Neuroticism scores increase with late-life 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.

Changes in Personality Before and During Cognitive Impairment

OBJECTIVES

Clinical observations and studies of retrospective observer ratings point to changes in personality in persons with cognitive impairment or dementia. The timing and magnitude of such changes, however, are unclear. This study used prospective self-reported data to examine the trajectories of personality traits before and during cognitive impairment.

DESIGN

Longitudinal observational cohort study.

SETTING AND PARTICIPANTS

Older adults from the United States in the Health and Retirement Study were assessed for cognitive impairment and completed a measure of the 5 major personality traits every 4 years from 2006 to 2020 (N = 22,611; n = 5507 with cognitive impairment; 50,786 personality and cognitive assessments).

METHODS

Multilevel modeling examined changes before and during cognitive impairment, accounting for demographic differences and normative age-related trajectories.

RESULTS

Before cognitive impairment was detected, extraversion (b = -0.10, SE = 0.02), agreeableness (b = -0.11, SE = 0.02), and conscientiousness (b = -0.12, SE = 0.02) decreased slightly; there was no significant change in neuroticism (b = 0.04, SE = 0.02) or openness (b = -0.06, SE = 0.02). During cognitive impairment, faster rates of change were found for all 5 personality traits: neuroticism (b = 0.10, SE = 0.03) increased, and extraversion (b = -0.14, SE = 0.03), openness (b = -0.15, SE = 0.03), agreeableness (b = -0.35, SE = 0.03), and conscientiousness (b = -0.34, SE = 0.03) declined.

CONCLUSIONS AND IMPLICATIONS

Cognitive impairment is associated with a pattern of detrimental personality changes across the preclinical and clinical stages. Compared with the steeper rate of change during cognitive impairment, the changes were small and inconsistent before impairment, making them unlikely to be useful predictors of incident dementia. The study findings further indicate that individuals can update their personality ratings during the early stages of cognitive impairment, providing valuable information in clinical settings. The results also suggest an acceleration of personality change with the progression to dementia, which may lead to behavioral, emotional, and other psychological symptoms commonly observed in people with cognitive impairment and dementia.

Association between personality and cognitive performance in middle-aged and older adults with human immunodeficiency virus (HIV)

BACKGROUND

Nearly half of adults with human immunodeficiency virus (HIV) experience HIV-Associated Neurocognitive Disorder (HAND), characterized by cognitive impairments in two or more cognitive domains, which can interfere with everyday functioning. Many factors are thought to influence such cognitive impairments in adults with HIV; one factor seldom examined is personality.

OBJECTIVE

This study investigated the association between five major dimensions of personality (openness, conscientiousness, extraversion, agreeableness, and neuroticism) and cognitive function in older adults with HIV.

METHODS

In this cross-sectional study, a secondary data analysis was conducted on 261 HIV + participants. Participants completed a norm-based cognitive battery covering seven cognitive domains, which yielded the following indices: global cognitive impairment, and global and domain-specific T-scores. The Big Five Inventory was used to assess personality traits.

RESULTS

Higher openness, conscientiousness, and agreeableness were associated with better performance on individual cognitive domains while agreeableness and openness were also positively associated with global cognitive T-scores (p < .01). Only openness significantly predicted global cognition when adjusting for covariates (p < .01).

DISCUSSION

Openness was associated with better global cognitive function in persons with HIV. This study provides a basis for further investigation of potential mechanisms for the association between personality and cognition in people with HIV in order to ultimately inform intervention strategies.

Higher levels of neuroticism in older adults predict lower executive functioning across time: the mediating role of perceived stress

Neuroticism has been associated with individual differences across multiple cognitive functions. Yet, the literature on its specific association with executive functions (EF) in older adults is scarce, especially using longitudinal designs. To disentangle the specific influence of neuroticism on EF and on coarse cognitive functioning in old adulthood, respectively, we examined the relationship between neuroticism, the Trail Making Test (TMT) and the Mini-Mental State Examination (MMSE) in a 6-year longitudinal study using Bayesian analyses. Data of 768 older adults (M age = 73.51 years at Wave 1) were included in a cross-lagged analysis. Results showed no cross-sectional link between neuroticism and TMT performance at Wave 1 and no longitudinal link between neuroticism at Wave 1 and MMSE at Wave 2. However, neuroticism at Wave 1 predicted TMT performance at Wave 2, indicating that the more neurotic participants were, the lower they performed on the TMT six years later. Additional analyses showed that this relation was fully mediated by participants' perceived stress. Our results suggest that the more neurotic older adults are the more stress they may perceive six years later, which in turn negatively relates to their EF. In sum, this study demonstrates that neuroticism may lead to lower EF in older age across six years. It further suggests older adults' perceived stress as mediator, thereby providing novel insights into the mechanisms underlying this relation. Possible intervention approaches to counter these effects are discussed.

