Midlife Neuroticism and the age of onset of Alzheimer's disease

Personality and its Relationship to Depression and Cognition in Older Adults: Implications for Practice

OBJECTIVES

Personality is an important contributor to an individual's mental health and is consistently linked to the two most prevalent mental health conditions among older adults: dementia and depression. This review summarizes the current findings on personality and its association with cognitive decline and depression, as well as treatment outcomes and possible intervention strategies.

METHODS

Literature searches were conducted in Web of Science, PubMed, and PsycINFO. Search terms included 'personality traits,' 'depression,' 'treatment,' and 'older adults.'

RESULTS

Cognitive decline and depressive disorders are both associated with a common personality profile: high neuroticism, and low conscientiousness, extraversion, openness, and agreeableness. Across studies, the most consistent predictor of late-life depression, its course, and treatment outcomes is higher neuroticism.

CONCLUSIONS

Personality traits are associated with cognitive decline, as well as the diagnosis and course of late-life depression in older adults. However, formal personality assessment is not typically incorporated in clients' treatment plans, even though personality traits may influence treatment efficacy and outcomes.

CLINICAL IMPLICATIONS

Formal assessment of personality traits may be beneficial in terms of treatment adherence and outcomes for older adults. Tailored interventions that specifically target the client's strengths are likely to be well received by both clients and clinicians.

Factors underlying cognitive decline in old age and Alzheimer's disease: the role of the hippocampus

There are many factors that strongly influence the aetiology, development, and progression of cognitive decline in old age, mild cognitive impairment (MCI), and Alzheimer's disease (AD). These factors include not only different personality traits and moods but also lifestyle patterns (e.g. exercise and diet) and awareness levels that lead to cognitive decline in old age. In this review, we discuss how personality traits, mood states, and lifestyle impact brain and behaviour in older adults. Specifically, our review shows that these lifestyle and personality factors affect several brain regions, including the hippocampus, a region key for memory that is affected by cognitive decline in old age as well as AD. Accordingly, appropriate recommendations are presented in this review to assist individuals in decreasing chances of MCI, dementia, AD, and associated symptoms.

Mindfulness and meditation: treating cognitive impairment and reducing stress in dementia

This study investigates the relationship between mindfulness, meditation, cognition and stress in people with Alzheimer’s disease (AD), dementia, mild cognitive impairment and subjective cognitive decline. Accordingly, we explore how the use of meditation as a behavioural intervention can reduce stress and enhance cognition, which in turn ameliorates some dementia symptoms. A narrative review of the literature was conducted with any studies using meditation as an intervention for dementia or dementia-related memory conditions meeting inclusion criteria. Studies where moving meditation was the main intervention were excluded due to the possible confounding of exercise. Ten papers were identified and reviewed. There was a broad use of measures across all studies, with cognitive assessment, quality of life and perceived stress being the most common. Three studies used functional magnetic resonance imaging to measure functional changes to brain regions during meditation. The interventions fell into the following three categories: mindfulness, most commonly mindfulness-based stress reduction (six studies); Kirtan Kriya meditation (three studies); and mindfulness-based Alzheimer’s stimulation (one study). Three of these studies were randomised controlled trials. All studies reported significant findings or trends towards significance in a broad range of measures, including a reduction of cognitive decline, reduction in perceived stress, increase in quality of life, as well as increases in functional connectivity, percent volume brain change and cerebral blood flow in areas of the cortex. Limitations and directions for future studies on meditation-based treatment for AD and stress management are suggested.

Hostile attitudes and effortful coping in young adulthood predict cognition 25 years later

OBJECTIVE

We studied the relation of early-life (mean age 25 years) and mid-life (mean age 50 years) cognitive function to early measures of hostile attitudes and effortful coping.

