Is it Anxiety and Does it Matter? Exploring the Manifestations and Costs of Anxiety and Other Symptoms of Distress in Youth with ASD

Background: Despite growing study and treatment, questions remain about presentation, measurement and impact of anxiety in ASD. Do symptoms of anxiety in ASD resemble traditional anxiety disorder symptoms? Do they incur similar costs? Few studies have directly addressed these crucial issues, which underscore the importance of this research. Limitations of prior studies include lack of (a) well-characterized ASD samples and (b) methods for differentiating anxiety and ASD symptoms or quantifying dissimilarities in anxiety presentation across youth with and without ASD.

Objectives: This project (1) examines the degree to which the underlying construct of self- and parent-reported anxiety is consistent across putatively anxious children with and without ASD, and (2) assesses challenges independently associated with DSM-consistent and -inconsistent manifestations of anxiety in well-characterized samples of youth.

Methods: Study 1 employs Multigroup Factorial Invariance (MFI) analyses using Structural Equation Modeling to examine degree of construct equivalence of anxiety on the Multidimensional Anxiety Scale for Children (parent and child reports). The sample includes children with anxiety disorders and ASD with intact verbal ability (n = 109, M_age = 11.67 years) and a matched comparison group with anxiety disorders, but not ASD (n = 342, M_age = 11.25 years). Study 2 examines associations between parent reports of behavior, social assertiveness and parent stress with impairing levels of DSM-consistent and inconsistent anxiety, which were differentiated via a parent/child semi-structured diagnostic interview in 59 participants (7–17 years, M_age= 10.56 years; IQ range: 47-158) with ASD.

Results: Study 1. MFI analyses indicated similar factors (i.e., physical avoidance, harm avoidance, social anxiety, separation/panic) in children with ASD using the MASC-C, but not the MASC-P. Dissimilar factors were found for the MASC-P (i.e. metric invariance was not supported): Exploratory Factor Analysis in the ASD group indicated four novel MASC-P factors: a subset of separation/panic, low social anxiety, physical, and performance anxiety symptoms. Study 2. DSM-consistent anxiety disorders were associated with more self-injurious behavior and depression in youth with ASD, but also better functional communication, after controlling for other influential variables (e.g. ASD severity, IQ, DSM-inconsistent anxiety). By comparison, DSM-inconsistent anxiety was associated with increased parental stress, after controlling for correlation with other variables (e.g. ASD severity, DSM-consistent anxiety disorders). Neither DSM-consistent nor inconsistent anxiety was associated with social assertiveness.

Conclusions: Similarities in the latent factor structure of child, but not parent, reports on the MASC add to the notion that youth with ASD may manifest anxiety and distress in ways both similar and dissimilar to typically-developing youth. Findings from Study 2 support a specific profile of challenges and relative strengths associated with distinct manifestations of anxiety in ASD. Whereas traditional anxiety disorders were uniquely associated with more self-injurious behavior and depression, parent stress was associated with DSM-inconsistent symptoms. Results provide a strong rationale for efforts to better understand and measure anxiety as it presents in ASD. Whether the dissimilar presentations elucidated in these studies reflect variants of anxiety disorder, general distress or symptoms of ASD will be considered, and implications for treatment and future research discussed.