These are the most used for assessment of ASD

Diagnostic Assessment


Autism Diagnostic Interview - Revised


The Autism Diagnostic Interview-Revised (ADI-R) is a semi-structured, investigator-based interview for caregivers of children and adults for whom autism or pervasive developmental disorders is a possible diagnosis. Two studies (Lord, Rutter, R LeCouteur, 1994; Lord, Storoschuk, Rutter, R Pickles, 1993) were conducted to assess the psychometric properties of the ADI-R. Reliability was tested among 10 autistic (mean age 48.9 months) and 10 mentally handicapped or language-impaired children (mean age 50.1 months), and validity was tested among an additional 15 autistic and 15 nonautistic children. Results indicated the ADI-R was a reliable and valid instrument for diagnosing autism in preschool children. Inter-rater reliability and internal consistency were good, and inter-class correlations were very high.


A standard diagnostic interview is conducted at home or in a clinic. The ADI-R is considered by some professionals in the field as a measure of high diagnostic accuracy. It takes several hours to administer and score. The ADI-R is recognized as one of the better standardized instruments currently available for establishing a diagnosis of autism. It is a semi-structured interview administered to subjects' caregivers which determines whether or not an individual meets the Diagnostic and Statistical Manual of Mental Disorders (3rd ed., revised) criteria for autism. The authors of the ADI-R plan to update the scoring procedure so it reflects DSM-IV criteria. The assessment begins with a home visit by a therapist who interviews the child's parents. A home visit provides a chance to meet the child and to get a sense of the parents' priorities. This interview may be scheduled as part of the in-clinic assessment (Rutter, Lord, & LeCouteur, 1990).


Prelinguistic Autism Diagnostic Observation Schedule


The Prelinguistic Autism Diagnostic Observation Schedule (PL-ADOS) (DiLavore, Lord, & Rutter, 1995) is a semi-structured observation scale for diagnosing children who are not yet using phrase speech and who are suspected of having autism. The scale is administered to the child with the help of a parent. This instrument provides an opportunity to observe specific aspects of the child's social behavior, such as joint attention, imitation, and sharing of affect with the examiner and parent. PL-ADOS scores are reported to discriminate between children with autism and children with nonautistic developmental disabilities. The resulting diagnostic algorithm is theoretically linked to diagnostic constructs associated with International Classification of Diseases (10th revision) and DSM-IV criteria for autism.


Childhood Autism Rating Scale


The Childhood Autism Rating Scale (CARS) was developed by the Treatment and Education of Autistic and Related Communication Handicapped Children (TEACCH) program staff in North Carolina to formalize observations of the child's behavior throughout the day. This 15-item behavior-rating scale helps to identify children with autism and to distinguish them from developmentally disabled children who are not autistic. Brief, convenient, and suitable for use with any child older than two years of age, the CARS makes it much easier for clinicians and educators to recognize and classify autistic children. Developed over a 15-year period, with more than 1,500 cases, CARS includes items drawn from five prominent systems for diagnosing autism. Each item covers a particular characteristic, ability, or behavior. After observing the child and examining relevant information from parent reports and other records, the examiner rates the child on each item. Using a seven-point scale, he or she indicates the degree to which the child's behavior deviates from that of a normal child of the same age. A total score is computed by summing the individual ratings on each of the 15 items. Children who score above a given point are categorized as autistic. In addition, scores falling within the autistic range can be divided into two categories: mild-to-moderate and severe. Professionals who have had only minimal exposure to autism can easily be trained to use CARS. Two training videos showing how to use and score the scale are available from Western Psychological Services (WPS) (Schopler, Reichler, DeVellis, & Daly, 1988; Schopler, Reichler, & Renner, 1986).