METHODS

In 3,126 black and white men and women (born in 1955-1968) from the Coronary Artery Risk Development in Young Adults Study (CARDIA), we used linear regression to examine the association of hostile attitudes (Cook-Medley questionnaire) and effortful coping assessed at baseline (1985-1986) to cognitive ability measured in 1987 and to a composite cognitive Z score of tests of verbal memory, psychomotor speed, and executive function ascertained in midlife (2010-2011).

RESULTS

Baseline hostility and effortful coping were prospectively associated with lower cognitive function 25 years later, controlling for age, sex, race, education, long-term exposure to depression, discrimination, negative life events, and baseline cognitive ability. Compared to the lowest quartile, those in the highest quartile of hostility performed 0.21 SD units lower (95% confidence interval [CI] -0.39, -0.02). Those in the highest quartile of effortful coping performed 0.30 SD units lower (95% CI -0.48, -0.12) compared to those in the lowest quartile. Further adjustment for cumulative exposure to cardiovascular risk factors attenuated the association with the cognitive composite Z score for hostility.

CONCLUSIONS

Worse cognition in midlife was independently associated with 2 psychological characteristics measured in young adulthood. This suggests that interventions that promote positive social interactions may have a role in reducing risk of late-age cognitive impairment.

Personality and cognitive decline in the Baltimore Epidemiologic Catchment Area follow-up study

OBJECTIVE

To determine the association between personality domains and 11-year cognitive decline in a sample from a population-based study.

METHOD

Data from Waves 3 (1993-1996) and 4 (2003-2004) of the Baltimore cohort of the Epidemiologic Catchment Area (ECA) study were used for analyses. The sample included 561 adults (mean age ± SD: 45.2 ± 10.78 years) who completed the NEO Personality Inventory-Revised prior to Wave 4. Participants also completed the Mini-Mental State Examination (MMSE) and immediate and delayed word recall tests at Wave 3, and at Wave 4, 10.9 ± 0.6 years later.

RESULTS

In models adjusted for baseline cognitive performance, demographic characteristics, medical conditions, depressive symptoms, and psychotropic medication use, each 10-point increase in Neuroticism T-scores was associated with a 0.15-point decrease in MMSE scores (B = -0.15, 95% confidence interval [CI]: -0.30, -0.01), whereas each 10-point increase in Conscientiousness T-scores was associated with a 0.18-point increase on the MMSE (B = 0.18, 95% CI: 0.04, 0.32) and a 0.21-point increase in immediate recall (B = 0.21, 95% CI: 0.003, 0.41) between baseline and follow-up.

CONCLUSION

Findings suggest that greater Neuroticism is associated with decline, and greater Conscientiousness is associated with improvement in performance on measures of general cognitive function and memory in adults. Further studies are needed to determine the extent to which personality traits in midlife are associated with clinically significant cognitive outcomes in older adults, such as mild cognitive impairment and dementia, and to identify potential mediators of the association between personality and cognitive trajectories.

Neuroticism, extraversion, and motor function in community-dwelling older persons

OBJECTIVE

Personality traits are associated with adverse health outcomes in old age, but their association with motor function is unclear. We tested the hypothesis that neuroticism and extraversion are associated with motor decline in older persons.

DESIGN

Prospective, observational cohort study.

SETTING

Retirement communities across metropolitan Chicago.

PARTICIPANTS

Nine hundred eighty-three older persons without dementia.

MEASUREMENTS

At baseline, neuroticism and extraversion were assessed and annual assessment of 18 motor measures were summarized in a composite measure.

RESULTS

Average follow-up was 5 years. Separate linear mixed-effects models controlling for age, sex, and education showed that baseline levels of neuroticism and extraversion were associated with the rate of motor decline. For each 7-point (∼1 SD) higher neuroticism score at baseline, the average annual rate of motor decline was more than 20% faster. This amount of motor decline was associated with a 10% increased risk of death compared to a participant with an average neuroticism score. Each 6-point (∼1 SD) lower extraversion score at baseline was associated with an 8% faster rate of motor decline. This amount of motor decline was associated with about a 9% increased risk of death compared to a participant with an average extraversion score. Neuroticism and extraversion were relatively independently associated with motor decline. These associations were unchanged when controlling for depressive symptoms and current health status but were partially attenuated when controlling for late-life cognitive and social activities.

