title: Reliability and validity of the Japanese version of the 24-item Dysfunctional Attitude Scale.
abstract: BACKGROUND
  The 24-item Dysfunctional Attitude Scale (DAS-24) is a short version of the Dysfunctional Attitude Scale, which is a self-report inventory for depressogenic schemata.
  
  
  OBJECTIVE
  The object of this study was to examine the reliability and validity of the Japanese version of the DAS-24 (DAS-24-J).
  
  
  METHODS
  Subjects consisted of non-clinical sample 1 (248 university students), non-clinical sample 2 (872 Japanese company employees) and a clinical sample (59 depressed out-patients).
  
  
  RESULTS
  Internal consistency was satisfactory in all three samples, Cronbach's α coefficient being higher than 0.85. Test-retest reliability was satisfactory in non-clinical sample 1. The interclass correlation coefficient was 0.79 and there was no significant difference in the average score of DAS-24-J between the two points. The DAS-24-J showed satisfactory concurrent validity with the Japanese Irrational Belief Test-20 (r= 0.76); Automatic Thoughts Questionnaire - Revised total (r= 0.46), negative (r= 0.53) and positive (r=-0.41); and the Beck Depression Inventory-II (r= 0.44 for non-clinical sample, r= 0.63 for clinical sample). The clinical sample showed a significantly higher DAS-24-J score than non-clinical sample 2. According to a factor analysis combining all three samples, three factors were extracted: factor 1 (11 items) corresponded with 'achievement' in the original version, factor 2 (6 items) with 'self-control' and factor 3 (5 items) with 'dependency'.
  
  
  CONCLUSIONS
  The DAS-24-J is a reliable and valid instrument to measure depressogenic schemata in Japanese.
authors.affiliation: 1Department of Mental Health, Tokyo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Tajima
authors.affiliation: 2Department of Neuropsychiatry, Kanto Medical Center NTT EC, Tokyo, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Akiyama
authors.affiliation: 2Department of Neuropsychiatry, Kanto Medical Center NTT EC, Tokyo, Japan.
authors.forename: Hatsue
authors.initials: H
authors.lastname: Numa
authors.affiliation: 4The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Kawamura
authors.affiliation: 2Department of Neuropsychiatry, Kanto Medical Center NTT EC, Tokyo, Japan.
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Okada
authors.affiliation: 2Department of Neuropsychiatry, Kanto Medical Center NTT EC, Tokyo, Japan.
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Sakai
authors.affiliation: 7National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Miyake
authors.affiliation: 8Health Center, Keio University, Tokyo, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Ono
authors.affiliation: 9Department of Clinical and Health Psychology, University of Edinburgh Medical School, Edinburgh, UK.
authors.forename: M J
authors.initials: MJ
authors.lastname: Power