Article

‘Occupational social and mental stimulation and cognitive decline with advancing age’

Authors:
  • University of South Florida and University of Lige
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Abstract

Objective: this study investigates the role of social and mental occupational characteristics in cognitive decline after retirement. Methods: the study included 1,048 subjects aged ≥65 years from the Three City cohort. Participants were evaluated at home at the initial visit and at 2-year intervals for a period of 12 years. The study includes detailed assessments of cognition, health and information about the subjects’ main occupation. The four cognitive tests have been grouped into one latent factor. Three independent raters specialised in employment were asked to evaluate the level of social and intellectual stimulation for each occupation, which was then rated as low, medium and high. Results: after controlling for potential confounding factors, no association was found between higher levels of social stimulation at work and baseline cognition (medium score, P = 0.440; high score, P = 0.700) as compared with a low level. While cognitive trajectories were initially similar between high and medium levels of social stimulation compared with that of a low level, with advancing age this association diverged whereby more social stimulation during work years was related to accelerated cognitive decline that further grew in magnitude with older age. For mental stimulation, differences were only observed at baseline, with greater levels of mental stimulation during work years being associated with better cognitive performance (medium score, β = 0.573, P = 0.015; and high score, β = 0.510; P = 0.090) compared with a low level of mental stimulation. Conclusion: workers retiring from occupations characterised by high levels of social stimulation may be at risk of accelerated cognitive decline with advancing age.

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... The following sociodemographic variables were studied: gender, age, level of education, civil status, and mental occupational, physical occupational, and clinical states, such as high blood pressure (HBP), diabetes, hypercholesterolemia, obesity, and cerebrovascular accidents (CVA). Moreover, an analysis of the subgroups was considered according to the level of education (primary/higher), physical occupational status and mental occupational status based on three levels: low, medium, and high (for each) [33]. ...
... When analyzing the occupational elements, our study revealed that men developed mental capacities when they worked better than women. Similar results were reported by other authors, who demonstrated that those occupations involving higher mental demands enhance cognitive functioning, which may come over as better cognitive performance after retirement in older adults [21,33]. Mental demand has been considered a factor that protects older adults from functional loss [76]. ...
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Older adults are particularly vulnerable to cognitive impairment with age, and gender differences are remarkable. However, there is very little evidence to identify both baseline cognitive and occupational gender differences prior to older adults’ retirement to design more efficient personalized cognitive interventions. This descriptive observational study examined gender differences in initial cognitive performance in 367 older adults with subjective memory complaints from a primary healthcare center in Zaragoza (Spain). To evaluate initial cognitive performance, the Spanish version of the Mini-Mental State Examination (MEC-35) and the set test were used to measure verbal fluency. Sociodemographic and clinical characteristics were evaluated, and cognitive and occupational differences were analyzed per gender. Men had higher educational and occupational levels, were older and more of them were married (p < 0.001) than women. Regarding cardiovascular risk factors, diabetes and cerebrovascular accidents were more frequent in women, while hypercholesterolemia and obesity were more frequent in men (p < 0.001). High blood pressure was more frequent in women, but not significantly so (p = 0.639). Global cognition was higher in men (p < 0.001) for attention, calculation, and language (p < 0.001). Verbal fluency was higher in women, but the difference was not statistically significant (p = 0.105). These results could be generalized to other health centers in the province and other Spanish autonomous communities as their sociodemographic variables are similar. Individualized interventions that adapt to gender, cognitive and initial occupational performance should be developed and adapted to elderly populations living in the general community to maintain their cognitive capacity and prevent their cognitive impairment and the social health costs this would imply.
... The following socio-demographic variables were studied: gender, age, level of education, marital status, and mental occupational, physical occupational, and clinical statuses such as AHT, diabetes, hypercholesterolemia, obesity, and CVA. An analysis of the subgroups was considered according to both the physical occupational and mental occupational statuses based on three levels for each one: low, medium, high [33]. The presence of SMC was evaluated by the question: Do you have complaints about your memory? ...
