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Objective We examined changes in participation in cognitive, social, and physical leisure activities across middle and older adulthood and tested moderation of trajectories of change in participation by gender. Method In all, 1,398 participants in the Swedish Adoption/Twin Study of Aging (SATSA) completed a 7-item leisure activity questionnaire up to 4 times over 17 years. Mean baseline age was 64.9 years (range = 36–91); 59% were women. Factor analysis identified physical, social, and cognitive/sedentary leisure activity participation factors. Age-based latent growth curve models adjusted for marital status, gender, education, depressive symptoms, and physical health were used. Results Overall, results indicated stability in social activities, increase in cognitive/sedentary activities, and decrease in physical activities, as well as accelerated decline in all three types of activities after about the age of 70 years. Social activity remained mostly stable for women and declined for men. Women reported higher levels of cognitive/sedentary leisure activity across the study. Both men and women declined in physical leisure activity. Variance in leisure activities increased with age; men demonstrated more variance in social activities and women in physical activities. Conclusions Understanding change in leisure activities with age and by gender can have important implications for interventions and for use of leisure activity data in epidemiological research. [ABSTRACT FROM AUTHOR]

The primary objective was to investigate the life course hypotheses – sensitive period, chain of risks, and accumulation of risks – in relation to financial hardship and psychological distress in old age. We used two Swedish longitudinal surveys based on nationally representative samples. The first survey includes people 18–75 years old with multiple waves, the second survey is a longitudinal continuation, including people 76 + years old. The analytical sample included 2990 people at baseline. Financial hardship was assessed in childhood (retrospectively), at the mean ages of 54, 61, 70, and 81 years. Psychological distress (self-reported anxiety and depressive symptoms) was assessed at the same ages. Path analysis with WLSMV estimation was used. There was a direct path from financial hardship in childhood to psychological distress at age 70 (0.26, p = 0.002). Financial hardship in childhood was associated with increased risk of psychological distress and financial hardship both at baseline (age 54), and later. Financial hardship, beyond childhood, was not independently associated with psychological distress at age 81. Higher levels of education and employment decreased the negative effects of financial hardship in childhood on the risk of psychological distress and financial hardship later on. There was a bi-directional relationship between psychological distress and financial hardship; support for health selection was slightly higher than for social causation. We found that psychological distress in old age was affected by financial hardship in childhood through a chain of risks that included psychological distress earlier in life. In addition, financial hardship in childhood seemed to directly affect psychological distress in old age, independent of other measured circumstances (i.e., chains of risks). Education and employment could decrease the effect of an adverse financial situation in childhood on later-life psychological distress. We did not find support for accumulation of risks when including tests of all hypotheses in the same model. [ABSTRACT FROM AUTHOR]

Background: Survival reflects the accumulation of multiple influences experienced over the life course. Given the amount of time usually spent at work, the influence of work may be particularly important. We examined the association between work-related stress in midlife and subsequent mortality, investigating whether sense of coherence modified the association. Methods: Self-reported work-related stress was assessed in 1393 Swedish workers aged 42-65 who participated in the nationally representative Level of Living Survey in 1991. An established psychosocial job exposure matrix was applied to measure occupation-based stress. Sense of coherence was measured as meaningfulness, manageability and comprehensibility. Mortality data were collected from the Swedish National Cause of Death Register. Data were analyzed with hazard regression with Gompertz distributed baseline intensity. Results: After adjustment for socioeconomic position, occupation-based high job strain was associated with higher mortality in the presence of a weak sense of coherence (HR, 3.15; 1.62-6.13), a result that was stronger in women (HR, 4.48; 1.64-12.26) than in men (HR, 2.90; 1.12-7.49). Self-reported passive jobs were associated with higher mortality in the presence of a weak sense of coherence in men (HR, 2.76; 1.16-6.59). The link between work stress and mortality was not significant in the presence of a strong sense of coherence, indicating that a strong sense of coherence buffered the negative effects of work-related stress on mortality. Conclusions: Modifications to work environments that reduce work-related stress may contribute to better health and longer lives, especially in combination with promoting a sense of coherence among workers. [ABSTRACT FROM AUTHOR]

