title: The validity of the symptom checklist depression and anxiety subscales: A general population study in Sweden.
abstract: BACKGROUND
  The Symptom Checklist (SCL) is used as a screening tool in patient settings, but is also used as a diagnostic proxy for depression and anxiety in public health surveys. However, there are few validation studies based on general population samples. This study aims to validate the SCL subscales for depression and anxiety in a general population sample in Stockholm, Sweden.
  
  
  METHODS
  We used a stratified random sample answering first a postal questionnaire covering SCL (n=8613) and then a semi-structured psychiatric interview based using Schedules for Clinical Assessment in Neuropsychiatry (SCAN, n=881). Agreement between SCL depression (SCL-DEP) and anxiety (SCL-ANX) scales and their respective DSM-IV disorder was examined by ROC analysis. Discriminant analysis was performed with factor analysis on the SCL depression and anxiety items. The SCL-DEP scale was also compared with the ability of the Major Depression Inventory (MDI) in detecting depressive disorders.
  
  
  RESULTS
  A factor analysis with two factors differentiated the two subscales, with some cross loading items. The SCL-DEP and ANX subscales agreement with depression and anxiety disorders was good. SCL-DEP MDI performed better in detecting DSM-IV depression.
  
  
  CONCLUSIONS
  The questionnaire only included the SCL depression, anxiety and hostility subscales and not the full SCL-90. Also, no other anxiety scale was available for comparison.
  
  
  CONCLUSIONS
  We conclude that depression and anxiety subscales are suitable instrument for proxies of depression and anxiety disorder in public health surveys.
authors.affiliation: Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden. Electronic address: andreas.lundin@ki.se.
authors.forename: Andreas
authors.initials: A
authors.lastname: Lundin
authors.affiliation: Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden. Electronic address: mats.hallgren@ki.se.
authors.forename: Mats
authors.initials: M
authors.lastname: Hallgren
authors.affiliation: Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden. Electronic address: yvonne.forsell@ki.se.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Forsell
mesh_terms: D000328:Adult; D001007:Anxiety / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D057189:Checklist / Q000706:statistics & numerical data*; D003863:Depression / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008603:Mental Health / Q000706:statistics & numerical data*; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales / Q000592:standards*; D011594:Psychometrics; D015203:Reproducibility of Results; D013548:Sweden / Q000453:epidemiology
keywords: Anxiety; Depression; HSCL; SCL; Sensitivity and specificity