Background An association between social isolation, loneliness and disability and ill-health has been found previously. Limited data are available on the effect of quality of social relationships on physical and psychosocial health. This study aimed to determine if social networks were associated with physical and mental health in adults aged over 50 in Ireland and whether these effects were influenced by the quality of the social relationships.

Methods We analysed two waves (2009–2011, and 2012–2013) of the Irish Longitudinal Study of Ageing (TILDA), a stratified probability sample prospective cohort of men and women aged over 50, resident in Ireland. A total of 4,575 respondents were included. We used multivariate regression models to determine whether social integration, family structure and quality of social relationships was associated with 2-year changes in mental and physical health outcomes, adjusting for age, socio-economic variables, and baseline health measures. Number of physical impairments (IADL), loneliness (UCLA scale), depression (20-item Centre for Epidemiological Studies Depression (CES-D) scale), and Quality of Life (CASP 19) were outcomes. Social integration (Berkman-Syme scale), proximity to children and quality of relationships measured through measures of social support and relationship strain from spouse/partners, children, other family members and friends were examined. All analyses were conducted in STATA 12.

Results Both social network (social integration, numbers and proximity to children) and positive and negative social exchanges with partners and with children were independently associated with depression, loneliness and quality of life, adjusting for age, gender, wealth, employment and baseline depression. Negative relationships with children were associated with an increase in physical impairments, and positive relationships with spouse with reduced physical impairments. Positive relationships with spouses (OR 0.88, 95% CI 0.0.83–0.95) and friends (OR 0.90, 95% CI 0.85–0.95) were associated with a reduced likelihood of severe depression (CESD > 15). The negative effect of disability on mental health and well-being was attenuated by positive social relationships.

Conclusion Social networks and negative and positive relationships with partners and children are important for depression onset, loneliness and quality of life. While social network may decrease in older people, these findings highlight the importance of the quality of social relationships within the social support network for long-term health and well-being.