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Gilliam Autism Rating Scale (GARS)

The Gilliam Asperger’s Disorder Scale (GADS; Gilliam, 2001) is a 32-item questionnaire designed to identify individuals with Asperger’s Disorder.


The tool includes several subscales: Social Interaction, Restricted Patterns, Cognitive Patterns, and Pragmatic Skills. The GADS can be completed by parents/caregivers or teachers. Respondents indicate the frequency of behaviors from “never observed” to “frequently observed.” The GADS includes a parent interview form that inquires about language and cognitive development, self-help skills, adaptive behavior, and curiosity. There is also a section of “key questions” for parents/caregivers to complete.


Author (yr) Age Range (yrs) Method of Administration/Format Approx. Time to Administer Subscales
Gilliam Autism Rating Scale-Third Edition (GARS-3) Gilliam (2013) 3-22

56 items: 6 subscales

Items are based on the DSM-5 diagnostic criteria

Yields standard scores, percentile ranks. severity level, and probability of autism

5-10 min.

Restrictive, Repetitive Behaviors; Social Interaction; Social Communication; Emotional Responses; Cognitive Style; Maladaptive Speech

Screening/Diagnosis: D

Availability: Pro-Ed,


Author (yr) Sample Size Topic(s) Addressed Outcome
Mazefsky & Oswald (2006) 78 - Age Range: 2-8 years Discriminative validity

Mean developmental delay score and mean AU Quotient did not significantly differ

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