The impact of personality on memory function in older adults-results from the Longitudinal Aging Study Amsterdam

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.

Episodic Memory Reliving and Personality

Abstract. There are considerable individual differences in remembering past episodes. The current study aimed to examine the link between episodic memory reliving and the Five-Factor Model personality traits. Altogether 422 participants (67% women) described an autobiographical episode and rated the vividness and clarity of that recollection. Next, they assessed their general tendencies of autobiographical recollections, which resulted in two autobiographical episodic memory scores (AEMS) for each participant – episodic and general. Participants also filled in the Estonian version of the International Personality Item Pool NEO questionnaire. Findings from partial correlation analysis (controlling for age and gender) revealed distinguishable patterns of associations for the episodic and general-level reports of memory reliving: the episodic AEMS was positively associated with E4: Activity Level and E1: Friendliness, whereas the general AEMS was negatively correlated with N4: Self-Consciousness, and positively with E1: Friendliness, E6: Cheerfulness, O1: Imagination, O5: Intellect, C2: Orderliness, and C3: Dutifulness (all significant at p < .005). The associations between the general (but not the episodic) AEMS and personality facets were significantly correlated with the average social desirability ratings of the respective facets. We conclude that greater social adaptation together with the motivation of positive self-perception are plausible explanations of the links between personality traits and reporting the quality of reliving personal memories.

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.

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.

High Cortisol and the Risk of Dementia and Alzheimer's Disease: A Review of the Literature

Introduction: Cortisol effects on the brain are exerted through two distinct receptors, inducing complex and even opposite effects on the cerebral structures implicated in the various cognitive functions. High cortisol may also have deleterious effects on the brain structures and contribute to neurodegeneration, in particular Alzheimer’s disease (AD), via different mechanisms.

Objective: To examine the interrelationships between cortisol, cognitive impairment and AD.

Methods: Review of the literature.

Results: Clinical studies found that elevated cortisol was associated with poorer overall cognitive functioning, as well as with poorer episodic memory, executive functioning, language, spatial memory, processing speed, and social cognition; while in animals, glucocorticoid administration resulted in cognitive impairment and abnormal behavior. In cognitively healthy subjects, higher cortisol levels have been associated with an increased risk of cognitive decline and AD. Subjects with dementia and Mild Cognitive Impairment (MCI) due to AD have been found to have higher CSF cortisol levels than cognitively healthy controls. Elevated CSF cortisol may also be associated with a more rapid cognitive decline in MCI due to AD. Elevated cortisol levels have been also found in delirium. High cortisol may mediate the impact of stressful life events, high neuroticism, depression, sleep disturbances, as well as cardiovascular risk factors on cognitive performance, neurodegeneration, and cognitive decline. High cortisol may also exert neurotoxic effects on the hippocampus, and promote oxidative stress and amyloid β peptide toxicity. Further possible underlying mechanisms include the interactions of cortisol with inflammatory mediators, neurotransmitters, and growth factors.

Conclusion: Elevated cortisol levels may exert detrimental effects on cognition and contribute to AD pathology. Further studies are needed to investigate cortisol-reducing and glucocorticoidreceptor modulating interventions to prevent cognitive decline.

The relationships between perceived control and episodic memory in adulthood: a review

The goal of the current paper is to review the literature on the relationships between perceived control and episodic memory throughout adulthood. More specifically, three major questions are pursued: (1) Are higher levels of perceived control related to better memory performance? (2) Is the relationship between perceived control and memory similar or different as a function of age? (3) Does perceived control moderate memory decline? Although there is a great deal of evidence that perceived control and episodic memory are positively related in adulthood, the current review showed that very few studies have investigated whether age moderated this relationship. Moreover, only a limited number of studies have explored the role of perceived control in memory decline, and the results are inconsistent. We suggest some avenues for future research that could help understand by which mechanisms, and under what circumstances, perceived control and episodic memory are related across the lifespan.

Psychological well-being in elderly adults with extraordinary episodic memory

Objectives

The Northwestern University SuperAging Program studies a rare cohort of individuals over age 80 with episodic memory ability at least as good as middle-age adults to determine what factors contribute to their elite memory performance. As psychological well-being is positively correlated with cognitive performance in older adults, the present study examined whether aspects of psychological well-being distinguish cognitive SuperAgers from their cognitively average-for-age, same-age peers.

Method

Thirty-one SuperAgers and 19 cognitively average-for-age peers completed the Ryff 42-item Psychological Well-Being questionnaire, comprised of 6 subscales: Autonomy, Positive Relations with Others, Environmental Mastery, Personal Growth, Purpose in Life, and Self-Acceptance.

Results

The groups did not differ on demographic factors, including estimated premorbid intelligence. Consistent with inclusion criteria, SuperAgers had better episodic memory scores. Compared to cognitively average-for-age peers, SuperAgers endorsed greater levels of Positive Relations with Others. The groups did not differ on other PWB-42 subscales.

Discussion

While SuperAgers and their cognitively average-for-age peers reported similarly high levels of psychological well-being across multiple dimensions, SuperAgers endorsed greater levels of positive social relationships. This psychological feature could conceivably have a biological relationship to the greater thickness of the anterior cingulate gyrus and higher density of von Economo neurons previously reported in SuperAgers.

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.