Is personality associated with dementia risk? A meta-analytic investigation

This study provides a quantitative synthesis of the prospective associations between personality traits (neuroticism, extraversion, openness, agreeableness, conscientiousness) and the risk of incident Alzheimer's disease and related dementias. We conducted five separate meta-analyses with 8-12 samples (N = 30,036 to 33,054) that were identified through a systematic literature search following the MOOSE guidelines. Higher neuroticism (HR = 1.24, 95% CI [1.17, 1.31]) and lower conscientiousness (HR = 0.77, 95% CI [0.73, 0.81]) were associated with increased dementia risk, even after accounting for covariates such as depressive symptoms. Lower extraversion (HR = 0.92, 95% CI [0.86, 0.97]), openness (HR = 0.91, 95% CI [0.86, 0.96]), and agreeableness (HR = 0.90, 95% CI [0.83, 0.98]) were also associated with increased risk, but these associations were less robust and not significant in fully adjusted models. No evidence of publication bias was found. The strength of associations was unrelated to publication year (i.e., no evidence of winner's curse). Meta-regressions indicated consistent effects for neuroticism, openness, and conscientiousness across methods to assess dementia, dementia type, follow-up length, sample age, minority, country, and personality measures. The association of extraversion and agreeableness varied by country. Our findings indicate robust associations of neuroticism and conscientiousness with dementia risk.