To Study Reliability and Validity for A Brief Measure for Assessing Generalized Anxiety Disorder (GAD-7)

The objective of this study was to investigate reliability and validity of a brief self-report scale (GAD-7) developed to identify probable cases of generalized anxiety disorder. The GAD-7 is a 7-item self-report questionnaire developed by Spitrzer in 2006, for screening for GAD and assessing its severity in clinical practice and research. 199 students selected from Shahed University for the study as non clinical group and 24 patients suffered from generalized anxiety disorder, selected from a psychiatric clinic in Tehran. Research tools employed in the study were Brief Measure for Assessing Generalized Anxiety Disorder (GAD-7), State-Trait anxiety inventory (STAI), Short-Form General Health Survey (SF-36) and anxiety subscale of Symptom Checklist (SCL- 90). The coefficient Alpha obtained for the total scale, and coefficient Alpha obtained for each part of the scale, and also the test–retest correlation obtained indicated a suitable reliability for the scale. Correlations calculated among GAD-7 and other instruments used in this study, suggested acceptable validity for the scale. Factorial analysis for the scale also showed one factor loading. And the scale was able to differentiate between clinical and non clinical group.