Background: Generalized anxiety disorder (GAD) often remains undiagnosed in patients with migraine, while comorbidity of GAD with migraine is associated with increased dysfunction and risk of chronic migraine. Generalized Anxiety Disorder Scale 7-item (GAD-7) and Generalized Anxiety Disorder Scale 2-item (GAD-2) are the commonly employed screening measures for generalized anxiety symptoms in different patient groups. The present study aimed to evaluate psychometric properties of the Persian version of GAD-7 and GAD-2 in migraine.
Methods: In this cross-sectional study, patients were diagnosed with migraine headaches according to the International Classification of Headache Disorders, 3rd edition (ICHD-3); then they participated in the psychiatric diagnostic interview, and filled out GAD-7, GAD-2, Beck Anxiety Inventory (BAI), Headache Impact Test-6 (HIT-6), and Migraine-Specific Quality of Life Questionnaire version 2.1 (MSQv2.1). The psychometric properties of GAD-7 and GAD-2 were examined using SPSS and LISREL.
Results: Final samples were 186 patients with migraine that 83 patients received a diagnosis of GAD. Confirmatory factor analysis (CFA) indicated that the one-factor model of GAD-7 fit the data well. Internal consistency, test-retest, and Guttman split-half reliability of GAD-7 and GAD-2 were good. Significant correlation results, average variance extracted (AVE), and composite reliability (CR) supported the construct validity of the GAD-7. A score of ≥ 10 in GAD-7 and ≥ 3 in GAD-2 achieved satisfactory sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) (GAD-7: 92%, 90%, 88%, and 93%, respectively; GAD-2: 79%, 88%, 71%, and 91%, respectively).
Conclusion: Our findings supported GAD-7 and GAD-2 for assessing GAD in patients with migraine. It seems that GAD-7 and GAD-2 accurately diagnosed GAD in this group of patients.