Are there different types of ASDs? Are some cases of ASD more severe than others?
Within the category of Autism Spectrum Disorder, there are a number of subtypes that are associated with different levels of severity in different areas. Autism is the disorder that has received the most study and has been recognized for the longest time. It is defined by the presence of difficulties in each of the three areas listed above (social deficits, communication problems and repetitive or restricted behaviours), with onset in at least one area by age 3 years. It may or may not be associated with language delays or mental retardation. Asperger Syndrome is a form of ASD that is often identified later (e.g., after age 3, usually after age 5) and is associated with the social symptoms of autism and some repetitive interests or behaviours, but not with language delay or mental retardation. Many parents and professionals use this term with older and/or more verbally fluent individuals with autism because they feel it is less stigmatizing. Rett Syndrome and Child Disintegrative Disor
