The psychophysiology of generalized anxiety disorder: 1. Pretreatment characteristics.

Generalized anxiety disorder (GAD) patients have been reported to have more muscle tension than controls, which has provided a rationale for treating them with muscle relaxation therapies (MRT). We tested this rationale by comparing 49 GAD patients with 21 controls. Participants underwent 5-min relaxation tests, during which they either just sat quietly (QS) or sat quietly and tried to relax (R). GAD patients reported themselves to be more worried during the assessment than the controls, had higher heart rates and lower end-tidal pCO2, but not higher muscle tension as measured by multiple EMGs. QS and R did not differ on most psychological and physiological measures, indicating that intention to relax did not affect speed of relaxation. In the GAD group, self-reported anxiety was not associated with electromyographic or autonomic measures. We conclude that GAD is not necessarily characterized by chronic muscle tension, and that this rationale for MRT should be reconsidered.