Impact Feature Issue on Supporting Success in School and Beyond for Students with Autism Spectrum Disorders

Autism Spectrum Disorders: Definitions and Implications


Travis Thompson is Professor in the Department of Pediatrics, University of Minnesota School of Medicine, Minneapolis.

Autism (Early Childhood Autism) was first described by Leo Kanner in 1943 in a paper titled, Autistic Disturbances of Affective Contact.Kanner captured the three core features of what later came to be called Autism Spectrum Disorders (ASDs): disturbances of social relationships, limited use of language to communicate, and fixed repetitive interests and routines (Kanner, 1943). In 1994, the American Psychiatric Association provided a new definition in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), recognizing Autism as a family of related neurodevelopmental disabilities with degrees of disability (APA 1994/2000).

Autism Spectrum Disorders include Autistic Disorder, Pervasive Developmental Disorder Not Otherwise Specified, and Asperger’s Disorder. Autistic Disorderinvolves a combination of impairment in social interaction and in communication, and restricted repetitive patterns of behavior, interests, and activities, with an onset prior to 36 months of age. Autistic Disorder differs from Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS) in that repetitive stereotyped behavior is not necessary for a PDD-NOS diagnosis, but is necessary for an Autistic Disorder diagnosis. Asperger’s Disorderis an Autism Spectrum Disorder first identified by Hans Asperger in 1944. Individuals with Asperger’s Disorder have impairment in social interactions, restricted and stereotyped interests that cause limitations in social and other areas of functioning, but with no significant language or cognitive development delay, nor lack of age-appropriate self-help skills (Asperger, 1944). Individuals with Asperger’s Disorder often have a pedantic, literal way of speaking and narrow interests.

Some children appear to be developing relatively typically, but around two years of age lose skills, including language and social skills. This is called Regressive Autism.Though there are theories about the cause of Regressive Autism, there is no compelling evidence of what causes the regression. Because many children who develop Autism (including those with regressive Autism) exhibit social differences within the first year of life, it is possible the causes of Autism are present at birth, but skill loss progresses rapidly around two years.

Judith Miles at the University of Missouri identified two major categories of Autism that may be important for understanding the multiplicity of causes: Essential and Complex (Miles et al., 2005). Complex Autism includes individuals for whom there is evidence of abnormal early embryonic development, with either differences in physical appearance or small head size. The remainder have Essential Autism. Complex Autism accounts for 20% of the Autism population. Individuals with Complex Autism tend to have lower IQs, more seizures, more abnormal EEGs, and more brain MRI differences. Essential Autism appears to be inherited, occurring in individuals who have more relatives with Autism and at a higher male to female ratio. Individuals with Essential Autism have fewer seizures and are more apt to develop Autism with a regressive onset.

Intensive early intervention studies indicate that about half of children with an ASD diagnosis overcome many of the language and social skills deficits that limit their participation with their families, schools, and communities by the time they enter kindergarten or first grade (Sallows & Graupner, 2005). These rapidly-learning children function intellectually within the typical range and are integrated in regular education classrooms. Many continue to display subtle language and social differences, but participate meaningfully in school and in their communities. Children with lower entry IQ, no language, and lack of joint attention or imitation tend to learn less rapidly during early intervention and profit more from a functional curriculum and augmentative communication.

As children with ASDs progress through middle and high school, academic and social challenges may require accommodations and adapted curricula. For example, youth with Asperger’s Disorder or high functioning Autism may read words and sentences well, but comprehension requiring inferential reasoning may create limitations, requiring adapted assignments. Relationships with peers requiring understanding figures of speech and metaphorical language that is typical of teenagers’ communication often requires support from parents and teachers.

ASDs are complex, and additional research is needed to more fully understand them. Nonetheless, for all students on the Autism spectrum, the presence of appropriate supports in school, home, and community settings – supports based on the best available knowledge about ASDs and on individual student needs – can create the context for students with ASDs to meaningfully participate in school and in life.


  • American Psychiatric Association (APA). (2000). Diagnostic and statistical manual of mental disorders: DSM-IV-TR (4th edition, text revision). Washington, DC: American Psychiatric Association.

  • Asperger, H. (1944). Die ‘Autistischen Psychopathen’ im Kindesalter, Archiv fur Psychiatrie und Nervenkrankheiten. In U. Frith (1991) (Ed.), Autism and Asperger Syndrome. New York: Cambridge University Press.

  • Kanner, L. (1943). Autistic disturbances of affective contact. Nervous Child, 2, 217–250.

  • Miles, J. H., & et. al. (2005). Essential versus complex Autism: Definition of fundamental prognostic subtypes. American Journal of Medical Genetics Part A, 135(2), 171–180.

  • Sallows, G. O., & Grraupner, T. D. (2005). Intensive behavioral treatment for children with Autism: Four-year outcome and predictors. American Journal on Mental Retardation, 110, 417–438.