Cognitive Reserve and Alzheimer Disease

Investigation of risk of Alzheimer's disease diagnosis and survival based on variation to life experiences used to operationalize cognitive reserve

BackgroundAlzheimer's disease dementia (AD) is a debilitating progressive neurodegenerative disease. Life experiences are hypothesized to build cognitive reserve (CR), a theoretical construct associated with delayed onset of AD symptoms. While CR is a key moderator of cognitive decline, operationalization of CR is varied resulting in inconsistencies within the literature.ObjectiveThis study explored the relationship between life experiences used as proxies of CR and risk of AD diagnosis and death following diagnosis.MethodsWe explored results based on 30 different published CR operationalizations, including two standardized questionnaires and an investigator-developed lifecourse indicator. Using data from the Memory and Aging Project, we applied Cox proportional hazard models to evaluate the impact of operationalization on time to outcomes.ResultsHazard ratios, indicating instantaneous risk of AD or death for a standard deviation increase in the CR proxy utilized as a predictor, ranged from 0.80-1.40 for AD diagnosis and 0.80-1.29 for death following diagnosis. Among nine predictors that showed a significant reduction in risk of AD, there was a decrease of between 12% and 20%. Two predictors were associated with reduced risk of death, with 13%-20% reduction, while three predictors were associated with 18%-22% heightened risk of death following diagnosis.ConclusionsModel results were highly sensitive to CR operationalization. Based on the variation in results, composite measures that incorporate multiple lifecourse variables may still be the most comprehensive and faithful representation of CR. Attention to methodology and refining of measurement are needed to make use of CR and promote healthy aging.

Cognitive reserve types and depressive symptoms development in late-life: A population-based cohort study

INTRODUCTION

Cognitive reserve (CR) describes individual differences in susceptibility to brain damage that translates into varying dementia onsets and may also influence the occurrence of depressive symptoms. Within a population-based cohort of older people, we investigated two operationalizations of CR, residual- and activity-based approaches, in their association with the development of depressive symptoms.

METHODS

We analyzed longitudinal data on 402 dementia- and depression-free adults aged 60+ from the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K) who underwent brain MRI at baseline. Residual-based reserve was derived by regressing episodic memory on a brain-integrity index incorporating six structural MRI markers. Activity-based reserve factored lifelong CR-enhancing experiences, including education, work complexity, social network, and leisure activities. Clinically relevant depressive symptoms were defined as a Montgomery-Åsberg Depression Rating Scale score >6. Cox hazard models were used to explore the association between both residual- and activity-based CR measures (categorized in tertiles) and incidence of depressive symptoms over a 15-year follow-up, while accounting for sociodemographic, clinical, behavioral factors, and brain integrity. Analyses for the activity-based measure were replicated in the full SNAC-K sample (N = 2709), further exploring depression diagnosis as additional outcome.

RESULTS

Compared to low levels, higher levels of residual-based CR were associated with a lower hazard of depressive symptom onset in fully adjusted models (HR: .43, 95%CI .22, .84). While activity-based CR was not significantly associated with developing depressive symptoms in the MRI subsample (HRhigh .47, 95%CI .21, 1.04), it was in the full sample (HRhigh .52, 95%CI .39, .71). Activity-based CR was further associated with depression diagnoses in the full sample (HRhigh: .45, 95%CI .31, .65).

DISCUSSION

Largely independent of its measurement, CR appears to influence depressive symptomatology in late life. Reserve-enhancing initiatives may be beneficial not only for cognitive but also for mental health in older people.

The Role of Well-Being, Divergent Thinking, and Cognitive Reserve in Different Socio-Cultural Contexts

BACKGROUND

Many protective factors promote psychological well-being (PWB) in the elderly and contribute to healthy aging, such as engagement, positive emotions, and cognitive reserve (CR), which includes education, leisure, and work activities. CR sustains cognitive functioning and positively correlates with creativity, particularly divergent thinking (DT), helping older adults cope with everyday challenges and enhancing their PWB.

OBJECTIVES

The present study aimed to investigate the relationships between DT, CR, PWB, memory functions, depression, stress, and anxiety indexes even in the Blue Zone (BZ), an area known for extraordinary longevity and high PWB.

METHODS

A total of 165 Italian healthy older adults (Mage = 73.8, SD = 6.7) from Milan (MI), Bergamo (BG), Cagliari (CA), and BZ were enrolled and divided into four groups according to their origin. Generalized linear models (GLMs) with normal and gamma link functions were used.

RESULTS

BZ presented higher DT and PWB indices than the cities but lower CR, particularly in education.

CONCLUSIONS

This study highlights the influence of DT in supporting cognitive functions and PWB, suggesting that PWB and DT are key protective factors in aging.

