Clinical Testing and Diagnosis for Autism Spectrum Disorder

Key points

  • Diagnosing autism spectrum disorder (ASD) usually relies on two main sources of information: parents' or caregivers' descriptions of their child's development and a professional's observation of the child's behavior.
  • The American Psychiatric Association's Diagnostic and Statistical Manual, Fifth Edition (DSM-5) provides standardized criteria to help diagnose ASD.
Young child playing with colorful blocks

Diagnostic tools

There are many tools to assess ASD in young children, but no single tool should be used as the basis for diagnosis. Diagnostic tools usually rely on two main sources of information—parents' or caregivers' descriptions of their child's development and a professional's observation of the child's behavior.

In some cases, the primary care provider might choose to refer the child and family to a specialist for further assessment and diagnosis. Such specialists include neurodevelopmental pediatricians, developmental-behavioral pediatricians, child neurologists, geneticists, and early intervention programs that provide assessment services.

DSM-5 Diagnostic Criteria for Autism Spectrum Disorder‎

In addition to diagnostic tools, the American Psychiatric Association's Diagnostic and Statistical Manual, Fifth Edition (DSM-5) provides standardized criteria to help diagnose ASD.



Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition

Examples of diagnostic tools

Selected examples of diagnostic tools:

  • The ADI-R is a clinical diagnostic instrument for assessing autism in children and adults. The instrument focuses on behavior in three main areas: reciprocal social interaction; communication and language; and restricted and repetitive, stereotyped interests and behaviors. The ADI-R is appropriate for children and adults with mental ages about 18 months and above.

  • The ADOS-G is a semi-structured, standardized assessment of social interaction, communication, play, and imaginative use of materials for individuals suspected of having ASD. The observational schedule consists of four 30-minute modules, each designed to be administered to different individuals according to their level of expressive language.

  • The CARS is a brief assessment suitable for use with any child over 2 years of age. The CARS includes items drawn from five prominent systems for diagnosing autism; each item covers a particular characteristic, ability, or behavior.

  • The GARS-2 assists teachers, parents, and clinicians in identifying and diagnosing autism in individuals ages 3 through 22. It also helps estimate the severity of the child's disorder.

Diagnostic criteria for autism spectrum disorder

The American Psychiatric Association's Diagnostic and Statistical Manual, Fifth Edition (DSM-5) provides standardized criteria to help diagnose ASD.

Meeting Diagnostic Criteria for ASD (DSM-5)‎

To meet diagnostic criteria for ASD according to DSM-5, a child must have persistent deficits in each of three areas of social communication and interaction (see A.1. through A.3. below) plus at least two of four types of restricted, repetitive behaviors (see B.1. through B.4. below).

  1. Deficits in social-emotional reciprocity, ranging, for example, from abnormal social approach and failure of normal back-and-forth conversation; to reduced sharing of interests, emotions, or affect; to failure to initiate or respond to social interactions
  2. Deficits in nonverbal communicative behaviors used for social interaction, ranging, for example, from poorly integrated verbal and nonverbal communication; to abnormalities in eye contact and body language or deficits in understanding and use of gestures; to a total lack of facial expressions and nonverbal communication
  3. Deficits in developing, maintaining, and understanding relationships, ranging, for example, from difficulties adjusting behavior to suit various social contexts; to difficulties in sharing imaginative play or in making friends; to absence of interest in peers

Specify current severity:

Severity is based on social communication impairments and restricted, repetitive patterns of behavior. For either criterion, severity is described in 3 levels:A

  • Level 3—Requires very substantial support
  • Level 2—Requires substantial support
  • Level 1—Requires support

  1. Stereotyped or repetitive motor movements, use of objects, or speech (e.g., simple motor stereotypes, lining up toys or flipping objects, echolalia, idiosyncratic phrases).
  2. Insistence on sameness, inflexible adherence to routines, or ritualized patterns of verbal or nonverbal behavior (e.g., extreme distress at small changes, difficulties with transitions, rigid thinking patterns, greeting rituals, need to take same route or eat same food every day).
  3. Highly restricted, fixated interests that are abnormal in intensity or focus (e.g., strong attachment to or preoccupation with unusual objects, excessively circumscribed or perseverative interests).
  4. Hyper- or hyporeactivity to sensory input or unusual interest in sensory aspects of the environment (e.g., apparent indifference to pain/temperature, adverse response to specific sounds or textures, excessive smelling or touching of objects, visual fascination with lights or movement).

Specify current severity:

Severity is based on social communication impairments and restricted, repetitive patterns of behavior. For either criterion, severity is described in 3 levels:A

  • Level 3—Requires very substantial support
  • Level 2—Requires substantial support
  • Level 1—Requires support

Note:

  • Individuals with a well-established DSM-IV diagnosis of autistic disorder, Asperger's disorder, or pervasive developmental disorder not otherwise specified should be given the diagnosis of autism spectrum disorder. Individuals who have marked deficits in social communication, but whose symptoms do not otherwise meet criteria for autism spectrum disorder, should be evaluated for social (pragmatic) communication disorder.

Specify if:

  • With or without accompanying intellectual impairment
  • With or without accompanying language impairment
  • Associated with a known medical or genetic condition or environmental factor
    • Coding note: Use additional code to identify the associated medical or genetic condition.
  • Associated with another neurodevelopmental, mental, or behavioral disorder
    • Coding note: Use additional code[s] to identify the associated neurodevelopmental, mental, or behavioral disorder[s].
  • With catatonia (refer to the criteria for catatonia associated with another mental disorder)
    • Coding note: Use additional code 293.89 catatonia associated with autism spectrum disorder to indicate the presence of the comorbid catatonia.
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Content Source:
National Center on Birth Defects and Developmental Disabilities
  1. American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 5th ed. Arlington, VA: American Psychiatric Association; 2013.
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