Societal Adaptation to Aging and Prevalence of Depression Among Older Adults: Evidence From 20 Countries.

Policy Points Countries have adopted different strategies to support aging populations, which are broadly reflected in social, economic, and contextual environments. Referred to as "societal adaptation to aging," these factors affect countries' capacity to support older adults. Results from our study show that countries with more robust societal adaptation to aging had lower depression prevalence. Reductions in depression prevalence occurred among every investigated sociodemographic group and were most pronounced among the old-old. Findings suggest that societal factors have an underacknowledged role in shaping depression risk. Policies that improve societal approaches to aging may reduce depression prevalence among older adults.

Context: Countries have adopted various formal and informal approaches to support older adults, which are broadly reflected in different policies, programs, and social environments. These contextual environments, broadly referred to as "societal adaptation to aging," may affect population health.

Methods: We used a new theory-based measure that captured societal adaptation to aging, the Aging Society Index (ASI), which we linked with harmonized individual-level data from 89,111 older adults from 20 countries. Using multi-levels models that accounted for differences in the population composition across countries, we estimated the association between country-level ASI scores and depression prevalence. We also tested if associations were stronger among the old-old and among sociodemographic groups that experience more disadvantage (i.e., women, those with lower educational attainment, unmarried adults).

Findings: We found that countries with higher ASI scores, indicating more comprehensive approaches to supporting older adults, had lower depression prevalence. We found especially strong reductions in depression prevalence among the oldest adults in our sample. However, we did not find stronger reductions among sociodemographic groups who may experience more disadvantage.

Conclusions: Country-level strategies to support older adults may affect depression prevalence. Such strategies may become increasingly important as adults grow older. These results offer promising evidence that improvements in societal adaptation to aging-such as through adoption of more comprehensive policies and programs targeting older adults-may be one avenue to improve population mental health. Future research could investigate observed associations using longitudinal and quasi-experimental study designs, offering additional information regarding a potential causal relationship.