Chapter II - Background: Understanding Autism



Since the 1980's, we have gained a better understanding of the broad diagnostic category that includes autism and autism-like disorders. Autistic Disorder (autism) is now believed to represent only one part of a clinical spectrum or group of disorders collectively termed pervasive developmental disorders.

What is Autism?

Autism is a neurobehavioral syndrome caused by a dysfunction of the central nervous system that leads to disordered development. According to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), published by the American Psychiatric Association (1994, pp. 70-71), the onset of symptoms in autism occurs within the first 3 years of life and includes three general categories of behavioral impairment common to all persons who have autism:

  • qualitative impairments in social interaction
  • qualitative impairments in communication
  • restricted, repetitive, and stereotyped patterns of behavior, interest, and activities

As defined in the DSM-IV, Autistic Disorder (Tables III-1 and III-2 ) is one of the clinical conditions classified within the spectrum of pervasive developmental disorders. Autistic Disorder is distinct from other pervasive developmental disorders such as Rett's disorder or childhood disintegrative disorder, two other distinctive clinical conditions classified within the spectrum of pervasive developmental disorders.

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What Are the Symptoms of Autism?

Children with autism demonstrate the three core symptoms as described in the DSM-IV. The symptoms vary according to the severity of the disorder.

Qualitative impairments in social interaction

Much current research suggests that the lack of reciprocal social interaction is the primary symptom in autism. Sometimes this deficit in social relatedness is noticeable during the first months of life; parents may report that their child has poor eye contact, lacks interest in being held, or stiffens when held. Young children who have autism often do not initiate or sustain play with their peers and often do not take part in groups. They may lack the ability to judge appropriate reactions in social situations; they may not feel anxiety around strangers, or not be aware of how close to stand to someone. As they become adolescents and adults, some children with milder, higher functioning autism may demonstrate relatively normal social interactions, but they still "tend to show a lack of cooperative group play, failure to make close friendships, and inability to recognize feelings in others or to show deep affection" (Newson and Havanitz, 1997).

Qualitative impairments in communication

Research suggests that a significant majority of children with autism are not using language for functional communication at the time of their initial diagnosis. Earlier studies suggested that about half of all children with autism remain "functionally mute" throughout their lives, although that may be an overestimate given the effectiveness of current interventions and the broader current definition of autism. Some children with autism initially develop some language and then show language loss or regression, usually during the second year. Others show significant generalized delays in all aspects of language and communication.

When language is present in a young child with autism, it tends to be rote, repetitive, and lacking in apparent communicative intent. Certain unique features of language use are especially characteristic of autism. Children with autism frequently demonstrate echolalia (rote repetition of what has been heard), confusion of personal pronouns (such as referring to self in second or third person), verbal perseveration (repeating certain phrases over and over or dwelling on a single topic), and abnormalities of prosody (rate, rhythm, inflection, or volume of speech). Children who have autism, particularly when younger, often do not use gestures, such as pointing at objects to show shared interest, shaking their head to indicate yes or no, conveying emotion through facial expression, or engaging in pantomime. Lack of these types of early nonverbal communication can provide some of the earliest diagnostic evidence for the presence of autism.

Restricted, repetitive, and stereotyped patterns of behavior, interest, and activities

Most young children who have autism will demonstrate repetitive motor or verbal actions. Children may, for example, flap their hands, bang their heads, rock, pace, spin on their feet, or use repetitive finger movements. In some children, these stereotyped behaviors tend to occur primarily when the child is excited, stressed, or upset. Children with autism also have a tendency to be preoccupied with a small number of activities, interests, or objects. The nature of their play tends to be restricted or repetitive; a child might, for example, prefer to line up cars in identical patterns rather than to play with the cars imaginatively. Some children with autism demonstrate a "compulsive adherence" (DSM-IV) to routines or rituals. This behavior may represent the cognitive inflexibility and preference for sameness that characterize the style of most autistic children.

Are There Symptoms Not Included in the DSM-IV?

A number of other common findings in children with autism do not fit easily into the symptoms described above. These symptoms may include:

Unusual responses to sensory stimuli: Many children with autism, especially when they are young, are either almost oblivious to sound (such as human voices or their own spoken name) or extremely sensitive to certain sounds, even very soft sounds. The same child can have both kinds of responses to sound. Children with autism frequently respond in a similar fashion to visual stimuli; they are attracted to some stimuli and distressed by others. These children may also have similar responses to the other sensory stimuli such as touch, texture, taste, smell, or pain.

Behavior disturbances: Although not specific to autism, certain behavior patterns are often observed. Especially when they are young, children with autism have difficulty attending to topics or activities that they have not chosen. Some children with autism may be considered hyperactive and some may have significant anxiety. Some children may respond to minor changes or frustrations with aggressive outbursts, and some children, particularly those with more severe developmental delays, may have problems with self-injurious behaviors such as head-banging or self-biting.

Cognitive characteristics: Children with autism who have intelligence quotients over 100 have relative strengths in a number of cognitive areas. Even children who are higher functioning, however, have the tendency to think concretely rather than abstractly or symbolically. Some children with autism have "splinter skills," usually involving an aptitude for rote memory or calculation which far exceeds their other skills. A small group of people with autism have "savant skills" such as being able to perform complex mental calculations.

