PURPOSE: Screening tools such as the Patient Health Questionnaire-9 (PHQ-9) and the Generalized Anxiety Disorder-7 (GAD-7) could potentially be used in resource-limited settings to identify adolescents who need mental health support. We examined the criterion validity of the isiXhosa versions of the PHQ-9 and GAD-7 in detecting depression and anxiety among adolescents (10-19 years) in South Africa.

METHODS: Adolescents were recruited from the general population and from nongovernmental organizations working with adolescents in need of mental health support. The PHQ-9 and GAD-7 were culturally adapted and translated into isiXhosa and administered to 302 adolescents (56.9% female). The Kiddie Schedule for Affective Disorders and Schizophrenia was administered by trained clinicians as the gold standard diagnostic measure for depression and anxiety.

RESULTS: For the PHQ-9, the area under the curve was 0.88 for the full sample of adolescents (10-19 years old). A score of ≥10 had 91% sensitivity and 76% specificity for detecting adolescents with depression. For the GAD-7, the area under the curve was 0.78, and cutoff scores with an optimal sensitivity-specificity balance were low (≥6). A score of ≥6 had 67% sensitivity and 75% specificity for detecting adolescents with anxiety.

DISCUSSION: The culturally adapted isiXhosa version of the PHQ-9 can be used as a valid measure for depression in adolescents. Further research on the GAD-7 for use with adolescents is recommended.