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Introduction: Successful aging lies in cognitive and functional maintenance, and in the optimal performance of daily tasks that keep the elderly free of disability and dependence. However, there is little evidence for functional differences for gender and age, and how cognitive and physical demands in past working lives can affect them, to design more personalized occupational therapy interventions to prevent functional and cognitive impairment. Method: This observational descriptive study evaluated 367 older adults living in a community with subjective memory complaints and scored between 24 and 35 with the Spanish version of the “Mini-Mental State Examination (MEC-35)”. Basic activities of daily living (BADL) were studied with the Barthel Index, while instrumental ADL (IADL) were examined with the Lawton–Brody scale. Functional differences for gender, age, and physico-mental occupation were examined. Results: The significant differences found for gender indicated that men did better in BADL (p = 0.026) and women better performed IADL (p < 0.001). Differences between age groups suggest that the younger group (aged 64–75) obtained better results for BADL (p = 0.001) and IADL (p < 0.001). For physico-mental occupation, statistically significant differences were found only in IADL for mental (p = 0.034) and physical occupation (p = 0.005). Conclusions: Gender, age, and the cognitive and physical demands of occupational stages, can be important predictors of cognitive and functional impairment. These results can be generalized to other health centers in the province and to other Spanish Autonomous Communities because their socio-demographic variables are similar. It would be interesting to carry out multimodal personalized interventions that consider the factors that might affect functional impairment to preserve personal autonomy.
... Although employment can provide older persons with an opportunity for intellectual engagement, this may be dependent on the type of occupation and the mental stimulation involved (Grotz et al. 2018). In turn, intellectual engagement may be important for maintaining cognitive ability to make sound future investment and consumption decisions and detect attempts at fraud. ...
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Population studies show the importance of active aging for maintaining cognitive health, but much of the research has focused on episodic memory and verbal skills. Aging and ability to make rational intertemporal financial decisions is less understood, despite its critical role in consumer finance. This study describes the relationship between age, retirement and intertemporal decision ability. A survey of adults examines the interplay of aging and retirement related to completing simple calculations with time tradeoffs in benefits. A negative association between intertemporal skills and age is indicated, with a sharp downward inflection around age 66. Regression analysis results in a significant, negative retirement‐age interaction term. This research has implications for policy and consumer decision‐making. The negative relationship of age and retirement status may suggest limits to career extension, or alternatively, that extending some types of careers could provide cognitive benefits. Further research is needed to understand the direction of causality. This article is protected by copyright. All rights reserved.
... On the other hand, a differential preservation pattern shows that, at the time of retirement, individuals with higher complexity of work exhibit higher cognitive performance than those with lower complexity of work and show reduced decline compared with those retiring from less-complex jobs. In terms of types of complexity, higher complexity of work with people has been associated with a faster rate of decline after retirement more consistently, although complexity of work with data shows similar patterns (Finkel et al., 2009;Grotz et al., 2018). Studies that applied an overall measure of complexity without differentiating between the three types of complexity (i.e., data, people, and things) found that higher-complex jobs were associated with slower cognitive aging (Fisher et al., 2014) and lower risk of cognitive impairment Boots et al., 2015) post-retirement. ...
