Changes in neighborhood-level socioeconomic disadvantage and older Americans' cognitive functioning

Early-life socioeconomic position and later-life cognitive functioning: A meta-analysis

OBJECTIVES

This meta-analysis aimed to quantify the association between childhood SEP and later-life cognitive functioning and identify possible moderators.

METHOD

We conducted random-effects meta-analyses of 39 reports, contributing 49 independent subsamples from 229,824 respondents. Moderators were analyzed using meta-regression and subgroup analyses.

RESULTS

There was a small, positive correlation between childhood socioeconomic position (SEP) and cognitive functioning in older adulthood across the overall summary effect (r = 0.161), global cognitive functioning (r = 0.183), verbal episodic memory (r = 0.148), verbal fluency (r = 0.196), and processing speed (r = 0.130), but not inhibition (r = 0.058). An older mean sample age was linked with a weaker correlation for the overall summary effect and verbal episodic memory. Higher sample education was a significant moderator for verbal episodic memory only, such that the association between childhood SEP and verbal episodic memory was weaker at higher levels of education. Across all domains, mother's education was more strongly linked with cognitive functioning than other SEP constructs were. There was no significant moderation by gender, national income inequality, study design (whether prospective or retrospective), or the age of the childhood SEP measure (ages 0-4 or 9-15). Minimal publication bias was present.

DISCUSSION

The socioeconomic conditions of one's childhood are related to cognitive performance in older adulthood. Policymakers should consider legislation and programs to improve circumstances for low-income children and families, particularly those that increase women's educational access, as targets for improving cognitive outcomes in later life.

The Association between Residential Environment and Self-Rated Mental Health among Older Canadians: The Moderating Effects of Education and Gender

This study examined the associations between residential environment and self-rated mental health (SRMH) among Canadians aged 65 or older (n = 16,304) and whether education and gender moderated the associations. Data came from the 2018 Canadian Housing Survey. Hierarchical multiple regressions were conducted to test the associations. Analyses revealed that increased dwelling size was associated with better SRMH among older women with high school education. Older adults with higher satisfaction with their dwelling design were more likely to report better SRMH, except for women with some college education. Feeling safer in the community was uniquely associated with better SRMH for men with high school education and women with a university degree. Results confirmed significant associations between specific home and residential environment features and SRMH for each gender-by-education group. Environmental programs designed to improve SRMH for older adult populations should consider within- and between-group diversity.

A Scoping Review of Neighborhoods and Cognitive Health Disparities Among US Midlife and Older Adults

Objectives: The neighborhood environment may be an important determinant of racial/ethnic disparities in cognitive function. To understand how neighborhoods are linked to cognition across racial/ethnic groups, this scoping review organizes research investigating relationships between multiple neighborhood domains and cognitive function in diverse samples of US midlife and older adults. Methods: PubMed/MEDLINE, Web of Science, and CAHL were used to extract quantitative disparities-focused studies (n = 17) that included US adults ages 50+, racial/ethnic minoritized populations, cognitive dependent variable(s), and neighborhood-level independent variable(s) published from January 2010 to October 2021. Results: Studies demonstrate variation within and between racial/ethnic groups in how neighborhood factors are associated with cognition. Economically and socially advantaged neighborhoods were associated with better cognition. Findings were mixed for built and neighborhood composition measures. Discussion: More research with greater racial/ethnic representation is needed to disentangle which aspects of the neighborhood are most salient for specific cognitive function domains across diverse populations.

Characteristics of urban neighbourhood environments and cognitive age in mid-age and older adults

In this cross-sectional study, we examined the extent to which features of the neighbourhood natural, built, and socio-economic environments were related to cognitive age in adults (N = 3418, Mage = 61 years) in Australia. Machine learning estimated an individual's cognitive age from assessments of processing speed, verbal memory, premorbid intelligence. A 'cognitive age gap' was calculated by subtracting chronological age from predicted cognitive age and was used as a marker of cognitive age. Greater parkland availability and higher neighbourhood socio-economic status were associated with a lower cognitive age gap score in confounder- and mediator-adjusted regression models. Cross-sectional design is a limitation. Living in affluent neighbourhoods with access to parks maybe beneficial for cognitive health, although selection mechanisms may contribute to the findings.

