The prevalence of depressive symptoms in older Chinese adults has increased recently. Intergenerational relationships play an important role in the mental health conditions of older adults, especially in Chinese culture. Therefore, this study aims to unravel the complex connection between intergenerational relationships and depression, and to explore the potential mediating roles of loneliness and nighttime insomnia symptoms within that connection. A cross-sectional household survey was conducted in China with 2038 participants aged 65 years or above. Variables were measured using the Center for Epidemiologic Studies Short Depression Scale, the Intergenerational Relationship Quality Scale for Aging Chinese Parents (IRQS-AP), three nighttime insomnia symptoms extracted from the Insomnia Severity Index and the De Jong Gierveld Six-Item Loneliness Scale. The IRQS-AP includes four subdimensions: consensual-normative solidarity, structural-associational solidarity, affectual closeness and intergenerational conflicts. Path analyses were performed in Mplus to investigate regression coefficients and mediating effects. Results showed that three general intergenerational relationships (consensual-normative solidarity, affectual closeness and intergenerational conflicts) were significantly correlated with all mental health outcomes, including their symptoms of loneliness, insomnia and depression. A serial mediation model suggested that loneliness mediated the connection between those constructs of intergenerational relationships and depression, with an independent path to insomnia symptoms via loneliness. The proposed mediators fully mediated the effects of affectual closeness on depression. Nighttime insomnia symptoms alone mediated only the relationship between intergenerational conflicts and depression independently from paths involving depression. Removal of sleep item from CES-D did not affect the results of paths. Our findings highlight the importance of intergenerational relationships for mental health, especially for the mediating effects of loneliness and nighttime insomnia symptoms on the relationship between intergenerational relationships and depression. Effective mental health services for older adults can address their feelings of loneliness and sleep problems, especially for those who have a poor relationship with their adult children.
