over the past two decades, it is estimated that up to 500,000 individuals between the ages of 0 to 21 have an ASD.
Many autistic children aren't diagnosed until they reach school age. CDC researchers emphasize the importance of affected children being identified to receive appropriate intervention services as early as possible.