Impact of Personality on Cognitive Aging: A Prospective Cohort Study

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 both directly (e.g., by physiological correlates) and indirectly (e.g., healthy or risky behaviors) the risk of developing dementia and mild cognitive impairment (MCI) - a preclinical form of cognitive decline. Despite the great amount 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: (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. Neuroticism emerged as a significant risk factor for MCI and dementia; Conscientiousness and Openness appear to offer protection against dementia and moderate cognitive decline. Overall, these findings suggest a pivotal role of personality structure in shaping cognitive outcomes on the long run.

Psychiatric Disease as a Potential Risk Factor for Dementia: A Narrative Review

Neurodegenerative disease is a major global health problem with 150 million people predicted to have dementia by 2050. Genetic factors, environmental factors, demographics, and some diseases have been associated with dementia. In addition to associations between diseases such as hypertension and cerebrovascular disease and dementia, emerging findings associate some psychiatric disorders with incident dementia. Because of the high and increasing global prevalence of dementia and the high worldwide prevalence of psychiatric disorders, the primary objective of this narrative review was to evaluate published findings that evaluate the association between bipolar disorder, depression, anxiety, post-traumatic stress disorder, obsessive-compulsive disorder, attention-deficit/hyperactivity disorder, autism spectrum disorder, schizophrenia and other psychosis syndromes, and personality disorders and personality traits and incident dementia. Here, we highlight findings indicating possible associations between these psychiatric disorders and subsequent dementia and suggest that some psychiatric disorders may be risk factors for incident dementia. Further research, including more large longitudinal studies and additional meta-analyses, however, is needed to better characterize the associations between psychiatric disorders and incident dementia, to identify possible mechanisms for these putative associations, and to identify risk factors within psychiatric disorders that predispose some people with a psychiatric disorder but not others to subsequent dementia. Additional important questions concern how the treatment of psychiatric disorders might affect the risk of incident dementia.

Revised Temperament and Character Inventory factors predict neuropsychiatric symptoms and aging-related cognitive decline across 25 years

Introduction

Personality traits and neuropsychiatric symptoms such as neuroticism and depression share genetic overlap and have both been identified as risks factors for development of aging-related neurocognitive decline and Alzheimer's disease (AD). This study aimed to examine revised personality factors derived from the Temperament and Character Inventory, previously shown to be associated with psychiatric disorders, as predictors of neuropsychiatric, cognitive, and brain trajectories of participants from a population-based aging study.

Methods

Mixed-effect linear regression analyses were conducted on data for the full sample (Nmax = 1,286), and a healthy subsample not converting to AD-dementia during 25-year follow-up (Nmax = 1,145), complemented with Cox proportional regression models to determine risk factors for conversion to clinical AD.

Results

Two personality factors, Closeness to Experience (CE: avoidance of new stimuli, high anxiety, pessimistic anticipation, low reward seeking) and Tendence to Liabilities (TL: inability to change, low autonomy, unaware of the value of their existence) were associated with higher levels of depressive symptoms, stress (CE), sleep disturbance (TL), as well as greater decline in memory, vocabulary and verbal fluency in the full sample. Higher CE was additionally associated with greater memory decline across 25 years in the healthy subsample, and faster right hippocampal volume reduction across 8 years in a neuroimaging subsample (N = 216). Most, but not all, personality-cognition associations persisted after controlling for diabetes, hypertension and cardiovascular disease. Concerning risks for conversion to AD, higher age, and APOE-ε4, but none of the personality measures, were significant predictors.

Conclusion

The results indicate that personality traits associated with psychiatric symptoms predict accelerated age-related neurocognitive declines even in the absence of neurodegenerative disease. The attenuation of some personality effects on cognition after adjustment for health indicators suggests that those effects may be partly mediated by somatic health. Taken together, the results further emphasize the importance of personality traits in neurocognitive aging and underscore the need for an integrative (biopsychosocial) perspective of normal and pathological age-related cognitive decline.

Association of Self-Reported Psychological Stress with Cognitive Decline: A Systematic Review

Psychological stress is a potential modifiable risk factor for cognitive decline. However, the extent to which self-reported psychological stress is differentially associated with decline in specific cognitive domains remains unclear. Differences may be due to heterogeneity in the aspects of psychological stress investigated, for example, neuroticism (which is linked to vulnerability to stress), perceived stress, or exposure to stressful life events. This review aims to establish the associations between these aspects of self-reported psychological stress and cognitive decline. PsychINFO, Embase and MEDLINE were searched from database inception to September 2021. Studies were included if they were observational, prospective, and if they investigated the association between self-reported psychological stress and cognitive decline in adults with a minimum mean age of 40 years at baseline. Thirty studies satisfied the inclusion criteria, with most examining neuroticism (n = 17) as a predictor of cognitive decline. Fewer examined perceived stress (n = 7) or stressful life events (n = 6). There was evidence of an association between neuroticism and cognitive decline, particularly in the domain of memory. Similarly, across studies, perceived stress was also associated with memory decline. Research investigating the relationship between stressful life events and cognitive decline had fewer outcomes to interpret. Overall, the findings highlight that memory may be particularly susceptible to high levels of neuroticism and perceived stress. We identified a lack of research into some cognitive domains, such as executive function, which should be addressed by future studies.

Openness and age influence cognitive progression: a longitudinal study

BACKGROUND

Some psychological and personality characteristics of individuals seem to determine behavioral patterns that are associated with better health throughout life and, consequently, prevent the progression of early cognitive changes to dementia.

OBJECTIVE

To identify which individuals have modified cognitive ratings after 24 months of follow-up and correlating with personality traits.

METHODS

One hundred and two volunteers were evaluated clinically and for personality characteristics and neuropsychological testing. Of these, 25 subjects were classified as cognitively normal (CN), 25 as subjective cognitive decline (SCD), 28 as nonamnestic mild cognitive impairment (naMCI), and 24 as amnestic mild cognitive impairment (amMCI) at baseline. Follow-up occurred over 2 years from the initial assessment, and the cognitive categories of the participants were re-analyzed every 6 months to observe differences in their classification.

RESULTS

Out of the 102 subjects, 65 remained at follow-up. The sample followed-up longitudinally was composed predominantly of women (65%), white (74%), with a mean age of 78 (±7.5) years old and 12 (±4.8) years of schooling. Throughout the process, 23% of CN, 15% of SDC, and 27% of naMCI individuals worsened cognitively. Amnestic with mild cognitive impairment volunteers remained stable or improved. Individuals with older age show more significant cognitive deterioration, and those with very low or high rates of the openness personality trait are associated with cognitive decline utilizing the Fisher exact test, probably because the open extremes influence choices, stress management, and behavioral maintenance.