Mediating role of obesity on the association between disadvantaged neighborhoods and intracortical myelination

We investigated the relationship between neighborhood disadvantage (area deprivation index [ADI]) and intracortical myelination (T1-weighted/T2-weighted ratio at deep to superficial cortical levels), and the potential mediating role of the body mass index (BMI) and perceived stress in 92 adults. Worse ADI was correlated with increased BMI and perceived stress (p's<.05). Non-rotated partial least squares analysis revealed associations between worse ADI and decreased myelination in middle/deep cortex in supramarginal, temporal, and primary motor regions and increased myelination in superficial cortex in medial prefrontal and cingulate regions (p<.001); thus, neighborhood disadvantage may influence the flexibility of information processing involved in reward, emotion regulation, and cognition. Structural equation modelling revealed increased BMI as partially mediating the relationship between worse ADI and observed myelination increases (p=.02). Further, trans-fatty acid intake was correlated with observed myelination increases (p=.03), suggesting the importance of dietary quality. These data further suggest ramifications of neighborhood disadvantage on brain health.

The causal association between empty nest and depressive symptoms with cognitive impairments in China

BACKGROUND

In the context of rapid aging, "empty nest syndrome" is becoming a major public health concern. The causal effects of empty nest on depressive symptoms have been studied in developed countries, but the mediating mechanism of depressive symptoms in the association between empty nest and cognitive impairments has not been studied. This study estimated the causal association of empty nest with depressive symptoms and cognitive impairments in China, and then estimated how depression mediates the association between empty nest and cognitive impairments.

METHODS

Using data of 23,614 urban older adults (65+) obtained from the Shandong Province Aging and Mental Health Survey in 2020, a weighted linear regression model combined with instrumental variable was applied to explore the causal effects of empty nest, and a four-step mediation model was run to test the mediator of depressive symptoms. The Ascertain Dementia 8-item Questionnaire and Patient Health Questionnaire-9 were used to measure cognitive impairments and depressive symptoms.

RESULTS

Empty nest was associated with 0.13 (95%CI: 0.04-0.23) and 0.23 (95%CI: 0.14-0.33) increases in the Ascertain Dementia 8-item Questionnaire and the Patient Health Questionnaire-9 scores, respectively. The association between empty nest and the Ascertain Dementia 8-item Questionnaire scores was mediated by the Patient Health Questionnaire-9 scores.

CONCLUSIONS

Empty nest affected depression in adulthood with cognitive impairments. A focus on integrative intervention for empty nesters is recommended, taking depression and cognition into account.

LIMITATIONS

It is a cross-sectional study and the data is not nationally representative.

Adolescent neighborhood disadvantage and memory performance in young adulthood

OBJECTIVE

Using data from the National Longitudinal Study of Adolescent to Adult Health, we estimated the average causal effect of neighborhood disadvantage in adolescence on memory performance in young adulthood. We contrasted several different ways of operationalizing a continuous measure of neighborhood disadvantage including a continuous neighborhood disadvantage score and ordinal measures.

RESULTS

Neighborhood disadvantage was measured in Wave I when participants were a mean age of 15.41 years (SE: 0.12) and memory performance was measured in Wave IV when participants were a mean age of 28.24 years (SE: 0.12). We found that adolescent neighborhood disadvantage was associated with decreased memory performance in young adulthood. Notably, we observed a linear decline in word recall score among those in the less disadvantaged tail of the distribution (neighborhood disadvantage <1), a finding not observed using traditional ordinal variable classifications of disadvantage.

CONCLUSION

Experiencing neighborhood disadvantage in adolescence may have lasting impacts on cognitive health throughout the life course.