Is There More Than One Type of Autism?

Autism is a spectrum disorder, meaning that the symptoms and characteristics of autism can present themselves in a wide variety of combinations, from mild to severe. Although autism is defined by a certain set of behaviors, children and adults can exhibit any pattern of behaviors to any degree of severity. Two children, both diagnosed with autism, can act very differently from one another.
Professionals utilize a diagnostic handbook, the Diagnostic and Statistical Manual, now in its fourth edition (DSM-IV). Autism falls under the category of Pervasive Developmental Disorders.

Other disorders which are classified as Pervasive Developmental Disorders include:

CDD and Rett’s Disorder occur rarely in the general population. More common is PDD-NOS, in which the child has some of the symptoms of autism, but does not fully meet the criteria for Autistic Disorder. Asperger’s Disorder is often referred to as “high functioning autism.” This is a misnomer. The difference between high functioning autism and Asperger’s is that early language development in children with Asperger’s is mostly typical, while language development is delayed or deviant in children with autism.

Some diagnosticians use terms not in the DSM-IV, such as “autistic like”, “learning disabled with autistic tendencies”,” autistic traits”, etc. These labels do not describe differences between the children as much as they indicate differences between the professionals’ training, vocabulary, and exposure to autism.