Background: Midlife alcohol consumption (beer, wine, and spirits) was examined in relation to dementia incidence over 43 years. Methods: Participants were 12,326 members of the population-based Swedish Twin Registry born during 1907-1925 who responded to items about alcohol consumption in 1967/1970, subsequently classified as nondrinking (0 grams of ethanol per day), light (1-5g/d), moderate (5-12g/d), heavy (12-24g/d), and very heavy (>24g/d) drinking. Dementia was identified from the National Patient and Cause of Death Registries. Cox proportional hazard models adjusted for cluster-correlated data were used in cohort analyses. Conditional logistic regression (dementia-discordant pairs) and mixed effects models (dementia-concordant pairs) were used in twin analyses. Results: Overall, nondrinkers did not differ from light drinkers in dementia risk. Heavy drinking (hazard ratio = 1.10, p = .028) and very heavy drinking (hazard ratio = 1.18, p = .033) were associated with increased dementia risk controlling for sociodemographic, lifestyle, and cardiovascular factors. More alcohol from spirits was related to increased risk of dementia, whereas more alcohol from wine with decreased risk, although the association for wine reversed direction at high amounts. Relative to co-twins drinking light amounts, moderate-to-heavy drinking twins had (a) greater risk of dementia by 57% (p = .006, 300% in monozygotic pairs only) and (b) reduced time to dementia by 4.76 years (p = .019, 4.78 years in monozygotic pairs only). Conclusion: Averaging more than 12 grams of alcohol per day may increase risk of dementia. Alcohol from spirits appears particularly important for the increased dementia risk. Genetic and/or familial factors do not explain these associations. Alcohol use reduction may be a useful population-wide intervention strategy. [ABSTRACT FROM AUTHOR]

Objective: To assess occupational complexity in midlife in relation to psychological distress in older adulthood (69+ years) and explore the role of socioeconomic position. Method: Baseline data from the Swedish Level of Living Survey and follow-up data from the Swedish Longitudinal Study of Living Conditions of the Oldest Old were combined, resulting in 20+ years of follow-up. Data were analyzed using ordered logistic regressions. Results: Higher occupational complexity was associated with less psychological distress 20 years later adjusted for age, sex, follow-up year, hours worked the year before baseline, and psychological distress at baseline. Higher socioeconomic position yielded the same pattern of results. Socioeconomic position partially accounted for the association between occupational complexity and psychological distress. Discussion: With social gradient not easily amenable to modification, efforts to increase engagement at work may offer a viable option to attenuate the influence of work environment on psychological distress later in life. [ABSTRACT FROM AUTHOR]

Objective. To examine whether occupational complexity of working with data or people, and cognitive or social leisure activity at midlife predicted cognition in advanced old age. Methods. We used 810 eligible participants from Longitudinal Study of Living Conditions of the Oldest Old, a Swedish nationally representative study of individuals aged 77+ with cognitive assessments (an abridged version of the Mini-Mental State Exam) administered in 1992 and 2002 and linked to information about their midlife occupation and leisure activities collected in 1968 and 1981. A bootstrapping technique was applied to examine the direct and interactive associations of occupational complexity and leisure activity with late-life cognition. Results. Controlling for demographic and health-related factors from childhood, midlife, and late life, we found that greater work complexity, both with people and with data, and greater participation in cognitive or social leisure activities independently related to better late-life cognitive scores. The complexity-cognition link was moderated by leisure activity such that the cognitive benefit related to the complexity of work—especially complexity of working with people—was rendered insignificant when participation in leisure activities—especially social activities—was above average. Discussion. Results are discussed in terms of using work complexity to compensate for lack of leisure activity as well as in terms of promoting leisure engagement to compensate for long-term cognitive disadvantage imposed by working in less challenging occupations. [ABSTRACT FROM PUBLISHER]