Is There More Than One Type of Autism?

In recent years, the definition of autism has broadened so that autism is now seen as a spectrum disorder. Each case of autism can be placed along a continuum ranging from milder to more severe based on the level of functional skills in areas such as communication, cognitive abilities, social interactions, etc. The majority of specialists believe that the boundaries along that continuum are overlapping and indistinct. Others believe that it is possible to define discrete subgroups within the continuum. For example, the term Pervasive Developmental Disorder – Not Otherwise Specified (PDD-NOS) has been applied in the DSM-IV to milder cases that do not meet the full criteria for Autistic Disorder.

How Common is Autism?

Autism may be more common than previously realized, particularly if the broader definition of autism as a spectrum disorder is used to determine the number of cases. Earlier studies suggested that about three to four children in 10,000 have autism, but more recent studies have suggested higher rates, up to greater than 20 in 10,000. A range of 10-15 per 10,000 is a commonly accepted "middle range" estimate. The higher estimated rates probably reflect inclusion of the broader range of autism, including milder subtypes on the spectrum (PDD-NOS and Asperger disorder). The apparent increase may also be a result of improved diagnosis, but a real increase in prevalence cannot be absolutely ruled out.

Current estimates suggest that there are three to four boys for every girl with autism. The ratio of boys to girls is even greater in cases at the milder end of the spectrum. In cases when autism is associated with more severe mental retardation, however, the ratio of boys to girls is lower (Gillman, 1992).

What Causes Autism?

Many different types of research support the concept that autism is a biologically based developmental disorder. Various types of investigations including imaging studies, electroencephalographic studies, electrophysiologic studies, tissue studies on autopsy material, and neurochemical studies have demonstrated abnormalities in many cases of autism, although a clear pattern has yet to emerge (Bauer, 1995). Recent research, however, is beginning to suggest possible answers to some pieces of the autism puzzle.

Is Autism Associated With Any Other Medical Conditions or Genetic Syndromes?

In some cases, children with autism also have other associated medical conditions or genetic syndromes that are not part of autism but are seen more frequently in children with autism than in the general population. Such associated medical conditions include such things as seizures, muscular dystrophy, and other neurological conditions. Fragile X syndrome is the most common specific genetic disorder that is sometimes associated with the clinical picture of autism.

Rett's disorder, another condition that includes autistic features, is now believed to be a neurological disorder. Autism and autistic symptoms have also been described in some cases of neurocutaneous disorders (especially tuberous sclerosis), metabolic disorders (phenylketonuria, disorders of purine metabolism), intrauterine infections (rubella, cytomegalovirus), and a number of other syndromes (Williams syndrome, Mobius syndrome) (Gillman, 1992). Specific diagnostic approaches are discussed in more detail in Chapter III.

How is Autism Diagnosed?

Arriving at the diagnosis typically involves experienced professionals gathering information about the child's behavior from the parents and from direct observation of the child. In the United States, the current criteria for diagnosing autism and other types of pervasive developmental disorders (PDD) are those given in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV). In New York State, only licensed physicians and licensed clinical psychologists are authorized to make the formal diagnosis of autism.

Establishing a diagnosis is usually only one part of a comprehensive assessment process for a child with possible autism. Recommendations for the appropriate assessment and diagnosis of young children with possible autism are given in Chapter III. That chapter includes specific recommendations for: (1) identification of children with possible autism, (2) establishing a diagnosis, (3) looking for associated developmental and health problems, (4) assessing the child's overall function in all developmental domains, and (5) assessing the child's family and environment.

Assessing children with autism can be complex. Some manifestations of autism are also seen in children who do not have autism but have other conditions such as cognitive delays, language disorders, attention deficit and hyperactivity disorders, and various types of emotional problems. In addition, disorders such as cognitive delays and language problems often coexist with autism.

When or How Early Can Autism Be Diagnosed?

One of the recent developments in the field of autism is an increasing ability to recognize this disorder at a very early age. In most cases, young children (under the age of 3) with autism can now be recognized by their difficulties in orienting to social stimuli, diminished social gaze, and impairments in the areas of shared attention and motor imitation that accompany the language delays that are generally present. It is difficult, however, to make a definitive diagnosis at an early age in some children. It is not yet known with certainty just how early the diagnosis can be made with high reliability or whether very early diagnosis is as accurate or predictive as later diagnosis. Multiple observations may be required, sometimes over an extended period of time, to confirm the diagnosis of autism.

Is There a Prenatal Test For Autism?

There is no genetic test for autism. There are, however, prenatal biological tests for other conditions sometimes associated with autism, such as Fragile X syndrome. The fact that autism is now known often to have a genetic component (with recurrence risk in some studies of up to 7% in siblings) offers hope that prenatal diagnosis or screening may someday be possible (Bailey, 1995).

Who Can Make the Diagnosis?

While the diagnosis of autism may seem fairly apparent in many cases, and many experienced professionals who work with young children may be trained to recognize autism-like behaviors, the practice acts of New York State require that the diagnosis of autism be made only by licensed psychologists and physicians.

