Abstract
BACKGROUND: Apathy is a common symptom in degenerative diseases such as dementia. In this study, we developed the Japanese version of the brief Dimensional Apathy Scale (b-J-DAS), which requires caregivers to rate patient apathy using three apathy sub-scales: executive, emotional and initiation. METHODS: Study 1 recruited 429 non-clinical participants, and Study 2 recruited 52 patients with dementia and their caregivers. Confirmatory factor analysis was conducted to identify the factor structure of the b-J-DAS. Reliability and convergent/discriminant validity were assessed based on correlations between the b-J-DAS and apathy, depression, and executive function measures. The association between the caregiver-rated b-J-DAS and care burden was also examined. RESULTS: The b-J-DAS had the same factor structure as the Japanese version of the self-rated DAS. Except for self-rated scores in patients with dementia, the b-J-DAS demonstrated acceptable reliability. Significant positive correlations with apathy and executive function measures were observed, as were negative and no correlations with depression measures. Executive and initiation apathy were correlated with care burden. CONCLUSIONS: The present findings suggest that the b-J-DAS, which requires caregivers to assess patient apathy, is a suitable multidimensional apathy scale with acceptable reliability and validity. However, further studies on the influence of caregiver-related factors are required.