CONCLUSION

The factors most associated with cognitive change in this group of older adults were age and the intensity of the openness aspects of personality.

The Big Five as Predictors of Cognitive Function in Individuals with Bipolar Disorder

The connection between cognitive function and the "Big Five" personality traits (openness, conscientiousness, extraversion, agreeableness, and neuroticism) in the general population is well known; however, studies researching bipolar disorder (BD) are scarce. Therefore, this study aimed to investigate the Big Five as predictors of executive function, verbal memory, attention, and processing speed in euthymic individuals with BD (cross-sectional: n = 129, including time point t1; longitudinal: n = 35, including t1 and t2). Participants completed the NEO Five-Factor Inventory, the Color and Word Interference Test, the Trail Making Test, the d2 Test of Attention Revised, and the California Verbal Learning Test. The results showed a significant negative correlation between executive function and neuroticism at t1. Changes in cognitive function between t1 and t2 did not correlate with and could not be predicted by the Big Five at t1. Additionally, worse executive function at t2 was predicted by higher neuroticism and lower conscientiousness at t1, and high neuroticism was a predictor of worse verbal memory at t2. The Big Five might not strongly impact cognitive function over short periods; however, they are significant predictors of cognitive function. Future studies should include a higher number of participants and more time in between points of measurement.

Five-Factor Model Personality Traits and the Trajectory of Episodic Memory: Individual-Participant Meta-Analysis of 471,821 Memory Assessments from 120,640 Participants

OBJECTIVES

Five-factor model (FFM) personality traits are associated with concurrent memory function and risk of incident dementia but are less consistently associated with the change in episodic memory. The present research analyzes multiple large-scale studies with a consistent analytic approach to evaluate the association between personality and change in episodic memory over time.

METHOD

Across nine public longitudinal data sets, 120,640 participants provided 471,821 memory assessments over up to 26 years (age range 18-108). FFM traits were tested as predictors of the average level (intercept) and change over time (slope) of episodic memory. Results from the individual samples were meta-analyzed to summarize the associations.

RESULTS

Consistent with expectations for the intercept, higher neuroticism was associated with worse memory performance, whereas higher openness and conscientiousness were associated with better performance; extraversion and agreeableness were also associated with better performance. Higher neuroticism and lower conscientiousness were related to declines in memory only in samples with more than two assessments of memory. The other three traits were unrelated to memory slope. The pattern was similar when participants with dementia were excluded from the analysis, and the association with the slope was not moderated by age.

DISCUSSION

FFM traits have a robust association with average memory performance. Higher neuroticism and lower conscientiousness were associated with declines in memory performance only among samples with more than two memory assessments. The heterogeneity across studies suggests that multiple memory assessments are needed to reliably detect change over time, which may be one reason for past inconsistencies across studies.

Insights about personality traits and cognitive performance and decline in adults 51-59 Years old from the Wisconsin longitudinal study

OBJECTIVES

To delineate midlife personality dimensions of early cognitive change in an age-homogenous sample of U.S. older adults.

DESIGN

Longitudinal study of 6133 adults from the Wisconsin Longitudinal Study (WLS).

MEASURES

Middle-aged participants (mean age = 53.2; SD = 0.6) from the WLS completed the 'Big-5' personality assessment in 1992. Mixed effects models examined whether midlife personality traits were associated with change in cognitive performance from participant's mid-60s (2004-2005) to early 70s (2011). The cognitive battery assessed abstract reasoning (AR), category fluency (CF), working memory (WM), and delayed verbal memory (DVM). Models adjusted for sex, education, and subjective health.

RESULTS

High Openness was a significant predictor of change in AR, CF, and DVM. These cognitive outcomes declined less among those with high Openness, but the effect sizes for Openness by time were small (R2 s < 0.01). AR and CF were characterized by higher overall performance with high Openness, but with relatively parallel change for the highest and lowest Openness quartiles. There was no advantage of Openness to DVM by the second assessment. High Conscientiousness was a predictor of more change for DVM, though the effect size was small (R 2  < 0.01).

CONCLUSIONS

None of the midlife personality traits were uniformly associated with change in cognitive performance in early older adulthood. High midlife Openness had the most noteworthy impact on cognition. Interventions designed to target Openness have potential to elevate and maintain a higher threshold of performance in some cognitive domains, but may only have a small impact on cognitive change.

The effect of perceived stress on cognition is mediated by personality and the underlying neural mechanism

Perceived stress impairs cognitive function across the adult lifespan, but the extent to which cognition decline is variable across individuals. Individual differences in the stress response are described as personality traits. Substantial individual differences in the magnitude of cognitive impairment that is induced by short-term perceived stress are poorly understood. The present study tested the hypothesis that the relationship between short-term perceived stress and different aspects of cognition is mediated by personality traits. The study included 1066 participants with behavior and neuroimaging data from the Human Connectome Project after excluding individuals with missing variables. In the result, the parallel multiple mediation model demonstrated that the influence of perceived stress on the total and crystalized cognition is mainly mediated by neuroticism (indirect effect = -0.04, p < 0.05) and conscientiousness (indirect effect = 0.05, p < 0.05) in adults. Cortical thickness value (n = 1066) of the right superior frontal gyrus (SFG) showed not only positive correlations with short-term perceived stress and neuroticism, but negative associations with cognition. The chain mediation model found that the right SFG and neuroticism play a small but significant chain mediating effect between stress and total cognition. The strength of the resting-state functional connectivity (n = 968) between the left orbitofrontal cortex versus the left superior medial frontal cortex was positively correlated with crystallized cognition and negatively associated with conscientiousness. These results extend previous findings by the impacts of short-term perceived stress on cognitive function is mediated by neuroticism and the right SFG was the underlying neural mechanism.

Mediation of perceived stress and cortisol in the association between neuroticism and global cognition in older adults: A longitudinal study

Neuroticism has been associated with a greater dementia risk, but its association with cognitive decline in healthy older adults remains unclear. Stress has been proposed as one of the mechanisms that could explain this relationship. Our aim was to analyse, in healthy older people, the mediating role of perceived stress and the Hypothalamic-Pituitary-Adrenal (HPA) axis in the association between neuroticism and global cognition. At Waves 1 and 2 (4-year follow-up), 87 older people (49.4% women; M age = 65.08, SD = 4.54 at Wave 1) completed a neuropsychological battery and the Perceived Stress Scale (PSS), and provided saliva samples on two (Wave 1) and three (Wave 2) consecutive days to measure the wake-to-bed slope. In Wave 2, neuroticism was assessed with the NEO-Five-Factor Inventory. PSS, but not the wake-to-bed slope, mediated the negative associations between neuroticism and global cognition (Waves 1, 2 and change). Regarding gender differences, PSS (Waves 1, 2 and change) and the wake-to-bed slope (Wave 2 and change) mediated these associations in men. Our results suggest that perceived stress and HPA-axis dysregulation could act as mechanisms underlying the association between neuroticism and cognitive functioning and decline, at least in older men.

