Does personality affect the cognitive decline in aging? A systematic review

Cognitive decline is a natural consequence of aging, but several genetic, environmental, and psychological factors can influence its trajectories. Among the most enduring factors, the Big Five personality traits – defined as relatively stable tendencies to think, behave, and react to the environment – can influence the risk of developing dementia and mild cognitive impairment (MCI) – a preclinical form of cognitive decline - directly (e.g., by physiological correlates) and indirectly (e.g., healthy or risky behaviors). Despite the great number of studies focusing on the relationship between personality and cognitive decline, an updated systematic synthesis of the results, including a broader range of study designs, is still lacking. This systematic review aims to summarize the findings of studies investigating three key areas: (i) differences in personality traits between groups of healthy individuals and those with MCI, (ii) the impact of personality traits on the risk for both MCI and dementia, and (iii) changes in personality traits among individuals progressing from normal cognition to MCI. The results indicated that Neuroticism is a significant risk factor for MCI and dementia. Conversely, Conscientiousness and Openness are found to offer protection against dementia and moderate cognitive decline. These findings suggest a pivotal role of personality structure in shaping long-term cognitive outcomes and may be useful in planning psychological interventions to prevent or delay cognitive decline.