Supplementary materials to: Biased perception of physiological arousal in child social anxiety disorder before and after cognitive behavioral treatment

Background: A biased perception of physiological hyperreactivity to social-evaluative situations is crucial for the maintenance of social anxiety disorder (SAD). Alterations in interoceptive accuracy (IAc) when confronted with social stressors may play a role for SAD in children. We expected a biased perception of hyperarousal in children with SAD before treatment and, consequently, a reduced bias after successful cognitive behavioral therapy (CBT). Method: In two centers, 64 children with the diagnosis of SAD and 55 healthy control (HC) children (both 9 to 13 years) participated in the Trier Social Stress Test for Children (TSST-C), which was repeated after children with SAD were assigned to either a 12-week group CBT (n = 31) or a waitlist condition (n = 33). Perception of and worry about physiological arousal and autonomic variables (heart rate, skin conductance) were assessed. After each TSST-C, all children further completed a heartbeat perception task to assess IAc. Results: Before treatment, children with SAD reported both a stronger perception of and more worry about their heart rate and skin conductance than HC children, while the objective reactivity of heart rate did not differ. Additionally, children with SAD reported heightened perception of and increased worry about trembling throughout the TSST-C compared to HC children, but reported increased worry about blushing only after the stress phase of the TSST-C compared to HC children. Children with and without SAD did not differ in IAc. Contrary to our hypothesis, after treatment, children in the CBT group reported heightened perception of physiological arousal and increased worry on some parameters after the baseline phase of the TSST-C, whereas actual IAc remained unaffected. IAc before and after treatment were significantly related. Conclusions: Increased self-reported perception of physiological arousal may play a role in childhood SAD and could be an important target in CBT. However, further studies should examine if this is an epiphenomenon, a temporarily occurring and necessary condition for change, or indeed an unwanted adverse intervention effect.