Personality Associations With Amyloid and Tau: Results From the Baltimore Longitudinal Study of Aging and Meta-analysis

BACKGROUND

Higher neuroticism and lower conscientiousness are risk factors for Alzheimer's disease and related dementias, but the underlying neuropathological correlates remain unclear. Our aim was to examine whether personality traits are associated with amyloid and tau neuropathology in a new sample and meta-analyses.

METHODS

Participants from the BLSA (Baltimore Longitudinal Study of Aging) completed the Revised NEO Personality Inventory and underwent amyloid (11C-labeled Pittsburgh compound B) and tau (18F-flortaucipir) positron emission tomography.

RESULTS

Among cognitively normal BLSA participants, neuroticism was associated with higher cortical amyloid burden (odds ratio 1.68, 95% CI 1.20-2.34), and conscientiousness was associated with lower cortical amyloid burden (odds ratio 0.61, 95% CI 0.44-0.86). These associations remained significant after accounting for age, sex, education, depressive symptoms, hippocampal volume, and APOE ε4. Similar associations were found with tau in the entorhinal cortex. Random-effects meta-analyses of 12 studies found that higher neuroticism (N = 3015, r = 0.07, p = .008) and lower conscientiousness (N = 2990, r = -0.11, p < .001) were associated with more amyloid deposition. Meta-analyses of 8 studies found that higher neuroticism (N = 2231, r = 0.15, p < .001) and lower conscientiousness (N = 2206, r = -0.14, p < .001) were associated with more tau pathology. The associations were moderated by cognitive status, with stronger effects in cognitively normal compared with heterogeneous samples, suggesting that the associations between personality and proteopathies are not phenomena that emerge with neuropsychiatric clinical symptoms.

CONCLUSIONS

By aggregating results across samples, this study advances knowledge on the association between personality and neuropathology. Neuroticism and conscientiousness may contribute to resistance against amyloid and tau neuropathology.

Personality traits are consistently associated with blood mitochondrial DNA copy number estimated from genome sequences in two genetic cohort studies

Background

Mitochondrial DNA copy number (mtDNAcn) in tissues and blood can be altered in conditions like diabetes and major depression and may play a role in aging and longevity. However, little is known about the association between mtDNAcn and personality traits linked to emotional states, metabolic health, and longevity. This study tests the hypothesis that blood mtDNAcn is related to personality traits and mediates the association between personality and mortality.

Methods

We assessed the big five personality domains and facets using the Revised NEO Personality Inventory (NEO-PI-R), assessed depressive symptoms with the Center for Epidemiologic Studies Depression Scale (CES-D), estimated mtDNAcn levels from whole-genome sequencing, and tracked mortality in participants from the Baltimore Longitudinal Study of Aging. Results were replicated in the SardiNIA Project.

Results

We found that mtDNAcn was negatively associated with the Neuroticism domain and its facets and positively associated with facets from the other four domains. The direction and size of the effects were replicated in the SardiNIA cohort and were robust to adjustment for potential confounders in both samples. Consistent with the Neuroticism finding, higher depressive symptoms were associated with lower mtDNAcn. Finally, mtDNAcn mediated the association between personality and mortality risk.

Conclusions

To our knowledge, this is the first study to show a replicable association between mtDNAcn and personality. Furthermore, the results support our hypothesis that mtDNAcn is a biomarker of the biological process that explains part of the association between personality and mortality.

Funding

Support for this work was provided by the Intramural Research Program of the National Institute on Aging (Z01-AG000693, Z01-AG000970, and Z01-AG000949) and the National Institute of Neurological Disorders and Stroke of the National Institutes of Health. AT was also supported by the National Institute on Aging of the National Institutes of Health Grant R01AG068093.

Subjective Cognitive Decline: Is a Resilient Personality Protective Against Progression to Objective Cognitive Impairment? Findings from Two Community-Based Cohort Studies

BACKGROUND

Subjective cognitive decline (SCD) is related to personality functioning and risk of subsequent objective cognitive impairment.

OBJECTIVE

The aim of this study was to examine whether lower neuroticism and higher conscientiousness-resilient personality traits-protect against conversion from SCD to objective cognitive impairment in two longitudinal community-based cohorts.

METHODS

Data from the Health and Retirement Study (N = 1,741, Mean age = 68.64 years, Follow-up mean = 7.34 years) and the National Health and Aging Trends Survey (N = 258, Mean age = 79.34 years, Follow-up mean = 4.31 years) were analyzed using Cox regression analysis, controlling for sociodemographic covariates, symptoms of anxiety and depression, and apolipoprotein ɛ4.

RESULTS

The pooled results showed that lower neuroticism and higher conscientiousness were associated with decreased risk of conversion from SCD to objective cognitive impairment.

CONCLUSION

Among individuals with SCD, those with a resilient personality may have more cognitive and psychological reserve to maintain cognitive functioning and delay conversion to objective cognitive impairment. The findings further contribute to a better understanding of personality along the cognitive continuum: The observed effect sizes were smaller than those reported in cognitively normal individuals but larger than in individuals with mild cognitive impairment. Personality could provide useful information to identify individuals with SCD who may develop objective cognitive impairment-namely those who hold a vulnerable personality (higher neuroticism, lower conscientiousness).

Determinants of Cognitive Trajectories in Normal Aging: A Longitudinal PET-MRI Study in a Community-based Cohort

BACKGROUND

The determinants of the progressive decrement of cognition in normal aging are still a matter of debate. Alzheimer disease (AD)-signature markers and vascular lesions, but also psychological variables such as personality factors, are thought to have an impact on the longitudinal trajectories of neuropsychological performances in healthy elderly individuals.

OBJECTIVE

The current research aimed to identify the main determinants associated with cognitive trajectories in normal aging.

METHODS

We performed a 4.5-year longitudinal study in 90 older community-dwellers coupling two neuropsychological assessments, medial temporal atrophy (MTA), number of cerebral microbleeds (CMB), and white matter hyperintensities (WMH) at inclusion, visual rating of amyloid and FDG PET at follow-up, and APOE genotyping. Personality factors were assessed at baseline using the NEO-PIR. Univariate and backward stepwise regression models were built to explore the association between the continuous cognitive score (CCS) and both imaging and personality variables.

