The influence of childhood intelligence, social class, education and social mobility on memory and memory decline in late life

The effect of education level on depressive symptoms in Chinese older adults-parallel mediating effects of economic security level and subjective memory ability

BACKGROUND

Depression in older adults needs urgent attention. Increased education level may reduce depressive symptoms in older adults, and that economic security level and subjective memory ability may also have an impact on depressive symptoms in older adults, but the mechanisms between education level and depressive symptoms in older adults are unclear. This study endeavors to investigate the parallel mediating roles of economic security level and subjective memory ability between education level and depressive symptoms in older adults.

METHODS

A total of 4325 older adults people aged 60 years and above were selected from the China Family Panel Studies (CFPS) as the study population, and all data were analyzed using SPSS 25.0 software. Spearman correlation analysis was used to explore the correlation between the variables. Model 4 from the SPSS macro was used to assess the parallel mediating role of economic security level and subjective memory ability in the relationship between education level and depressive symptoms in older adults.

RESULTS

Education level, economic security level, and subjective memory ability were significantly associated with depressive symptoms in older adults (p < 0.01). Educational level was a negative predictor of depressive symptoms (β=-0.134, P < 0.001). Education level was a positive predictor of economic security level (β = 0.467, P < 0.001) and subjective memory ability (β = 0.224, P < 0.001). Education level, economic security level, and subjective memory ability were significant negative predictors of depressive symptoms (β= -0.039, P < 0.05; β= -0.122, P < 0.001; β= -0.169, P < 0.001). Education level influenced depressive symptoms through parallel mediating effects of economic security level and subjective memory ability, with mediating effects accounting for 42.70% and 28.30% of the total effect, respectively.

CONCLUSIONS

Education level not only directly influences depressive symptoms in older adults, but also indirectly through the economic security level and subjective memory ability. Educational level can reduce depressive symptoms in older adults by increasing their economic security level and enhancing their subjective memory ability. The findings of this study emphasize the importance of improving the educational level of the population as it affects people's mental health in old age.

Association of preschool children behavior and emotional problems with the parenting behavior of both parents

BACKGROUND

Parental behaviors are key in shaping children's psychological and behavioral development, crucial for early identification and prevention of mental health issues, reducing psychological trauma in childhood.

AIM

To investigate the relationship between parenting behaviors and behavioral and emotional issues in preschool children.

METHODS

From October 2017 to May 2018, 7 kindergartens in Ma'anshan City were selected to conduct a parent self-filled questionnaire - Health Development Survey of Preschool Children. Children's Strength and Difficulties Questionnaire (Parent Version) was applied to measures the children's behavioral and emotional performance. Parenting behavior was evaluated using the Parental Behavior Inventory. Binomial logistic regression model was used to analyze the association between the detection rate of preschool children's behavior and emotional problems and their parenting behaviors.

RESULTS

High level of parental support/participation was negatively correlated with conduct problems, abnormal hyperactivity, abnormal total difficulty scores and abnormal prosocial behavior problems. High level of maternal support/participation was negatively correlated with abnormal emotional symptoms and abnormal peer interaction in children. High level of parental hostility/coercion was positively correlated with abnormal emotional symptoms, abnormal conduct problems, abnormal hyperactivity, abnormal peer interaction, and abnormal total difficulty scores in children (all P < 0.05). Moreover, paternal parenting behaviors had similarly effects on behavior and emotional problems of preschool children compared with maternal parenting behaviors (all P > 0.05), after calculating ratio of odds ratio values.

CONCLUSION

Our study found that parenting behaviors are associated with behavioral and emotional issues in preschool children. Overall, the more supportive or involved the parents are, the fewer behavioral and emotional problems the children experience; conversely, the more hostile or controlling the parents are, the more behavioral and emotional problems the children face. Moreover, the impact of fathers' parenting behaviors on preschool children's behavior and emotions is no less significant than that of mothers' parenting behaviors.

Cognition and Wealth Changes in Mid-to-later Life: A Latent Class Trajectories Approach Using the Health and Retirement Study

ObjectivesTo assess how cognitive trajectories from mid-to-later life relate to wealth change, overall and by mid-life income. Methods: Data were from participants (51-64 years) in the 2000-2018 U.S. Health and Retirement Study who were cognitively healthy at baseline (year 2000; unweighted n = 3821). Longitudinal latent class analyses generated cognitive and wealth trajectories, independently, and multinomial logistic regressions estimated the association between cognitive trajectories and wealth profiles, overall and by median income. Results: We identified three cognitive: cognitively healthy (CH), increasing cognitive impairment (ICI), and increasing dementia (ID) and four wealth profiles: stable wealth loss (SWL), delayed gradual wealth loss (DGWL), stable wealth gain (SWG), and gradual wealth gain (GWG). The ID group had higher probability of being in the SWL group and lower probability of SWG, which was more pronounced in respondents with greater median income. Discussion: Individuals with ID may be vulnerable to wealth loss, particularly for middle-class households.

