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Exploring the Relationship Between Anxiety and Insistence on Sameness in Autism Spectrum Disorders


  • Conflict of Interest Statement: Dr. C. Lord receives royalties from the publisher of the Autism Diagnostic Interview-Revised (ADI-R) and the Autism Diagnostic Observation Schedule (ADOS), described in this paper. She donates all profits generated by the Simons Simplex Collection use of these measures to charity. Drs. Gotham and Bishop will receive royalties from the ADOS-2, the second edition of the measure described here; both plan to donate all proceeds from research use to charity. Drs. Huerta, Lund, Buja, Krieger, and Ms. Hus have no conflicts of interest.
  • This work was supported by:

    Grant Sponsor: The Simons Foundation (SFARI); Grant Number: Not Applicable (Grants to authors K.G., A.B., and A.K.).

    Grant Sponsor: National Institutes of Health; Grant Numbers: T32-MH18921; P30HD15052, R01MH081873-01A1, and RC1MH089721 to C.L.; R01HD065277 to S.B.

Address for correspondence and reprints: Katherine Gotham, 1006 Caldwell Lane, Nashville, TN 37204. Email:


Elevated anxiety symptoms are one of the most common forms of psychopathology to co-occur with autism spectrum disorders (ASDs). The purpose of this study was to explore the association between anxiety and ASD symptoms, particularly the degree to which the relationship is explained by insistence on sameness (IS) behaviors and/or cognitive ability. The sample included 1429 individuals aged 5:8–18:0 years who participated in the Simons Simplex Collection, a genetic consortium study of ASD. Child Behavior Checklist Anxiety Problems T-scores and Autism Diagnostic Interview-Revised “IS“ item raw totals were treated as both categorical and continuous measures of anxiety and IS, respectively. Chronological age, verbal intelligence quotient (IQ), and a variety of ASD phenotype-related and other behavioral variables were assessed for potential association with anxiety and IS. Anxiety and IS continuous variables were minimally, although significantly, associated with each other and with chronological age and verbal IQ. Neither anxiety nor IS was associated with other core autism diagnostic scores. Anxiety was associated with a variety of other psychiatric and behavioral symptoms in ASD, including irritability, attention problems, and aggression, while IS was not. Anxiety and IS appear to function as distinct constructs, each with a wide range of expression in children with ASD across age and IQ levels. Thus, both variables could be of use in ASD behavioral research or in dimensional approaches to genetic exploration. Unlike IS, however, anxiety is related to non-ASD-specific behavioral symptoms. Autism Res 2012, ●●: ●●–●●. © 2012 International Society for Autism Research, Wiley Periodicals, Inc.