Autism Spectrum Disorder

Definition and Diagnostic Criteria

“Autism Spectrum Disorder” (ASD) is a neurodevelopmental disorder ranging from mild to severe and characterized by core features of social/communication deficits, repetitive/restrictive behaviors and a lack of emotional reciprocity.

The source for understanding the exact nature of ASD is the most recent edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The DSM-5 combines into one category previously distinct but overlapping subtypes (i.e., autistic disorder, Asperger’s disorder and pervasive developmental disorder). While all people with ASD share the core features of the disorder, specific manifestations in developmental, cognitive, emotional and behavioral domains are unique to each individual and should be addressed in any documentation submitted.

Documentation should address diagnostic criteria as outlined in the DSM-5:

1. Persistent deficits in social communication and social interaction across multiple contexts, as manifested by the following, currently or by history (examples are illustrative, not exhaustive; see text):
   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.

1. Restrictive, repetitive patterns of behavior, interests or activities, as manifested by at least two of the following, currently or by history (examples are illustrative, not exhaustive; see text):
   1. Stereotyped or repetitive motor movements, use of objects or speech (e.g., simple motor stereotypies, 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.

1. Symptoms must be present in the early developmental period (but may not become fully manifest until social demands exceed limited capacities, or may be masked by learned strategies in later life).
2. Symptoms cause clinically significant impairment in social, occupational or other important areas of current functioning.
3. These disturbances are not better explained by intellectual disability (intellectual developmental disorder) or global developmental delay. Intellectual disability and autism spectrum disorder frequently co-occur; to make co-morbid diagnoses of autism spectrum disorder and intellectual disability, social communication should be below that expected for general developmental level.

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 ASD, should be evaluated for social (pragmatic) communication disorder.

Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, (Copyright 2013). American Psychiatric Association.

Documenting ASD

Documentation should address relevant domains that provide information concerning the impact of ASD on major life activities as well as on the types of accommodations needed in an academic setting. Evaluators may find it helpful to review ODS’ list of standardized measures for evaluating disability. Additional measures specific to assessing for ASD are included below.

• Autism Diagnostic Observation Schedule – Second Edition (ADOS-2)
• Gilliam Autism Rating Scale – Third Edition (GARS-3)