title: Evaluation of the PHQ-2 as a brief screen for detecting major depression among adolescents.
abstract: 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.
authors.affiliation: Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington, USA. laura.richardson@seattlechildrens.org
authors.forename: Laura P
authors.initials: LP
authors.lastname: Richardson
authors.forename: Carol
authors.initials: C
authors.lastname: Rockhill
authors.forename: Joan E
authors.initials: JE
authors.lastname: Russo
authors.forename: David C
authors.initials: DC
authors.lastname: Grossman
authors.forename: Julie
authors.initials: J
authors.lastname: Richards
authors.forename: Carolyn
authors.initials: C
authors.lastname: McCarty
authors.forename: Elizabeth
authors.initials: E
authors.lastname: McCauley
authors.forename: Wayne
authors.initials: W
authors.lastname: Katon
mesh_terms: D000293:Adolescent; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D005260:Female; D006279:Health Maintenance Organizations / Q000706:statistics & numerical data; D006801:Humans; D007406:Interview, Psychological; D008297:Male; D008403:Mass Screening; D010552:Personality Assessment / Q000706:statistics & numerical data; D010555:Personality Inventory / Q000706:statistics & numerical data*; D011594:Psychometrics / Q000706:statistics & numerical data; D012372:ROC Curve; D015203:Reproducibility of Results; D014861:Washington