title: Patient health questionnaire-9 as an effective tool for screening of depression among Indian adolescents.
abstract: OBJECTIVE
  Detection of depression among adolescents in the primary care setting is of paramount importance, especially in resource-constrained countries such as India. This article discusses the diagnostic accuracy, reliability, and validity of the Patient Health Questionnaire-9 (PHQ-9) when pediatricians use it among Indian adolescents.
  
  
  METHODS
  Pediatricians administered the PHQ-9 to 233 adolescent students aged 14-18 years, along with the Beck Depression Inventory. Our psychologist clinically diagnosed depression based on an International Classification of Diseases, 10th Revision, interview of participants. One month later, the PHQ-9 was readministered among students. We conducted appropriate analyses for validity and diagnostic accuracy.
  
  
  RESULTS
  A total of 31 students (13.3%) had a form of depression on psychiatric interview. A PHQ-9 score of ≥5 was ideal for screening (sensitivity, 87.1%; specificity, 79.7%). In addition to good content validity, PHQ-9 had good 1-month test-retest reliability (r = .875) and internal consistency (Cronbach's α = .835). There was high convergent validity with the Beck Depression Inventory (r = .76; p = .001). The concordance rate between the PHQ-9 threshold score of ≥10 and the International Classification of Diseases, 10th Revision based diagnosis was good (Cohen's κ = .62). The area under the receiver operating characteristic curve for PHQ-9 was .939.
  
  
  CONCLUSIONS
  The PHQ-9 is a psychometrically sound screening tool for use by pediatricians in a primary care setting in India. Because it is a short, simple, easy to administer questionnaire, the PHQ-9 has tremendous potential in helping to tackle the growing problem of depression among adolescents in developing countries.
authors.affiliation: Department of Pediatrics, Medical College and Hospitals, Kolkata, India. 1samratganguly@gmail.com
authors.forename: Samrat
authors.initials: S
authors.lastname: Ganguly
authors.forename: Moumita
authors.initials: M
authors.lastname: Samanta
authors.forename: Prithwish
authors.initials: P
authors.lastname: Roy
authors.forename: Sukanta
authors.initials: S
authors.lastname: Chatterjee
authors.forename: David W
authors.initials: DW
authors.lastname: Kaplan
authors.forename: Bharati
authors.initials: B
authors.lastname: Basu
mesh_terms: D000293:Adolescent; D019540:Area Under Curve; D003863:Depression / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D007406:Interview, Psychological; D008297:Male; D008403:Mass Screening; D011320:Primary Health Care; D011594:Psychometrics; D012372:ROC Curve; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires