Questionnaire May Help Screen Teens for Major Depression in Primary Care
By Laurie Barclay, MD
Medscape Medical News
April 13, 2010 — The Patient Health Questionnaire 2-item depression screen (PHQ-2) has good sensitivity and specificity for the detection of major depression among adolescents, according to the results of a study reported online April 5 in Pediatrics.
"The US Preventive Services Task Force recommends screening for depression among adolescents," write Laura P. Richardson, MD, from University of Washington School of Medicine in Seattle, and colleagues. "However, few tools have been validated among adolescents in primary care settings. No studies have examined brief 2-item screening tools among adolescents."
The goal of the study was to assess the validity of the PHQ-2 among adolescents. The study sample consisted of 499 youth, aged 13 to 17 years, who were enrolled in an integrated healthcare system. After completing a brief depression screen, these adolescents were invited to undergo a full assessment, including a longer depression-screening scale (PHQ 9-item depression screen) and a structured mental health interview (Diagnostic Interview Schedule for Children depression modules [DISC-IV]). A total of 444 adolescents (89%) completed the full evaluation, and the investigators tested criterion validity and construct validity by evaluating associations between the PHQ-2 and other measures of depression and functional impairment.
With a cutoff PHQ-2 score of 3 or more, sensitivity was 74%, and specificity was 75% for identifying youth who met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria for major depression on the DISC-IV. Sensitivity was 96%, and specificity was 82% for detecting adolescents who met criteria for probable major depression on the PHQ-9.
Area under the curve was 0.84 (95% confidence interval, 0.75 - 0.92) for the PHQ-2, based on receiver operating characteristic analysis. A cutoff point of 3 allowed maximal sensitivity without loss of specificity for identifying major depression. Compared with youth who had PHQ-2 scores of less than 3, those with a PHQ-2 score of 3 or more had significantly higher functional-impairment scores and significantly higher scores for parent-reported internalizing problems.
Limitations of this study include lack of generalizability to all adolescent populations, possible selection bias, and time-window differences between the DISC-IV and the PHQ-2. In addition, PHQ-2 was part of the PHQ-9; therefore, the results should be highly correlated, and the sensitivity and specificity may be slightly lower if they were administered separately.
"The PHQ-2 has good sensitivity and specificity for detecting major depression," the study authors write. "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."
The Group Health Community Foundation Child and Adolescent Grant Program, the University of Washington Royalty Research Fund, a Seattle Children's Hospital Steering Committee Award, and the National Institute of Mental Health supported this study. The study authors have disclosed no relevant financial relationships.