RESULTS

The number of strictly lobar CMB at baseline (4 or more) was related to a significant increase in the risk of cognitive decrement. In multivariable models, amyloid positivity was associated with a 1.73 unit decrease of the CCS at follow-up. MTA, WMH and abnormal FDG PET were not related to the cognitive outcome. Among personality factors, only higher agreeableness was related to better preservation of neuropsychological performances.

CONCLUSION

CMB and amyloid positivity are the only imaging determinants of cognitive trajectories in this highly selected series of healthy controls. Among personality factors, higher agreeableness confers a modest but significant protection against the decline of cognitive performances.

How do older drivers perceive visual information under increasing cognitive load? Significance of personality on-road safety

The ability to properly receive information and respond to stimuli is a prerequisite for road safety. The aim of this study was to determine the changes in oculomotor activity under conditions of increasing cognitive load depending on personality traits in older drivers (65 years and above). We assessed 44 male active drivers (M = 69, SD = 8.1) in a road traffic simulator in the dual-task paradigm: n-back reaction test (central task) and memory test (peripheral task). During the test in the simulator, oculomotor activity was recorded. Drivers' personality traits were determined using the EPQ-R questionnaire. With the increase of cognitive load in drivers with high levels of neuroticism and extraversion, the time of saccades and fixation significantly increased. The decrease in the effectiveness of visual attention shifting in older drivers intensified as the difficulty of performing tasks increased and manifested itself in longer saccade and fixation times. A higher level of neuroticism and the resulting stress and emotional tension can translate into a greater tendency to make mistakes in older drivers.

Is neuroticism differentially associated with risk of Alzheimer's disease, vascular dementia, and frontotemporal dementia?

This study examines whether neuroticism is differentially associated with risk of incident Alzheimer's disease (AD), vascular dementia (VD), and frontotemporal dementia (FTD) using a prospective study design. Participants from the UK Biobank (N = 401,422) completed a self-report neuroticism scale in 2006-2010 and incident all-cause dementia, AD, VD, and FTD were ascertained using electronic health records or death records up to 2018. During an average follow-up of 8.8 years (3,566,123 person-years), there were 1798 incident of all-cause dementia, 675 AD, 376 VD, and 81 FTD. Accounting for age and sex, compared to individuals in the low quartile, individuals in the top quartile of neuroticism had higher risk of all-cause dementia (HR = 1.70; 95% CI: 1.49-1.93), AD (HR = 1.42; 1.15-1.75), VD (HR = 1.73; 1.30-2.29), but not FTD (HR = 0.89; 0.49-1.63). The associations with AD and VD were attenuated but remained significant after further accounting for education, household income, deprivation index, diabetes, hypertension, stroke, heart attack, ever smoker, physical activity, obesity, hemoglobin A1c, C-reactive protein, and low-density lipoprotein. The associations were not moderated by socioeconomic status. The findings were consistent in analyses that excluded cases that occurred within the first 5 years of follow-up. In conclusion, neuroticism is a robust predictor of incident AD and VD, but not FTD. This pattern suggests that the affective symptoms that distinguish dementia types may partly reflect premorbid differences in trait neuroticism.

Self-reported and mother-rated personality traits at age 16 are associated with cognitive function measured concurrently and 30 years later

BACKGROUND

Models of personality and health suggest that personality contributes to health outcomes across adulthood. Personality traits, such as neuroticism and conscientiousness, have long-term predictive power for cognitive impairment in older adulthood, a critical health outcome. Less is known about whether personality measured earlier in life is also associated with cognition across adulthood prior to dementia.

METHODS

Using data from the British Cohort Study 1970 (N = 4218; 58% female), the current research examined the relation between self-reported and mother-rated personality at age 16 and cognitive function concurrently at age 16 and cognitive function measured 30 years later at age 46, and whether these traits mediate the relation between childhood social class and midlife cognition.

RESULTS

Self-reported and mother-rated conscientiousness at age 16 were each associated with every cognitive measure at age 16 and most measures at age 46. Self-reported openness was likewise associated with better cognitive performance on all tasks at age 16 and prospectively predicted age 46 performance (mothers did not rate openness). Mother-rated agreeableness, but not self-reported, was associated with better cognitive performance at both time points. Adolescent personality mediated the relation between childhood social class and midlife cognitive function.

CONCLUSIONS

The current study advances personality and cognition by showing that (1) adolescent personality predicts midlife cognition 30 years later, (2) both self-reports and mother-ratings are important sources of information on personality associated with midlife cognition, and (3) adolescent personality may be one pathway through which the early life socioeconomic environment is associated with midlife cognition.

Larger increase in trait negative affect is associated with greater future cognitive decline and vice versa across 23 years

BACKGROUND

Trait negative affect (NA) is a central feature of anxiety and depression disorders. Neurocognitive and scar models propose that within-person increase in NA across one period of time relates to a decline in cognitive functioning at a future period of time and vice versa. Yet, there has been little research on whether a within-person change in trait NA across one time-lag precedes and is associated with a change in cognition across a future time lag and vice versa. Due to a growing aging population, such knowledge can inform evidence-based prevention.

METHODS

Participants were 520 dementia-free community-dwelling adults (mean age = 59.76 years [standard deviation = 8.96], 58.08% females). Trait-level NA (negative emotionality scale), spatial cognition (block design and card rotations), verbal working memory (WM; digit span backward), and processing speed (symbol digit modalities) were assessed at five time points (waves) across 23 years. Bivariate dual latent change score (LCS) approaches were used to adjust for regression to the mean, lagged outcomes, and between-person variability.

RESULTS

Unique bivariate LCS models showed that within-person increase in trait NA across two sequential waves was related to declines in spatial cognition, verbal WM, and processing speed across the subsequent two waves. Moreover, within-person reductions in spatial cognition, verbal WM, and processing speed across two sequential waves were associated with future increases in trait NA across the subsequent two waves.

CONCLUSIONS

Findings concur with neurobiological and scar theories of psychopathology. Furthermore, results support process-based emotion regulation models that highlight the importance of verbal WM, spatial cognition, and processing speed capacities for downregulating NA.

Memory and Personality Development in Adulthood: Evidence From Four Longitudinal Studies

OBJECTIVES

Personality traits have been related to concurrent memory performance. Most studies, however, have focused on personality as a predictor of memory; comparatively less is known about whether memory is related to personality development across adulthood. Using 4 samples, the present study tests whether memory level and change are related to personality change in adulthood.

