A multimethod assessment of anxiety and problem behavior in children with autism spectrum disorders and intellectual disability.

Despite the increased risk for anxiety disorders in children with autism spectrum disorders (ASD), there is a lack of research on the assessment and treatment of anxiety in this population, particularly for those with an intellectual disability (ID). The present study evaluated a multimethod strategy for the assessment of anxiety and problem behavior in three children with ASD and ID. Anxiety was operationally defined using: (1) behavioral data from anxious behaviors, (2) affective/contextual data from parent-report and observer ratings of overall anxiety, and (3) physiological data (heart rate [HR] and respiratory sinus arrhythmia [RSA]). A functional assessment of problem behavior during high- and low-anxiety conditions was conducted. Higher levels of problem behavior and HR and lower RSA were found in the high-anxiety than in the low-anxiety conditions.