Objective: To explore the role of working conditions in the association between socioeconomic position and health after retirement age using over 20 years follow-up. Method: Two Swedish nationally representative Level of Living Surveys (total N = 1,131) were used. Ordered logistic regression was used to assess the association between socioeconomic position and health (self-rated health, psychological distress, musculoskeletal pain, circulatory problems, physical and cognitive impairment). The role of physical and psychological working conditions was also assessed. Results: Lower socioeconomic position was associated with more adverse physical, but not psychological, working conditions. Physical working conditions partially explained the differences in physical impairment and musculoskeletal pain in old age attributed to socioeconomic position, but not differences in self-rated health, circulatory problems, psychological distress, and cognitive impairment. Socioeconomic position was a stronger correlate of health than psychological working conditions alone. Discussion: Improving physical working conditions may be important for reducing the influence of socioeconomic position on health after retirement. [ABSTRACT FROM PUBLISHER]

Objectives To examine job control, job demands, social support at work, and job strain (ratio of demands to control) in relation to risk of any dementia, Alzheimer's disease ( AD), and vascular dementia ( VaD). Design Cohort study. Setting The population-based Study of Dementia in Swedish Twins. Participants Two hundred fifty-seven people with dementia (167 AD, 46 VaD) and 9,849 without. Measurements Dementia diagnoses were based on telephone screening for cognitive impairment followed by in-person clinical examination. An established job exposure matrix was matched to main occupation categories to measure work characteristics. Results In generalized estimating equations (adjusted for the inclusion of complete twin pairs), lower job control was associated with greater risk of any dementia (odds ratio ( OR) = 1.17, 95% confidence interval ( CI) = 1.04-1.31) and VaD specifically ( OR = 1.39, 95% CI = 1.07-1.81). Lower social support at work was associated with greater risk of dementia ( OR = 1.15, 95% CI = 1.03-1.28), AD ( OR = 1.14, 95% CI = 1.00-1.31), and VaD ( OR = 1.28, 95% CI = 1.02-1.60). Greater job strain was associated with greater risk of VaD only ( OR = 1.28, 95% CI = 1.02-1.60), especially in combination with low social support ( OR = 1.35, 95% CI = 1.11-1.64). Age, sex, and education were controlled for. Work complexity, manual work, and vascular disease did not explain the results. No differences in work-related stress scores were observed in the 54 twin pairs discordant for dementia, although only two pairs included a twin with VaD. Conclusion Work-related stress, including low job control and low social support at work, may increase the risk of dementia, particularly VaD. Modification to work environment, including attention to social context and provision of meaningful roles for employees, may contribute to efforts to promote cognitive health. [ABSTRACT FROM AUTHOR]

Objectives. We used data from SWEOLD, a Swedish nationally representative study of individuals aged 77 years or older, to examine midlife indicators of job strain in relation to cognitive performance and impairment. Methods. In all, 827 participants completed an abridged 11-point version of the Mini-Mental State Examination in-person in 1992 and/or 2002 and had self-reported and/or occupation-based scores for job control and demands from data collected in 1968. Seventeen percent scored below the cutoff for cognitive impairment. Results. Controlling for age, sex, education, self-rated health, and year of cognitive screening, low self-reported and occupation-based job control at midlife was associated with poorer cognitive performance later (ps < .001). For the occupation-based measure, low job control was also associated with greater likelihood of impairment, whereas having an active job (high job control/high job demands) was associated with better cognitive performance and lower likelihood of impairment (ps < .01). Childhood environment, midlife depressive symptoms, and social activity had limited influence, whereas the influence of both adulthood socioeconomic position and work complexity on these results was more pronounced. Discussion. Job control at midlife, by itself and in combination with job demands, may influence cognitive functioning later above and beyond demographic variables and other occupational characteristics. [ABSTRACT FROM PUBLISHER]

