Anxiety Disorders Interview Schedule–Autism Addendum: Reliability and Validity in Children With Autism Spectrum Disorder

Abstract

Assessing anxiety in autism spectrum disorder (ASD) is inherently challenging due to overlapping (e.g., social avoidance) and ambiguous symptoms (e.g., fears of change). An ASD addendum to the Anxiety Disorders Interview Schedule–Child/Parent, Parent Version (ADIS/ASA) was developed to provide a systematic approach for differentiating traditional anxiety disorders from symptoms of ASD and more ambiguous, ASD-related anxiety symptoms. Interrater reliability and convergent and discriminant validity were examined in a sample of 69 youth with ASD (8–13 years, 75% male, IQ = 68–143) seeking treatment for anxiety. The parents of participants completed the ADIS/ASA and a battery of behavioral measures. A second rater independently observed and scored recordings of the original interviews. Findings suggest reliable measurement of comorbid (intraclass correlation = 0.85–0.98, κ = 0.67–0.91) as well as ambiguous anxiety-like symptoms (intraclass correlation = 0.87–95, κ = 0.77–0.90) in children with ASD. Convergent and discriminant validity were supported for the traditional anxiety symptoms on the ADIS/ASA, whereas convergent and discriminant validity were partially supported for the ambiguous anxiety-like symptoms. Results provide evidence for the reliability and validity of the ADIS/ASA as a measure of traditional anxiety categories in youth with ASD, with partial support for the validity of the ambiguous anxiety-like categories. Unlike other measures, the ADIS/ASA differentiates comorbid anxiety disorders from overlapping and ambiguous anxiety-like symptoms in ASD, allowing for more precise measurement and clinical conceptualization. Ambiguous anxiety-like symptoms appear phenomenologically distinct from comorbid anxiety disorders and may reflect either symptoms of ASD or a novel variant of anxiety in ASD.

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ACKNOWLEDGMENTS

We acknowledge the contributions of the many research coordinators, scientists, students, and clinicians who supported this study, including Erika Crawford, Roger Mercado, Brigid Garvin, John Danial, Alexandra Hoff, Jane Mutch, Elana Kagan, Adam Lewin, Nicole McBride, Sophie Palitz, Sami Klebanoff, Cori Fujii, Hannah Frank, Mark Knepley, Elizabeth Gosch, and Craig Newschaffer.

FUNDING

This work was supported by grant funding from Autism Science Foundation (Kerns) and NICHD (Kerns K23 HD 087482; Wood, Kendall, Storch R01 HD 080097).

DISCLOSURES

Dr. Kendall has received royalties from the sale of materials regarding the treatment of anxiety, and his spouse has an interest and has received payment from the publishing of some of these materials. Dr. Storch receives research support from NIH, Agency for Healthcare Research and Quality, International OCD Foundation, and All Children’s Hospital Research Foundation. He has received royalties from Elsevier Publications; Springer Publications; American Psychological Association; Wiley, Inc.; and Lawrence Erlbaum. He is a consultant for Prophase, Inc. and Rijuin Hospital, China. Dr. Storch is on the Speaker’s Bureau and Scientific Advisory Board for the International OCD Foundation. He receives research support from the All Children’s Hospital Guild Endowed Chair.

Dr Kerns receives research support from NIH, Autism Science Foundation, Pershing Charitable Trust and Adelphi University’s Center for Health Innovation. She has also received honoraria from Elsevier Publications.