Autism Diagnostic Interview-Revised

Autism Diagnostic Interview-Revised. The Autism Diagnostic Interview-Revised is a structured, investigator-based interview designed to assess individuals for a potential diagnosis of autism spectrum disorder. It is considered a gold-standard instrument, often used in conjunction with the Autism Diagnostic Observation Schedule to provide a comprehensive diagnostic evaluation. The interview is administered to a caregiver or parent who is familiar with the individual's developmental history and current behavior, focusing on key diagnostic domains.

Overview

The instrument is a comprehensive diagnostic tool primarily used in clinical research and specialized assessment settings to evaluate the presence and severity of core symptoms associated with autism spectrum disorder. It provides a detailed, standardized method for gathering developmental history, which is crucial for differentiating autism from other developmental conditions such as intellectual disability or language disorder. Its development was spearheaded by researchers including Michael Rutter, Ann Le Couteur, and Catherine Lord, building upon earlier diagnostic frameworks. The assessment is aligned with diagnostic criteria from major classification systems like the Diagnostic and Statistical Manual of Mental Disorders and the International Classification of Diseases.

Development and history

The original Autism Diagnostic Interview was developed in the late 1980s by a team at the Institute of Psychiatry in London, with key contributions from Michael Rutter and Ann Le Couteur. It was revised in the 1990s to create the current version, a process that involved Catherine Lord and her colleagues, enhancing its reliability and alignment with evolving diagnostic concepts. The revision process incorporated extensive field trials and statistical analysis to improve its discriminative validity, particularly for individuals across a wider range of ages and cognitive abilities. This work was supported by research grants from institutions like the Medical Research Council and the National Institutes of Health.

Structure and administration

The assessment is organized into several thematic sections that probe specific behavioral domains, including qualitative abnormalities in reciprocal social interaction, communication, and restricted, repetitive behaviors. Administration involves a trained clinician conducting a semi-structured interview with a caregiver, which typically lasts between one and a half to two and a half hours. The interview contains 93 items that are scored based on detailed coding guidelines, requiring the interviewer to probe for specific examples and clarifications. Proper administration necessitates certification through official training workshops, often provided by organizations like the University of Michigan or Western Psychological Services.

Scoring and interpretation

Scores are generated for three core diagnostic domains: Reciprocal Social Interaction, Communication, and Restricted, Repetitive Behaviors and Interests. A diagnostic algorithm converts item scores into domain totals and an overall total, which are compared against established cut-off points to determine classification. Interpretation involves comparing the individual's profile against these cut-offs for either Autism or the broader Autism Spectrum, as defined in the algorithm corresponding to systems like the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. The results are used to inform a clinical diagnosis but are not solely determinative, requiring integration with other assessments like the Autism Diagnostic Observation Schedule.

Psychometric properties

Extensive research, including studies published in journals like the Journal of Autism and Developmental Disorders and the Journal of Child Psychology and Psychiatry, has demonstrated high inter-rater reliability and test-retest reliability for the instrument. Its validity has been established through strong correlations with clinical diagnosis and other diagnostic measures, showing good sensitivity and specificity in distinguishing autism from other developmental disorders. Psychometric evaluations have been conducted across diverse populations and age groups, though some studies note variations in performance when used with very young children or individuals with profound intellectual disability.

Applications and use

It is predominantly employed in academic research settings, including studies funded by the National Institute of Mental Health, and in specialized clinical centers for diagnosing complex cases. Its detailed nature makes it a valuable tool for phenotyping in genetic studies, such as those conducted by the Simons Foundation or the Autism Genetic Resource Exchange. While less common in general clinical practice due to its length and required training, it remains a cornerstone for establishing diagnosis in major longitudinal studies and treatment trials, such as those coordinated by the Autism Treatment Network.