Background: Caregivers of people with dementia are likely to have psychological distress that sometimes results in mental health problems, such as depression. The objective of this study was to examine some predictive factors that are thought to be associated with psychological distress of caregivers of people with dementia in Japan.; Methods: Design: A cross-sectional study.; Sample: As part of a study to estimate the cost of dementia in Japan, 1,437 people with dementia-caregiver dyads were enrolled in the current informal care time study.