The relationship between personality traits and Alzheimer's disease: a narrative review

The relationship between personality traits and Alzheimer's disease (AD) has received increasing attention in recent research. A narrative literature search was conducted in PubMed (2014-2025) using predefined keywords, with studies selected based on relevance and methodological quality. Personality traits-particularly high neuroticism and low conscientiousness-have been consistently associated with an increased risk of AD, influencing both its onset and clinical progression. Neuroticism emerges as the most robust and consistent risk factor, linked to accelerated cognitive decline, increased risk of mild cognitive impairment (MCI), and dementia through biological, psychological, and behavioral pathways. In contrast, conscientiousness appears to exert a protective effect, being associated with reduced risk of cognitive decline and greater cognitive resilience, likely mediated by health-related behaviors and neurobiological mechanisms. Extraversion and openness show more variable and context-dependent associations, with some evidence suggesting protective roles through social engagement and cognitive reserve, whereas agreeableness demonstrates weak and inconsistent relationships with AD risk. Longitudinal studies provide the strongest evidence, indicating that personality traits act as premorbid risk or protective factors rather than solely reflecting disease-related changes, while cross-sectional findings primarily capture the clinical phenotype of AD. Overall, personality traits contribute to individual differences in vulnerability to cognitive decline, highlighting their potential utility in early risk identification and prevention strategies.