Unconditional quantile regression analysis of volunteering and cognitive functioning: Implications for cognitive impairment and dementia.

INTRODUCTION: Volunteering is widely recognized for its health benefits, including improved cognitive functioning and delayed onset of cognitive impairment and dementia. However, the extent to which these cognitive benefits vary across individuals with different levels of cognitive functioning, particularly among those with cognitive impairment, remains unclear.

METHODS: This study used 195,633 person-wave observations from 31,371 adults in the Health and Retirement Study (HRS; 1998-2020). Unconditional quantile regression (UQR) models with fixed effects were employed to examine how the cognitive benefits of volunteering-measured by participation status and annual time commitment-differ across the population distribution of cognitive functioning.

RESULTS: Volunteering was associated with better cognitive functioning on average, but the benefits were most pronounced at the lower end of the distribution, corresponding to those experiencing cognitive impairment or probable dementia. Moderate engagement (approximately 2-4 hours per week) yielded the largest cognitive benefits for these groups, while benefits plateaued at higher levels of engagement.

CONCLUSIONS: Volunteering may serve as a scalable, lifestyle-based strategy for maintaining or improving cognitive health, particularly among those at risk for or already experiencing cognitive decline. These findings highlight the importance of tailoring volunteer opportunities to match individual capacities and suggest that even modest engagement can produce meaningful cognitive benefits.