What is the ADOS (Autism Diagnostic Observation Schedule)?

The Autism Diagnostic Observation Schedule-Second Edition (ADOS-2) is a standardized assessment tool that helps providers diagnose autism spectrum disorders (ASD) in children and adults.  The ADOS involves a semi-structured play or interview session determined by the age and communication level of the individual.

The ADOS provides standardized activities and questions that give the examiner opportunities to observe behaviors that are directly relevant to the diagnosis of ASD. The ADOS-2 incorporates the use of planned social activities designed for different developmental levels and chronological ages that provide situations in which social interactions, communication and particular types of behaviors are likely to appear.

The examiner chooses from five different modules depending on age (12 months through adulthood), language and developmental level. The assessment usually takes 40 - 60 minutes to complete. The examiner scores the ADOS-2 based on observations noted during the session on several aspects of social behavior. The score on the ADOS-2 indicates whether or not the individual’s presentation is consistent with a diagnosis of an ASD. 

Although widely used in research because of its standardization, the ADOS requires clinical judgment from a professional with ASD expertise when making a diagnosis. It is common to make an ASD diagnosis without use of the ADOS; the ADOS is an additional tool that can be completed as needed.

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