Event-related potential markers of subjective cognitive decline and mild cognitive impairment during a sustained visuo-attentive task

Subjective cognitive decline (SCD), mild cognitive impairment (MCI), and Alzheimer's disease stages lack well-defined electrophysiological correlates, creating a critical gap in the identification of robust biomarkers for early diagnosis and intervention. In this study, we analysed event-related potentials (ERPs) recorded during a sustained visual attention task in a cohort of 178 individuals (119 SCD, 40 MCI, and 19 healthy subjects, HS) to investigate sensory and cognitive processing alterations associated with these conditions. SCD patients exhibited significant attenuation in both sensory (P1, N1, P2) and cognitive (P300, P600, P900) components compared to HS, with cognitive components showing performance-related gains. In contrast, MCI patients did not show a further decrease in any ERP component compared to SCD. Instead, they exhibited compensatory enhancements, reversing the downward trend observed in SCD. This compensation resulted in a non-monotonic pattern of ERP alterations across clinical conditions, suggesting that MCI patients engage neural mechanisms to counterbalance sensory and cognitive deficits. These findings support the use of electrophysiological markers in support of medical decision-making, enhancing personalized prognosis and guiding targeted interventions in cognitive decline.

Cortical excitability and the aging brain: toward a biomarker of cognitive resilience

This perspective article addresses the potential use of cortical excitability (CE) as an indicator of cognitive health in aging people. Changes in CE may be considered a sign of resilience to cognitive decline in old age. The authors describe research on CE and its link to cognitive function in older adults and emphasize that it is a promising, non-invasive measure of healthy aging. They also address the current challenges in its implementation, the need for standardized measurement protocols and possible future avenues of research. If properly considered, CE could pave the way for early detection of cognitive decline and facilitate targeted interventions to promote cognitive resilience.

Repeated exposure to novelty promotes resilience against the amyloid-beta effect through dopaminergic stimulation

RATIONALE

The accumulation of beta-amyloid peptide (Aβ) in the forebrain leads to cognitive dysfunction and neurodegeneration in Alzheimer's disease. Studies have shown that individuals with a consistently cognitively active lifestyle are less vulnerable to Aβ toxicity. Recent research has demonstrated that intrahippocampal Aβ can impact catecholaminergic release and spatial memory. Interestingly, exposure to novelty stimuli has been found to stimulate the release of catecholamines in the hippocampus. However, it remains uncertain whether repeated enhancing catecholamine activity can effectively alleviate cognitive impairment in individuals with Alzheimer's disease.

OBJECTIVES

Our primary aim was to investigate whether repeated exposure to novelty could enable cognitive resilience against Aβ. This protection could be achieved by modulating catecholaminergic activity within the hippocampus.

METHODS

To investigate this hypothesis, we subjected mice to three different conditions-standard housing (SH), repeated novelty (Nov), or daily social interaction (Soc) for one month. We then infused saline solution (SS) or Aβ (Aβ1-42) oligomers intrahippocampally and measured spatial memory retrieval in a Morris Water Maze (MWM). Stereological analysis and extracellular baseline dopamine levels using in vivo microdialysis were assessed in independent groups of mice.

RESULTS

The mice that received Aβ1-42 intrahippocampal infusions and remained in SH or Soc conditions showed impaired spatial memory retrieval. In contrast, animals subjected to the Nov protocol demonstrated remarkable resilience, showing strong spatial memory expression even after Aβ1-42 intrahippocampal infusion. The stereological analysis indicated that the Aβ1-42 infusion reduced the tyrosine hydroxylase axonal length in SH or Soc mice compared to the Nov group. Accordingly, the hippocampal extracellular dopamine levels increased significantly in the Nov groups.

CONCLUSIONS

These compelling results demonstrate the potential for repeated novelty exposure to strengthen the dopaminergic system and mitigate the toxic effects of Aβ1-42. They also highlight new and promising therapeutic avenues for treating and preventing AD, especially in its early stages.

Employing Verbal Divergent Thinking to Mitigate Cognitive Decline: Current State of Research and Reasons to Support Its Use

BACKGROUND/OBJECTIVES

Divergent thinking (DT), the ability to generate alternative responses to open-ended problems, has become an increasingly relevant topic in aging research due to its inverse relationship with cognitive decline.

METHODS

In this narrative review, we explore the latest evidence supporting DT training as a potential strategy for dementia prevention.

RESULTS

We identify two pathways through which DT may protect against cognitive decline: (1) by fostering creative cognition and (2) by stimulating DT-related domains. Our findings suggest that verbal DT remains relatively well preserved in older adults, although there is limited empirical evidence to support the idea that DT training enhances creative cognition or DT-related domains in this population.

CONCLUSIONS

Therefore, while tools designed to enhance DT in older individuals seem promising, it is crucial to rigorously test their effects on the target population to maximize their impact on both the cognitive and psychological domains.

The complex interplay between cognitive reserve, age of diagnosis and cognitive decline in Alzheimer's disease: a retrospective study

OBJECTIVE

The present study examined the cognitive reserve (CR) theory at late stages of Alzheimer's disease (AD). The objective is to replicate previous studies and examine the complex role of education and family size as indicators of CR.

PARTICIPANTS AND METHODS

This is a retrospective study included 642 patients diagnosed with AD after age 65, categorized into low education (LE, ≤ 8 years, n = 141) and medium-high education (MHE, ≥ 9 years, n = 442) groups. Participants were followed up longitudinally using the Mini Mental State Examination.

RESULTS

Higher education in the MHE group, but not in the LE group, correlated with delayed diagnosis. In both groups, higher education correlated with accelerated cognitive decline. In the MHE group, country of origin was associated with cognitive decline, while in the LE group, it was linked to family size.

