Chronic disease multimorbidity and mental health among older adults in China: The moderating roles of family and social support

Population aging has been accompanied by a growing prevalence of chronic disease multimorbidity among older adults, raising increasing concerns about its implications for mental health. Although previous studies have documented the negative association between multimorbidity and mental health, evidence regarding how support systems influence this relationship remains limited. Using nationally representative cross-sectional data from the 2020 China Longitudinal Aging Social Survey (CLASS), this study examined the association between self-reported multimorbidity and mental health among older adults in China, with particular attention to the moderating roles of family support and social support. Multivariate regression models incorporating interaction terms were employed to estimate both direct and interaction effects. The results indicate that, first, multimorbidity is significantly associated with poorer mental health among older adults. Second, although both social support and family support are positively associated with better mental health, only family support significantly moderates the association between multimorbidity and mental health. Third, marginal effects analysis shows that the negative association between multimorbidity and mental health becomes progressively stronger as the level of family support increases. Fourth, subgroup analysis reveals that the direct association between family support and mental health follows a U-shaped pattern across age groups, whereas its moderating effect on the relationship between multimorbidity and mental health gradually weakens with advancing age and becomes statistically insignificant among adults aged 80 years and above. These findings contribute to a more nuanced understanding of interpersonal resources in later life and highlight the need to integrate family-centered approaches into geriatric care and mental health interventions for older adults living with multimorbidity.