AUTONOMIC CHARACTERISTICS OF GENERALIZED ANXIETY DISORDER AND WORRY

Autonomic characteristics of generalized anxiety disorder (GAD) and wo rry were examined using measures of heart period variability. The card iorespiratory responses of 34 GAD clients and 32 nonanxious control su bjects were recorded during resting baseline, relaxation, and worry pe riods. Results indicated differences between GAD subjects and controls as well as among baseline, relaxation, and worry periods. GAD clients exhibited shorter cardiac interbeat intervals (IBIs) and lower high f requency spectral power across all task conditions. Relative to baseli ne and relaxation conditions, worry, was associated with (I) shorter I BIs, (2) smaller mean successive differences (MSD) of the cardiac IBIs , and (3) lower high frequency spectral power. These findings suggest that GAD and its cardinal feature (worry), are associated with lower c ardiac vagal control. The findings of the present study provide eviden ce for the utility of further exploration of the role of autonomic ner vous system activity in GAD.