CONCLUSIONS

This study shows that in patients with MHE but not in LE, higher education resulted in delayed diagnosis. Conversely, in cases of LE, this measure may not fully reflect CR and abilities. Additionally, higher education was associated with faster deterioration, a finding that has not been replicated often in the literature. The study illustrates the complex impact of CR proxies on age of diagnosis and cognitive decline.

Predictors of dementia among the oldest old: longitudinal findings from the representative "survey on quality of life and subjective well-being of the very old in North Rhine-Westphalia (NRW80+)"

BACKGROUND/AIMS

Our current study aimed to investigate the determinants of dementia among the oldest old using longitudinal data from a representative sample covering both community-dwelling and institutionalized individuals.

METHODS/DESIGN

Longitudinal representative data were taken from the "Survey on quality of life and subjective well-being of the very old in North Rhine-Westphalia (NRW80+)" that surveyed community-dwelling and institutionalized individuals aged 80 years and above (n = 1,296 observations in the analytic sample), living in North Rhine-Westphalia (most populous state of Germany). The established DemTect was used to measure cognitive impairment (i.e., probable dementia). A logistic random effects model was used to examine the determinants of probable dementia.

RESULTS

The mean age was 86.3 years (SD: 4.2 years). Multiple logistic regressions revealed that a higher likelihood of probable dementia was positively associated with lower education (e.g., low education compared to medium education: OR: 3.31 [95% CI: 1.10-9.98]), a smaller network size (OR: 0.87 [95% CI: 0.79-0.96]), lower health literacy (OR: 0.29 [95% CI: 0.14-0.60]), and higher functional impairment (OR: 13.45 [3.86-46.92]), whereas it was not significantly associated with sex, age, marital status, loneliness, and depressive symptoms in the total sample. Regressions stratified by sex were also reported.

DISCUSSION

Our study identified factors associated with dementia among the oldest old. This study extends current knowledge by using data from the oldest old; and by presenting findings based on longitudinal, representative data (also including individuals residing in institutionalized settings).

CONCLUSIONS

Efforts to increase, among other things, formal education, network size, and health literacy may be fruitful in postponing dementia, particularly among older women. Developing health literacy programs, for example, may be beneficial to reduce the burden associated with dementia.

Vocabulary knowledge as a reliable proxy of cognitive reserve in multiple sclerosis: a validation study

INTRODUCTION

The present study aimed to explore the suitability of the vocabulary knowledge (VOC) test as an accurate and reliable proxy of cognitive reserve (CR) by evaluating its psychometric properties and discrimination accuracy compared with other CR measures in multiple sclerosis (MS).

METHODS

Sixty-eight consecutive people with multiple sclerosis (pwMS), followed at our MS outpatient clinic, completed a clinical evaluation and neuropsychological assessment including: VOC, Brief Repeatable Battery of Neuropsychological Tests (BRB-N), Cognitive Reserve Index Questionnaire (CRIq), Beck Depression Inventory-II, and State-Trait Anxiety Inventory. Reliability, convergent and divergent validity, and discrimination accuracy of the VOC were assessed using educational level as reference standard. The possible effects of sociodemographic and clinical factors on VOC and their role in predicting global cognitive status were also explored.

RESULTS

VOC demonstrated good internal consistency (Cronbach's α = 0.894) and adequate construct validity. It showed an acceptable level of discrimination between pwMS with high and low CR, comparable to the CRIq score. Education strongly affected VOC scores, which in turn were independent of MS features. VOC emerged as an independent predictor of global cognitive status together with MS-related disability.

CONCLUSION

We demonstrated the validity of VOC as a reliable CR measure in pwMS. Thus, CR may also be estimated using fixed objective measures, independent of brain pathology and clinical features. Early CR estimation may help clinicians identify pwMS at a higher risk of cognitive decline and plan strict neuropsychological monitoring and cognitive interventions.

Charting Alzheimer's Disease and Dementia: Epidemiological Insights, Risk Factors and Prevention Pathways

Alzheimer's disease (AD), the most common cause of dementia, is a complex and multifactorial condition without cure at present. The latest treatments, based on anti-amyloid monoclonal antibodies, have only a modest effect in reducing the progression of cognitive decline in AD, whereas the possibility of preventing AD has become a crucial area of research. In fact, recent studies have observed a decrease in dementia incidence in developed regions such as the US and Europe. However, these trends have not been mirrored in non-Western countries (Japan or China), and the contributing factors of this reduction remain unclear. The Lancet Commission has delineated a constrained classification of 12 risk factors across different life stages. Nevertheless, the scientific literature has pointed to over 200 factors-including sociodemographic, medical, psychological, and sociocultural conditions-related to the development of dementia/AD. This narrative review aims to synthesize the risk/protective factors of dementia/AD. Essentially, we found that risk/protective factors vary between individuals and populations, complicating the creation of a unified prevention strategy. Moreover, dementia/AD explanatory mechanisms involve a diverse array of genetic and environmental factors that interact from the early stages of life. In the future, studies across different population-based cohorts are essential to validate risk/protective factors of dementia. This evidence would help develop public health policies to decrease the incidence of dementia.

