One of the most frustrating aspects of autism is the inability to explicitly define the disorder. With every case unique, there always seems to be an exception to the rule. There are, however, five general diagnoses as defined by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV).
- Autistic Disorder – this is the type most people think of when they hear the word “autism.” It typically appears before the age of three and is marked by problems with social interaction, communication and imaginative play.
- Asperger’s Syndrome – another commonly known type of autism. Individuals with Asperger’s typically don’t have problems with language, but do struggle with social situations and tend to focus on a limited scope of interests.
- Pervasive Developmental Disorder-Not Otherwise Specified – also known as “atypical autism.” This category encompasses individuals with autistic behaviors who don’t neatly fit into another category.
- Rett Syndrome – individuals develop normally, and then begin losing communication and social skills at 6 to 18 months. The disorder is more common in girls.
- Childhood Disintegrative Disorder – individuals develop normally until they are two or more years old, and then begin to lose communication and social skills.
Within each diagnosis, an individual may also be considered high- or low-functioning, based on their level of cognitive abilities. Those with near- to above-average abilities have “high-functioning” autism.
These various “types” of autism help us understand different characteristics and levels of the spectrum. Yet, it is important to recognize that grey areas exist, as well as the difficulty of precisely defining such a wide spectrum of disorders.