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.

Personality-cognition associations across the adult life span and potential moderators: Results from two cohorts

OBJECTIVE

Personality and cognitive abilities have been previously linked. However, there are inconsistencies regarding whether this relationship varies as a function of age, and a lack of evidence on whether gender contributes to this relation, particularly across the adulthood. Therefore, this study investigated the association between personality and cognition across the adult life span, accounting for age and gender.

METHODS

We examined the association between personality and cognition in two large samples (Sample 1: N = 422; Sample 2: N = 549) including young, middle-aged and older adults. Participants completed personality scales and several cognitive measures related to reasoning, language, memory and speed of processing. Structural equation modeling was applied in order to investigate associations between personality and cognition, and moderation of age and gender within this relationship. We also conducted a mini-meta-analysis procedure in order to examine personality-cognition associations, combining results from the two samples.

RESULTS

Openness was the main trait associated with cognitive performance; however, Extraversion, Conscientiousness, and Neuroticism were also independently associated with cognition. Age and gender did not consistently moderate personality-cognition in each sample, but the mini-metanalysis showed that gender moderated Conscientiousness-cognition associations.

CONCLUSIONS

We provided robust evidence of personality-cognition associations across the adult life span, which was not consistently moderated by age, but in part by gender.

Personality traits and cognitive function in old-adults with type-2 diabetes

Objectives: Personality may constitute an important domain of influence on cognitive function in old-adults. We assessed the relationship of personality traits and cognitive performance in individuals with Type-2 Diabetes (T2D), and explored possible mediators. Method: The sample includes 377 dementia-free subjects with T2D participating in the Israel Diabetes and Cognitive Decline study who underwent assessment of cognition and personality (mean age 72 ± 4y; 42% females). We assessed the relationships of personality traits with episodic memory, semantic categorization, attention/working memory, executive function and overall cognition using linear regression models adjusting for age, education, sex, BMI, T2D duration, Hemoglobin A1C (HbA1C), hypertension, c-reactive protein, total- to HDL-cholesterol ratio and ApoEɛ4 genotype. A post-hoc mediation analysis was conducted with HbA1C, proportion of days covered (PDC) by T2D prescription claims and depressive symptoms. Results: After adjustment for multiple covariates, high neuroticism levels were associated with poorer performance overall (β= -0.16 ± 0.05; p = 0.001) and with poorer episodic memory, attention/working memory, and semantic categorization (β= -0.14 ± 0.05; p = 0.007, β= -0.12 ± 0.05; p = 0.017 and β= -0.12 ± 0.05; p = 0.018, respectively). High scores on openness to experience were associated with better global cognition (β = 0.11 ± 0.05; p = 0.026), executive functions (β = 0.13 ± 0.05; p = 0.013) and semantic categorization (β = 0.17 ± 0.05; p = 0.001, respectively). Depressive symptoms mediated the association of neuroticism with executive function, and the association of openness with executive function and overall cognition. Conclusion: Personality may play an important role in cognitive health among elderly subjects with T2D. Future studies should address the mechanisms underlying these relationships and specifically the potential role of depressive symptoms which may be in the causal pathway between personality traits and cognitive outcomes.

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 Changes With Dementia From the Informant Perspective: New Data and Meta-Analysis

OBJECTIVE

To examine changes in personality in individuals with mild cognitive impairment (MCI) or dementia as observed by family members using both new data and a meta-analysis with the published literature.

DESIGN

Current and retrospective personality assessments of individuals with dementia by family informants. PubMed was searched for studies with a similar design and a forward citation tracking was conducted using Google Scholar in June 2018. Results from a new sample and from published studies were combined in a random effect meta-analysis.

SETTING AND PARTICIPANTS

Family members of older adults with MCI or dementia.

MEASURES

The 5 major dimensions (neuroticism, extraversion, openness, agreeableness, and conscientiousness) and facets of personality were assessed with NEO Personality Inventory questionnaires.

