Autism is not a single disease or disorder, but a disturbance of intellectual, perceptual, behavioral and social abilities. It expresses itself in disturbances in communication and the presence of stereotypic or repetitive behavior. The joke among educators, psychologists and physicians who work with children on the spectrum is "Once you've met a child with autism, you met A child with autism."
First discovered by Dr. Leo Kanner in the early 1940's, he realized that children described as having "infantile schizophrenia" did not, in fact, have schizophrenia, but a developmental disorder that was significantly different. In the 40's and 50's the prevalence of autism was one in ten thousand. Recently (2010) three studies place the prevalence at somewhere between one in 97 to one in 105 or so. There has no doubt been an increase in the number of children per thousand that are born with autism, though improvements in diagnosis may have also have lead to an increase in the number of children diagnosed with the syndrome. Autistic Spectrum Disorders impact many more boys than girls, in a ratio of 4 to 1.
The diagnosis of autism needs to be made by experienced and qualified professionals, not a teacher or psychologist, but by a physician or psychiatrist trained to identify the child's disorder. The diagnosis is based on the Diagnostic and Statistical Manual IV (DSM IV), which was published in 1994 and revised in 2000. A new version, the DSM 5, is slated for publication in May of 2013.
Autism has a profound influence on the function of a child, and parents need to have support to successfully rear a child with autism.
