VAGAL TONE IN GENERALIZED ANXIETY DISORDER AND THE EFFECTS OF AVERSIVE IMAGERY AND WORRISOME THINKING

Vagal tone was assessed in 15 generalized anxiety disorder (GAD) and 1 5 nonanxious control participants during initial baseline, aversive im agery related to worry topics, worrisome thinking, and final baseline. The GAD group showed significantly lower vagal tone at initial baseli ne and little change over experimental tasks, suggesting the possibili ty of chronic reduction in parasympathetic tone. Nonanxious participan ts, on the other hand, displayed significant decreases in vagal tone f rom baseline to imagery and further reductions from imagery to worriso me thinking. Participants reported greater anxiety during worry than d uring aversive images but also greater ease of generation and maintena nce of the worrisome thoughts. The results support prior theorizing th at GAD is characterized by autonomic inflexibility, that this phenomen on is partly due to deficient parasympathetic tone, and that worrisome thinking in particular causes phasic reductions in vagal tone.