Objective: The 15-item Geriatric Depression Scale (GDS-15) is one of the most widely used screening instruments for depression among the elderly. The aim of this study was to examine the validity and reliability of the Japanese version of the GDS-15 (GDS-15-J) in comparison with the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) criteria for depression.
Methods: The study participants were 128 elderly outpatients (age range, 55 to 92 years) categorized into two groups (76 non-depressive patients, 52 depressive patients) based on the DSM-IV-TR criteria for depression.
Results: Logistic regression analysis showed that regardless of age and sex, the GDS-15-J score could be used to screen patients for depression (p < .001). The validity of the GDS-15-J for depression assessed against DSM-IV-TR criteria was excellent based on receiver operating characteristic analysis (optimal cutoff point: 6/7; sensitivity: .98; specificity: .86). The recommended optimal cutoff score when screening for depression is 6/7. To evaluate the constructive validity of the GDS-15-J, factor analysis was performed. Three factors were extracted. Cronbach's alpha reliability coefficient was .83 to the GDS-15-J scale, which indicated a high degree of internal consistency.
Conclusion: The GDS-15-J is a clinically applicable screening instrument for depression.
Clinical implications: In this study this version of the GDS-15-J displayed excellent psychometric properties using a 6/7 cut off. Analyses suggest some items that might be removed in future studies of an abbreviated scale.
Keywords: Depression; Geriatric Depression Scale; optimal cutoff point; reliability; validity.