METHOD

Participants were drawn from 2 waves of the Wisconsin Longitudinal Study Graduates (WLSG; N = 3,232, mean age = 64.28, SD = 0.65) and Wisconsin Longitudinal Study Siblings (WLSS; N = 1,570, mean age = 63.52, SD = 6.69) samples, the Midlife in the United States (MIDUS; N = 1,901, mean age = 55.43, SD = 10.98), and the Health and Retirement Study (HRS; N = 6,038, mean age = 65.47, SD = 8.28). Immediate and delayed recall and the 5 major personality traits were assessed at baseline and follow-up.

RESULTS

There was heterogeneity in the associations across samples. A meta-analysis of latent change in the four samples indicated that lower baseline memory performance was related to an increase in neuroticism (B = -0.002; 95% CI = -0.004, -0.0008) and a decrease in agreeableness (B = 0.004; 95% CI = 0.002, 0.007) and conscientiousness (B = 0.005; 95% CI = 0.0008, 0.010). In addition, declines in memory were related to steeper declines in extraversion (B = 0.06; 95% CI = 0.003, 0.11), openness (B = 0.04; 95% CI = 0.007, 0.069), and conscientiousness (B = 0.05; 95% CI = 0.019, 0.09).

DISCUSSION

The present study indicates that poor memory and declines in memory over time are related to maladaptive personality change. These associations, however, were small and inconsistent across samples.

Conscientiousness is associated with less amyloid deposition in cognitively normal aging

Little is known about the association between personality and Alzheimer's disease (AD) biomarkers, and existing results are inconsistent. We aimed to determine whether personality was associated with β-amyloid (Aβ) accumulation in cognitively normal aging. One hundred twenty-nine participants were included in this cross-sectional study. Personality was measured with the Big Five Inventory (BFI) and brain Aβ deposition was assessed with [11C] Pittsburgh compound B (PiB)-positron emission tomography (PET) imaging. Conscientiousness scores had a negative association with global PiB distribution volume ratio (DVR) in all participants after adjusting for age, sex, education, and vascular risk factors (β[SE] = -0.19[0.09], 95% confidence interval [CI: -0.35, -0.02], p = .031), while agreeableness, extraversion, neuroticism, and openness had no association with global PiB DVR. Assuming the relative stability of personality traits, these findings suggest that conscientiousness may protect against Aβ accumulation in cognitively normal aging through mechanisms that are as yet unknown. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Impact of Apolipoprotein E gene polymorphism during normal and pathological conditions of the brain across the lifespan

The central nervous system (CNS) is the cellular substrate for the integration of complex, dynamic, constant, and simultaneous interactions among endogenous and exogenous stimuli across the entire human lifespan. Numerous studies on aging-related brain diseases show that some genes identified as risk factors for some of the most common neurodegenerative diseases - such as the allele 4 of APOE gene (APOE4) for Alzheimer's disease (AD) - have a much earlier neuro-anatomical and neuro-physiological impact. The impact of APOE polymorphism appears in fact to start as early as youth and early-adult life. Intriguingly, though, those same genes associated with aging-related brain diseases seem to influence different aspects of the brain functioning much earlier actually, that is, even from the neonatal periods and earlier. The APOE4, an allele classically associated with later-life neurodegenerative disorders as AD, seems in fact to exert a series of very early effects on phenomena of neuroplasticity and synaptogenesis that begin from the earliest periods of life such as the fetal ones.We reviewed some of the findings supporting the hypothesis that APOE polymorphism is an early modifier of various neurobiological aspects across the entire human lifespan - from the in-utero to the centenarian life - during both normal and pathological conditions of the brain.

Personality and Motoric Cognitive Risk Syndrome

OBJECTIVES

To examine whether five major personality traits are related to the motoric cognitive risk (MCR) syndrome, a pre-dementia syndrome characterized by cognitive complaints and slow gait speed.

DESIGN

Cross-sectional.

SETTING

Health and Retirement Study (HRS) and the National Health and Aging Trends Survey (NHATS).

PARTICIPANTS

Dementia-free older adults aged 65 to 107 years (N > 8000).

MEASUREMENTS

In both samples, participants provided data on personality, cognitive complaints, and measures of gait speed, as well as on demographic factors, physical activity, depressive symptoms, and body mass index (BMI).

RESULTS

Across the two samples and a meta-analysis, higher neuroticism was related to higher risk of MCR (combined odds ratio [OR] = 1.32; 95% confidence interval [CI] = 1.21-1.45; P < .001), whereas higher extraversion (combined OR = .71; 95% CI = .65-.79; P < .001) and conscientiousness (combined OR = .70; 95% CI = .62-.78; P < .001) were associated with a lower likelihood of MCR. Higher openness was also related to a lower risk of MCR in the HRS and the meta-analysis (combined OR = .77; 95% CI = .70-.85; P < .001), whereas agreeableness was protective only in the HRS (OR = .83; 95% CI = .74-.92; P < .001). Additional analyses indicated that physical activity, depressive symptoms, and BMI partially accounted for these associations.

CONCLUSION

This study adds to existing research on the factors related to the risk of MCR by showing an association with personality traits. Personality assessment may help to identify individuals who may be targeted by interventions focused on reducing the risk of MCR and ultimately of dementia. J Am Geriatr Soc 68:803-808, 2020.

Associations between personality and whole-brain functional connectivity at rest: Evidence across the adult lifespan

INTRODUCTION

Personality is associated with cognitive, emotional, and social functioning, and can play a role in age-related cognitive decline and dementia risk; however, little is known about the brain dynamics underlying personality characteristics, and whether they are moderated by age.

METHODS

We investigated the associations between personality and resting-state functional MRI data from 365 individuals across the adult lifespan (20-80 years). Participants completed the 50-item International Personality Item Pool and a resting-state imaging protocol on a 3T MRI scanner. Within-network connectivity values were computed based on predefined networks. Regression analyzes were conducted in order to investigate personality-connectivity associations, as well as moderation by age. All models controlled for potential confounders (such as age, sex, education, IQ, and the other personality traits).

RESULTS

We found that openness was positively associated with connectivity in the default-mode network, neuroticism was negatively associated with both the ventral and dorsal attention networks, and agreeableness was negatively associated with the dorsal attention network. In addition, age moderated the association between conscientiousness and the frontoparietal network, indicating that this association become stronger in older age.