Toward digitally screening and profiling AD: A GAMLSS approach of MemTrax in China

PURPOSES

To establish a normative range of MemTrax (MTx) metrics in the Chinese population.

METHODS

The correct response percentage (MTx-%C) and mean response time (MTx-RT) were obtained and the composite scores (MTx-Cp) calculated. Generalized additive models for location, shape and scale (GAMLSS) were applied to create percentile curves and evaluate goodness of fit, and the speed-accuracy trade-off was investigated.

RESULTS

26,633 subjects, including 13,771 (51.71%) men participated in this study. Age- and education-specific percentiles of the metrics were generated. Q tests and worm plots indicated adequate fit for models of MTx-RT and MTx-Cp. Models of MTx-%C for the low and intermediate education fit acceptably, but not well enough for a high level of education. A significant speed-accuracy trade-off was observed for MTx-%C from 72 to 94.

CONCLUSIONS

GAMLSS is a reliable method to generate smoothed age- and education-specific percentile curves of MTx metrics, which may be adopted for mass screening and follow-ups addressing Alzheimer's disease or other cognitive diseases.

HIGHLIGHTS

GAMLSS was applied to establish nonlinear percentile curves of cognitive decline. Subjects with a high level of education demonstrate a later onset and slower decline of cognition. Speed-accuracy trade-off effects were observed in a subgroup with moderate accuracy. MemTrax can be used as a mass-screen instrument for active cognition health management advice.

Association of Childhood and Midlife Neighborhood Socioeconomic Position With Cognitive Decline

Importance

Early-life socioeconomic adversity may be associated with poor cognitive health over the life course.

Objective

To examine the association of childhood and midlife neighborhood socioeconomic position (nSEP) with cognitive decline.

Design, Setting, and Participants

This cohort study included 5711 men and women enrolled in the community-based Atherosclerosis Risk in Communities (ARIC) Study with repeated cognitive data measured over a median 27.0 years (IQR, 26.0-27.9 years) (1990-2019). Statistical analysis was performed from December 2022 through March 2023.

Exposure

Residence addresses for ARIC Study cohort participants were obtained at midlife (1990-1993) and as recalled addresses at 10 years of age (childhood). A composite nSEP z score was created as a sum of z scores for US Census-based measures of median household income; median value of owner-occupied housing units; percentage of households receiving interest, dividend, or net rental income; percentage of adults with a high school degree; percentage of adults with a college degree; and percentage of adults in professional, managerial, or executive occupations. Childhood nSEP and midlife nSEP were modeled as continuous measures and discretized into tertiles.

Main Outcomes and Measures

A factor score for global cognition was derived from a battery of cognitive tests administered at 5 in-person visits from baseline to 2019. The rate of cognitive decline from 50 to 90 years of age was calculated by fitting mixed-effects linear regression models with age as the time scale and adjusted for race, sex, birth decade, educational level, and presence of the apolipoprotein E ε4 allele.

Results

Among 5711 ARIC Study participants (mean [SD] baseline age, 55.1 [4.7] years; 3372 women [59.0%]; and 1313 Black participants [23.0%]), the median rate of cognitive decline was -0.33 SDs (IQR, -0.49 to -0.20 SDs) per decade. In adjusted analyses, each 1-SD-higher childhood nSEP score was associated with a slower (β, -9.2%; 95% CI, -12.1% to -6.4%) rate of cognitive decline relative to the sample median. A comparable association was observed when comparing the highest tertile with the lowest tertile of childhood nSEP (β, -17.7%; 95% CI, -24.1% to -11.3%). Midlife nSEP was not associated with the rate of cognitive decline.

Conclusions and Relevance

In this cohort study of contextual factors associated with cognitive decline, childhood nSEP was inversely associated with trajectories of cognitive function throughout adulthood.

