Association of the Big Five personality traits with cognitive decline: a 24-week multidomain intervention study

Multidomain lifestyle interventions have been implemented internationally to improve cognitive function affected by neurodegenerative changes; however, treatment effects vary across individuals. Personality traits are established correlates of cognitive function, but their potential association with individual differences in response to such interventions remains unclear.

This 24-week prospective study investigated the associations between personality traits and cognitive trajectories among participants within the SoUth Korean study to PrEvent cognitive impaiRment and protect BRAIN health through lifestyle intervention in at-risk older adults (SUPERBRAIN) randomized controlled trial. A total of 136 older adults (mean age = 71.6 years; 64% women) who completed the intervention were included. Personality traits were assessed at baseline using the ten-item Big Five Inventory, and cognitive function was evaluated using the Korean Mini-Mental State Examination at baseline and follow-up. Logistic regression models were adjusted for sociodemographic factors, family history of dementia, health behaviors, depressive symptoms, and daily functioning.

Among the five personality domains, only extraversion was significantly associated with reduced odds of cognitive decline within the intervention group over 24 weeks (fully adjusted model: OR = 0.35; 95% CI: 0.15-0.82).

These findings suggest that personality traits may be associated with cognitive stability and highlight the importance of considering personality profiles when understanding inter-individual variability in multidomain dementia prevention strategies.