Does personality affect risk for dementia? A systematic review and meta-analysis.

Objective: A life course epidemiologic approach suggests that personality may have lifelong pathways of influence on risk of dementia and mild cognitive impairment (MCI). This article aimed to systematically review case-control and prospective studies on the association between personality and risk of these cognitive disorders.

Methods: Studies were identified through Scopus, Medline, PubMed, and PsycINFO. Searches combined terms for personality with those for dementia and MCI. Data were extracted and checked by a second reviewer, systematically reviewed, and meta-analyzed where appropriate.

Results: Twelve longitudinal and three case-control studies were included. Five of nine studies found that higher neuroticism was associated with greater dementia risk (pooled hazard ratio [HR] per unit increase on neuroticism score, HR = 1.13, 95% confidence interval [CI] = 1.08-1.18, z = 5.11, p <0.001, N = 3,285), and two studies showed it increased risk of MCI. Three of four studies showed that higher conscientiousness was protective against dementia (pooled HR = 0.88, 95% CI = 0.81-0.97, z = 3.34, p = 0.001, N = 1,687), and one of two studies suggested it reduced risk of MCI. Three of four studies found no association between openness and dementia; however, pooled data suggested openness was protective (HR = 0.88, 95% CI = 0.81-0.97, z = 2.34, p = 0.008, N = 1,687). Seven studies indicated that extraversion was not linked with dementia, and four found no association between agreeableness and dementia.

Conclusions: Neuroticism increased risk for dementia, and conscientiousness reduced risk. The protective effect of openness was tentative. Extraversion and agreeableness were not associated with dementia. Personality should be incorporated in conceptual models of dementia risk. Clinicians and public health professionals should consider personality when planning dementia risk reduction strategies.