Objective: To examine the validity of the Patient Health Questionnaire 2 (PHQ-2), a 2-item depression-screening scale, among adolescents.
Methods: After completing a brief depression screen, 499 youth (aged 13-17 years) who were enrolled in an integrated health care system were invited to participate in a full assessment, including a longer depression-screening scale (Patient Health Questionnaire 9-item depression screen) and a structured mental health interview (Diagnostic Interview Schedule for Children). Eighty-nine percent (n = 444) completed the assessment. Criterion validity and construct validity were tested by examining associations between the PHQ-2 and other measures of depression and functional impairment.
Results: A PHQ-2 score of > or =3 had a sensitivity of 74% and specificity of 75% for detecting youth who met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria for major depression on the Diagnostic Interview Schedule for Children and a sensitivity of 96% and specificity of 82% for detecting youth who met criteria for probable major depression on the Patient Health Questionnaire 9-item depression screen. On receiver operating characteristic analysis, the PHQ-2 had an area under the curve of 0.84 (95% confidence interval: 0.75-0.92), and a cut point of 3 was optimal for maximizing sensitivity without loss of specificity for detecting major depression. Youth with a PHQ-2 score of > or =3 had significantly higher functional-impairment scores and significantly higher scores for parent-reported internalizing problems than youth with scores of <3.
Conclusions: The PHQ-2 has good sensitivity and specificity for detecting major depression. These properties, coupled with the brief nature of the instrument, make this tool promising as a first step for screening for adolescent depression in primary care.