GAD1 and generalized anxiety disorder: Rodebaugh et al. (2008) found that responses from a sample of college students (N = 1,038) to the GAD-Q-IV are best represented by a one-factor structure, which accounted for 25% of the variance of GAD-Q-IV item responses. Robinson, Klenck, and Norton (2010) found this one-factor structure of the GAD-Q-IV to be consistent among various racial/ethnic groups for another sample of college students (n = 585), which suggests that the GAD-Q-IV measures the construct of GAD uniformly across ethnic groups.