The relationship between subtypes of repetitive behaviors and anxiety in children with autism spectrum disorder.

Highlights • All four subtypes were moderately to strongly positively correlated with each other. • All four subtypes were positively correlated with anxiety problems. • The Sameness and Self-Injury factors accounted for unique variance in anxiety. Abstract Background Many children with autism spectrum disorder (ASD) experience comorbid anxiety problems. Research suggests that anxiety symptoms are related to restricted and repetitive behaviors (RRBs) in general, and insistence on sameness behaviors, in particular. However, the extent to which other subtypes of RRBs are related to anxiety is less clear. Method This study evaluated the relationship between anxiety symptoms and subtypes of restricted and repetitive behaviors (RRBs) using the Repetitive Behavior Scale-Revised (RBS-R) in a large sample of children ages 68 months to 18 years-old with autism spectrum disorder (ASD) from the Simons Simplex Collection (N = 2093). Results An exploratory factor analysis suggested a four-factor solution to the RBS-R. All four factors were significantly correlated with each other and with anxiety symptoms (ps≤0.001). A hierarchical regression controlling for age and IQ indicated that the Sameness and Self-Injury factors accounted for unique variance in anxiety. There were no interactions between IQ and any of the RRB factors in predicting anxiety. Conclusions Results suggest that researchers and clinicians should consider the role of anxiety when understanding and treating RRBs in children with ASD. High endorsement of items that load on the Sameness and Self-Injury subscales of the RBS-R might be used to identify children who are at risk for anxiety but who may not show overt symptoms. [ABSTRACT FROM AUTHOR]