Comparison of relaxation techniques for group cognitive behavioral therapy for generalized anxiety disorder

Research has shown that individuals with generalized anxiety disorder (GAD) have rigid autonomic nervous systems, evidenced by low heart rate variability (HRV) and cardiac vagal tone. Cognitive behavioral therapy (CBT) is established as an effective method for treating GAD. However, there is a need for greater treatment effectiveness, especially given the high prevalence and disability rates for GAD. An HRV biofeedback intervention could enhance CBT for GAD by targeting the specific physiological dysfunction underlying GAD. This study investigated if CBT plus HRV biofeedback resulted in a greater reduction of GAD symptoms, improved autonomic reactivity, and an increase in cardiac vagal tone and HRV compared with CBT plus progressive muscle relaxation (PMR). Seventy-nine participants with GAD were randomized to use the StressEraser, a portable respiratory sinus arrhythmia (RSA; a measure of HRV) biofeedback device, or PMR, as part of an eight session CBT group. All patients completed psychological and physiological measures before, during and after treatment, and at 1 and 3 months follow-up. Statistical analyses showed no differential improvement in GAD symptoms for the StressEraser group compared to the PMR group at the end of treatment. However, significant within-group differences were found on measures of GAD, anxiety and depression from pre to post-treatment and throughout the 3 month follow-up assessment. This indicates that in combination with a CBT group use of the StressEraser is as effective as PMR; although, both could be equally ineffective since there was no control group to evaluate if the CBT group alone produced the symptom reductions. Despite significant changes on self-report measures and ample relaxation practice, neither group showed a clear pattern of improved autonomic reactivity, increase in cardiac vagal tone or HRV. Furthermore, the amount of StressEraser use was not significantly related to changes in GAD symptoms. These results suggest that changes in autonomic functioning do not need to occur in order to benefit from CBT and that the StressEraser might not have been an adequate HRV intervention. Based on these findings, further research should examine if other HRV interventions could increase HRV in GAD patients and if so, if increases in HRV augment CBT.