Autism is a spectrum disorder. 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 combination of the behaviors in any degree of severity. Two children, both with the same diagnosis, can act very differently from one another and have varying skills/ (Autism Society of America, 2001)
• Asperger’s Disorder – Characterized by impairments in social interactions and the presence of restricted interests and activities, with no clinically significant general delay in language, and testing in the range of average to above average intelligence.
• Pervasive Developmental Disorder (not otherwise specified) – Commonly referred to as atypical autism, a diagnosis of PDD-NOS may be made when a child does not meet the criteria for a specific diagnosis, but there is a severe and pervasive impairment in specified behaviors.
• Rett’s Disorder– A progressive disorder which, to date, has occurred only in girls. Distinguished by a period of normal development and then loss of previously acquired skills, loss of purposeful use of the hands replaced with repetitive hand movements beginning at 1 to 4 years of age.
• Childhood Disintegrative Disorder – Characterized by normal development for at least the first two years, significant loss of previously acquired skills
Source: American Psychiatric Association