Preliminary reliability and validity of the generalized anxiety disorder questionnaire - IV: A revised self-report diagnostic measure of generalized anxiety disorder

This study examined the Generalized Anxiety Disorder Questionnaire-IV (GAD-Q-IV), a revised self-report diagnostic measure of generalized anxiety disorder (GAD) based on the fourth edition of the Diagnostic and Statistical Manual. GAD-Q-IV diagnoses were compared to structured interview diagnoses of individuals with GAD, social phobia, panic disorder, and nonanxious controls. Using Receiver Operating Characteristics analyses, the GAD-Q-IV showed 89% specificity and 83% sensitivity. The GAD-Q-IV also demonstrated test-retest reliability, convergent and discriminant validity, and kappa agreement of .67 with a structured interview. Students diagnosed with GAD by the GAD-Q-IV were not significantly different on two measures than a GAD community sample, but both groups had significantly higher scores than students identified as not meeting criteria for GAD, demonstrating clinical validity of the GAD-Q-IV.