Correlates of cognitive impairment and depressive symptoms among older adults in Korea and Japan

BACKGROUND: Cognitive impairment and depressive symptoms impose a heavy burden on the care of the elderly in Japan and Korea, two of the fastest aging nations in Asia. The purpose of this study was to examine and compare factors associated with cognitive impairment and depressive symptoms among older persons in the two countries. METHODS: In 2002, representative samples of community-dwelling people aged 65 and older were selected among residents in Anyang, Korea and Yoita, Japan. Mini-Mental State Examination and Geriatric Depression Scale were used to assess the elderly's mental status. Sociodemographics, physical function, chronic conditions, social support, and health behaviors were examined to identify significant associations. RESULTS: The prevalence of cognitive impairment in older adults was 17.0% in Anyang and 14.6% in Yoita. The rates for depressive symptoms were 15.2% and 19.8%, respectively. Overall, functional capacity was the universal factor significantly associated with mental conditions. Self-rated health and social support were also found to be independently associated with depressive symptoms in the study subjects. Differences in the patterns of association by community, however, were notable for other characteristics. For example, in factors associated with cognitive impairment, sociodemographic factors such as age, gender, and education were significant among Koreans, whereas socio-behavioral factors such as obesity, social support and hospitalization experience were found to be significant for older Japanese residents. CONCLUSIONS: Similarities in the patterns of association indicate the need for joint explorations into the role these factors play in affecting the mental health of older persons. Socioeconomic and regional differentials, however, may account for the disparity in the associations observed, suggesting the importance of developing mental health programs sensitive to the older individual's culture.