Investigating the Trivariate Reciprocal Longitudinal Relationships Between Purpose, Loneliness, and Cognitive Function

Objectives As medical interventions for cognitive decline and dementia continue to evolve, the identification of modifiable psychosocial factors has become increasingly important. Sense of purpose and loneliness represent potential targets for intervention. In this study, we aimed to understand the potentially reciprocal relationship between sense of purpose, loneliness, and cognitive function. Methods The current project draws upon data from the Memory and Aging Project and Minority and Aging Research Study led by the Rush Alzheimer's Disease Center, two longitudinal cohort studies of 3,118 older adults (Mage=78.4 years; 75% female; 31% Black) without dementia at enrollment. Participants completed annual assessments of cognitive function and completed self-report measures on sense of purpose and loneliness every year for up to 12 years. Using trivariate random intercept cross-lagged panel models, we examined between-person, prospective within-person, and concurrent within-person associations among sense of purpose, loneliness, and cognitive function. Results At the between-person level, a higher sense of purpose and lower loneliness were associated with better cognitive function. At the prospective within-person level, decreases in sense of purpose and increases in loneliness predicted subsequent cognitive decline, independent of ApoE genotype, race, sex, education, depressive symptoms, and social activity. Discussion Changes in both sense of purpose and loneliness independently predicted cognitive decline in older adults, suggesting these constructs are unique targets for potential interventions to promote cognitive health.