We examined the association between complexity of the main lifetime occupation and changes in cognitive ability in later life. Data on complexity of work with data, people, and things and on 4 cognitive factors (verbal, spatial, memory, and speed) were available from 462 individuals in the longitudinal Swedish Adoption/Twin Study of Aging. Mean age at the first measurement wave was 64.3 years (SD = 7.2), and 65% of the sample had participated in at least three waves of data collection. Occupational complexity with people and data were both correlated with cognitive performance. Individuals with more complex work demonstrated higher mean performance on the verbal, spatial, and speed factors. Latent growth curve analyses indicated that, after correcting for education, only complexity with people was associated with differences in cognitive performance and rate of cognitive change. Continued engagement as a result of occupational complexity with people helped to facilitate verbal function before retirement, whereas a previous high level of complexity of work with people was associated with faster decline after retirement on the spatial factor. [ABSTRACT FROM AUTHOR]

Background. With the number of people with dementia increasing, identifying potential protective factors has become more important. We explored the association between physical exercise at midlife and subsequent risk of dementia among members of the HARMONY study. Methods. Measures of exercise were obtained by the Swedish Twin Registry an average of 31 years prior to dementia assessment. Dementia was diagnosed using a two-stage procedure--screening for cognitive impairment followed by full clinical evaluation. We used two study designs: case--control analyses included 264 cases with dementia (176 had Alzheimer's disease) and 2870 controls; co-twin control analyses included 90 twin pairs discordant for dementia. Results. In case--control analyses, controlling for age, sex, education, diet (eating fruits and vegetables), smoking, drinking alcohol, body mass index, and angina, light exercise such as gardening or walking and regular exercise involving sports were associated with reduced odds of dementia compared to hardly any exercise (odds ratio [OR] = 0.63, 95% confidence interval [CI], 0.43-0.91 for light exercise; OR = 0.34, 95% CI, 0.16-0.72 for regular exercise). Findings were similar for Alzheimer's disease alone. In co-twin control analyses, controlling for education, the association between higher levels of exercise and lower odds of dementia approached significance (OR = 0.50, 95% CI, 0.23-1.06; p = .072). Conclusions. Exercise at midlife may reduce the odds of dementia in older adulthood, suggesting that exercise interventions should be explored as a potential strategy for delaying disease onset. [ABSTRACT FROM AUTHOR]

Aims: Leisure activity helps people engage with life, and it promotes health and well-being as we age. This study investigated whether individuals with active jobs (high psychological demands, high control) in mid-life were more active during leisure time in old age compared with those with less active jobs. Methods: Two individually linked Swedish surveys were used ( N =776) with 23 years of follow-up. Data were analysed with logistic regression. Results: Having an active job in mid-life was associated with greater engagement in intellectual/cultural, social and physical activity in old age, even when leisure activity in mid-life was taken into account. Conclusions: The results suggest that active jobs in mid-life may be replaced by active leisure during retirement. Active job conditions may promote engagement in society in old age, which in turn may have positive health consequences.

Background: Increasing life expectancy has made understanding the mechanisms underlying late-life health and function more important. We set out to investigate whether trajectories of change in psychosocial working conditions are associated with late-life physical function., Methods: Two Swedish surveys, linked at the individual level, were used (n = 803). A psychosocial job exposure matrix was used to measure psychosocial working conditions during people's first occupation, as well as their occupation every five years thereafter until baseline in 1991. Physical function was measured in 2014. Random effects growth curve models were used to calculate intraindividual trajectories of working conditions. Predictors of physical function were assessed with ordered logistic regression., Results: A more active job at baseline was associated with increased odds of late-life physical function (OR 1.15, CI 1.01-1.32). Higher baseline job strain was associated with decreased odds of late-life physical function (OR 0.75, CI 0.59-0.96). A high initial level followed by an upward trajectory of job strain throughout working life was associated with decreased odds of late-life physical function (OR 0.32, CI 0.17-0.58)., Conclusions: Promoting a healthier workplace by reducing chronic stress and inducing intellectual stimulation, control, and personal growth may contribute to better late-life physical function.