The Alzheimer's patients interaction through digital and arts (AIDA) program: A feasibility study to improve wellbeing in people with Alzheimer's disease

Alzheimer's disease (AD) presents a growing global challenge, with an increasing prevalence and significant impact on individuals and public health. Effective pharmacological treatments directly impacting the disease are still lacking, highlighting the importance of programs and interventions aimed at improving the wellbeing of those affected. The present feasibility study aimed to evaluate the effectiveness and feasibility of the Alzheimer's patients Interaction through Digital and Arts (AIDA) program. AIDA's main objective is to enhance perceived wellbeing and quality of life of people with AD and their caregivers through a series of structured activities through museum- and art-based activities over five sessions. Pre- and post-program evaluations were conducted using Visual Analog Scales (VASs) to measure various dimensions of perceived wellbeing such as confidence, happiness, interest, optimism, and wellness. Results showed significant improvements in all considered dimensions for people with AD following AIDA activities, highlighting its potential to enhance overall wellbeing. Caregivers also reported increased perceived wellness post-program, demonstrating some positive effects also in healthy participants. The feasibility of AIDA was supported by positive feedback and engagement of participants. Overall, the AIDA program offers a non-intrusive and engaging approach to improve the perceived wellbeing of people with AD and caregivers while facilitating meaningful experiences (e.g., silence, sharing etc.) in cultural settings.

Underlying Mechanisms of the Protective Effects of Lifestyle Factors On Age-Related Diseases

The rise in life expectancy has significantly increased the occurrence of age-related chronic diseases, leading to escalating expenses for both society and individuals. Among the main factors influencing health and lifespan, lifestyle takes a forefront position. Specifically, nutrition, mental activity, and physical exercise influence the molecular and functional mechanisms that contribute to the prevention of major age-related diseases. Gaining deeper insights into the mechanisms that drive the positive effects of healthy lifestyles is valuable for creating interventions to prevent or postpone the development of chronic degenerative diseases. This review summarizes the main mechanisms that underlie the positive effect of lifestyle factors in counteracting the major age-related diseases involving brain health, musculoskeletal function, cancer, frailty, and cardiovascular diseases, among others. This knowledge will help to identify high-risk populations for targeted intervention trials and discover new biomarkers associated with healthy aging.

Memory self-efficacy and working memory

Dementia affects multiple aspects of cognitive functioning, including working memory and executive functioning. Memory self-efficacy (MSE) has previously been related to episodic memory performance and to executive functioning, but little research has examined the relations between MSE and working memory. United States older adults (N  = 197) were recruited via MTurk to complete an MSE questionnaire before completing a digit span working memory task. Hierarchical regression results revealed that the model accounted for a significant amount of variance in working memory performance after statistically controlling for several covariates, F(11, 179) = 4.94, p < .001, adjusted R2 = .19. MSE explained a large and unique portion of variance (B = 1.02, SE = 0.17, p < .001). Based on our findings, one's beliefs about their memory are positively associated with their working memory performance. These novel findings provide support for neuropsychologists to consider using MSE measures and utilizing MSE interventions.

Prevalence of Cognitive Defects Among Senior Inmates of Old-Age Homes in a District of South Kerala

Background Cognitive decline, including mild cognitive impairment and major neurocognitive disorder, is a growing concern among aging populations. The prevalence of these disorders is especially relevant in regions experiencing a surge in elderly care infrastructure, such as Kerala, India. Within the context of sociocultural shifts and a rising elderly population, old-age homes are increasingly becoming the focal point of care and support for cognitive health. This study aims to examine the prevalence of cognitive defects among elderly individuals residing in old-age homes in the Kottayam district of Kerala, India. Additionally, it investigates the relationship between cognitive disorders and sociodemographic variables of the inhabitants in these institutionalized settings. Methodology In this study, 535 elderly subjects were selected from 85 registered old-age homes in Kottayam, Kerala, through systematic cluster sampling. The response rate was 89.6%. Data collection involved a sociodemographic questionnaire, the Picture Memory Impairment Screen (PMIS), and the Mini-Mental Status Examination (MMSE) translated into Malayalam. Data were gathered either from participants, caretakers, or medical records. Ethical guidelines were strictly followed. Statistical analysis was conducted using SPSS Statistics Version 25.0 (IBM Corp., Armonk, NY, USA), employing the chi-square test, t-test, and logistic regression, with a p-value less than 0.05 deemed significant. Results In our study of 535 elderly individuals in Kottayam's old-age homes, age, gender, and education were significantly associated with cognitive impairment, with p-values <0.001, 0.049, and <0.001, respectively. Behavioral factors such as smoking and alcohol consumption showed no significant association. The mean MMSE and PMIS scores were 25.24 and 5.57, respectively. The prevalence of cognitive defects was 170 (31.80%) as per MMSE and 182 (34.00%) according to PMIS. Given the wider acceptance of MMSE, the study established a cognitive defect prevalence of 170 (31.80%) among senior inmates. Conclusions This study reveals a high prevalence (170, 31.80%) of cognitive defects among elderly residents in Kottayam's old-age homes. Age and education were significant predictors, while behavioral factors such as smoking and alcohol were not. These findings underscore the need for targeted healthcare strategies to address cognitive decline in aging populations.

