Autism Spectrum Disorders

Updated on Dec 23, 2009

Autism was first described in 1943 by child psychiatrist Leo Kanner. About fifty years later, in 1991, autism became its own eligibility category for special education services. Until the end of the twentieth century, autism was considered a low incidence disability. Over the years, research resulted in a broader definition of autism as well as better trained professionals who had increased knowledge and reliable tools to identify children with autism in the preschool years. Autism is recognized as a relatively common developmental disorder, more prevalent than childhood cancer, diabetes, and Down syndrome. Classroom teachers as well as school psychologists can expect to work with children with autism and related disorders.


Autism is a neurodevelopmental disorder defined by behaviors rather than by medical tests. That is, there are no blood tests, brain scans, or medical procedures available to identify autism. Instead, a diagnosis is based on observation of social and communication behaviors that take into account a spectrum of symptom expression which ranges from severe to mild and also varies with age and developmental level. Autism is a retrospective diagnosis, and in order to make a differential diagnosis, careful assessment of developmental history is essential. Finally, the complexity of diagnostic assessment of autism is increased because it frequently occurs in association with other syndromes and developmental disabilities, such as Down syndrome, fragile X, and intellectual disability. Research suggests that the prevalence of autism may be about 1 in 600 children and when combined with related disorders, the incidence increases to about 1 in about 160 (Chakrabarti & Fombonne, 2001).


The Diagnostic and Statistical Manual of Mental Disorders, Text Revision (4th ed., DSM-IV-TR; American Psychiatric Association, 2000) describes the diagnostic criteria for pervasive developmental disorders (PDDs) used by medical personnel. PDD is an umbrella term that includes the diagnosis of autism as well as four other

Autistic children and their teachers working on an art projectAutistic children and their teachers working on an art projectAP IMAGES.

PDDs. The DSM is independent from the classification system established by State Departments of Education. Although autism has been defined in the Individuals with Disabilities Education Act (IDEA; 1997), classification criteria may vary considerably from state to state as states execute their own discretion in developing special education eligibility criteria using IDEA criteria as the minimal standard (see Table 1). Some states use DSM-IV criteria, and other states use their own criteria.


The PDDs have some features in common. But of the five PDDs, three have the most overlap with one another— autistic disorder, Asperger disorder (AD), and pervasive developmental disorder not otherwise specified (PDD-NOS). The shared social impairments are the hallmark features of the PDDs that distinguish them from other childhood disorders. Also, instead of the term PDD, some researchers advocate for the term Autism spectrum disorder (ASD) to emphasize both the shared overlap and lack of clear distinctions between these PDDs and the fact that these children often benefit from the same services (Lord & Risi, 2001) even though AD and PDD-NOS are not recognized as independent special education eligibility categories. If a student is performing well academically, problems with social interaction with peers and pragmatic language use should be addressed in educational programs. These skills are critical for success on the job after high school. Therefore, it is suggested that these students be classified under autism for educational purposes (Schopler, 1998). The DSM-IV-TR criteria are presented below.


Although autism becomes evident within the first three years of life, it often remains undiagnosed until 4 years of age. This delay is unfortunate because research indicates that children can be identified reliably before 3 years of age (Lord, 1995; Stone, 1999), and an early diagnosis is critical because it allows the child the opportunity to obtain specialized early intervention services that have been shown to result in significant developmental gains (NRC, 2001).

The first component of the definition of autism, social impairment, is characterized by significant impairment in at least two of the following four areas: (a) coordinated use of nonverbal behaviors to regulate social and communicative interactions (e.g., eye-to-eye gaze, gestures, facial


expressions); (b) development of peer relationships appropriate to the child's developmental level; (c) active pursuit of shared enjoyment, interests, and achievements with others; and (d) establishment of social and emotional reciprocity (e.g., the ability to engage in social play for older children or peek-a-boo for younger children).

The second feature of autism, impaired communication, is characterized by significant impairment in at least one of the four areas: (a) problems in development of spoken language (also accompanied by a lack of compensation through other modes of communication such as gestures); (b) inability to initiate or sustain a conversation with others in individuals with spoken language; (c) the presence of stereotyped and repetitive use of language or idiosyncratic use of language (e.g., repetition of words or phrases without regard to meaning); and (d) a lack of varied, spontaneous make-believe play or social imitative play consistent to the child's developmental level.

The third and final area of impairment is restricted, repetitive, and stereotyped patterns of behavior interests, and activities in at least one of the following four areas: (a) preoccupation with one or more stereotyped and restricted patterns of interest that is abnormal in intensity or focus; (b) inflexible adherence to specific nonfunctional routines or rituals; (c) stereotyped and repetitive motor mannerisms; and (d) a persistent preoccupation with parts of objects.

In addition to meeting the criteria described above, the child must also demonstrate abnormal functioning in at least one of the following areas prior to 3 years of age: (a) social interaction; (b) language as used in social communication; and (c) symbolic or imaginative play.