Background: Stress has been suggested as a contributing factor in the etiology of Parkinson's Disease (PD), but epidemiological evidence is sparse., Objective: The objective of this study was to explore the association between occupational stress according to the job demands-control model and the risk for PD., Methods: We conducted a population-based cohort study with 2,544,748 Swedes born 1920 to 1950 who had an occupation reported in the population and housing censuses in 1980 or, if missing, in 1970. Job demands and control were measured using a job-exposure matrix. Incident PD cases were identified using Swedish national health registers from 1987 to 2010. Data were analyzed with Cox regression with age as the underlying time scale, adjusting for sex, education, and chronic obstructive pulmonary disease as a proxy for smoking., Results: During a mean follow-up time of 21.3 years, 21,544 incident PD cases were identified. High demands were associated with increased PD risk among men, most evident in men with high education. High control was associated with increased PD risk among the low educated. This association was more pronounced in women. High-strain jobs (high demands and low control) was only associated with increased PDrisk among men with high education, whereas active jobs (high demands and high control) were associated with increased PD risk among men with low education., Interpretation: High job demands appear to increase PD risk in men, especially in men with high education, whereas high job control increases PD risk among low educated, more strongly in women. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society., (© 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.)

Objective: Sleep problems may adversely affect neuronal health. We examined a subjective report of change (reduced duration and/or depth) in sleep pattern in relation to subsequent risk of incident all-cause dementia and Alzheimer disease (AD) over 9 years., Methods: This longitudinal study used data from a population-based sample of 214 Swedish adults aged 75 and over who were dementia-free both at baseline and at first follow-up (3 years later). The sample was 80% female and, on average, 83.4 years of age at baseline. All participants underwent a thorough clinical examination to ascertain all-cause dementia and AD., Results: Forty percent of participants reported a change in sleep duration at baseline. Between the 6th and 9th year after baseline, 28.5% were diagnosed with all-cause dementia, 22.0% of whom had AD. Reduced sleep was associated with a 75% increased all-cause dementia risk (hazard ratio: 1.75; 95% confidence interval: 1.04-2.93; Wald = 4.55, df = 1, p = 0.035) and double the risk of AD (hazard ratio: 2.01; 95% confidence interval: 1.12-3.61; Wald = 5.47, df = 1, p = 0.019) after adjusting for age, gender, and education. The results remained after adjusting for lifestyle and vascular factors but not after adjusting for depressive symptoms. No evidence supported a moderating effect of the use of sleeping pills, and the sleep-dementia relationship remained after controlling for the presence of the apolipoprotein E ε4 allele., Conclusion: Self-reported sleep problems may increase the risk for dementia, and depressive symptoms may explain this relationship. Future research should determine whether treatment, in particular, behavioral or nonpharmacologic treatment, may represent one avenue toward reduction of dementia risk in late life., (Copyright © 2014 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.)

Background: The etiology of Parkinson's disease (PD) remains unclear, and environmental risk-factors such as occupation have attracted interest., Objective: The goal was to investigate occupational complexity in relation to PD., Methods: We conducted a population-based cohort study based on the Swedish Twin Registry that included 28,778 twins born between 1886 and 1950. We identified 433 PD cases during the study period. Data on occupation were collected from either the 1970 or 1980 Swedish census, and occupational complexity was assessed via a job exposure matrix. Cox proportional hazard regression analyses with age as the underlying time scale were used to assess PD risk as a function of the three domains of occupational complexity: data, people, and things. Sex and smoking were included as covariates. Analyses stratified by twin pair were conducted to test for confounding by familial factors., Results: High occupational complexity with data and people was associated with increased risk overall (Hazard Ratio [HR]  = 1.07, 95% confidence interval [CI] 1.02-1.14, and HR = 1.10, 95% CI 1.01-1.21, respectively), and in men (HR = 1.08, 95% CI 1.01-1.16, and HR = 1.15, 95% CI 1.03-1.28, respectively). Complexity with things was not associated with risk of PD. When the analyses were stratified by twin pair, the HRs for occupational complexity with data and people were attenuated in men., Conclusions: High complexity of work with data and people is related to increased risk of PD, particularly in men. The attenuation of risk observed in the twin pair-stratified analyses suggests that the association may partly be explained by familial factors, such as inherited traits contributing to occupational selection or other factors shared by twins.

