The relation between electrodermal activity in sleep, negative affect, and stress in patients referred for nocturnal polysomnography

The study of electrodermal activity (EDA) began over a century ago, and the phenomenon has been linked to many aspects of emotion, arousal and attention. A subset of studies has focused on the occurrence of EDA in sleep (EDAS). These investigations have led to definitive conclusions on when EDA is most likely to occur doing the sleep cycle, i.e., slow-wave sleep. Studies have also shown that at least moderate stress tends to increase EDAS, but these studies have fallen short methodologically. The aims of the present study were: (a) to investigate the relation of negative affect and stress to EDAS, and to determine the extent to which these variables are predictive of EDAS; and (b) to explore the utility of EDAS as an index of sympathetic nervous system arousal and of sleep quality. Several additional hypotheses were also tested.;Participants were 70 referrals to a local sleep disorders center. Subjects completed a demographic profile form and self-report measures of mood disturbance, worry and stress and underwent skin potential measurement during an overnight sleep study. Correlation and multiple regression analyses determined that weak relations exist between negative affect, worry and stress and EDAS, and that these variables are largely ineffective in predicting EDAS in a sleep-disordered population. Further, EDAS had no relation to self-reported sleep quality in this sample. Additional analyses found significant associations between apneic and periodic limb movement events and both central (EEG) and autonomic arousals (EDAS), and that a combination of both central and autonomic nervous system arousal variables might provide a better indicator of the amount of sleep disturbance present.