Life-course socioeconomic conditions and cognitive performance in older adults: a cross-cohort comparison

OBJECTIVES

Socioeconomic disadvantage predicts the level of cognitive performance in old age, but findings have been mixed for trajectories of performance. This study examined associations between life-course socioeconomic conditions, including social mobility, and cognitive performance assessed in terms of level and change, across multiple cognitive domains in two independent cohorts of older adults.

METHODS

Data were from two Swiss population-based cohorts: CoLaus|PsyCoLaus (N = 1210, mean age 72 years) and Vivre/Leben/Vivere (N = 993, mean age 75 years). Verbal fluency, processing speed, cognitive flexibility, memory, and global cognitive performance were assessed at two time points, each spaced 6 years apart. Associations between socioeconomic conditions (father's occupation, parental education, own education, own occupation, household income, and social mobility) and cognitive performance were examined within each cohort, and using pooled data. Covariates included health behaviors, comorbidities, and depressive symptoms.

RESULTS

Across cohorts, socioeconomic disadvantage predicted a lower level of performance across different cognitive domains, including processing speed, verbal fluency, and memory. Moreover, individuals who experienced life-course socioeconomic disadvantage performed worse than those who experienced upward social mobility. Associations between socioeconomic disadvantage and cognitive decline were less consistent.

CONCLUSION

Life-course socioeconomic conditions predict performance level across different cognitive domains, and, to a lesser extent, performance trajectories.

Cognitive Test Scores and Progressive Cognitive Decline in the Aberdeen 1921 and 1936 Birth Cohorts

The Aberdeen birth cohorts of 1921 and 1936 (ABC21 and ABC36) were subjected to IQ tests in 1932 or 1947 when they were aged about 11y. They were recruited between 1997–2001 among cognitively healthy community residents and comprehensively phenotyped in a long-term study of brain aging and health up to 2017. Here, we report associations between baseline cognitive test scores and long-term cognitive outcomes. On recruitment, significant sex differences within and between the ABC21 and ABC36 cohorts supported advantages in verbal ability and learning among the ABC36 women that were not significant in ABC21. Comorbid physical disorders were self-reported in both ABC21 and ABC36 but did not contribute to differences in terms of performance in cognitive tests. When used alone without other criteria, cognitive tests scores which fell below the −1.5 SD criterion for tests of progressive matrices, namely verbal learning, digit symbol and block design, did not support the concept that Mild Cognitive Impairment (MCI) is a stable class of acquired loss of function with significant links to the later emergence of a clinical dementia syndrome. This is consistent with many previous reports. Furthermore, because childhood IQ-type data were available, we showed that a lower cognitive performance at about 64 or 78 y than that predicted by IQ at 11 ± 0.5 y did not improve the prediction of progress to MCI or greater cognitive loss. We used binary logistic regression to explore how MCI might contribute to the prediction of later progress to a clinical dementia syndrome. In a fully adjusted model using ABC21 data, we found that non-amnestic MCI, along with factors such as female sex and depressive symptoms, contributed to the prediction of later dementia. A comparable model using ABC36 data did not do so. We propose that (1) MCI criteria restricted to cognitive test scores do not improve the temporal stability of MCI classifications; (2) pathways towards dementia may differ according to age at dementia onset and (3) the concept of MCI may require measures (not captured here) that underly self-reported subjective age-related cognitive decline.

Education and Income Show Heterogeneous Relationships to Lifespan Brain and Cognitive Differences Across European and US Cohorts

Higher socio-economic status (SES) has been proposed to have facilitating and protective effects on brain and cognition. We ask whether relationships between SES, brain volumes and cognitive ability differ across cohorts, by age and national origin. European and US cohorts covering the lifespan were studied (4-97 years, N = 500 000; 54 000 w/brain imaging). There was substantial heterogeneity across cohorts for all associations. Education was positively related to intracranial (ICV) and total gray matter (GM) volume. Income was related to ICV, but not GM. We did not observe reliable differences in associations as a function of age. SES was more strongly related to brain and cognition in US than European cohorts. Sample representativity varies, and this study cannot identify mechanisms underlying differences in associations across cohorts. Differences in neuroanatomical volumes partially explained SES-cognition relationships. SES was more strongly related to ICV than to GM, implying that SES-cognition relations in adulthood are less likely grounded in neuroprotective effects on GM volume in aging. The relatively stronger SES-ICV associations rather are compatible with SES-brain volume relationships being established early in life, as ICV stabilizes in childhood. The findings underscore that SES has no uniform association with, or impact on, brain and cognition.

