Psychometric properties of the Generalized Anxiety Disorder 7-item (GAD-7) scale in Chilean adolescents

Background: The Generalized Anxiety Disorder 7-item (GAD-7) scale is widely used for the assessment of generalized anxiety disorder. Aim: To adapt the GAD-7 to the Chilean adolescent population and to evaluate its psychometric properties. Material and Methods: The GAD-7 was adapted and administered to 2,022 adolescents between 13 and 19 years of age, recruited from eight schools in the northern area of Santiago, Chile. Other self-report instruments were used to assess depressive symptoms and health-related quality of life. The one factor structure and invariance by sex were examined using Confirmatory Factor Analysis. Its reliability and validity based on its relationship with other variables were assessed. Results: The one-factor structure and invariance by sex were confirmed. The results showed an adequate internal reliability (Cronbach's alpha = 0.86, Spearman-Brown coefficient = 0.82). As expected, significant correlations were observed with measures of depressive symptoms and health-related quality of life. Higher scores were observed in women than in men. Conclusions: The Chilean version adapted for adolescents of the GAD-7 has good psychometric properties. Thus, it may be a useful and valid instrument for the assessment of generalized anxiety disorder in adolescents in Chile.