In the early 2000s debate continued whether Asperger disorder (AD) can be distinguished from high functioning autism (children with autism who do not have cognitive impairment) (Klin & Volkmar, 1997; Schopler, 1998). In order to meet criteria for AD, the child must


demonstrate impairments in two of the areas previously described for autistic disorder: (a) social interaction and (b) restricted, repetitive patterns of behavior, interests, and activities. The child must not demonstrate any clinically significant general delay in language and should use single words by age 2 and communicative phrases by age three. In addition, the child also must not exhibit any significant delay in cognitive development or adaptive behavior (except for social interaction), and show curiosity about the environment in childhood.


Pervasive developmental disorder not otherwise specified (PDD-NOS) is diagnosed when a child does not meet criteria for autism because of late age at onset, atypical symptomatology, or subthreshold symptomatology. Children with PDD-NOS do demonstrate the (a) social impairments and either (b) communication impairments or (c) restricted, repetitive patterns of behavior, interests, and activities.

The other two PDDs, childhood disintegrative disorder (CDD) and Rett disorder, are degenerative disorders, a feature not present in the other PDDs. Table 2 provides a brief comparison between the most related of the ASDs.



The development of appropriate and specialized intervention programs begins with a diagnostic assessment. One issue that may pose a barrier for children obtaining a diagnosis is the presumed stigma of labeling. Ideally, a label facilitates communication among professionals and families, allows access to intervention services, provides a basis for research and prevention, leads to appropriate treatment planning and intervention, and provides a framework for gathering information on outcome, etiology, and associated problems. Most importantly, a label allows teachers as well as parents to become informed. It gives professionals and families the basis to gather information, read, join support groups, advocate, and become organized in their efforts to obtain resources and improve outcomes. From the point of view of many helping professionals, the benefits of a diagnosis/identification far outweigh the liabilities.

Assessment of the characteristic features of autism— social and communication impairments and restricted patterns of behaviors and interests—require varied assessment approaches. Two gold standard tools are the Autism Diagnostic Observation Schedule (ADOS-G; Lord, Rutter, DiLavore, & Risi, 1999) and the Autism Diagnostic Interview (ADI-R: Lord, Rutter, & Le Cou-teur, 1994). The ADOS-G is a child interaction assessment and the ADI-R is a parent interview.

Social assessment consists of two main strategies: structured and unstructured observation and parent interview. In the very young child, the social impairments may be expressed by reduced play in baby games such as peek-a-boo; reduced attempts to draw attention to themselves for the purpose of showing off to adults; reduced ability to imitate vocal sounds, body movements, and actions with objects; and reduced ability to point to objects, show objects, and follow an adult's point to objects for purely social reasons.


Communication assessment consists of informal and formal testing, observational assessment, and parent interview. Assessment should also include information on the child's functional communication abilities, that is on the forms (how child communicates), the functions or purposes (what child communicates), and the contexts (where and with whom child communicates) of communication. Young children with autism demonstrate difficulty understanding and using nonverbal means, such as gestures, to communicate. Children with autism who have verbal speech may exhibit both the difficulty understanding the meaning of words and phrases (semantics) and using communication in a functional manner with others (pragmatics).

Assessment of repetitive behaviors and restricted range of activities and interests is best conducted by parent interview and observations. Resistance to change in environment and new routines and an insistence on following familiar routines characterize these behaviors. Parents can provide information on the child's narrow interests and unusual attachment to objects. Often sensory input that incorporates a visual, auditory, tactile, olfactory, or motor component is either excessively sought or strongly avoided. An example of a visual interest is a child who enjoys spinning objects, twirling, and watching fans or objects that rotate. The stereotypic behaviors of these children include jumping up and down and hand flapping when excited, flipping fingers in front of their eyes, and rocking their body.


Education is considered one of the primary methods of intervention for ASD (NRC, 2001). Recognizing its critical role in the education and treatment of children with autism, the U.S. Department of Education's Office of Special Education Programs requested the National Research Council to report on the scientific evidence regarding educational interventions for young children with autism (from three to eight years) (see Table 3). The NRC also provided guidelines on content areas critical in the educational plans of students with autism (see Table 4).

Several types of teaching strategies have been evaluated for children with autism. These methods include structured teaching (Schopler, Mesibov, and Hearsey, 1995), incidental teaching (McGee, Morrier, & Daly, 1999), discrete trial training (Smith, Eikeseth, Klevstrand, & Lovaas, 1997), pivotal response training (Koegel, Koe-gel, Shoshan, & McNerney, 1999), and functional communication training (Carr, 1993). All of these approaches are research supported and represent systematic and plan-ful teaching techniques designed to increase desired behaviors, decrease undesirable behaviors, and teach new skills. Applied behavior analysis (ABA) is a framework that takes these techniques into account. No single teaching method, however, has been reported as of the early 2000s as being more effective than any other approach; in fact, all have demonstrated effectiveness, and it is likely that a multi-component approach is most effective. Regardless of which approach is selected, it is essential to first generate treatment goals based on the results of individualized assessments of the child's various areas of development and make adjustments of the treatment goals and methods based on the child's progress.