What Are the Most Effective Intervention Approaches?

The question of intervention approaches is the most difficult question for families to answer, and one that may change over time, both as the child develops and as we learn more. Parents are advised to engage in ongoing discussions of intervention options and approaches regarding the progress and effectiveness of the current intervention(s). This guideline addresses several approaches, including behavioral, educational, and medical. Specific intervention approaches are discussed in more detail in Chapter IV.

Are There Any Medications Available for Autism?

Most physicians treating children with autism believe the role for medications in autism is quite limited at the present time, especially in young children. Nonetheless, medications have sometimes been helpful in the management of certain specific symptoms associated with autism in some children. None of the available medications, however, can "cure" the symptoms, and none has even had consistently positive effects across large groups of children with autism.

Is There a Cure?

Given that autism is a spectrum disorder with a wide range of presentations and no known specific etiology, it seems less likely that any single cure will be found. Over the years, a variety of interventions have shown promise for improving symptoms of autism in some children.

What is the Prognosis for Children With Autism?

The prognosis for children with autism varies considerably. Traditional estimates suggest that about two-thirds of children diagnosed with autism have an overall poor outcome, as defined by social adjustment, ability to work, and ability to function independently. However, the more recent broader definitions of autism and PDD include many children with milder symptoms for whom the long-term prognosis may well be better. Currently, the majority of children with autism can be expected to continue to need some degree of assistance as adults. A much smaller group, perhaps 10% of cases, seems to have much better outcomes, and may actually seem to "outgrow" their autism and improve to near "normal" functioning. Some data suggest that intensive behavioral approaches, when started at an early age, significantly improve the outcomes for at least some children with autism.

Where Can I Get More Information?

There are many ways to learn more about autism. Several resources are listed in the Appendix. In providing this list of resources, it is important to note as a caution to families and professionals that the guideline panel has not specifically reviewed or endorsed the information provided by the resources identified in the Appendix.

Caution is advised when considering
intervention options that have not
been studied using good scientific
methodology that demonstrates the
effectiveness of the approach.

What Are Some Common Misconceptions About Autism?

Although much has been learned about autism in recent years, there are still some commonly held misconceptions. Those misconceptions may include the following:

Misconception: Autism is a mental illness.
Fact: Autism is a neurologically based disorder of development. It is not considered to be a mental illness.
Misconception: Children with autism are mentally retarded.
Fact: Although mental retardation may frequently coexist with autism, not all children with autism are mentally retarded. The intelligence quotients of children with autism span a range from very low to very high.
Misconception: Children with autism are unruly kids who choose not to behave.
Fact: Certain aggressive behaviors may be symptoms associated with autism. There may be many reasons why certain children with autism sometimes demonstrate disruptive or aggressive behaviors (such as confusion due to language deficits, high anxiety, or low tolerance for change, to name a few) however, these behaviors are generally not "chosen" by the child.
Misconception: Bad parenting causes autism.
Fact: There is no credible evidence that autism can be caused by deficient or improper parenting, contrary to what may have been believed in the past.



  1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), 4th edition. Washington, DC: American Psychiatric Association, 1994, pp. 70-71.
  2. Arvidsson T, Danielsson B, Forsberg P, Gillberg C, Johansson M, Kjellgren G. Autism in 3-6 year old children in a suburb of Goteborg, Sweden. Autism 1997, 1(2): 263-173.
  3. Bailey A, Le Couteur A, Gottesman J, Bolton P, Simonoff E, Yuzda E, Rutter M. Autism as a strongly genetic disorder: Evidence from a British twin study. Psychological Medicine 1995, 25(1): 63-77.
  4. Bailey A, Phillips, W, Rutter M. Autism: Toward integration of clinical, genetic, neuropsychological, and neurobiological perspectives. Journal of Child Psychology and Psychiatry 1996, 37: 89-126.
  5. Bauer S. Autism and the pervasive developmental disorders: Part 1. Pediatrics in Review 1995, 16: 130-136.
  6. Bauer S. Autism and the pervasive developmental disorders: Part 2. Pediatrics in Review 1995, 16: 168-177.
  7. Gillman. The Biology of Autistic Syndromes, 2nd edition. New York, NY: Cambridge University Press, 1992.
  8. Ornitz EM, Guthrie D, Farley A. The early development of autistic children. Journal of Autism and Childhood Schizophrenia 1977, 7: 207-229.
  9. Newsom C, Hovanitz C. Autistic Disorder. In Behavioral Assessment of Childhood Disorders, 3rd edition. Mash EJ, Terdal LG (ed.). New York, NY: Guilford Press, 1997: 408-451.
  10. Ritvo ER, Freeman BJ, Pingree C, Mason-Brothers A, Jorde L, Jenson WR, McMahon WM, Peterson PB, Mo A, Ritvo A. The UCLA-University of Utah epidemiologic survey of autism: Prevalence. American Journal of Psychiatry 1989, 146(2): 194-199.
  11. Rutter M., Greenfeld, D, Lockyer, L. A five to fifteen year follow-up study of infantile psychosis. British Journal of Psychology 1967, 113: 1183-1119.