CONCLUSIONS

Our findings demonstrate that personality is associated with brain connectivity, which may contribute to identifying personality profiles that play a role in protection against or risk for age-related brain changes and dementia.

The Ups and Downs of Cognitive Function: Neuroticism and Negative Affect Drive Performance Inconsistency

OBJECTIVES

Response time inconsistency (RTI)-or trial-to-trial variability in speeded performance-is increasingly recognized as an indicator of transient lapses of attention, cognitive health status, and central nervous system integrity, as well as a potential early indicator of normal and pathological cognitive aging. Comparatively, little research has examined personality predictors of RTI across adulthood.

METHODS

We evaluated the association between the personality trait neuroticism and RTI in a community-dwelling sample of 317 adults between the ages of 19-83 and tested for two indirect pathways through negative affect (NA) and cognitive interference (CI).

RESULTS

The personality trait neuroticism predicted greater RTI independent of mean response time performance and demographic covariates; the results were age-invariant. Furthermore, NA (but not CI) accounted for this association and moderated mediation model results indicated that older adults were more vulnerable to the adverse effects of NA.

DISCUSSION

Neuroticism predicts greater RTI irrespective of mean performance and this effect is driven largely by heightened negative emotionality that may be particularly detrimental for older adults.

Personality and memory performance over twenty years: Findings from three prospective studies

OBJECTIVE

The present study examined whether personality traits are related to episodic memory over the long-term.

METHOD

Participants were adults from the Wisconsin Longitudinal Study Graduate (WLSG, N = 3726) and Sibling samples (WLSS, N = 1720), and the Midlife in the United States Study (MIDUS, N = 2411). Five factor model personality traits and demographic factors were measured at baseline. Memory performance on immediate and delayed free recall tasks was assessed at follow-up, almost 20 years later.

RESULTS

In regression models that accounted for demographic factors, consistent evidence was found across three samples that middle-aged adults who scored higher on neuroticism performed significantly worse on a memory test 20 years later. In the WLSG and WLSS and a meta-analysis, higher openness was also associated with better memory at follow-up. High neuroticism and low openness were also associated with a 20 to 40% increased risk of performing below one and a half standard deviation from the sample mean on the memory task.

CONCLUSIONS

The present study extends previous research with evidence that the association between personality traits and memory function persist over two decades.

Personality Traits are Related to Selective Cognitive Impairment in Early Alzheimer's Disease

BACKGROUND

A link between personality traits and cognitive performance has been shown in normal adults and elderly individuals. Very few studies have evaluated this link in Alzheimer's disease (AD).

OBJECTIVE

To better understand cognitive performance as regards to personality traits, our study was aimed to evaluate the role of premorbid personality on cognitive functioning in a population of patients presenting prodromal or mild AD.

METHODS

181 elderly with prodromal or mild AD participated in a cross-sectional, prospective cohort study. The participants completed a personality inventory and a neuropsychological battery exploring memory, attention, executive function, language, and praxis. Cognitive performance were compared according to the level of each personality trait, using multivariate MANOVA models.

RESULTS

A higher level of neuroticism was associated with lower performance at similarities test (D = 9.49, p = 0.003), delayed Free and Cued Selective Reminding test (D = 5.22, p = 0.02), and digit span score (D = 7.99, p = 0.006). A higher level of openness was related to better performance at similarities (D = 4.33, p = 0.04), letter fluency (D = 11.45, p = 0.001), and category fluency test (D = 5.85, p = 0.02). Neuroticism interfered negatively with cognitive functioning at the prodromal stage; the association between openness and cognitive function was observed at both prodromal and mild AD stage.

CONCLUSION

These results suggest that personality traits, in particular neuroticism and openness, modulate cognitive abilities in patients with early AD. These results encourage the development of stress management programs to prevent its negative effects on cognitive aging.

Evaluations of a Previous Day as a Pathway Between Personality and Healthy Cognitive Aging

Objective: To examine the association between Five-Factor Model personality traits and how individuals evaluate a recent day in their lives (yesterday) and whether these evaluations mediate personality and cognitive function over time. Methods: Participants were a subsample from the Health and Retirement Study who completed personality measures in 2008/2010, the day evaluation in 2011, and cognitive tasks in 2012 (N = 3,454). Results: Lower Neuroticism and Higher Extraversion, Openness, Agreeableness, and Conscientiousness were associated with a more engaging day, fewer negative feelings, better subjective health, and less time spent alone. Active engagement and subjective health were associated with cognitive function and mediated the prospective associations between Neuroticism, Openness, and Conscientiousness and cognitive function. Discussion: Personality is associated with how individuals evaluated their previous day, which contributes to cognition over time. The present research contributes to a mechanistic model that aims to identify pathways through which personality contributes to cognitive aging.

Low neuroticism and cognitive performance are differently associated to overweight and obesity: A cross-sectional and longitudinal UK Biobank study

BACKGROUND

A growing body of research has linked personality traits to cognitive performance. This relationship might play a role in the predisposition toward obesity. Neuroticism and executive function seem to be particularly involved, and reduced executive function has been proposed to underlie the association of neuroticism with sedentary behaviors and fatty food consumption. Despite the link between neuroticism, cognitive functions and obesity has been largely reported, conflicting evidence exists. Moreover, information regarding other cognitive domains, and studies on overweight individuals, are still scarce.

METHODS

We examined cross-sectional associations of neuroticism and cognitive function with overweight and obesity in a sample of 170 310 individuals from the UK Biobank cohort, adjusted for sociodemographic and life-style factors. Measures on fluid intelligence (FI) (reasoning ability), trail making test (TMT) (executive function), numeric memory test and pairs matching (PM) task (short-term memory) were extracted from the database. Correlations between neuroticism and cognitive performance were explored. Moreover, we investigated whether neuroticism and executive function could predict BMI variability over time.

RESULTS

Reduced FI and short-term memory were associated with overweight and obesity, while reduced executive function was associated with obesity but not with overweight. Low neuroticism was associated with being overweight rather than lean or obese independently of gender and life-style. Furthermore, baseline neuroticism scores could predict BMI variations over 5-10 years follow-up, and high neuroticism correlated with lower cognitive performance.

CONCLUSIONS

Lower cognitive performance is associated with both overweight and obesity, except for executive function, which was only related to obesity. Neuroticism correlated with performance on most of the cognitive domains tested, supporting the link between personality and cognition. Our findings also support the role of neuroticism in leading to greater weight variability over time, rather than to overweight/obesity itself.