Association of Early-Life Cognitive Enrichment With Alzheimer Disease Pathological Changes and Cognitive Decline

Importance

Indicators of early-life cognitive enrichment (ELCE) have been associated with slower cognitive decline and decreased dementia in late life. However, the mechanisms underlying this association have not been elucidated.

Objective

To examine the association of ELCE with late-life Alzheimer disease (AD) and other common dementia-related pathological changes.

Design, Setting, and Participants

This clinical-pathological community-based cohort study, the Rush Memory and Aging Project, followed up participants before death for a mean (SD) of 7.0 (3.8) years with annual cognitive and clinical assessments. From January 1, 1997, through June 30, 2019, 2044 participants enrolled, of whom 1018 died. Postmortem data were leveraged from 813 participants. Data were analyzed from April 12, 2019, to February 20, 2020.

Exposures

Four indicators of ELCE (early-life socioeconomic status, availability of cognitive resources at 12 years of age, frequency of participation in cognitively stimulating activities, and early-life foreign language instruction) were obtained by self-report at the study baseline, from which a composite measure of ELCE was derived.

Main Outcomes and Measures

A continuous global AD pathology score derived from counts of diffuse plaques, neuritic plaques, and neurofibrillary tangles.

Results

The 813 participants included in the analysis had a mean (SD) age of 90.1 (6.3) years at the time of death, and 562 (69%) were women. In a linear regression model controlled for age at death, sex, and educational level, a higher level of ELCE was associated with a lower global AD pathology score (estimate, -0.057; standard error, 0.022; P = .01). However, ELCE was not associated with any other dementia-related pathological changes. In addition, a higher level of ELCE was associated with less cognitive decline (mean [SD], -0.13 [0.19] units per year; range, -1.74 to 0.85). An indirect effect through AD pathological changes constituted 20% of the association between ELCE and the rate of late-life cognitive decline, and 80% was a direct association.

Conclusions and Relevance

These findings suggest that ELCE was associated with better late-life cognitive health, in part through an association with fewer AD pathological changes.

Interpersonal relationships and drug use over time among homeless people: a qualitative study

Background

Homelessness is one of the most severe forms of social exclusion and is an important public health issue. It is characterized by processes of weakening of interpersonal bonds. The objective of this study was, therefore, to elucidate how interpersonal relationships change over the life cycle of homeless drug and alcohol users.

Method

We used a qualitative methodology. The participants were adults who had a history of homelessness and use of alcohol and other drugs. The interviews were semi structured and used a timeline instrument. All interview were audio recorded, transcribed, and submitted to thematic analysis.

Results

Twenty individuals participated in the study. Reports on social exclusion over time stood out in respect of four main themes and their respective subthemes: Theme 1 – Childhood: instability upbringing, abuse, violence, and an absent or not very present father figure; Theme 2 – Adolescence: school dropout and failure; acceptance of gender and sexual orientation; birth of first child, living with a partner or getting married: Theme 3 – Adulthood: estrangement or conflicting relationship with family; health problems; drug trafficking and prostitution; Theme 4 – Cross-cutting factors: death of relatives and substance use.

Conclusion

The results suggest that interpersonal relationships are permeated by successive breakups, conflicts and other events that start in childhood and can have a cumulative effect in later stages of life, and cross the subsequent phases. Substance abuse and dependence are mentioned as cross-cutting factors that intensify social exclusion in all stages of life.

Supplementary Information

Supplementary information accompanies this paper at 10.1186/s12889-020-09880-2.

Education and age-related decline in cognitive performance: Systematic review and meta-analysis of longitudinal cohort studies

Central theories of cognitive aging propose that education is an important protective factor for decline in cognitive performance in older age. We conducted a systematic review and meta-analysis of reported estimates of an association between educational attainment and change in performance in six cognitive domains (episodic memory, processing speed, verbal fluency, crystallized intelligence, fluid intelligence, and global ability) in the general population of older individuals. The systematic search (11^th of October 2019) identified 92 eligible articles. The episodic memory domain had the highest number of estimates (37 estimates from 18 articles, n = 109,281) included in the meta-analysis. The fewest estimates (6 estimates from 6 articles, n = 5263) were included for fluid intelligence. Pooled mean estimates from an inverse-variance weighted random effects analysis were not statistically significant and indicated that any association between education and change in cognitive performance is likely of a negligible magnitude. The estimates for education's role (one additional year) for change in cognitive performance ranged from -0.019 (95 % confidence interval, CI = -0.047, 0.010) to 0.004SD (CI = -0.003, 0.012) per decade. Even if the larger positive point estimates (i.e., protective effects) are selectively considered, the influence of education on change is still at least 12 times less important for the cognitive functioning of an older individual than the association between education and level of cognitive performance. Sensitivity analyses did not substantially alter these results. However, heterogeneity was substantial, and remained largely unexplained by mean age, mean educational attainment, Gini coefficient, GDP per capita, maximum follow-up period, and publication year. Overall, education is an important factor in aging due to its robust association with level of performance, but the current base of empirical evidence is not revealing a consistent and substantial association between educational attainment and changes in cognitive performance in the general population. Theories of cognitive aging must be updated to incorporate this pattern of findings.

