Correlates of memory and executive function in mid-aged and older adults in the CLSA: A minority stress approach

Risk of impairment in cognitive instrumental activities of daily living for sexual and gender minority adults with reported Parkinson's disease

Objective: To investigate the risk of impairment in cognitive instrumental activities of daily living (IADL) for people with Parkinson's (PwP) identifying as sexual and/or gender minorities (SGM). Method: Data were obtained from Fox Insight, an online, longitudinal study with self/informant-report questionnaires from PwP and people without Parkinson's. Groups consisted of PwP without cognitive IADL impairment at baseline, identifying as (1) SGM with female sex assigned at birth (SGM-F, n = 75); (2) cisgender, heterosexual with female sex assigned at birth (CH-F, n = 2046); (3) SGM with male sex assigned at birth (SGM-M, n = 84); (4) cisgender, heterosexual with male sex assigned at birth (CH-M, n = 2056). Impairment in cognitive IADL was based on Penn Parkinson's Daily Activities Questionnaire-15 (PDAQ-15). Group differences for PDAQ-15 and impairment likelihood during follow-up were assessed with unadjusted models and adjusting for variables that differed between the groups. Results: SGM-F were the youngest at Parkinson's diagnosis; SGM-M had the lowest PDAQ-15 at baseline (p ≤ .014 for all). Scores declined more for males than females in unadjusted and adjusted models (p < .001 for both). In unadjusted models, SGM-M had a higher impairment risk than PwP identifying as cisgender and heterosexual (p ≤ .018). In adjusted models, females had a lower impairment risk than males (p < .001). Age, education, and discrimination level were significant moderators (p < .001 for all). Conclusions: SGM-M can be at a higher risk for impairment in cognitive IADL, associated with social determinants. Female sex assigned at birth may be associated with a lower level of impairment risk, although this advantage can disappear with social determinants.

Cognitive Impairment in Sexual and Gender Minority Groups: A Scoping Review of the Literature

Purpose: The purpose of this review was to synthesize evidence on differences in cognitive impairment by sexual orientation/gender identity (SOGI) status. Methods: A scoping review of the literature was conducted. Five databases (PubMed/Medline, Cumulated Index to Nursing and Allied Health Literature, Web of Science, PsycInfo, and Embase) were searched for primary articles comparing incidence or prevalence of cognitive impairment among sexual and gender minority (SGM) groups versus non-SGM groups. Two reviewers independently screened articles and conducted risk-of-bias assessment on eligible articles. Results: Fifteen primary studies were eligible. Most studies (n = 13) were cross-sectional, with moderate to critical risk of bias. Among eight studies examining self-reported cognitive impairment, seven reported a higher prevalence among some SGM groups versus non-SGM groups. Among seven studies using objective measures of cognitive impairment, three examined prevalence of clinician-documented diagnosis of dementia, of which two reported a higher prevalence specifically among transgender versus cisgender individuals. Among the other four studies examining objective measures, two reported poorer cognitive performance or memory, one reported better performance, and another reported no difference. Comparisons across studies were challenging due to inconsistencies in how SOGI and cognitive impairment were operationalized, and the factors used for statistical adjustment; some studies adjusted for putative intermediary factors that potentially explain differences in cognitive impairment. Conclusions: Whereas most published studies identified a positive relationship between SOGI status and self-reported cognitive impairment, evidence is mixed with regard to objective cognitive performance. Well-designed longitudinal, observational studies are needed, using objective measures of cognitive function, with careful consideration of confounding versus intermediary risk factors.

Sexual orientation and cognition in aging populations: Results from the Canadian Longitudinal Study on Aging

The current study utilized the Canadian Longitudinal Study on Aging (CLSA) data to investigate the relationship between sexual orientation and cognitive health of the aging population. Cognitive flexibility and verbal fluency were examined as outcome variables in the study. A total of 45,993 respondents were included in the analyses. Each model had social support or social participation as a mediator. A series of mediation analysis, stratified by gender, revealed that aging gay men performed better in cognitive tasks related to cognitive flexibility when compared to their heterosexual counterparts. The results also indicated that social support is a protective factor for cognitive health in aging lesbian women. This study provides an opportunity to consider how clinical and social services can strategize to build inclusive environments for the aging sexual minority population.

Which variables moderate the relationship between depressive symptoms and global neurocognition across adulthood?

