Reduced Anxiety Following Pivotal Response Treatment in Young Children with Autism Spectrum Disorder

Background: Up to 40% of children with ASD exhibit co-occurring symptoms of anxiety, further impairing social functioning. Despite recent successes in mitigating anxiety symptoms in school-aged children with ASD using adapted versions of Cognitive Behavioural Therapy, little is known about treatments for younger children. Pivotal Response Treatment (PRT) is a behavioural intervention that primarily aims to increase social communication skills in children with ASD by reinforcing social interactions in a naturalistic and contingent manner. To date, no studies have explicitly examined the therapeutic potential of PRT at reducing anxiety symptoms in young children with ASD.

Objectives: To explore changes in anxiety in young children (4-8 years) with ASD following a 16-week open-label trial PRT. We examined whether changes in anxiety may be independent from co-occurring changes in social communication skills, which is directly addressed by PRT, to hypothesise and evaluate whether any changes observed in anxiety may be driven by differential therapeutic elements of PRT.

Methods: Participants included 21 children (9 female, 12 male) with high-functioning ASD (M IQ=102, SD=16, measured by Differential Abilities Scale – 2^nd Edition) between the ages of 4 and 8 years. Each child received three treatment sessions, with a total of 7 hours, on a weekly basis for 16 weeks. Parents completed outcome measures both before and after the 16 weeks of PRT. We conducted paired sample t-tests to evaluate changes in anxiety (Child and Adolescent Symptom Inventory – Anxiety Subscale, CASI-Anx), internalising symptoms (Child Behaviour Checklist – Internalising domain), and social communication (Social Responsiveness Scale, SRS) over the course of treatment. We conducted repeated-measures ANCOVA to evaluate changes in anxiety after controlling for changes social communication. Finally, we partitioned the variance of change observed in anxiety over the course of treatment, by including changes observed in social communication (SRS), IQ, and age in a step-wise hierarchical regression analysis.

Results: Participants showed significant reductions in anxiety (CASI-Anx) from pre-treatment to post-treatment (CASI-Anx Total; p = .02), internalising symptoms (CBCL; p = .001), and social communication (SRS; p = .001) (Table 1). After controlling for changes in social communication, participants still showed a significant reduction in anxiety, F (1,19) = 6.13, p = .023, partial η² = .24. Hierarchical linear regression model (Table 2) showed that residualised change in social communication accounted for little variance associated with change reported in anxiety, R² = .02, p = .55. Further addition of IQ and age, as covariates did not alter the model’s ability to account for changes observed in anxiety over PRT.

Conclusions: This open-label study shows promising results for PRT to help reduce anxiety, and internalising symptoms more broadly, in young children with ASD. To our knowledge, this study is the first to address the gap in literature on evaluating anxiety reduction following intervention in young children with ASD, providing evidence supporting PRT’s significant additional therapeutic potential in terms of reducing severity of anxiety. Future studies can evaluate whether current finding may hold using larger sample sizes, and translated to lower-functioning young children with ASD.