Personality predictors of dementia diagnosis and neuropathological burden: An individual participant data meta-analysis

Abstract

Introduction: The extent to which the Big Five personality traits and subjective well-being (SWB) are discriminatory predictors of clinical manifestation of dementia versus dementia-related neuropathology is unclear.

Methods: Using data from eight independent studies (N_total = 44,531; N_dementia = 1703; baseline M_age = 49 to 81 years, 26 to 61% female; M_follow-up range = 3.53 to 21.00 years), Bayesian multilevel models tested whether personality traits and SWB differentially predicted neuropsychological and neuropathological characteristics of dementia.

Results: Synthesized and individual study results indicate that high neuroticism and negative affect and low conscientiousness, extraversion, and positive affect were associated with increased risk of long-term dementia diagnosis. There were no consistent associations with neuropathology.

Discussion: This multistudy project provides robust, conceptually replicated and extended evidence that psychosocial factors are strong predictors of dementia diagnosis but not consistently associated with neuropathology at autopsy.

Highlights: N(+), C(-), E(-), PA(-), and NA(+) were associated with incident diagnosis. Results were consistent despite self-report versus clinical diagnosis of dementia. Psychological factors were not associated with neuropathology at autopsy. Individuals with higher conscientiousness and no diagnosis had less neuropathology. High C individuals may withstand neuropathology for longer before death.

Keywords: Braak stage; CERAD; Lewy body disease; TDP-43; agreeableness; arteriosclerosis; cerebral amyloid angiopathy; cerebral atherosclerosis; extraversion; gross cerebral infarcts; gross cerebral microinfarcts; hippocampal sclerosis; individual participant data meta-analysis; openness; positive affect; satisfaction with life.

FIGURE 1

Forest plots of prospective associations between eight personality characteristics and incident dementia diagnoses. Point estimates (OR) represent the exponentiated mean of the posterior distribution. Interval estimates represent the 95% credible intervals (CI) of the exponentiated posterior distribution of the overall estimate and linear combinations of the overall estimate and random effects for sample‐specific estimates. N indicates the sample size with complete data for each predictor, outcome, and set of covariates.

FIGURE 2

Forest plots of significant overall and sample‐specific estimates of age (in years, centered at 60) and education (in years, centered at 12) moderating the association between Big Five personality characteristics (8) and later dementia diagnosis (left). OR = median exponentiated log odds ratio of the posterior; CI = 95% Bayesian credible interval. Simple effects plots visualizing the relationship between conscientiousness (in POMP units, 0 to 10) and probability of dementia diagnosis (OR) across ages in all samples (overall; thick, black lines) and for each sample separately (shaded and dashed lines).

FIGURE 3

Forest plots of overall and sample‐specific estimates of clinical dementia diagnosis (0 = no, 1 = yes) moderating the association between Big Five personality characteristics (8) and neuropathology indicators at autopsy (left). OR = median exponentiated log odds ratio of posterior; CI = 95% Bayesian credible interval. Simple effects plots visualizing the relationship between conscientiousness (in POMP units, 0 to 10) and neuropathology (in stages 0 to 6 for Braak stage across all samples (overall; thick, black lines) and for each sample separately (shaded lines).