Validation of brief screening measures for depression and anxiety in young people with substance use disorders.

Background: It is critical to promptly identify and monitor mood and anxiety symptoms in young people with SUD. The primary aim of this study was to conduct a psychometric validation of the Patient Health Questionnaire (PHQ-9) and Generalized Anxiety Disorder scale (GAD-7) for depression and anxiety screening in young people seeking outpatient treatment for SUD. Our secondary aim was to compare the performance of the PHQ-9 and GAD-7 to their briefer two-item versions (PHQ-2 and GAD-2) in terms of detecting probable mood and anxiety disorders.

Method: Data were extracted from the electronic health records of patients (ages 14 to 26) who received a diagnostic evaluation following clinical implementation of the PHQ-9 and GAD-7 at a hospital-based outpatient SUD treatment program (N=121, average age 19.1 ± 3.1 years).

Results: The PHQ-9 and GAD-7 showed excellent internal consistency. A PHQ-9 cut score of 7 or 8 (PHQ-2 cut score: 2) and GAD-7 cut score of 6 (GAD-2 cut score: 2) had the best balance of sensitivity, specificity, and positive and negative predictive power in these data. These measures also showed good convergent and acceptable discriminant validity.

Limitations: The sample was predominantly White and non-Hispanic, and a validated (semi-)structured diagnostic interview was not used to establish mood and anxiety disorder diagnoses.

Conclusions: Results suggest the PHQ-9 and GAD-7 are reliable and potentially clinically useful screening tools for depression and anxiety in young people with SUD, and that the two-item versions may have similar clinical utility as the full measures.