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Retirement has been associated with cognitive decline. However, the influence of specific job characteristics like occupational complexity on post-retirement cognitive outcomes is not well understood. Data from the Midlife in the United States (MIDUS) study were used to examine occupational complexity in relation to cognitive performance and cognitive change after retirement. Initial sample included 471 workers between 45 and 75 years of age. At 9-year follow-up (T2), 149 were retired and 322 were still working. All six tasks from the Brief Test of Adult Cognition by Telephone (BTACT) were used. Hierarchical regression with workers at T1 indicated that, controlling for sociodemographic variables, complexity of work with people significantly contributed to explaining variance in overall cognitive performance (1.7%) and executive function (2%). In Latent Change Score (LCS) models, complexity of work with people was the only significant predictor of cognitive change in retirees, with those retiring from high-complexity jobs showing less decline. In conclusion, high complexity of work with people is related to better executive functioning and overall cognition during working life and slower decline after retirement. The finding that more intellectually stimulating work carries cognitive advantage into retirement fits the cognitive reserve concept, where earlier intellectual stimulation brings about lower risks of cognitive problems later. Study results also go along with the unengaged lifestyle hypothesis, whereby people may slip into so-called "mental retirement," leading to post-retirement cognitive loss, which may be most apparent among those retiring from jobs with low complexity of work with people. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
... A c c e p t e d M a n u s c r i p t Occupation is often a major source of a person's mentally challenging activities during adulthood; therefore the nature of work tasks during midlife may afford protections or confer risks for long-term brain health (Nexø, Meng, & Borg, 2016;Then et al., 2013). Although it is relatively well-established that engaging in cognitively stimulating activities in the workplace is associated with higher levels of cognition (Opdebeeck, Martyr, & Clare, 2016;Then et al., 2013), conflicting results have been reported in the association of mentally stimulating activities with rates of cognitive change, with some studies showing slower cognitive decline (Fisher et al., 2014;Marquié et al., 2010;Pool et al., 2016;Then et al., 2015), others reporting more rapid decline (Singh-Manoux Archana et al., 2011), and other studies showing no significant association (Gow, Avlund, & Mortensen, 2012;Grotz et al., 2017). In the current study, we investigate the rates of cognitive decline in late life associated with working in mentally challenging occupations. ...
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With an ever increasing population of aging people in the western world, it is more crucial than ever that we try to understand how and why cognitive competence breaks down with advancing age why do some people follow normal patterns of cognitive change, while others follow a path of progressive decline, with neurodegenerative diseases such as Alzheimer's. What can be done to prevent cognitive decline or - to avoid neurodegenerative diseases? The answers, if they come, will not emerge from research within one discipline, but from work being done across a range of scientific and medical specialities. This book delves into the subjects of cognitive aging, neuroscience, pharmacology, health, genetics, sensory biology, and epidemiology. This book is about new frontiers rather than past research and accomplishments. Recently cognitive aging research has taken several new directions, linking with, and benefiting from, rapid technological and theoretical advances in these neighbouring disciplines. This book provides unique interdisciplinary coverage of the topic. © Roger A. Dixon, Lars Bäckman, and Lars Göran-Nilsson 2004. All rights reserved.
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The recent availability of longitudinal data on the possible association of different lifestyles with dementia and Alzheimer's disease (AD) allow some preliminary conclusions on this topic. This review systematically analyses the published longitudinal studies exploring the effect of social network, physical leisure, and non-physical activity on cognition and dementia and then summarises the current evidence taking into account the limitations of the studies and the biological plausibility. For all three lifestyle components (social, mental, and physical), a beneficial effect on cognition and a protective effect against dementia are suggested. The three components seem to have common pathways, rather than specific mechanisms, which might converge within three major aetiological hypotheses for dementia and AD: the cognitive reserve hypothesis, the vascular hypothesis, and the stress hypothesis. Taking into account the accumulated evidence and the biological plausibility of these hypotheses, we conclude that an active and socially integrated lifestyle in late life protects against dementia and AD. Further research is necessary to better define the mechanisms of these associations and better delineate preventive and therapeutic strategies.
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Objective: To describe the baseline characteristics of the participants in the Three-City (3C) Study, a study aiming to evaluate the risk of dementia and cognitive impairment attributable to vascular factors. Methods: Between 1999 and 2001, 9,693 persons aged 65 years and over, institutionalized, were recruited from the electoral rolls of three French cities, i.e. Bordeaux, Dijon and Montpellier. Health-related data were collected during face-to-face interviews using standardized questionnaires. The baseline examination included cognitive testing and diagnosis of dementia, and assessment of vascular risk factors, including blood pressure measurements, ultrasound examination of the carotid arteries, and measurement of biological parameters (glycemia, total, high-density lipoprotein and low-density lipoprotein cholesterol, triglycerides, creatinemia); 3,442 magnetic resonance imaging (MRI) examinations were performed in subjects aged 65-79. Measurements of ultrasound, blood, and MRI parameters were centralized. Two follow-up examinations (at 2 and 4 years) were planned. Results: After exclusion of the participants who had subsequently refused the medical interview, the 3C Study sample consisted of 3,649 men (39.3%) and 5,645 women, mean age 74.4 years, with a relatively high level of education and income. Forty-two percent of the participants reported to be followed up for hypertension, about one third for hypercholesterolemia, and 8% for diabetes; 65% had elevated blood pressure measures (systolic blood pressure greater than or equal to 140 or diastolic blood pressure greater than or equal to 90). The proportion of Mini-Mental State Examination scores below 24 was 7% and dementia was diagnosed in 2.2% of the participants. Conclusion: Distribution of baseline characteristics of the 3C Study participants suggests that this study will provide a unique opportunity to estimate the risk of dementia attributable to vascular factors. Copyright (C) 2003 S. Karger AG, Basel.
