Background: Accurate assessment of anxiety symptomatology in autistic children can be difficult, in part due to a lack of appropriate assessment tools. The newly-developed Anxiety Scale for Children with Autism Spectrum Disorder (ASC-ASD) is designed specifically for the assessment of anxiety symptomatology in autistic children. The aim of this study was to use the ASC-ASD to explore the profile of typical and atypical anxiety symptomatology in autistic children; to explore associations of anxiety symptomatology with adaptive behaviour and autistic characteristics; and to identify level of agreement between ASC-ASD scores and parent-reported anxiety diagnoses.

Method: 100 parents of 9–12 year old autistic children completed the ASC-ASD, Vineland Adaptive Behavior Scales − Second Edition, and Social Communication Questionnaire as part of a longitudinal study.

Results: High rates of anxiety symptomatology were found, with 63% of parents rating their children in the clinical range. Atypical symptoms of anxiety were endorsed at high frequency. Items within the Uncertainty subscale were most frequently endorsed, and items within the Anxious Arousal scale were endorsed least often. Children with a parent-reported diagnosis of anxiety disorder scored significantly higher on the ASC-ASD than those without an anxiety diagnosis.

Conclusions: This is one of the first studies to explore anxiety symptomatology in autistic children using an autism-specific measure of anxiety. Findings suggest that the ASC-ASD may be a useful tool for the assessment of anxiety symptomatology in autistic children.