Background: We examined the association between extremely low-frequency magnetic fields (EMF) and the risk of dementia and Alzheimer's disease using all 9,508 individuals from the Study of Dementia in Swedish Twins (HARMONY) with valid occupational and diagnostic data., Methods: Dementia diagnoses were based on telephone screening followed by in-person clinical workup. Main lifetime occupation was coded according to an established EMF exposure matrix. Covariates were age, gender, education, vascular risk factors, and complexity of work. Based on previous research, data were also analyzed separately for cases with disease onset by age 75 years versus later, men versus women, and those with manual versus nonmanual main occupation. We used generalized estimating equations with the entire sample (to adjust for the inclusion of complete twin pairs) and conditional logistic regression with complete twin pairs only., Results: Level of EMF exposure was not significantly associated with dementia or Alzheimer's disease. However, in stratified analyses, medium and high levels of EMF exposure were associated with increased dementia risk compared with low level in cases with onset by age 75 years (odds ratio: 1.94, 95% confidence interval: 1.07-3.65 for medium, odds ratio: 2.01, 95% confidence interval: 1.10-3.65 for high) and in participants with manual occupations (odds ratio: 1.81, 95% confidence interval: 1.06-3.09 for medium, odds ratio: 1.75, 95% confidence interval: 1.00-3.05 for high). Results with 42 twin pairs discordant for dementia did not reach statistical significance., Conclusions: Occupational EMF exposure appears relevant primarily to dementia with an earlier onset and among former manual workers.

Objectives: Previous research has suggested that mental stimulation in different life periods may protect against dementia or delay disease onset. This study aimed to explore the association between work complexity factors at midlife and dementia risk in late life under the hypothesis that high work complexity may modulate the increased dementia risk due to low education., Design: Population-based follow-up study., Setting: Urban., Participants: A cohort of 931 nondemented subjects, aged 75+ years from the Kungsholmen Project, Stockholm, examined twice over 6 years., Measurements: Incident dementia cases were identified using Diagnostic and Statistical Manual of Mental Disorders, 3rd-Edition Revised criteria. Primary occupations were assigned into categories according to the Nordic Occupational Classification and matched to the 1970 U.S. Census to score the level of work complexity with data, people, and things by using a preformed matrix., Results: Lower dementia risk was associated with complexity of work with both data (age and gender adjusted relative risk [aRR]: 0.85, 95% confidence interval [CI]: 0.75-0.95) and with people (aRR: 0.88, 95% CI: 0.80-0.97). Adjusting for education led to similar results, although no longer statistically significant. Further, the highest degrees of complexity of work with data that involves analyzing, coordinating, and synthesizing data were associated with lower dementia risk even among lower educated subjects (relative risk: 0.52, 95% CI: 0.29-0.95). No gender differences were detected., Conclusions: This study suggests that work complexity with data and people is related to lower risk of dementia and that the highest levels of work complexity may modulate the higher dementia risk due to low education.

