Test–retest reliability of regional electroencephalogram (EEG) and cardiovascular measures in social anxiety disorder (SAD)

Although the search for psychophysiological manifestations of social anxiety has a rich history, there appear to be no published reports examining the reliability of continuous electrocortical measures that putatively index stress vulnerability and stress reactivity in socially anxious individuals. We examined the 1-week test-retest reliability of regional electroencephalogram (EEG) alpha asymmetry and power, respiratory sinus arrhythmia (RSA), heart period, and heart period variability measures at rest and during anticipation of an impromptu speech in 26 adults diagnosed with social anxiety disorder (SAD). Across the 1-week time period, we found medium-to-large correlations for regional EEG asymmetry and large correlations for regional EEG alpha power, RSA, heart period, and heart period variability measures at rest and during speech anticipation, before and after accounting for age and medication status. These results are similar to patterns observed in nonclinical samples and appear to provide the first documented evidence of test-retest reliability of psychophysiological measures that index central nervous system activity in socially anxious individuals. These findings also provide support for the notion that resting frontal EEG asymmetry and RSA constitute relatively stable individual differences in this clinical population.