Autism spectrum disorders (ASD) is three closely-related developmental disabilities of neurobiological origin which result in impaired social function, impaired communication and restrictive, repetative stereotypical interests, activities and behaviors. By definition, ASD manifest by age 3, but often are not diagnosed for several years later. Diagnosis is based on the the "triad of impairment" in accordance with criteria as defined in the DSM-IV. Approximately 1 in 91 children (age 3-17 years old) in the US are affected by the condition. It affects males about 4 times more often than females. There are no significant differences in social-economic classes or ethnic background of those affected. It does affect white, non-hispanic individuals more than black non-hispanics and affects the hispanic population less than the non-hispanic population. The reason for this is not yet well understood and the prevelance between races is small. The cause of ASD is very complex not well understood, although it is believed that there is a genetic connection. The only known risk factors are heredity (children with a sibling with an ASD are more likely to have it themselves) and chromosomal anomolies (children with certain genetic conditions are more likley to be diagnosed with an ASD).
The three disorders comprising ASD are autistic disorder, sometimes referred to as "classic autism," Asperger's syndrome and Pervasive Developmental Disabilities - Not Otherwise Specified (commonly referred to as "PDD-NOS"). The generic terms "autism" and "autistic" may refer to any of the three conditions.
ASD is part of a larger grouping of developmental disorders, known as Pervasive Developmental Disorders (PDD). This grouping also contains childhood disintegrative disorder (CDD) and Rett's Disorder. It is more important for EMS providers to recognize the terms "Autism," "Autistic Disorder," "PDD-NOS" and "Asperger's Syndrome" all refer to Autism Spectrum Disorders than to understand each specific diagnosis. For EMS providers, identifing the patient as having an ASD means modifing your approach and method of "doing business."