Not all children respond the same way to the same intervention. Children have individual learning styles and preferences and respond differently to various research supported approaches. The selection of an intervention must be based on individualized assessment of needs and ongoing monitoring of progress. It is not uncommon for a teacher to use many different methods to meet the needs of the children in the room (i.e., discrete trial, incidental teaching, and structured teaching).

The unique issues of autism require specialized planning on the IEP. The social and communication deficits in autism are often accompanied by intellectual impairment or issues with thinking and learning that often require the explicit teaching of skills that other children typically pick up naturally. These issues require that close attention be paid to the sequence of skills being taught and ensure that one skill builds upon another (Smith & Slattery, 1993).

Some teachers experience frustration understanding and managing the behavior of students with autism. They find that discipline strategies that work for other students do not work for these students. When confronted with challenging behaviors, it is necessary to consult a specialist in autism and behavior. The specialist can provide a functional behavioral analysis (FBA) to develop positive behavior supports. If problem behaviors are interfering with educational participation, it is necessary to have an FBA and a positive behavior support plan as part of the IEP.

School personnel have tools available to identify students with autism and select and implement effective teaching plans. The success of a teaching plan, however, depends on the quality of the teacher-student interaction as well was a teacher's ability to engage the student. Engagement is a key factor in an effective program (NRC, 2001), and research shows that both child and environmental factors influence engagement (Ruble & Robson, 2007). Establishing a collaborative relationship with former teachers of these children, their parents, and autism specialists is essential for optimal educational experiences and outcomes.


American Psychiatric Association. (2000). Diagnostic and statistical manual of mental disorders (4th ed., Test Revision ed.). Washington, DC: American Psychiatric Association.

Carr, E. (1993). Reduction of severe behavior problems in the community using a multicomponent treatment approach. Journal of Applied Behavior Analysis, 26(2), 157–172.

Chakrabarti, S., & Fombonne, E. (2001). Pervasive developmental disorders in preschool children. Journal of the American Medical Association, 285(24), 3093–3099.

Klin, A., & Volkmar, F. (1997). Asperger's syndrome (2nd ed.). New York: Wiley.

Koegel, L., Koegel, R., Shoshan, Y., & McNerney, E. (1999). Pivotal response intervention II: Preliminary long-term outcome data. Journal of the Association of Persons with Severe Handicaps, 24(3), 186–198.

Lord, C. (1995). Follow-up of two-year-olds referred for possible autism. Journal of Child Psychology and Psychiatry, 36(8), 1365–1382.

Lord, C., & Risi, S. (1998). Frameworks and methods in diagnosing autism spectrum disorders. Mental Retardation and Developmental Disabilities Research Review, 4(2), 90–96.

Lord, C., & Risi, S. (2001). Diagnosis of autism spectrum disorders in young children. In A. W. B. Prizant (Ed.), Autism Spectrum Disorders (Vol. 9, pp. 11–30). Baltimore: Brookes.

Lord, C., Rutter, M., & Le Couteur, A. (1994). Autism diagnostic interview-revised: A revised version of a diagnostic interview for caregivers of individuals with possible pervasive developmental disorders. Journal of Autism and Developmental Disorders, 24(5), 659–685.

McGee, G. G., Morrier, M. J., & Daly, T. (1999). An incidental teaching approach to early intervention for toddlers with autism. Journal of the Association for Persons with Severe Handicaps, 24(3), 133–146.

National Research Council. (2001). Educating children with autism. Washington, DC: National Academy Press.

Ruble, L., & Robson, D. (2007). Individual and environmental influences on engagement. Journal of Autism and Developmental Disorders, 37, 1457–1468.

Schopler, E. (1998). Premature popularization of Asperger syndrome. In G. M. E. Schopler (Ed.), Asperger syndrome or high-functioning autism? (pp. 385–400). New York: Plenum.

Schopler, E., Mesibov, G., & Hearsey, K. (1995). Structured teaching in the TEACCH system. In E. Schopler, & Mesibov, G. (Ed.), Learning and cognition in autism (pp. 243–268). New York: Plenum.

Smith, T., Eikeseth, S., Klevstrand, M., & Lovaas, O. (1997). Intensive behavioral treatment for preschoolers with severe mental retardation and pervasive developmental disorder. American Journal Mental Retardation, 102(3), 238–249.

Smith, S. W., & Slattery, W. J. (1993). Developing individualized education programs that work for students with autism. Added Focus on Autistic Behavior, 8, 1–15.

Stone, W., Lee, E., Ashford, L., Brissie, J., Hepburn, S., Coonrod, E., et al. (1999). Can autism be diagnoses accurately in children under three years? Journal of Child Psychology and Psychiatry, 40, 219–226.

U. S. Department of Education. (1997). Individuals with Disabilities Education Act Amendment of 1997, P.L. 105–117. Washington, DC: Author.

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