Muscle Tension in Generalized Anxiety Disorder During a Stressful Mental Arithmetic Task

Abstract

Introduction: The purpose of this study was to compare muscle tension between individuals with and without generalized anxiety disorder (GAD) during a resting state and a stressful mental arithmetic task. Methods: A total of 95 undergraduate students (68 females and 27 males; mean age=19.6, SD=3.5) completed an online survey on GAD symptoms and pathological worry, a diagnostic interview, and two laboratory tasks (resting and mental arithmetic tasks) while electromyography (EMG) signals were being recorded. Results: We found a significant main effect of condition, F(1,93) = 24.13, p<.001, and group, F(1,93) = 4.55, p=.036. Furthermore, there was a significant interaction effect between condition and group, F(1,93) = 5.85, p=.017. A post-hoc analysis revealed that the increase in EMG activity from the resting period, 95% CI [.002398 .003474], to the mental arithmetic task, 95% CI [.003850 .005086], was significant for the GAD group, but not for the non-GAD group. Conclusions: Individuals with and without GAD did not show significant differences in physiologically measured muscle tension at baseline. However, the GAD group showed higher levels of muscle tension during stressful situations when compared to the non-GAD group.