The 'dark side' of social capital: trust and self-rated health in European countries.

BACKGROUND Generalized interpersonal trust (as an indicator of social capital) has been linked to health status at both the individual and ecological level. We sought to examine how changes in contextual and individual trust are associated with changes in self-rated health in the European Social Surveys 2002-12. METHODS A multilevel analysis using a variance components model was performed on 203 452 individuals nested within 145 country cohorts covering 35 countries. Conditional on sociodemographic covariates, we sought to examine the association between self-rated health and individual trust, country average trust and a cross-level interaction between the two. RESULTS Although individual trust perceptions were significantly correlated with self-rated health [OR = 0.95, 95% confidence interval (0.94-0.96)], country-level trust was not associated [OR = 1.12, 95% confidence interval (0.95-1.32)]. There was, however, a strong crosslevel interaction between contextual and individual trust (P < 0.001), such that individuals with high interpersonal trust reported better health in contexts in which other individuals expressed high average interpersonal trust. Conversely, low trust individuals reported worse health in high trust contexts. CONCLUSION Our findings suggest that contexts with increasing average trust can be harmful for low trust individuals, which might reflect the negative impact that social capital can have in certain groups. These findings suggest that contextual trust has a complex role in explaining health inequalities and individual self-rated health.