Psychometric Validation of the Generalized Anxiety Disorder Scale (GAD-7) and Patient Health Questionnaire (PHQ-9) in an Inpatient Substance Use Disorder Treatment Program

OBJECTIVE: The Generalized Anxiety Disorder-7 (GAD-7) and Patient Health Questionnaire-9 (PHQ-9) are two widely used instruments for assessing anxiety and depression, respectively, but no studies have examined their psychometric properties among individuals with substance use disorders. This study's objectives were to (a) validate the factor structures, examining single and two-factor models, and (b) examine measurement invariance across age …