Disentangling sex-dependent effects of APOE on diverse trajectories of cognitive decline in Alzheimer's disease

Current diagnostic systems for Alzheimer's disease (AD) rely upon clinical signs and symptoms, despite the fact that the multiplicity of clinical symptoms renders various neuropsychological assessments inadequate to reflect the underlying pathophysiological mechanisms. Since putative neuroimaging biomarkers play a crucial role in understanding the etiology of AD, we sought to stratify the diverse relationships between AD biomarkers and cognitive decline in the aging population and uncover risk factors contributing to the diversities in AD. To do so, we capitalized on a large amount of neuroimaging data from the ADNI study to examine the inflection points along the dynamic relationship between cognitive decline trajectories and whole-brain neuroimaging biomarkers, using a state-of-the-art statistical model of change point detection. Our findings indicated that the temporal relationship between AD biomarkers and cognitive decline may differ depending on the synergistic effect of genetic risk and biological sex. Specifically, tauopathy-PET biomarkers exhibit a more dynamic and age-dependent association with Mini-Mental State Examination scores (p<0.05), with inflection points at 72, 78, and 83 years old, compared with amyloid-PET and neurodegeneration (cortical thickness from MRI) biomarkers. In the landscape of health disparities in AD, our analysis indicated that biological sex moderates the rate of cognitive decline associated with APOE4 genotype. Meanwhile, we found that higher education levels may moderate the effect of APOE4, acting as a marker of cognitive reserve.

Handicraft art leisure activities and cognitive reserve

ObjectiveOlder individuals face a higher likelihood of developing dementia. The rate of cognitive decline resulting from dementia is not equivalent for all, as some patients with dementia are able to function independently longer than others, despite having similar disease burden. The cognitive reserve (CR) theory provides one explanation for the differing rate of decline. CR suggests that there are factors-most notably, educational attainment and occupational attainment-that can protect against the cognitive decline. Although the beneficial effects of these notable CR factors are clear, not all are easily modifiable. Participation in leisure activities may represent a more easily modifiable factor. Some research hints at beneficial effects of leisure activities, although specific leisure activities have not been well examined. The present study examined the relations between handicraft art leisure activities (HALAs) and multiple cognitive domains. MethodArchival WAIS-IV and demographic data for 50 California retirement community residents were examined. ResultsHALA participation accounted for statistically significant variance in working memory performance (R2 = .40, β = .24%) over and above the established CR factors of age, depression, educational attainment, and occupational attainment. In addition, HALA participation was related to a better ability to perform abstract visual information tasks (Block Design subtest, r = .28, p = .05) and non-verbal reasoning tasks (Visual Puzzles subtest, r = .38, p = .008). ConclusionsHALA participation among older adults could contribute to the retention of cognitive function, supporting the role of HALA participation as a CR factor.

The Immunometabolic Gene N-Acetylglucosamine Kinase Is Uniquely Involved in the Heritability of Multiple Sclerosis Severity

The clinical severity of multiple sclerosis (MS), an autoimmune disorder of the central nervous system, is thought to be determined by environmental and genetic factors that have not yet been identified. In a recent genome-wide association study (GWAS), a single nucleotide polymorphism (SNP), rs10191329, has been associated with MS severity in two large independent cohorts of patients. Different approaches were followed by the authors to prioritize the genes that are transcriptionally regulated by such an SNP. It was concluded that the identified SNP regulates a group of proximal genes involved in brain resilience and cognitive abilities rather than immunity. Here, by conducting an alternative strategy for gene prioritization, we reached the opposite conclusion. According to our re-analysis, the main target of rs10191329 is N-Acetylglucosamine Kinase (NAGK), a metabolic gene recently shown to exert major immune functions via the regulation of the nucleotide-binding oligomerization domain-containing protein 2 (NOD2) pathway. To gain more insights into the immunometabolic functions of NAGK, we analyzed the currently known list of NAGK protein partners. We observed that NAGK integrates a dense network of human proteins that are involved in glucose metabolism and are highly expressed by classical monocytes. Our findings hold potentially major implications for the understanding of MS pathophysiology.

Graph kernel of brain networks considering functional similarity measures

As a tool of brain network analysis, the graph kernel is often used to assist the diagnosis of neurodegenerative diseases. It is used to judge whether the subject is sick by measuring the similarity between brain networks. Most of the existing graph kernels calculate the similarity of brain networks based on structural similarity, which can better capture the topology of brain networks, but all ignore the functional information including the lobe, centers, left and right brain to which the brain region belongs and functions of brain regions in brain networks. The functional similarities can help more accurately locate the specific brain regions affected by diseases so that we can focus on measuring the similarity of brain networks. Therefore, a multi-attribute graph kernel for the brain network is proposed, which assigns multiple attributes to nodes in the brain network, and computes the graph kernel of the brain network according to Weisfeiler-Lehman color refinement algorithm. In addition, in order to capture the interaction between multiple brain regions, a multi-attribute hypergraph kernel is proposed, which takes into account the functional and structural similarities as well as the higher-order correlation between the nodes of the brain network. Finally, the experiments are conducted on real data sets and the experimental results show that the proposed methods can significantly improve the performance of neurodegenerative disease diagnosis. Besides, the statistical test shows that the proposed methods are significantly different from compared methods.

