Are neighborhood bonding and bridging social capital protective against depressive mood in old age? A multilevel analysis in Japan.

While the importance of distinguishing between bonding and bridging social capital is now understood, evidence remains sparse on their contextual effects on health. We examined the associations of neighborhood bonding and bridging social capital with depressive mood among older Japanese. A questionnaire survey of all community residents aged 65 and older in the city of Yabu, Hyogo Prefecture, Japan was conducted in July and August 2012. Bonding and bridging social capital were assessed by evaluating individual homogeneous and heterogeneous social networks in relation to age, gender, and socioeconomic status. Individual responses in each neighborhood were aggregated to create an index of neighborhood-level bonding/bridging social capital. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the associations of such social capital with depressive mood using multilevel binomial logistic regression analysis. Of the 7271 questionnaires distributed, 6416 were analyzed (covering 152 administrative neighborhoods). Approximately 56.8% of respondents were women, and the mean age was 76.2 ± 7.1 years. Neighborhood-level bonding social capital was inversely associated with depressive mood (OR = 0.84, 95% CI = 0.75-0.94), but neighborhood-level bridging social capital was not. Gender-stratified analysis revealed that neighborhood-level bonding social capital was inversely associated with depressive mood in both genders (OR = 0.83, 95% CI = 0.72-0.96 for men; OR = 0.85, 95% CI = 0.72-0.99 for women), while neighborhood-level bridging social capital was positively associated with depressive mood in women (OR = 1.15, 95% CI = 1.00-1.34). There was also a significant interaction between individual- and neighborhood-level bonding social capital, indicating that people with a weaker homogeneous network and living in a neighborhood with weaker bonding social capital were more likely to have depressive mood. Our results suggest that neighborhood social capital does not necessarily benefit mental health in old age. These findings might stimulate further discussion on the relationship of bonding and bridging social capital with mental health.