title: Factor structure of the Hospital Anxiety and Depression Scale in Japanese psychiatric outpatient and student populations.
abstract: BACKGROUND
  The Hospital Anxiety and Depression Scale (HADS) is a common screening instrument excluding somatic symptoms of depression and anxiety, but previous studies have reported inconsistencies of its factor structure. The construct validity of the Japanese version of the HADS has yet to be reported. To examine the factor structure of the HADS in a Japanese population is needed.
  
  
  METHODS
  Exploratory and confirmatory factor analyses were conducted in the combined data of 408 psychiatric outpatients and 1069 undergraduate students. The data pool was randomly split in half for a cross validation. An exploratory factor analysis was performed on one half of the data, and the fitness of the plausible model was examined in the other half of the data using a confirmatory factor analysis. Simultaneous multi-group analyses between the subgroups (outpatients vs. students, and men vs. women) were subsequently conducted.
  
  
  RESULTS
  A two-factor model where items 6 and 7 had dual loadings was supported. These factors were interpreted as reflecting anxiety and depression. Item 10 showed low contributions to both of the factors. Simultaneous multi-group analyses indicated a factor pattern stability across the subgroups.
  
  
  CONCLUSIONS
  The Japanese version of HADS indicated good factorial validity in our samples. However, ambiguous wording of item 7 should be clarified in future revisions.
authors.affiliation: Department of Clinical Behavioural Sciences (Psychological Medicine), Kumamoto University, Graduate School of Medical Sciences, 1-1-1 Honjo, Kumamoto, Kumamoto, Japan 860-8556. m_tomomi@mvi.biglobe.ne.jp
authors.forename: Tomomi
authors.initials: T
authors.lastname: Matsudaira
authors.forename: Hiromi
authors.initials: H
authors.lastname: Igarashi
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Kikuchi
authors.forename: Rikihachiro
authors.initials: R
authors.lastname: Kano
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mitoma
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Ohuchi
authors.forename: Toshinori
authors.initials: T
authors.lastname: Kitamura
mesh_terms: D000328:Adult; D000368:Aged; D001007:Anxiety / Q000175:diagnosis*; D003863:Depression / Q000175:diagnosis*; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D001523:Mental Disorders; D008875:Middle Aged; D010045:Outpatients / Q000523:psychology*; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics / Q000295:instrumentation*; D011795:Surveys and Questionnaires / Q000592:standards*