The current study examined moderators of the relationship between depressive symptoms and global neurocognition in a large non-clinical community-dwelling sample spanning adulthood. Participants comprised 5,430 individuals between the ages of 18-99 years drawn from the Virginia Cognitive Aging Project. Depressive symptoms were measured via the Center for Epidemiologic Studies-Depression scale and neurocognition was operationalized as a composite variable comprising episodic memory, spatial visualization, processing speed, and reasoning tasks. Moderator variables included physical activity, cognitive activity, education, emotional stability, and openness. Hierarchical regressions were used to examine the influence of depressive symptoms and the moderators on neurocognition. Depressive symptoms significantly predicted neurocognition. Cognitive activity, years of education, and emotional stability moderated the depression-neurocognition relationship by buffering the impact of depressive symptoms on neurocognition. Cognitive activity engagement and level of education may function as a protective influence on those with higher levels of depressive symptoms, while emotional stability may be protective for individuals with lower levels of depressive symptoms. No differences in moderation were found across three age groups representing younger, middle, and older adults. Post-hoc analyses showed years of education and openness as moderators in a subsample excluding individuals with potentially clinically meaningful levels of depressive symptoms.

Nutrition risk and cognitive performance in community-living older adults without cognitive impairment: a cross-sectional analysis of the Canadian Longitudinal Study on Aging

Malnutrition is correlated with poor cognition; however, an understanding of the association between nutrition risk, which precedes malnutrition, and cognition is lacking. This study aimed to determine if nutrition risk measured with the SCREEN-8 tool is associated with cognitive performance among cognitively healthy adults aged 55+, after adjusting for demographic and lifestyle covariates. Sex- and age-stratified analyses were also explored. Baseline data from the Canadian Longitudinal Study on Aging was used. Cognition was determined using a 6-measure composite score based on four executive functions and two memory tasks, taking into account age, sex, and education. Multivariable linear regression was performed while adjusting for body mass index (BMI), lifestyle, and health covariates in the entire sample (n = 11 378) and then stratified by sex and age. Approximately half of participants were female (54.5%) aged 65+ (54.1%). Greater nutrition risk was associated with poorer cognitive performance in the entire sample (F[1, 11 368] = 5.36, p = 0.021) and among participants aged 55-64 (n = 5227; F[1, 5217] = 5.45, p = 0.020). Sex differences in lifestyle and health factors associated with cognition were apparent, but nutrition risk was not associated with cognition in sex-stratified models. Based on this analysis, there may be an association between nutrition risk and cognitive performance in older adults. When screening for either cognitive impairment or nutrition risk, complementary assessments for these conditions is warranted, as early intervention may provide benefit.

Minority Stress and Psychosocial Influences on Cognitive Performance in Sexual Minority Older Adults

Background and Objectives

Sexual minorities experience health inequalities, but little is known about differences in neurocognitive health between heterosexual and sexual minority older adults and potential risk factors. To investigate minority stress, depression, and marital status as risk factors for worse cognitive performance in sexual minority older adults.

Research Design and Methods

A total of 336 sexual minorities and 5,561 heterosexual participants aged 50+, noninstitutionalized, and free from neurodegenerative diseases from Wave 6 of the English Longitudinal Study of Ageing were included. Cognitive performance (i.e., temporal orientation, episodic memory, and fluid intelligence) of sexual minority and heterosexual older adults was compared using general linear models including age, sex, and education as covariates. The differential impact of minority stress, depressive symptoms, and marital status on cognition in the 2 groups were also tested. Analyses were weighted for sampling probability and differential nonresponse.

Results

Sexual minority participants were more likely to report minority stress and to be single but had better episodic memory than heterosexual participants. Depression and being single were associated with worse cognitive performance in both groups. However, minority stress was negatively associated (B = -2.116, p = .016) with fluid intelligence in the sexual minority group only.

Discussion and Implications

Better memory in sexual minority participants and a negative effect of risk factors on cognition are in line with previous studies. However, this study provides the first evidence of a potential negative impact of minority stress on cognitive performance in sexual minorities. Further investigations are needed to assess minority stress more in detail and clarify its potential mechanisms of action on cognition in sexual minorities.

The association between shift work exposure and cognitive impairment among middle-aged and older adults: Results from the Canadian Longitudinal Study on Aging (CLSA)

BACKGROUND

Shift work, especially rotating and night shift work, has been linked to a wide range of detrimental health outcomes. Occupational factors like shift work and their potential impact on cognitive functions have received little attention, and the evidence is inconclusive. The objective of our study is to explore associations between shift work exposure and cognitive impairment indicators based on comparisons with the normative standards from the Canadian population.

METHODS

Cross-sectional analyses were performed using baseline Canadian Longitudinal Study on Aging database, including 47,811 middle-aged and older adults (45-85 years). Three derived shift work variables were utilized: ever exposed to shift work, shift work exposure in longest job, and shift work exposure in current job. Four cognitive function tests were utilized, Rey Auditory Verbal Learning Tests (immediate and delayed) representing memory domain, and Animal Fluency, and Mental Alteration, representing the executive function domain. All cognitive test scores included in study were normalized and adjusted for the participant's age, sex, education and language of test administration (English and French), which were then compared to normative data to create "cognitive impairment' variables. Unadjusted and adjusted multivariable logistic regression models were used to determine associations between shift work variables and cognitive impairment individually (memory and executive function domains), and also for overall cognitive impairment.

