title: Detecting depression among adolescents in Santiago, Chile: sex differences.
abstract: BACKGROUND
  Depression among adolescents is common but most cases go undetected. Brief questionnaires offer an opportunity to identify probable cases but properly validated cut-off points are often unavailable, especially in non-western countries. Sex differences in the prevalence of depression become marked in adolescence and this needs to be accounted when establishing cut-off points.
  
  
  METHODS
  This study involved adolescents attending secondary state schools in Santiago, Chile. We compared the self-reported Beck Depression Inventory-II with a psychiatric interview to ascertain diagnosis. General psychometric features were estimated before establishing the criterion validity of the BDI-II.
  
  
  RESULTS
  The BDI-II showed good psychometric properties with good internal consistency, a clear unidimensional factorial structure, and good capacity to discriminate between cases and non-cases of depression. Optimal cut-off points to establish caseness for depression were much higher for girls than boys. Sex discrepancies were primarily explained by differences in scores among those with depression rather than among those without depression.
  
  
  CONCLUSIONS
  It is essential to validate scales with the populations intended to be used with. Sex differences are often ignored when applying cut-off points, leading to substantial misclassification. Early detection of depression is essential if we think that early intervention is a clinically important goal.
authors.affiliation: School of Social and Community Medicine, University of Bristol, Oakfield House, Bristol BS8 2PS, UK. riaraya.psych@gmail.com
authors.forename: Ricardo
authors.initials: R
authors.lastname: Araya
authors.forename: Jesus
authors.initials: J
authors.lastname: Montero-Marin
authors.forename: Sergio
authors.initials: S
authors.lastname: Barroilhet
authors.forename: Rosemarie
authors.initials: R
authors.lastname: Fritsch
authors.forename: Jorge
authors.initials: J
authors.lastname: Gaete
authors.forename: Alan
authors.initials: A
authors.lastname: Montgomery
mesh_terms: D000293:Adolescent; D002677:Chile; D003866:Depressive Disorder / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D015995:Prevalence; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D012727:Sex Characteristics; D011795:Surveys and Questionnaires