Article
To examine associations between complexity of main lifetime occupation and cognitive performance in later life. Occupational complexity ratings for data, people, and things were collected from the Dictionary of Occupational Titles for 1,066 individuals (men = 534, women = 532) in the Lothian Birth Cohort 1936. IQ data were available from mean age 11 years. Cognitive ability data across the domains of general ability, processing speed, and memory were available at mean age 70 years. General linear model analyses indicated that complexity of work with people and data were associated with better cognitive performance at age 70, after including age 11 IQ, years of education, and social deprivation. The current findings are supportive of the differential preservation hypotheses that more stimulating environments preserve cognitive ability in later life, although the continued effects into old age are still debated. Studies that have early-life cognitive ability measures are rare, and the current study offers interesting prospects for future research that may further the understanding of successful aging. © 2014 American Academy of Neurology.
Article
This paper analyses the effect of retirement on cognitive functioning using a longitudinal survey among older Americans, which allows controlling for individual heterogeneity and endogeneity of the retirement decision by using the eligibility age for social security as an instrument. The results highlight a significant negative effect of retirement on cognitive functioning. Our findings suggest that reforms aimed at promoting labour force participation at an older age may not only ensure the sustainability of social security systems but may also create positive health externalities for older individuals.
Article
SYNOPSIS As part of a 5-year, prospective, epidemiological survey of normal and pathological ageing, this cross-sectional analysis examines the relationship between depressive symptomatology (CES-D) and cognitive functioning (MMS) in a community sample of 2792 non-institutionalized persons (age ≥ 65) living in Southwest France. Of the sample, 13·4%, report depressive symptoms above the cut-off. A significant association was found between CES-D and MMS scores, but after adjusting for age, living arrangements, and especially functional limitations, the relationship remained strong only for women.
Article
The Set test, a simple rapid test of mental function, was applied to a sample of 189 elderly subjects. A score of under 15 on the test corresponded closely to a clinical diagnosis of dementia. Scores in the range 15 to 24 showed a lesser degree of association with dementia; while no subject with a score of 25 or over was demented. Low scores in the test were associated with physical illness, and to a limited extent with low social class, but not with affective illness. The test appears worthy of further studies in screening programs, and may have other clinical and epidemiological uses.
Article
Little is known about whether persons with mentally demanding jobs are protected against cognitive impairment and whether this association is independent of intellectual abilities and other confounders. Longitudinal data from the Maastricht Aging Study (MAAS) were used to examine this association. After the 1993-1995 baseline examination, there was a first 3-year follow-up examination (1996-1998) among 630 men and women, aged 50 to 80, who exhibited no cognitive impairment at baseline. Persons with mentally demanding jobs had lower risks of developing cognitive impairment during follow-up (36 cases), compared with persons without such jobs (odds ratio = 0.79; 95% confidence interval: 0.65-0.96). About 1.5% of the persons with high mental work demands developed impairment compared to 4% of the persons with few work demands. The protective effect was independent of intellectual abilities and other confounders. Our findings provide evidence that continued and potentially modifiable mental stimulation during adult life may protect men and women against cognitive impairment.
