Social capital and psychological distress of elderly in Japanese rural communities. 
The growing recognition of the social determinants of health has stimulated research on social capital and mental health.  We explored new empirical evidence regarding whether social capital was a determinant of psychological distress.  Baseline surveys examining psychological distress were conducted in two towns in 2006–2007 (participation rates for those aged 20 or over were 27.6 per cent, 6.1 per cent).  We also conducted follow-up surveys in 2008 to capture the social capital measured by trust.  By linking these data and excluding the missing data, 141 males and 234 females remained as the subjects of our study.  Results showed that the odds ratios of psychological distress was higher in groups with low social capital measured by trust (odds ratio 2.17; 95 per cent CI, 1.40-3.36), than those in groups with high social capital.  Further, we examined the interaction effect of social capital and social support.  The odds ratios of psychological distress was higher in groups with some social support/lower trust (odds ratio 2.21; 95 per cent CI, 1.36-3.58) or no social support/lower trust (odds ratio 2.07; 95 per cent CI, 1.06–4.05), than those in groups with some social support/higher trust.  These findings reinforce the hypothesized discussion regarding pathways from social capital to psychological distress via supportive relationships.