Personality and Alzheimer's disease: An integrative review

The objective of this article is to review and integrate interrelated areas of research on personality and Alzheimer's disease (AD). Prospective studies indicate that individuals who score higher on conscientiousness (more responsible and self-disciplined) and lower on neuroticism (less anxious and vulnerable to stress) have a reduced risk of developing dementia, even in the presence of AD neuropathology. Personality is also related to measures of cognitive performance and cognitive decline, with effect sizes similar to those of other clinical, lifestyle, and behavioral risk factors. These associations are unlikely to be due to reverse causality: Long-term prospective data indicate that there are no changes in personality that are an early sign of the disease during the preclinical phase of AD. With the onset and progression of dementia, however, there are large changes in personality that are reported consistently by caregivers in retrospective studies and are consistent with the clinical criteria for the diagnosis of dementia. The review also discusses potential mechanisms of the observed associations and emphasizes the need for prospective studies to elucidate the interplay of personality traits with AD neuropathology (amyloid and tau biomarkers) in modulating the risk and timing of onset of clinical dementia. The article concludes with the implications of personality research for identifying those at greater risk of AD and the potential of personality-tailored interventions aimed at the prevention and treatment of AD. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Personality and Hearing Acuity: Evidence From the Health and Retirement Study and the English Longitudinal Study of Ageing

OBJECTIVE

Several determinants of age-related hearing impairment have been identified, but little is known about the predictive value of psychological factors. The present study examined whether five-factor model personality traits are prospectively associated with hearing acuity in middle-aged and older adults.

METHODS

Participants were adults aged 50 to 97 years (N > 10,000) drawn from the Health and Retirement Study (2012-2016) and the English Longitudinal Study of Ageing (2010-2014). In each sample, personality, demographic factors, health-related behaviors, body mass index, and memory function were assessed at baseline, and objective hearing acuity was measured 4 years later.

RESULTS

In both samples, higher conscientiousness and openness were associated with better hearing acuity and lower risk of impairment, whereas neuroticism was associated with a higher risk of hearing impairment. In the Health and Retirement Study and English Longitudinal Study of Ageing, respectively, 1 standard deviation (1-SD) higher conscientiousness, 1-SD higher openness, and 1-SD lower neuroticism were related to 13% to 10%, 8% to 6%, and 10% to 13% lower likelihoods of hearing impairment, respectively. In both samples, additional analyses revealed that physical activity and memory mediated the association between personality and hearing.

CONCLUSIONS

The present study provides robust evidence for an association between personality traits and hearing function. The findings broaden knowledge on risk and mitigating factors for age-related hearing impairment, which has implications for the quality of life of middle-aged and older adults.

Polygenic Score for Alzheimer Disease and cognition: The mediating role of personality

Alzheimer's disease (AD) polygenic risk score (PGS) is associated with lower cognitive functioning even among older individuals without dementia. We tested the hypothesis that personality traits mediate the association between AD genetic risk and cognitive functioning. Participants (N > 7,000, aged 50-99 years old) from the Health and Retirement Study were genotyped and completed personality and cognition tests at baseline. Cognition was assessed again four years later. Bootstrap analysis revealed that a higher AD polygenic risk score was associated with lower cognitive scores at baseline through higher neuroticism, lower conscientiousness, and lower levels of the industriousness facet of conscientiousness. In addition, a higher polygenic score for AD was associated with decline in cognition over four years in part through higher neuroticism and lower conscientiousness. The findings support the hypothesis that the genetic vulnerability for AD contributes to cognitive functioning in part through its association with personality traits.

Apolipoprotein E genotype impact on memory and attention in older persons: the moderating role of personality phenotype

OBJECTIVES

To determine if phenotypic personality traits modify the association of Apolipoprotein E (APOE) genotypes with different domains of cognitive function.

DESIGN

Cross-sectional.

METHODS

172 non-demented older adults were administered the NEO-Five Factor Inventory (NEO-FFI), a battery of neuropsychological tests assessing memory, attention, executive function, language, and visuospatial ability, and underwent APOE genotyping. Multivariate (multiple-dependent variable) regression models predicting cognitive domains tested APOE interactions with personality traits, adjusting for age, sex, and education.

RESULTS

The APOE ε4 allele showed small to modest main effects on memory and executive function (1/3 SD deficits for carriers, p < .05), with ε2 status evidencing minimal and non-significant benefit. Neuroticism interacted with both ε2 and ε4 alleles in associations with attention scores (p = .001), with ε2 benefits and ε4 deficits being marked at high Neuroticism (Mean [M] covariate-adjusted Z-score = .39 for ε2, -.47 for ε4). The association of ε4 with memory was moderated by Conscientiousness (p < .001), such that ε4 memory deficits were apparent at low Conscientiousness (M = -.56), but absent at high levels of Conscientiousness. Weaker patterns (p < .05) also suggested ε4-related detriments in executive function only at lower Conscientiousness, and ε2 memory benefits only at higher Openness.

CONCLUSIONS

Conscientiousness and Neuroticism moderate APOE associations with memory and executive function. As such, they may be useful phenotypic markers in refining the prognostic significance of this polymorphism. Effect-modifying personality traits also provide clues about behavioral and psychological factors that influence the cognitive impact of APOE. Copyright © 2017 John Wiley & Sons, Ltd.

Personality Changes During the Transition from Cognitive Health to Mild Cognitive Impairment

BACKGROUND/OBJECTIVES

Behavioral problems in individuals with Alzheimer's disease (AD) impose major management challenges. Current prevention strategies are anchored to cognitive outcomes, but behavioral outcomes may provide another, clinically relevant opportunity for preemptive therapy. We sought to determine whether personality changes that predispose to behavioral disorders arise during the transition from preclinical AD to mild cognitive impairment (MCI).

DESIGN

Longitudinal observational cohort study.

SETTING

Academic medical center.

PARTICIPANTS

Members of an apolipoprotein E (APOE) ɛ4 genetically enriched cohort of Maricopa County residents who were neuropsychiatrically healthy at entry (N = 277). Over a mean interval of 7 years, 25 who developed MCI and had the Neuroticism, Extraversion, and Openness Personality Inventory-Revised (NEO-PI-R) before and during the MCI transition epoch were compared with 252 nontransitioners also with serial NEO-PI-R administrations.

INTERVENTION

Longitudinal administration of the NEO-PI-R and neuropsychological test battery.

MEASUREMENTS

Change in NEO-PI-R factor scores (neuroticism, extraversion, openness, agreeableness, conscientiousness) from entry to the epoch of MCI diagnosis or an equivalent follow-up duration in nontransitioners.