RESULT

Overall, one in every five individuals (21%) reported having been exposed to some kind of shift work during their jobs. Exposure to night shift work (both current and longest job) was associated with overall cognitive impairment. In terms of domain-based measures, night shift work (longest job) was associated with memory function impairment, and those exposed to rotating shift work (both current and longest job) showed impairment on executive function measures, when compared to daytime workers.

CONCLUSION

This study suggests disruption to the circadian rhythm, due to shift work has negative impact on cognitive function in middle-aged and older adults and this warrants further investigation.

Changes in executive function in the Canadian longitudinal study on aging over 3-years: A focus on social determinants of health

Maintaining executive functions, including planning, inhibition, and decision-making skills, is important for autonomy and activities of daily living. There is a growing body of evidence linking social determinants and cognitive aging, but less is known about the potential role of social determinants in changes in executive functioning over time. Using data from the Canadian Longitudinal Study on Aging (CLSA), a large cohort of mid-aged and older adults, we examined changes in executive function over a 3-year period. Specifically, we focused on the role of social determinants (i.e., social positioning, social support, education) in explaining these changes. Executive function was measured at baseline and follow-up 3 years later using the Mental Alteration Test (MAT). We computed a reliable change index (RCI) and used a multiple linear regression model to examine the associations between known correlates and change in executive function over the 3-year period (n = 29,344). Older age, higher household income, and greater educational attainment predicted declines in executive function. Health factors (e.g., depression symptoms, physical activity levels) and many social determinants (sexual orientation, gender identity, race, and perceived social standing) were not associated with change in executive function. These results suggest that social determinants of health may be related to initial differences in cognitive functioning (i.e., cross-sectional differences) rather than more rapid cognitive aging.

Cognitive Aging with Dementia, Mild Cognitive Impairment, or No Impairment: A Comparison of Same- and Mixed-Sex Couples

BACKGROUND

Lesbian and gay older adults have health disparities that are risk factors for Alzheimer's disease, yet little is known about the neurocognitive aging of sexual minority groups.

OBJECTIVE

To explore cross-sectional and longitudinal dementia outcomes for adults in same-sex relationships (SSR) and those in mixed-sex relationships (MSR).

METHODS

This prospective observational study utilized data from the National Alzheimer's Coordinating Center Uniform Data Set (NACC UDS) collected from contributing Alzheimer's Disease Research Centers. Participants were adults aged 55+ years at baseline with at least two visits in NACC UDS (from September 2005 to March 2021) who had a spouse, partner, or companion as a co-participant. Outcome measures included CDR® Dementia Staging Instrument, NACC UDS neuropsychological testing, and the Functional Activities Questionnaire. Multivariable linear mixed-effects models accounted for center clustering and repeated measures by individual.

RESULTS

Both MSR and SSR groups experienced cognitive decline regardless of baseline diagnosis. In general, MSR and SSR groups did not differ statistically on cross-sectional or longitudinal estimates of functioning, dementia severity, or neuropsychological testing, with two primary exceptions. People in SSR with mild cognitive impairment showed less functional impairment at baseline (FAQ M = 2.61, SD = 3.18 vs. M = 3.97, SD = 4.53, respectively; p < 0.01). The SSR group with dementia had less steep decline in attention/working memory (β estimates = -0.10 versus -0.18; p < 0.01).

CONCLUSION

Participants in SSR did not show cognitive health disparities consistent with a minority stress model. Additional research into protective factors is warranted.

Opportunities to Discuss Diversity-Related Topics in Neuroscience Courses

Diversity is a foundational topic in psychology, and APA recommends that diversity is covered across the psychology curriculum. Neuroscience courses face challenges with incorporating diversity-related topics owing to the historical lack of neuroscience research that focuses on diversity and the restricted range of diversity-related topics that neuroscience is typically associated with (i.e., health and disability status). This may limit students' learning of neuroscience's contributions towards understanding diversity. We review some specific examples of diversity-related topics that can be incorporated into neuroscience courses. These examples have been selected to include topics across the three major content domains of neuroscience (cellular/molecular, neuroanatomy/systems, and cognitive/behavioral), as well as across multiple diversity-related topics. Neuroscience instructors can use these examples to incorporate greater coverage of diversity-related topics within their courses and/or as points of inspiration for their own curricular additions. Providing systematic coverage of diversity-related topics in neuroscience courses highlights the ways neuroscience advances our understanding of human diversity and contributes to the educational objectives of psychology and neuroscience programs.