Systematic Review on the Impact of Intelligence on Cognitive Decline and Dementia Risk

BACKGROUND

Previous studies have shown that an intellectually stimulating lifestyle is associated with a lower risk for cognitive decline and Alzheimer's disease and related dementia (ADRD). It is unclear so far whether higher intelligence may protect against this. The aim of this study was to conduct a systematic review on the association between intelligence and cognitive decline and ADRD risk.

METHODS

We searched the PubMed, web of science, and Scopus databases following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) and Population, Intervention, Comparison, and Outcome (PICO) criteria. Quality of evidence was assessed using Critical Appraisal Skills Programme (CASP) checklists.

RESULTS

From an initial n=8,371 search hits, n= 14 studies met the inclusion criteria and had sufficient quality. Evidence indicates that cognitive decline in old age is not significantly associated with childhood intelligence (n=9). Evidence with regard to ADRD risk is inconclusive (n=5) with some studies showing no effects and other studies with significant effects having limitations in their design.

CONCLUSIONS

Even though the majority of the studies show no significant association, we cannot exclude a possible effect that might be moderated by other, so far unknown factors. Further studies are necessary to systematically assess the influence of intelligence on ADRD risk and what factors moderate this association.

Early-life adversity and neurological disease: age-old questions and novel answers

Neurological illnesses, including cognitive impairment, memory decline and dementia, affect over 50 million people worldwide, imposing a substantial burden on individuals and society. These disorders arise from a combination of genetic, environmental and experiential factors, with the latter two factors having the greatest impact during sensitive periods in development. In this Review, we focus on the contribution of adverse early-life experiences to aberrant brain maturation, which might underlie vulnerability to cognitive brain disorders. Specifically, we draw on recent robust discoveries from diverse disciplines, encompassing human studies and experimental models. These discoveries suggest that early-life adversity, especially in the perinatal period, influences the maturation of brain circuits involved in cognition. Importantly, new findings suggest that fragmented and unpredictable environmental and parental signals comprise a novel potent type of adversity, which contributes to subsequent vulnerabilities to cognitive illnesses via mechanisms involving disordered maturation of brain 'wiring'.

Intellectual engagement and cognitive ability in later life (the "use it or lose it" conjecture): longitudinal, prospective study

OBJECTIVES

To examine the association between intellectual engagement and cognitive ability in later life, and determine whether the maintenance of intellectual engagement will offset age related cognitive decline.

DESIGN

Longitudinal, prospective, observational study.

SETTING

Non-clinical volunteers in late middle age (all born in 1936) living independently in northeast Scotland.

PARTICIPANTS

Sample of 498 volunteers who had taken part in the Scottish Mental Health Survey of 1947, from one birth year (1936).

MAIN OUTCOME MEASURES

Cognitive ability and trajectory of cognitive decline in later life. Typical intellectual engagement was measured by a questionnaire, and repeated cognitive measurements of information processing speed and verbal memory were obtained over a 15 year period (recording more than 1200 longitudinal data points for each cognitive test).

RESULTS

Intellectual engagement was significantly associated with level of cognitive performance in later life, with each point on a 24 point scale accounting for 0.97 standardised cognitive performance (IQ-like) score, for processing speed and 0.71 points for memory (both P<0.05). Engagement in problem solving activities had the largest association with life course cognitive gains, with each point accounting for 0.43 standardised cognitive performance score, for processing speed and 0.36 points for memory (both P<0.05). However, engagement did not influence the trajectory of age related decline in cognitive performance. Engagement in intellectual stimulating activities was associated with early life ability, with correlations between engagement and childhood ability and education being 0.35 and 0.22, respectively (both P<0.01).

CONCLUSION

These results show that self reported engagement is not associated with the trajectory of cognitive decline in late life, but is associated with the acquisition of ability during the life course. Overall, findings suggest that high performing adults engage and those that engage more being protected from relative decline.