Social Capital and Suicidal Ideation in Community-Dwelling Older Residents: A Multilevel Analysis of 10,094 Subjects in Japan

Objective Social capital, the collective resources of groups including perceptions of trust and reciprocity, is recognized as an important contributor to suicide. We examined the association of individual- and community-level social capital with suicidal ideation after adjusting for social support among older adults living in the community. Methods In August 2010 we sent questionnaires to all residents aged 65 years and older living in 3 rural municipalities (N = 21,232) in Okayama Prefecture, Japan; 13,919 questionnaires were returned (response rate: 65.6%). The final analysis included 10,094 participants. The outcome variable was suicidal ideation. Exposure variables were individual-level mistrust and lack of reciprocity (level 1), and the aggregated responses of these variables from 35 communities in the municipalities (level 2). Covariates included age, sex, educational attainment, marital status, the number of cohabitants, years of residence, self-rated socioeconomic status, disability, social support, and psychological distress. Multilevel logistic regression analysis was performed to obtain odds ratios (ORs) and 95% confidence intervals (CIs). Results After adjusting for social support and psychological distress, we found that mistrust and lack of reciprocity were only associated with suicidal ideation at the individual level. Stratified analysis showed that among subjects with psychological distress, mistrust was associated with suicidal ideation at individual (OR: 1.88; 95% CI: 1.42–2.51) and community levels (OR: 1.98; 95% CI: 1.02–3.81). Conclusions Our findings show that individual- and community-level social capital is a possible protective factor for suicidal ideation, particularly for people with psychological distress.