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Gilliam Asperger’s Disorder Scale

James E. Gilliam, Ph.D.


The GADS has been particularly noted for its ability to distinguish Asperger Disorder from Autistic Disorder. Suitable for individuals between the ages of 3 and 22, the GADS provides documentation about the essential behavior characteristics necessary for diagnosis and can be used to document behavioral progress, to target goals for Individualized Education Programs (IEP), and for research purposes.

How to Use the Assessment
The GADS forms take only 5 to 10 minutes to complete and are to be completed by a parent and clinician or teacher—someone with ample opportunity to observe the child. Behaviors are rated using objective, frequency-based ratings.

GADS Characteristics:
  • Thirty-two items divided into four subscales depict specific, observable, and measurable behaviors 
  • The addition of two- and three-dimensional drawings for older children and adults–drawings that can reveal subtle visual-motor integration deficits.
  • A completely nonverbal format that makes the test appropriate for individuals from all cultural and ethnic backgrounds.
  • Eight additional items are included so that parents can contribute information about their child's development during the first 3 years of life.
  • Items are founded on the most up-to-date definitions of Asperger's Disorder.
  • The GADS was normed on 371 representative subjects with Asperger's Disorder from 27 states, the District of Columbia, Canada, and Australia.
  • The scale can be completed at home or school by parents and professionals.
  • Both validity and reliability support the test's stated purpose.
  • Behaviors are rated using objective, frequency-based ratings.
  • Percentiles and standard scores are provided.
  • A table is provided for determining the likelihood that a subject has Asperger's Disorder.
  • A list of journals, books, media, Internet sites, and organizations concerned about Asperger's Disorder are provided to give teachers, parents, and others information about Asperger's Disorder.
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Scales & Forms

  • Asperger's Disorder
  • Restricted Patterns
  • Social Interaction
  • Pragmatic Skills
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James E. Gilliam, Ph.D.

Age Range 3 to 22 years

Administration Time 5–10 minutes

Administration Type

  • Parent-completed
  • Clinician/Teacher-completed
Qualification Level B

Format Handscored