The present study investigates specificity of the six somatic symptoms that are associated with generalized anxiety disorder (GAD), according to the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders. A nonclinical sample of 183 students provided severity ratings for (a) restlessness, (b) easily fatigued, (c) difficulty concentrating, (d) irritability, (e) muscle tension, and (f) sleep disturbance. In addition, they responded to questionnaires assessing pathological worry and depression symptoms. Partial correlations and multiple regression analyses indicated that only muscle tension showed a unique relation to pathological worry. In contrast, difficulty concentrating was exclusively related to depression symptoms. Present findings corroborate psychophysiological findings that elevated muscle tension is a specific characteristic of pathological worriers. Moreover, they suggest that the problem of unclear boundaries between GAD and major depression may be reduced if future revisions of the somatic symptom list for GAD emphasize muscle tension while de-emphasizing difficulty concentrating
