Social capital has previously been reviewed in relation to mental health. However, none have focused specifically on positive aspects of mental health such as mental well-being. This review aimed to explore the relationship between social capital and mental well-being in older people. Ten relevant databases were systematically searched using an extensive search strategy for studies, analyzing the link between social capital and mental well-being. Criteria for inclusion in the systematic review were: the study sample included older people (≥50 years); the study reported a mental well-being outcome; social capital was an exposure variable; and empirical research using quantitative methods and published in English, between January 1990 and September 2011. Eleven studies met the inclusion criteria. Each study was assessed against seven possible exposure measures (structural, cognitive; bonding, bridging, linking; individual, collective). The results showed that all included studies found positive associations between parts of social capital and aspects of mental well-being. Typically, the relationship between social capital and mental well-being differed within as well as between studies. Our results highlight that there is no 'gold standard' of how to measure social capital or mental well-being. Social capital is generated in the interaction between individual and collective life. A possibility for future research is therefore to follow Bronfenbrenner's classical division into macro, meso, and micro levels. We consider family and friends at the micro level to be the key factors in generating social capital and well-being in older people.

BackgroundPrevious studies of loneliness have largely focused on establishing risk factors in specific age groups such as in later life or in young people. Researchers have paid less attention to the link between social capital and loneliness across different age groups. The aim of this study was to examine the association between social capital and experienced loneliness in different age groups in a Finnish setting.MethodsThe data originates from a population-based cross-sectional survey conducted among 4618 people aged 15–80 in Western Finland in 2011. The response rate was 46.2 %. The association between social capital, measured by frequency of social contacts, participation in organisational activities, trust and sense of belonging to the neighbourhood and loneliness was tested by logistic regression analyses stratified by four age groups.ResultsFrequent loneliness (defined as experienced often or sometimes) was higher among younger people (39.5 %) compared to older people (27.3 %). Low levels of trust were linked to loneliness in all four age groups. The association between other aspects of social capital and loneliness varied across age groups.ConclusionsFrequent loneliness is common among the general adult population and could be seen as a public health issue. Our findings imply that low social capital, especially in terms of low trust, may be a risk factor for loneliness. However, further research is needed to assess the influence of poor health and reverse causality as explanations for the findings.

Social capital and loneliness are context dependent (i.e., geographical or living environment). Among the very old, the link between social capital resources and loneliness is also highly influenced by health status.

Our review highlights the lack of evidence and the diversity among trials, while supporting the potential of social capital interventions to reach comprehensive health effects in older adults.

The findings underline the connection between adequate levels of both structural and cognitive individual social capital and mental health in later life. They also suggest that the connection differs depending on various network types; the cognitive aspect of relationships between friends was connected to depression, while the connection was not found for neighbours. Further, the oldest age group in the sample (80 years of age) is pointed out as a population especially vulnerable for depression that should not be overlooked in mental health promotion and depression prevention.