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.

Cognitive Reserve Moderates the Effects of Fatigue and Depressive Symptoms in Multiple Sclerosis

To investigate cognitive reserve as a possible moderator in the relationship between fatigue and depressive symptoms in persons with multiple sclerosis (PwMS). Fifty-three PwMS (37 female; mean age, 52.66; mean education, 14.81) completed comprehensive neuropsychological testing and psychosocial questionnaires assessing the perceived effects of fatigue (Fatigue Impact Scale) and depressive symptoms (Beck Depression Inventory-Fast Screen). Cognitive reserve (CR) was operationalized as Fixed CR and Malleable CR. Fixed CR was quantified as the standardized mean of years of education and a vocabulary-based estimate of premorbid intelligence. Malleable CR was quantified as the standardized mean of cognitive exertion, exercise, and socializing items from the Cognitive Health Questionnaire. Regressions on depressive symptoms examining fatigue, both conceptualizations of CR, and their interactions were explored. A Bonferroni correction was used; results were considered significant at an alpha level of p < .01. The interactions between fatigue and both conceptualizations of CR were significant, p = .005 (Fixed CR); p = .004 (Malleable CR). Simple effects tests revealed that fatigue only predicted depressive symptoms in PwMS with low Fixed CR or low Malleable CR (p's < .001), and not in those with high Fixed or high Malleable CR (p > .01). Cognitive reserve moderated the relationship between fatigue and depressive symptoms in PwMS. Specifically, fatigue does not appear to influence depression in PwMS with high cognitive reserve. Having higher cognitive reserve (either Fixed or Malleable) may reduce the likelihood that fatigue will lead to depressive symptoms in MS.

Sex differences in longitudinal changes of episodic memory-related brain activity and cognition in cognitively unimpaired older adults with a family history of Alzheimer's disease

Episodic memory decline is an early symptom of Alzheimer's disease (AD) - a neurodegenerative disease that has a higher prevalence rate in older females compared to older males. However, little is known about why these sex differences in prevalence rate exist. In the current longitudinal task fMRI study, we explored whether there were sex differences in the patterns of memory decline and brain activity during object-location (spatial context) encoding and retrieval in a large sample of cognitively unimpaired older adults from the Pre-symptomatic Evaluation of Novel or Experimental Treatments for Alzheimer's Disease (PREVENT-AD) program who are at heightened risk of developing AD due to having a family history (+FH) of the disease. The goal of the study was to gain insight into whether there are sex differences in the neural correlates of episodic memory decline, which may advance knowledge about sex-specific patterns in the natural progression to AD. Our results indicate that +FH females performed better than +FH males at both baseline and follow-up on neuropsychological and task fMRI measures of episodic memory. Moreover, multivariate data-driven task fMRI analysis identified generalized patterns of longitudinal decline in medial temporal lobe activity that was paralleled by longitudinal increases in lateral prefrontal cortex, caudate and midline cortical activity during successful episodic retrieval and novelty detection in +FH males, but not females. Post-hoc analyses indicated that higher education had a stronger effect on +FH females neuropsychological scores compared to +FH males. We conclude that higher educational attainment may have a greater neuroprotective effect in older +FH females compared to +FH males.

Depressive Symptomatology as a Predictor of Cognitive Impairment: Evidence from the Korean Longitudinal Study of Aging (KLOSA), 2006-2020

Depressive symptoms are recognized as risk factors for cognitive impairment with intricate underlying biological mechanisms. We explored the link between depressive symptoms and cognitive impairment onset; we also assessed how this association is influenced by educational levels. This study included 5843 individuals aged ≥45 years, comprising 27,908 observations from 2006 to 2020. Based on repeated measurements of each participant, we estimated the association between depressive symptoms and cognitive impairment onset after a 2-year follow-up by using generalized estimating equations. The incidence rate was 9.4% among those individuals without depressive symptoms, which was in contrast with a rate of 21.0% among those individuals experiencing depressive symptoms. The odds ratio (OR) (95% confidence interval [CI]) for the association between depressive symptoms and cognitive impairment onset in the overall sample was 1.61 (1.47-1.76). This association was more pronounced among individuals with higher educational levels. Specifically, the OR (95% CI) of the association between depressive symptoms and cognitive impairment was highest among individuals with a college education (2.60 [1.78-3.81]), and the association was lowest among individuals with elementary or no education levels (1.45 [1.28-1.63]). Our findings highlight the idea that although individuals with higher educational backgrounds exhibit a diminished risk of cognitive impairment, the detrimental impacts of depressive symptoms on cognitive performance are particularly more pronounced within this group.

Tipping points in neurodegeneration

In Alzheimer's disease (AD), Aβ deposits form slowly, several decades before further pathological events trigger neurodegeneration and dementia. However, a substantial proportion of affected individuals remains non-demented despite AD pathology, raising questions about the underlying factors that determine the transition to clinical disease. Here, we emphasize the critical function of resilience and resistance factors, which we extend beyond the concept of cognitive reserve to include the glial, immune, and vascular system. We review the evidence and use the metaphor of "tipping points" to illustrate how gradually forming AD neuropathology in the preclinical stage can transition to dementia once adaptive functions of the glial, immune, and vascular system are lost and self-reinforcing pathological cascades are unleashed. Thus, we propose an expanded framework for pathomechanistic research that focuses on tipping points and non-neuronal resilience mechanisms, which may represent previously untapped therapeutic targets in preclinical AD.

