Sustained purpose in life is associated with slower cognitive decline in older adults: A longitudinal analysis with a diverse national sample

Objectives
Purpose in life is positively associated with cognitive function and better maintenance of cognitive function over time in aging adults. However, purpose in life itself declines over time, and we examined whether such changes are related to changes in cognition and whether this varied by race and ethnicity.

Method
The current study used three waves of data from the nationally representative survey, Health and Retirement Study (HRS; N = 9,808), to examine the longitudinal associations between purpose in life and cognitive function in White, Black, and Hispanic adults age 65 and older. Purpose in life was measured using the 7-item version of the Ryff Psychological Well-Being scale. Cognitive function was assessed using a modified version of the TICS (Telephone Interview for Cognitive Status).

Results
Growth curve models showed that purpose in life and cognitive function both declined over time, initial levels of purpose and cognitive function were positively associated, and less decline in purpose was associated with less decline in cognitive function. Addition of interaction terms for race and ethnicity showed that the positive association between initial levels of purpose in life and cognitive function was stronger in Black participants than in White or Hispanic participants; there were no racial or ethnic differences in the longitudinal associations.

Discussion
These results show that maintaining higher levels of purpose in life may protect cognitive abilities in older adults from diverse racial and ethnic groups.