RESULTS

The new sample (n = 50) and meta-analysis (18 samples; n = 542) found consistent shifts in personality from the premorbid to current state in patients with cognitive impairment. The largest changes (>1 standard deviation) were declines in conscientiousness (particularly for the facets of self-discipline and competence) and extraversion (decreased energy and assertiveness), as well as increases in neuroticism (increased vulnerability to stress). The new sample suggested that personality changes were larger in individuals taking cognition-enhancing medications (cholinesterase inhibitors or memantine). More recent studies and those that examined individuals with MCI found smaller effects.

CONCLUSIONS AND IMPLICATIONS

Consistent with the clinical criteria for the diagnosis of dementia, the new study and meta-analysis found replicable evidence for large changes in personality among individuals with dementia. Future research should examine whether there are different patterns of personality changes across etiologies of dementia to inform differential diagnosis and treatments. Prospective, repeated assessments of personality using both self- and informant-reports are essential to clarify the temporal evolution of personality change across the preclinical, prodromal, and clinical phases of dementia.

Personality Change in the Preclinical Phase of Alzheimer Disease

IMPORTANCE

Changes in behavior and personality are 1 criterion for the diagnosis of dementia. It is unclear, however, whether such changes begin before the clinical onset of the disease.

OBJECTIVE

To determine whether increases in neuroticism, declines in conscientiousness, and changes in other personality traits occur before the onset of mild cognitive impairment or dementia.

DESIGN, SETTING, AND PARTICIPANTS

A cohort of 2046 community-dwelling older adults who volunteered to participate in the Baltimore Longitudinal Study of Aging were included. The study examined personality and clinical assessments obtained between 1980 and July 13, 2016, from participants with no cognitive impairment at first assessment who were followed up for as long as 36 years (mean [SD], 12.05 [9.54] years). The self-report personality scales were not considered during consensus diagnostic conferences.

MAIN OUTCOMES AND MEASURES

Change in self-rated personality traits assessed in the preclinical phase of Alzheimer disease and other dementias with the Revised NEO Personality Inventory, a 240-item questionnaire that assesses 30 facets, 6 for each of the 5 major dimensions: neuroticism, extraversion, openness, agreeableness, and conscientiousness.

RESULTS

Of the 2046 participants, 931 [45.5%] were women; mean (SD) age at first assessment was 62.56 (14.63) years. During 24 569 person-years, mild cognitive impairment was diagnosed in 104 (5.1%) individuals, and all-cause dementia was diagnosed in 255 (12.5%) participants, including 194 (9.5%) with Alzheimer disease. Multilevel modeling that accounted for age, sex, race, and educational level found significant differences on the intercept of several traits: individuals who developed dementia scored higher on neuroticism (β = 2.83; 95% CI, 1.44 to 4.22; P < .001) and lower on conscientiousness (β = -3.34; 95% CI, -4.93 to -1.75; P < .001) and extraversion (β = -1.74; 95% CI, -3.23 to -0.25; P = .02). Change in personality (ie, slope), however, was not significantly different between the nonimpaired and the Alzheimer disease groups (eg, neuroticism: β = 0.00; 95% CI, -0.08 to 0.08; P = .91; conscientiousness: β = -0.06; 95% CI, -0.16 to 0.04; P = .24). Slopes for individuals who developed mild cognitive impairment (eg, neuroticism: β = 0.00; 95% CI, -0.12 to 0.12; P = .98; conscientiousness: β = -0.09; 95% CI, -0.23 to 0.05; P = .18) and all-cause dementia (eg, neuroticism: β = 0.02; 95% CI, -0.06 to 0.10; P = .49; conscientiousness: β = -0.08; 95% CI, -0.16 to 0.00; P = .07) were also similar to those for nonimpaired participants.

CONCLUSIONS AND RELEVANCE

No evidence for preclinical change in personality before the onset of mild cognitive impairment or dementia was identified. These findings provide evidence against the reverse causality hypothesis and strengthen evidence for personality traits as a risk factor for dementia.

Effect of Life Events, Social Supports, and Personality on Mental Status in Later Life

The goal of this study was to explore the influences of proximal and distal life events on mental status in later life. Additionally, life events were categorized into positive and negative experiences. Data from 208 older adults over 80 years of age from the Georgia Centenarian Study were included in this study. Results from a series of blockwise regression analyses indicated that the number of distal negative life events that older adults had experienced was a predictor of older adults' better mental status. Oldest-old adults' age, education, social supports, and social provision were also associated with their cognition. Cumulative negative life events may protect people in cognitive function as implicated by our results.