Systematic examination of methodological inconsistency in operationalizing cognitive reserve and its impact on identifying predictors of late-life cognition

BACKGROUND

Cognitive reserve (CR) is the ability to maintain cognitive performance despite brain pathology. CR is built through lifecourse experiences (e.g., education) and is a key construct in promoting healthy aging. However, the operationalization of CR and its estimated association with late-life cognition varies. The purpose of this study was to systematically examine the operationalization of CR and the relationship between its operationalization and late-life cognition.

METHODS

We performed a comprehensive review of experiences (proxies) used to operationalize CR. The review informed quantitative analyses using data from 1366 participants of the Memory and Aging Project to examine 1) relationships between proxies and 2) the relationship between operationalization and late-life cognition. We also conducted a factor analysis with all identified CR experiences to create a composite lifecourse CR score. Generalized linear mixed models examined the relationship between operationalizations and global cognition, with secondary outcomes of five domains of cognition to examine consistency.

RESULTS

Based on a review of 753 articles, we found the majority (92.3%) of the 28 commonly used proxies have weak to no correlation between one another. There was substantial variability in the association between operationalizations and late-life global cognition (median effect size: 0.99, IQR: 0.34 to 1.39). There was not strong consistency in the association between CR operationalizations and the five cognitive domains (mean consistency: 56.1%). The average estimate for the 28 operationalizations was 0.91 (SE = 0.48), compared to 2.48 (SE = 0.40) for the lifecourse score and it was associated with all five domains of cognition.

CONCLUSIONS

Inconsistent methodology is theorized as a major limitation of CR research and barrier to identification of impactful experiences for healthy cognitive aging. Based on the weak associations, it is not surprising that the relationship between CR and late-life cognition is dependent on the experience used to operationalize CR. Scores using multiple experiences across the lifecourse may help overcome such limitations. Adherence to a lifecourse approach and collaborative movement towards a consensus operationalization of CR are imperative shifts in the study of CR that can better inform research on risk factors related to cognitive decline and ultimately aid in the promotion of healthy aging.

Cognitive reserve and other determinants of cognitive function in older adults: Insights from a community-based cross-sectional study

Background

India will be the home of 323 million elderly persons by 2050. This means a surge in the dependent population primarily due to age-related cognitive decline. Evidence suggests that life course factors may have a modulatory role on cognitive function. The present study explores such potential influence by investigating the effect of cognitive reserve (a latent construct using education and occupation) and physical, psychological, and social determinants on cognitive function in community dwelling elderly.

Methods

A community-based cross-sectional study was conducted in urban areas of West Bengal (India) among elderly aged ≥60 years. Data was collected by personal interviews for socio-demographic and medical profile. Cognitive function was assessed using Bangla Adaptation of Mini-Mental State Examination (BAMSE). Educational level and occupational complexity were used as proxy indicators for calculating cognitive reserve.

Results

Of the 370 elderlies interviewed (mean age = 68.9 years), cognitive function was abnormal in 13.5%. The cognitive function had a significant inverse relationship with depression symptoms, loneliness, hypertension, anemia, and basic activities of daily living. There was a significant difference in the cognitive reserve of the elderly with normal and abnormal cognitive function (mean 33.7 and 26.8, respectively). In the presence of covariates like sleep quality, depression, hypertension, and hemoglobin levels, the effect of age on cognitive function had a significant mediation influence of cognitive reserve - total effect = -0.2349; 95% CI = (-0.2972 to -0.1725) and direct effect = -0.2583; 95% CI = (-0.3172 to -0.1994).

Conclusion

The quantum of effect of the age on cognitive function decreases with good cognitive reserve as a cognitive reserve has a significant mediation effect on the relationship between age and cognitive function.

Prediction of mental effort derived from an automated vocal biomarker using machine learning in a large-scale remote sample

Introduction

Biomarkers of mental effort may help to identify subtle cognitive impairments in the absence of task performance deficits. Here, we aim to detect mental effort on a verbal task, using automated voice analysis and machine learning.

Methods

Audio data from the digit span backwards task were recorded and scored with automated speech recognition using the online platform NeuroVocalixTM, yielding usable data from 2,764 healthy adults (1,022 male, 1,742 female; mean age 31.4 years). Acoustic features were aggregated across each trial and normalized within each subject. Cognitive load was dichotomized for each trial by categorizing trials at >0.6 of each participants' maximum span as "high load." Data were divided into training (60%), test (20%), and validate (20%) datasets, each containing different participants. Training and test data were used in model building and hyper-parameter tuning. Five classification models (Logistic Regression, Naive Bayes, Support Vector Machine, Random Forest, and Gradient Boosting) were trained to predict cognitive load ("high" vs. "low") based on acoustic features. Analyses were limited to correct responses. The model was evaluated using the validation dataset, across all span lengths and within the subset of trials with a four-digit span. Classifier discriminant power was examined with Receiver Operating Curve (ROC) analysis.

