| Summary: | Although up to 40% of children with autism spectrum disorder (ASD) have a comorbid anxiety disorder, little is known about the origins and trajectory of change in anxiety symptoms in ASD. Characteristics specific to ASD such as social impairments and alexithymia may alter the experience of anxiety in this population. Consequently, anxiety may differ in the ASD population and merits focused study. This dissertation consists of two related studies that used data from the longitudinal Pathways in ASD study. The psychometric properties of the Spence Children’s Anxiety Scale – Parent Form (SCAS-P) in 238 children who were seen annually from ages 7.5 to 11 were examined in Study 1. While the original six-factor structure was not a good fit in this sample, four subscales reflecting Generalized, Separation Anxiety, Panic and Agoraphobia symptoms were identified. In Study 2, parent ratings of Generalized, Separation Anxiety, Panic and Agoraphobia symptoms were captured at snapshots in middle childhood, as well as changing over time in 262 children who were seen annually between ages 7.5 to 11. The proportion of children whose parents rated them as experiencing Elevated Generalized Anxiety was comparable to past reports, though rates of Elevated Separation Anxiety symptoms were higher than past reports. Parent-rated Generalized Anxiety, Separation Anxiety, Panic and Agoraphobia symptoms were stable over the middle childhood years, and there was little variance in the trajectories of all except the Separation Anxiety domain. Children with age-typical language abilities were rated as experiencing higher levels of Generalized and Separation Anxiety in middle childhood. Parent-rated anxiety in early childhood significantly predicted higher Generalized and Separation anxiety across middle childhood, while parental internalizing symptoms in early childhood were predictive of Generalized, but not Separation Anxiety symptoms. There were no differences in Generalized or Separation Anxiety levels across ages 7-11 between boys and girls. The results of this research offer a deeper understanding of the psychometric properties of one widely used anxiety rating scale, as well as its predictors, incidence and development over middle childhood. In turn, this understanding can support efforts aimed at preventing and treating anxiety disorders in ASD. === Education, Faculty of === Educational and Counselling Psychology, and Special Education (ECPS), Department of === Graduate
|
|---|
