Satisfaction With Life and Risk of Dementia: Findings From the Korean Longitudinal Study of Aging

Purpose in life and cognitive performance and informant ratings of cognitive decline, affect, and activities

OBJECTIVE

To examine (1) the association between purpose in life and multiple domains of cognitive function and informant-rated cognitive decline, affect, and activities; (2) whether these associations are moderated by sociodemographic factors, cognitive impairment, or depression; (3) whether the associations are independent of other aspects of well-being and depressive symptoms.

METHOD

As part of the 2016 Harmonized Cognitive Assessment Protocol from the Health and Retirement Study, participants completed a battery of cognitive tests and nominated a knowledgeable informant to rate their cognitive decline, affect, and activities. Participants with information available on their purpose in life from the 2014/2016 Leave Behind Questionnaire were included in the analytic sample (N = 2,812).

RESULTS

Purpose in life was associated with better performance in every cognitive domain examined (episodic memory, speed-attention, visuospatial skills, language, numeric reasoning; median β =.10, p <.001; median d =.53). Purpose was likewise associated with informant-rated cognitive decline and informant-rated affective and activity profiles beneficial for cognitive health (median β =.18, p < .001; median d =.55). There was little evidence of moderation by sociodemographic or other factors (e.g., depression). Life satisfaction, optimism, positive affect, and mastery were generally associated with cognition. When tested simultaneously with each other and depressive symptoms, most dimensions were reduced to non-significance; purpose remained a significant predictor.

CONCLUSIONS

Purpose in life is associated with better performance across numerous domains of cognition and with emotional and behavioral patterns beneficial for cognitive health that are observable by knowledgeable others. These associations largely generalize across demographic and clinical groups and are independent of other aspects of well-being.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

DISCUSSION

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

HIGHLIGHTS

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

The Association between Happiness and Cognitive Function in the UK Biobank

Feelings of happiness have been associated with better performance in creative and flexible thinking and processing. Less is known about whether happier individuals have better performance on basic cognitive functions and slower rate of cognitive decline. In a large sample from the UK Biobank (N=17,885; Age 40-70 years), we examine the association between baseline happiness and cognitive function (speed of processing, visuospatial memory, reasoning) over four assessment waves spanning up to 10 years of follow-up. Greater happiness was associated with better speed and visuospatial memory performance across assessments independent of vascular or depression risk factors. Happiness was associated with worse reasoning. No association was found between happiness and the rate of change over time on any of the cognitive tasks. The cognitive benefits of happiness may extend to cognitive functions such as speed and memory but not more complex processes such as reasoning, and happiness may not be predictive of the rate of cognitive decline over time. More evidence on the association between psychological well-being and different cognitive functions is needed to shed light on potential interventional efforts.

Age-group-specific association of oral health and systemic health on cognitive function: a cross-sectional study of Korean elders

BACKGROUND

Although the importance of oral and systemic healthcare for elderly people is increasing owing to the rapid ageing of the population in South Korea, studies on the relationship between oral health, systemic health, and cognitive function, as well as on the prediction of cognitive function by oral and systemic health depending upon age groups are lacking.

METHODS

We included 5,975 out of 6,488 participants from the 8th wave of the Korean Longitudinal Study of Aging (KLoSA) panel data, divided the participants into three age groups, and performed a hierarchical multiple linear regression analysis to explain cognitive function with four types of predictors: oral health status, sociodemographic factors, objective health status, and subjective health status.

RESULTS

Oral health status was positively correlated with systemic health status and cognitive function. Of all ages over 54, cognitive function was significantly predicted by oral health variables, such as the number of functional teeth, masticatory ability, and Geriatric Oral Health Assessment Index (GOHAI); sociodemographic variables, such as age, sex, education level, and residence; and systemic health variables, such as diagnosis of diabetes mellitus, cancer or malignant tumours, cerebrovascular disease and rheumatoid arthritis, depressive symptom, and self-rated health status. Oral health variables explained cognitive function differently by age group; GOHAI appeared important predictor in the group aged < 75 years, whereas the number of functional teeth did in the group aged ≥ 75 years. Educational level, masticatory ability, depressive symptoms, and self-rated health status were pivotal factors age-independently.

CONCLUSIONS

The general and age-group-specific association between oral health, systemic health, and cognitive function were confirmed, suggesting that age-group-specific oral healthcare should be emphasized for the effective management of systemic and cognitive health in the elderly group.

Well-Being as a Protective Factor Against Cognitive Decline and Dementia: A Review of the Literature and Directions for Future Research

OBJECTIVES

Treatments that target the biological causes of dementia remain limited, making prevention critically important. Well-being-defined broadly as living in accordance with one's potential and experiencing one's life as enjoyable and satisfying-is a promising avenue for prevention. It can be targeted by large-scale, noninvasive interventions and has been linked with better cognitive health and lower dementia risk. In the current review, we begin by summarizing empirical evidence linking well-being to cognitive functioning, cognitive decline, dementia diagnosis, and dementia-related neuropathology. Then, we highlight 3 key areas for future research.

METHODS

We searched the literature on wellbeing, cognitive decline, and dementia, focusing on prospective and longitidinal evidence.

RESULTS

The research reviewed here provides consistent evidence for associations of well-being with cognitive decline, dementia risk, and cognitive resilience to neuropathology. However, several open questions remain regarding (1) causality and mechanism(s), (2) specificity versus generalizability of associations, and (3) timing.

DISCUSSION

To inform potential intervention efforts, the field must address complex open questions about whether, how, when, and for whom well-being influences dementia risk. The majority of existing research on well-being and cognitive health is correlational, and few studies have tested potential mechanisms that may explain those associations. Further, relatively little is known about the generalizability of associations across different aspects of well-being and for different sociocultural groups. Finally, we do not yet understand when in the life span and on what timescale well-being might influence cognitive health. We discuss challenges and opportunities for addressing each of these open questions, including concrete recommendations for research designs and use of open science practices.

Multidimensional Assessment of Subjective Well-Being and Risk of Dementia: Findings from the UK Biobank Study

This study aimed to examine the associations between subjective well-being (SWB) and risk of all-cause dementia, Alzheimer's disease (AD), and vascular dementia (VD). We adopted a multidimensional approach to SWB that included the level and breadth of SWB, the latter indicating the extent to which SWB spreads across life domains. Participants (N=171,197; mean age=56.78; SD=8.16 years) were part of the UK Biobank and were followed up to 8.78 years. Domain-general and domain-specific SWB were measured by single items, and the breadth of SWB was indexed with a cumulative score of satisfaction across domains. Dementia incidence was ascertained through hospital and death records. Cox regression was used to examine the association between SWB indicators and risk of all-cause dementia, AD, and VD. General happiness, health and family satisfaction, and satisfaction breadth (satisfaction in multiple domains) were associated with lower risk of all-cause dementia. The associations held after accounting for socio-demographics, health, behavioral, and economic covariates, and depressive symptoms. Health satisfaction and the breadth of satisfaction were also associated with lower risk of AD and VD, with a pattern of slightly stronger associations for VD compared to AD. Some life domains (e.g., health) may be more fruitfully targeted to promote well-being and help protect against dementia, but it is also important to enhance well-being across multiple domains to maximize the protective effects.