Discriminant and Convergent Validity for the Anxiety Construct in Children with ASD

Background: Children with autism spectrum disorders (ASD) are at heightened risk for developing clinical anxiety. Despite reports of high anxiety in children with ASD there is controversy regarding differential diagnosis of ASD symptoms and anxiety symptoms. 

Objectives: To examine evidence of discriminant and convergent validity for anxiety and ASD symptoms in children with ASD.

Methods: This study examined 88 children (63 males), aged 7-11 years, with ASD referred for concerns about anxiety. A multitrait- (social anxiety, separation anxiety, overall anxiety severity, and overall ASD severity), multimethod- (self, parent, and diagnostician) analysis was conducted. Structural equation modeling was used to test for statistical discrimination between anxiety and autism severity and convergence among differing reports of the anxiety subdomains (e.g., separation anxiety).

Results: Findings suggest weak correlations between the ASD and anxiety latent variables (supporting discriminant validity) and moderate to strong loadings of indicator variables on ASD and anxiety latent variables (supporting convergent validity). Model comparisons also provide evidence of statistical discrimination between anxiety and ASD severity and convergence among differing reports of the anxiety subdomains (e.g., separation anxiety). 

Conclusions: These results suggest that anxiety symptoms experienced by children with ASD are separate from ASD symptom severity and may instead reflect anxiety syndromes (e.g., separation anxiety) similar to those that occur in typically developing children. Future research using other approaches (e.g. psychophysiology) should be conducted to further investigate ASD and anxiety symptom differentiation.