Aroused at Home: Basic Autonomic Regulation during Orthostatic and Physical Activation is Altered in Children with Social Anxiety Disorder.

Previous research has documented altered autonomic nervous system (ANS) reactivity to laboratory-based social stress tasks in children with social anxiety disorder (SAD). It is unclear, however, whether these alterations are caused by the unfamiliar and possibly threatening lab environment or whether they generalize to other, more representative contexts. Sympathetic and parasympathetic autonomic functioning was assessed in the home (minimizing environmental threat) during a supine baseline phase and two physical activation phases (orthostatic stress, stair stepping) in children (9-13 years) with SAD (n = 27) and healthy control children (n = 27). Relative to controls, children with SAD showed tonic autonomic hyperarousal as indicated by higher heart rate and electrodermal activity during the supine baseline phase. Further, there was evidence for stronger cardiac and vascular sympathetic reactivity (T-wave amplitude, pulse wave transit time) to moderate physical activation in children with SAD. Higher autonomic arousal during rest was related to measures of trait social anxiety and general psychopathology. Groups did not differ on parasympathetic parameters. Our results extend previous laboratory findings and provide the first evidence for alterations in children with SAD during basal autonomic regulation and in the absence of explicit social evaluative threat. They may further help to clarify conflicting study results from previous laboratory studies. The findings underline the importance of psychophysiological assessment using different environments and tasks to elucidate the physiological bases of SAD.