RESULTS

NEO-PI-R neuroticism T-scores increased significantly more in MCI transitioners than in nontransitioners (mean 2.9, 95% confidence interval (CI) = 0.9-4.9 vs 0, 95% CI = -0.7-0.7, P = .02), and openness decreased more in MCI transitioners than in nontransitioners (-4.8, 95% CI = -7.3 to -2.4 vs -1.0, 95% CI = -1.6 to -0.4, P < .001). Concurrent subclinical but statistically significant changes in behavioral scores worsened more in MCI transitioners than nontransitioners for measures of depression, somatization, irritability, anxiety, and aggressive attitude.

CONCLUSION

Personality and subclinical behavioral changes begin during the transition from preclinical AD to incident MCI and qualitatively resemble the clinically manifest behavioral disorders that subsequently arise in individuals with frank dementia.

Personality and Performance in Specific Neurocognitive Domains Among Older Persons

OBJECTIVE

Certain Big 5 personality dimensions have been repeatedly linked to global measures of cognitive function and outcome categories. We examined whether the Big 5 or their specific components showed differential evidence of associations with specific neurocognitive domains.

METHODS

Participants were 179 older adults (70+) from a broader study on cognitive aging. The NEO-Five Factor Inventory and a comprehensive battery of neuropsychological tests were used.

RESULTS

Adjusted for age, gender, and years of education, probability values, Bayes Factors, and measures effect size from linear models suggested strong evidence for associations between better delayed recall memory and higher Conscientiousness (principally the facets of Goal-Striving and Dependability) and Openness (specifically the Intellectual Interest component). Better executive function and attention showed moderate to strong evidence of associations with lower Neuroticism (especially the Self-conscious Vulnerability facet) and higher Conscientiousness (mostly the Dependability facet). Better language functioning was linked to higher Openness (specifically, the Intellectual Interests facet). Worse visual-spatial function was strongly associated with higher Neuroticism.

CONCLUSION

Different tests of neurocognitive functioning show varying degrees of evidence for associations with different personality traits. Better understanding of the patterning of neurocognitive-personality linkages may facilitate grasp of underlying mechanisms and/or refine understanding of co-occurring clinical presentation of personality traits and specific cognitive deficits.

How Does Psychosocial Behavior Contribute to Cognitive Health in Old Age?

With the aging of the U.S. population, the number of cognitively disabled persons is expected to substantially increase in coming decades, underscoring the urgent need for effective interventions. Here, we review the current evidence linking psychosocial factors to late-life cognitive loss and consider the study design needed to illuminate the biologic bases of the associations. We then examine an ongoing study that includes several of the key design elements, the Rush Memory and Aging Project. In this longitudinal clinical-pathological cohort study, indicators of personality, social connectedness, and psychological well-being were shown to predict late-life cognitive outcomes. Participants who died underwent a uniform neuropathologic examination to quantify common dementia-related pathologies. Some psychosocial indicators were associated with cerebral infarction; some indicators modified the association of neurodegenerative pathologies with cognitive loss; and the association of some indicators with cognitive outcomes appears to be independent of the pathologies traditionally associated with late-life dementia. These findings suggest that psychosocial behavior influences late-life cognitive health through multiple neurobiologic mechanisms. A better understanding of these mechanisms may lead to novel strategies for preserving cognitive health in old age.

Amygdala functional connectivity is associated with locus of control in the context of cognitive aging

Locus of control (LOC) measures the extent to which individuals perceive control over their lives. Those with a more "internal" LOC feel self-sufficient and able to determine important aspects of their own future, while those with a more "external" LOC feel that their lives are governed by events beyond their control. Reduced internal LOC and increased external LOC have been found in cognitive disorders, but the neural substrates of these control perceptions are yet unknown. In the present study, we explored the relationship between amygdala functional connectivity and LOC in 18 amnestic mild cognitive impairment (MCI) and age-, sex-, and education-matched, 22 cognitively healthy controls (HC). Participants completed cognitive challenge tasks (Stroop Word Color task and Dual 1-back) for 20min, and underwent resting-state functional magnetic resonance imaging immediately before and after the tasks. We found significantly lower internal LOC and higher external LOC in the MCI group than the HC group. Compared to HC, MCI group showed significantly stronger positive associations between internal LOC and baseline right amygdala connections (including right middle frontal gyrus and anterior cingulate cortex), and stronger negative associations between internal LOC and change of these right amygdala connections. Across all participants, external LOC explained the relationships between associations of another set of right amygdala connections (including middle cingulate cortex and right superior frontal gyrus), both at baseline and for change, and performance in the cognitive challenge tasks. Our findings indicate that the right amygdala networks might be critical in understanding the neural mechanisms underlying LOC's role in cognitive aging.

Personality, Cortisol, and Cognition in Non-demented Elderly Subjects: Results from a Population-Based Study

Certain personality traits, in particular higher neuroticism, have been associated, on one hand, with elevated cortisol levels, and on the other hand, with poorer cognitive performance. At the same time, several studies highlighted the association between high cortisol and poor cognitive functioning. Here, we hypothesized that increased cortisol may be associated with poorer cognition and with certain personality traits (mainly high neuroticism), and that personality might explain the association between cortisol and cognition. A cross-sectional analysis was conducted using data from Colaus/PsyColaus, a population-based study involving residents of Lausanne, Switzerland. Salivary cortisol samples (upon waking, 30 min after waking, at 11 am and at 8 pm) along with cognitive and personality measures were obtained from 643 non-demented participants aged at least 65. Personality traits were assessed using the NEO Five-Factor Inventory (NEO-FFI). We examined the links between the cortisol Area under the Curve (AUC), the Clinical Dementia Rating Sum of Boxes (CDRSOB) and the NEO-FFI scores. No association was found between personality traits and the CDRSOB or the MMSE score, controlling for age, sex, depression, education and BMI. However, the executive functioning domain z-score was negatively associated with agreeableness (p = 0.005; slope = -0.107 [-0.181; -0.033]) and openness (p = 0.029; slope = -0.081 [-0.154; -0.008]) after controlling for age, sex, depression, education and BMI. The CDRSOB score was positively associated with the cortisol AUC after controlling for age, sex, BMI, education and depression, (p = 0.003; slope = 0.686 [0.240; 1.333]). This association remained significant after controlling for personality traits and for the interaction between personality traits and the cortisol AUC (p = 0.006; slope = 0.792 [0.233; 1.352]. High agreeableness and openness might be associated with poorer executive performance in later life. Increased cortisol may be associated with both specific personality traits (high extraversion, low openness) and worse cognitive performance. Increased salivary cortisol does not mediate the relationship between personality traits and cognitive impairment.