Divergent patterns of cognitive deficits and structural brain alterations between older adults in mixed-sex and same-sex relationships

Background

Sexual minority (SM) older adults experience mental health disparities. Psychiatric disorders and neuropsychiatric symptoms (NPS) are risk factors for cognitive decline. Although older people in same-sex (SSR) compared to mixed-sex relationships (MSR) perform more poorly on cognitive screening tests, prior studies found no differences in rates of dementia diagnosis or neuropsychological profiles. We sought to explore the role of NPS on neurocognitive outcomes for SM populations. We compared cognitive performance and structural brain parameters of older adults in SSR and MSR.

Methods

Data were originally collected at Alzheimer's Disease Research Centers (ADRCs). Inclusion criteria were: age of 55+ years, a study partner identified as a spouse/partner, and availability of T1-MRI brain volumes/thickness. Participants were labeled as either SSR or MSR based on their/their co-participant's reported sex. We identified 1,073 participants (1,037 MSR−555 cognitively unimpaired [CU]; 36 SSR−23 CU) with structural MRI data, Mini-Mental State Exam (MMSE), and Neuropsychiatric Inventory Questionnaire (NPI-Q) scores. A subset of the overall sample completed comprehensive neuropsychological assessment (n = 939; 908 MSR−494 CU; 31 SSR−22 CU). Covariates included in statistical models were age, sex, education, total intracranial volume, and apolipoprotein E genotype.

Results

Multivariate general linear models showed significant diagnosis-by-relationship interaction effects on the left parahippocampal gyrus volume. After stratification by relationship group, only cognitively impaired (CI) MSR had significantly smaller left parahippocampal volumes than MSR-CU. The SSR group showed better episodic memory performance. Severity of neuropsychiatric symptoms was negatively associated with volume/thickness of bilateral fronto-temporal areas and with MMSE scores, predominantly in the MSR group.

Conclusion

In our study, MSR participants presented with a more compromised cognitive profile than SSR participants. MSR-CI participants showed significantly smaller left medio-temporal volumes, a neural signature of AD. Neuropsychiatric symptoms predicted smaller fronto-temporal volumes in the MSR more consistently than in the SSR group. These findings may be due to unexplored protective factors against cognitive decline in SM elders. Indeed, social support has been proposed as a protective factor warranting future investigation.

Biopsychosocial Correlates of Subjective Cognitive Decline and Related Worry in the Canadian Longitudinal Study on Aging

INTRODUCTION

Subjective cognitive decline (SCD), a self-reported decline in cognition in otherwise cognitively healthy people, has been acknowledged as a risk factor for Alzheimer's disease. Using data from the Canadian Longitudinal Study on Aging (CLSA), a large national study with participants' ages of 45-85 years at baseline, we sought to identify correlates of SCD and SCD-related worry.

METHODS

In our primary analysis using a Poisson regression model, associations between biopsychosocial variables and SCD were identified (analytic sample: n = 21,920). In a second analysis using an ordinal regression model, associations between biopsychosocial variables and SCD-related worry were identified (analytic sample: n = 12,694).

RESULTS

Multiple risk and protective factors of cognitive decline were not associated with SCD within our sample (i.e., physical activity, hypertension, vision problems), as well as minority stress variables such as sexual orientation and race. Rather, psychosocial variables (i.e., depression, perceived social status, and personality traits) showed a more consistent association with SCD within the sample. Greater SCD-related worry, which is believed to increase the risk of future dementia, was associated with specific personality traits, depression, age, gender, and sexuality.

CONCLUSION

The results from this study confirm the association between multiple health variables and SCD but also emphasize the importance of considering psychological and social factors when conceptualizing SCD and its risk factors.

Prospective Associations between Physical Activity and Memory in the Canadian Longitudinal Study on Aging: Examining Social Determinants

Objectives

To examine associations between physical activity (PA) and prospectively assessed memory in a cohort of cognitively healthy adults, after accounting for understudied social determinants.

Methods

We used data from the Canadian Longitudinal Study on Aging (CLSA). PA (exposure) and memory (outcome) were assessed using validated measures in 2013–2015 and 2015–2018, respectively. Respondents reported their daily number of hours spent engaging in five different PAs. We conducted multiple imputation and used linear regression (n = 41,394), adjusting for five categories of covariates: demographics, sensory health characteristics, health behaviors, health status, and social determinants (sex/gender, education, income, social support, perceived social standing, race, and sexual orientation).

Results

In crude models, nearly every intensity and duration of PA was associated with better memory. In fully adjusted models, protective associations were attenuated; however, some associations held: all durations of walking, most durations of light activities, moderate activities for ≥1 hour, and strenuous activities for 1 to <2 hours.

Discussion

Some forms of PA may be associated with better memory. The benefits of higher intensity PA may only be realized after social determinants are addressed.