Article
Clinical and pathological data from the Rush Memory and Aging Project were used to test the hypothesis that distress proneness is associated with increased risk of Alzheimer's disease (AD). More than 600 older persons without dementia completed a 6-item measure of neuroticism, a stable indicator of proneness to psychological distress. At annual intervals thereafter, they underwent uniform evaluations that included clinical classification of AD and administration of 18 cognitive tests. Those who died underwent brain autopsy from which composite measures of AD pathology were derived. During a mean of about 3 years of follow-up, 55 people were clinically diagnosed with AD. In analyses that controlled for age, sex, and education, persons with a high level of distress proneness (score = 24, 90th percentile) were 2.7 times more likely to develop AD than those not prone to distress (score = 6, 10th percentile). Adjustment for depressive symptomatology or frequency of cognitive, social, and physical activity did not substantially change this effect. Distress proneness was also associated with more rapid cognitive decline. Among 45 participants who died and underwent brain autopsy, distress proneness was unrelated to diverse measures of AD pathology and was inversely related to cognition after controlling for AD pathology. The results support the hypothesis that distress proneness is associated with increased risk of dementia and suggest that neurobiologic mechanisms other than AD pathology may underlie the association.
Article
To examine the effect of occupational characteristics on cognitive status change in members of the NAS-NRC Twins Registry of World War II veterans. Participants completed the modified Telephone Interview for Cognitive Status (TICS-m) on three occasions spanning a period of approximately 7 years. Based on factor analysis, occupational characteristics were interpreted as reflecting general intellectual demands (GI), human interaction and communication (HC), physical exertion (PE), and visual attention (VA). Based on regression analysis of TICS-m change that was dependent on twin pairing and additionally covarying for education, age at each testing event, medical conditions, and initial TICS-m score, higher GI was associated with a modest longitudinal improvement in TICS-m performance, whereas higher PE and VA were both associated with a modest decline. Subsequent analysis revealed that these significant effects were present among dizygotic twins, but not among monozygotic twins. Previous findings of a relationship between occupational characteristics and cognitive performance in later life may be partially explained by genetic factors; however, until these genes are identified, occupational characteristics may be useful markers.
Article
Cognition is not directly measurable. It is assessed using psychometric tests, which can be viewed as quantitative measures of cognition with error. The aim of this article is to propose a model to describe the evolution in continuous time of unobserved cognition in the elderly and assess the impact of covariates directly on it. The latent cognitive process is defined using a linear mixed model including a Brownian motion and time-dependent covariates. The observed psychometric tests are considered as the results of parameterized nonlinear transformations of the latent cognitive process at discrete occasions. Estimation of the parameters contained both in the transformations and in the linear mixed model is achieved by maximizing the observed likelihood and graphical methods are performed to assess the goodness of fit of the model. The method is applied to data from PAQUID, a French prospective cohort study of ageing.
Article
To examine the association of job characteristics and intelligence to cognitive status in members of the National Academy of Sciences-National Research Council Twins Registry of World War II veterans. Participants (n = 1,036) included individuals with an assessment of intelligence based on Armed Services testing in early adulthood. In late adulthood, these individuals completed the modified Telephone Interview for Cognitive Status (TICS-m) and occupational history as part of an epidemiologic study of aging and dementia. Occupational history was coded to produce a matrix of job characteristics. Based on factor analysis, job characteristics were interpreted as reflecting general intellectual demands (GI), human interaction and communication (HC), physical activity (PA), and visual attention (VA). Based on regression analysis of TICS-m score covarying for age, intelligence, and years of education, higher levels of GI and HC were independently associated with higher TICS-m performance, whereas higher PA was independently associated with lower performance. There was an interaction of GI and intelligence, indicating that individuals at the lower range of intellectual aptitude in early adulthood derived greater cognitive benefit from intellectually demanding work. Intellectually demanding work was associated with greater benefit to cognitive performance in later life independent of related factors like education and intelligence. The fact that individuals with lower intellectual aptitude demonstrated a stronger positive association between work and higher cognitive performance during retirement suggests that behavior may enhance intellectual reserve, perhaps even years after peak intellectual activity.
Manuel Pour l'Application du Test de Rétention Visuelle
  • A Benton
Benton A. Manuel Pour l'Application du Test de Rétention Visuelle. Applications Cliniques et Expérimentales, 2nd edition. Paris: Centre de Psychologie Appliquée, 1965.