We evaluated whether the association between low education and greater risk of dementia is explained by genetic influences, using three different types of analyses. The HARMONY study (Swedish for "health" (Hälsa), "genes" (ARv), "environment" (Miljö), "and" (Och), and "new" (NY)) includes members of the Swedish Twin Registry who were aged 65 and older and alive in 1998, and who were screened and clinically assessed for dementia. There were 394 cases with dementia and 7786 unrelated controls. Analyses included co-twin control, tests for association between education and a measured genotype, and bivariate twin modeling. Low education was a significant risk factor for dementia both in case-control analyses (odds ratio=1.77, 95% confidence interval 1.38 to 2.28) and co-twin control analyses with monozygotic twin pairs (odds ratio=3.17, 95% confidence interval 1.26 to 7.93). Apolipoprotein E genotype was not associated with education and did not account for the relationship between education and dementia. Bivariate twin modeling showed that the association between education and dementia was not mediated by genetic influences in common between education and dementia. The association was mediated by shared environmental influences that were related to both dementia and to education. Low education is confirmed as a risk factor for dementia. Findings from three different analytic approaches showed that genetic influences did not explain this association.

The purpose of this study was to examine associations for work-related stress, reactivity to stress, and subsequent risk of dementia. The sample consisted of members of the population-based Swedish Twin Registry who were participants in the HARMONY study (n=2,049). We used case control and cotwin control designs, with information on work-related stress and reactivity to stress collected as part of a questionnaire completed in 1967. Dementia was diagnosed approximately 30 years later using a 2-stage procedure-screening for cognitive impairment followed by full clinical evaluation. We found that measures of work-related stress (job dissatisfaction and high job demands) were not associated with dementia risk. Greater reactivity to stress predicted higher risk of dementia controlling for age, education, sex, occupational status, alcohol use, and smoking status (odds ratio=1.57, 95% confidence interval 1.08-2.31). Cotwin control analyses also showed that dementia probands were more likely to report high reactivity to stress than their nondemented cotwins. We did not find evidence of an interaction between work stress and reactivity in predicting dementia. Overall, indicators of stress due to environment (ie, work) were not associated with dementia, whereas the individual characteristic of reactivity to stress predicted dementia risk.

Objective: The authors explored the association between complexity of primary lifetime occupation and cognition in older adulthood., Method: The study included 386 participants from the Swedish Panel Study of Living Conditions of the Oldest Old, a nationally representative sample aged 77 years or older. The authors examined complexity of work with data, people, and things in relation to cognitive functioning, measured with a shortened version of Mini-Mental State Examination (MMSE) and cognitive impairment based on MMSE score cutoff., Results: Complexity of work with data and people were associated with better MMSE scores, controlling for age, sex, childhood socioeconomic status, and education. The association between complexity of work with data and MMSE remained statistically significant when adult occupational status was substituted for education as a covariate., Discussion: Complexity of primary lifetime occupation may be reflected in cognitive functioning even in advanced old age. This effect may be independent of education or occupational status.

The authors examined the relationship between personality and cognitive impairment in 4,039 members of the Swedish Twin Registry. Neuroticism and extraversion scores were collected in 1973 at midlife, and cognitive impairment was assessed in the same group 25 years later. Data were analyzed with case-control and co-twin control designs. Greater neuroticism was associated with higher risk of cognitive impairment in the results from case-control, but not from co-twin, analyses. Compared with both extraversion and introversion, moderate extraversion was associated with lower risk of cognitive impairment in both case-control and co-twin designs, as was the combination of high neuroticism and low extraversion. Findings are discussed in the context of theories related to personality, psychological distress, arousal, and cognitive function.

We examined the association between risk of dementia or Alzheimer's disease (AD) and occupation by using measures of complexity of work with data, people, and things. The study included 10,079 members of the population-based Swedish Twin Registry who were participants in the HARMONY study. We diagnosed dementia by means of a two-stage procedure--cognitive impairment screening followed by full clinical evaluation. We analyzed data with case-control and cotwin control designs. The cotwin control design provides control over genetic and familial factors. In the case-control study, controlling for age, gender, and level of education, we found that more complex work with people was associated with reduced risk of AD. Greater complexity of work with people and data was protective in twin pairs discordant for AD. Findings suggest that greater complexity of work, and particularly complex work with people, may reduce the risk of AD.