Methods: We used data from wave 1 through wave 8 of the National Health and Aging Trends Study, a nationally representative longitudinal data among Medicare beneficiaries aged 65 and older. Using an autoregressive cross-lagged panel design, we examined longitudinal relationships between social cohesion, functional disabilities (ADLs), and mental health (PHQ4) among older adults (N = 2,774), who had stayed in the community and residential cares through 8 waves. To decide best-fitted model, autoregressive and cross-lagged models and compared with chi-squares and alternative goodness-of-fit indices.
Results: Among autoregressive cross-lagged models (ADL mediation model, mental health mediation model, full autoregressive cross-lagged model) mental health medication model was best fitted model (χ2 = 1024.85, p<.001; CFI = .97; RMSEA = .04; and SRMR = .08). The results revealed that social cohesion and mental health were stable across eight years, while ADLs increased over time. Study results suggest a bidirectional causal relationship between mental health and functional disabilities over time. Functional disabilities measured one year predicted an increase in mental health in the following year, and mental health also predicted functional disabilities in the subsequent year. Furthermore, the cross-lagged effect of social cohesion was found to positively impact mental health, which indicates that higher social cohesion at a previous time point was associated with better mental health at the next time point. However, the cross-lagged effect of mental health on social cohesion was not found. These results suggest that mental health mediates the effect of social cohesion on functional disabilities among older adults.
Conclusions and Implications: This study clarified the relationships between social cohesion, mental health, and functional disabilities. Beyond identifying reciprocal relationships between physical and mental health, this longitudinal study identified the mediating effect of mental health and the protective role of social cohesion for mental health and functional disabilities in later life. According to the study results, community-based programs that may increase social cohesion among older adults can be effective for older adults’ mental and physical health. An intervention program to increase social cohesion can take place at the neighborhood level or through collaboration from multiple sectors. Thus, interventions such as civic engagement, social participation, and connecting older adults to the community, may be effective ways to increase the social cohesion of older adults.