CONCLUSIONS

Higher levels of neuroticism and lower levels of extraversion are associated with more rapid motor decline in old age.

Personality and risk for Alzheimer's disease in adults 72 years of age and older: a 6-year follow-up

[Correction Notice: An erratum for this article was reported in Vol 26(2) of Psychology and Aging (see record 2011-05802-001). This article contains an error in the Discussion, under the Implications, Caveats, Future Directions heading. The third paragraph includes the sentences that should have been removed. The corrected paragraph appears in the correction.] We conducted secondary analyses to determine the relationship between longstanding personality traits and risk for Alzheimer's disease (AD) among 767 participants 72 years of age or older who were followed for more than 6 years. Personality was assessed with the NEO-FFI. We hypothesized that elevated Neuroticism, lower Openness, and lower Conscientiousness would be independently associated with risk of AD. Hypotheses were supported. The finding that AD risk is associated with elevated Neuroticism and lower Conscientiousness can be added to the accumulating literature documenting the pathogenic effects of these two traits. The link between lower Openness and AD risk is consistent with recent findings on cognitive activity and AD risk. Findings have implications for prevention research and for the conceptualization of the etiology of AD.

Neuroticism in adolescence and cognitive function in midlife in the British 1946 birth cohort: The HALCyon program

We examined whether higher levels of neuroticism in adolescence were associated with poorer cognitive function in midlife in 2,071 members of the British 1946 birth cohort. Higher neuroticism at age 13 was associated with poorer performance on tests of verbal ability, verbal fluency, and verbal memory at age 53 in sex-adjusted analyses. However, higher neuroticism was also associated with poorer cognitive performance at age 8. After adjustment for childhood cognition or educational attainment, the associations between neuroticism at age 13 and midlife cognition ceased to be statistically significant. The link between neuroticism and subsequent cognitive ability may be a reflection of a long-standing correlation between the stable aspects of these traits since childhood, but further measurements of both traits are needed to confirm this.

APOE-4 genotype and neurophysiological vulnerability to Alzheimer's and cognitive aging

Many years before receiving a clinical diagnosis of Alzheimer's disease (AD), patients experience evidence of cognitive decline. Recent studies using a variety of brain imaging technologies have detected subtle changes in brain structure and function in normal adults with a genetic risk for AD; these brain changes have similar pathological features as AD, and some appear to be predictive of future cognitive decline. This review examines the most recent data on brain changes in genetic risk for AD and discusses the benefits and potential risks of detecting individuals at risk.

Modifiable Midlife Risk Factors for Late-Life Cognitive Impairment and Dementia

The baby boom generation is approaching the age of greatest risk for cognitive impairment and dementia. There is growing interest in strategies to modify the environment in midlife to increase the probability of maintaining cognitive health in late life. Several potentially modifiable risk factors have been studied in relation to cognitive impairment and dementia in late life, but methodological limitations of observational research have resulted in some inconsistencies across studies. The most promising strategies are maintaining cardiovascular health, engagement in mental, physical, and social activities, using alcohol in moderation, abstaining from tobacco use, and following a heart-healthy diet. Other factors that may influence cognitive health are occupational attainment, depression, personality, exposure to general anesthesia, head injury, postmenopausal hormone therapy, non-steroidal anti-inflammatory medications, and nutritional supplements such as antioxidants. Some long-term observational studies initiated in midlife or earlier, and some randomized controlled trials, have examined the effects of specific cognitive health promotion behaviors in midlife on the risk of cognitive impairment in late life. Overall, these studies provide limited support for risk reduction at this time. Recommendations and challenges for developing effective strategies to reduce the burden of cognitive impairment and dementia in the future are discussed.