Personality and Transition From Mild Cognitive Impairment to Normal Cognition vs Dementia.

Objectives: Mild cognitive impairment (MCI) is a critical stage preceding incident dementia, but not all individuals with MCI progress to dementia and some revert to normal cognition. This study examined whether personality is associated with the probability of transition from MCI to normal cognition or dementia.

Design: Longitudinal observational study.

Setting And Participants: Older adults with MCI from the Health and Retirement Study (N = 1608, 56% female, mean age = 72.29, SD = 9.91). Personality traits; cognitive status; and demographic (age, sex, education, race, and ethnicity), clinical (diabetes, hypertension), behavioral (smoking, physical activity), psychological (depressive symptoms), and genetic (apolipoprotein E ε4) covariates were obtained in 2006/2008. Follow-up data on cognitive status were collected every 2 years up to the 2020 wave.

Methods: Cox regression analyses tested the association between personality and reversion from MCI to normal cognition and progression to dementia, controlling for demographic, clinical, behavioral, psychological, and genetic covariates.

Results: Controlling for demographic factors, lower neuroticism and higher openness and conscientiousness were associated with a higher likelihood of reversion from MCI to normal cognition and a lower risk of progression to dementia over time. Higher agreeableness was related to a lower risk of progression to dementia. Clinical, behavioral, psychological, and genetic factors partially accounted for these associations. There was little evidence that demographic, genetic factors, or baseline cognition moderated these associations.

Conclusions And Implications: Personality traits can help identify individuals who are more likely to revert from MCI and not progress to dementia. These findings suggest that even during mild impairment, personality may modulate dementia risk and thus inform targeted interventions.