Results

Participants reached a mean span of 6.34 out of 8 items (SD = 1.38). The Gradient Boosting classifier provided the best performing model on test data (AUC = 0.98) and showed excellent discriminant power for cognitive load on the validation dataset, across all span lengths (AUC = 0.99), and for four-digit only utterances (AUC = 0.95).

Discussion

A sensitive biomarker of mental effort can be derived from vocal acoustic features in remotely administered verbal cognitive tests. The use-case of this biomarker for improving sensitivity of cognitive tests to subtle pathology now needs to be examined.

Early socioeconomic status, social mobility and cognitive trajectories in later life: A life course perspective

Using the Chinese Longitudinal Healthy Longevity Survey (CLHLS) from 2008 to 2018 accompanied by the growth curve model, we examined the association between early socioeconomic status, social mobility, and divergent cognitive trajectories in later life within a society undergoing significant transformation. The study confirmed a positive relationship between socioeconomic status in early life and cognitive ability in later life. However, socioeconomic status in adulthood is associated with better cognitive ability in old age compared to that in childhood. Meanwhile, upward social mobility mitigates the negative correlation between socioeconomic disadvantage in early life and cognitive ability in later life. In addition, the inequality in socioeconomic status at earlier stages resulted in heterogeneous cognitive trajectories, with the double cumulative disadvantage effect resulting from education being particularly noteworthy. Thus, Chinese health policy should focus on the earlier stages of life, actively promoting inclusive family policies and improving the family's role in protecting childhood from an adverse environment. Simultaneously, education and employment fairness should be strengthened to accelerate social mobility and enhance the "Health Repair Mechanism" of the second life course.

An Examination of the Joint Effect of the Social Environment and Air Pollution on Dementia Among US Older Adults

Evidence suggests exposure to air pollution increases the risk of dementia. Cognitively stimulating activities and social interactions, made available through the social environment, may slow cognitive decline. We examined whether the social environment buffers the adverse effect of air pollution on dementia in a cohort of older adults.

Methods

This study draws from the Ginkgo Evaluation of Memory Study. Participants aged 75 years and older were enrolled between 2000 and 2002 and evaluated for dementia semi-annually through 2008. Long-term exposure to particulate matter and nitrogen dioxide was assigned from spatial and spatiotemporal models. Census tract-level measures of the social environment and individual measures of social activity were used as measures of the social environment. We generated Cox proportional hazard models with census tract as a random effect and adjusted for demographic and study visit characteristics. Relative excess risk due to interaction was estimated as a qualitative measure of additive interaction.

Results

This study included 2,564 individuals. We observed associations between increased risk of dementia and fine particulate matter (µg/m3), coarse particulate matter (µg/m3), and nitrogen dioxide (ppb); HRs per 5 unit increase were 1.55 (1.01, 2.18), 1.31 (1.07, 1.60), and 1.18 (1.02, 1.37), respectively. We found no evidence of additive interaction between air pollution and the neighborhood social environment.

Conclusions

We found no consistent evidence to suggest a synergistic effect between exposure to air pollution and measures of the social environment. Given the many qualities of the social environment that may reduce dementia pathology, further examination is encouraged.

Cognitive impairment in young adults with post COVID-19 syndrome

In this study, we aimed to examine different cognitive domains in a large sample of patients with post COVID-19 syndrome. Two hundred and fourteen patients, 85.04% women, ranged 26 to 64 years (mean = 47.48 years) took part in this investigation. Patients' processing speed, attention, executive functions and various language modalities were examined online using a comprehensive task protocol designed for this research. Alteration in some of the tasks was observed in 85% of the participants, being the attention and executive functions tests the ones that show the highest percentage of patients with severe impairment. Positive correlations were observed between the age of the participants in almost all the tasks assessed, implying better performance and milder impairment with increasing age. In the comparisons of patients according to age, the oldest patients were found to maintain their cognitive functions relatively preserved, with only a mild impairment in attention and speed processing, while the youngest showed the most marked and heterogeneous cognitive impairment. These results confirm the subjective complaints in patients with post COVID-19 syndrome and, thanks to the large sample size, allow us to observe the effect of patient age on performance, an effect never reported before in patients with these characteristics.

Moderating effects of cognitive reserve on the relationship between brain structure and cognitive abilities in middle-aged and older adults

The cognitive reserve (CR) hypothesis is reinforced by negative moderating effects, suggesting that those with higher CR are less reliant on brain structure for cognitive function. Previous research on CR's moderating effects yielded inconsistent results, motivating our 3 studies using UK Biobank data. Study I examined five CR proxies' moderating effects on global, lobar, and regional brain-cognition models; study II extended study I by using a larger sample size; and study III investigated age-related moderating effects on the hippocampal regions. In study I, most moderating effects were negative and none survived the multiple comparison correction, but study II identified 13 global-level models with significant negative moderating effects that survived correction. Study III showed age influenced CR proxies' moderating effects in hippocampal regions. Our findings suggest that the effects of CR proxies on brain integrity and cognition varied depending on the proxy used, brain integrity indicators, cognitive domain, and age group. This study offers significant insights regarding the importance of CR for brain integrity and cognitive outcomes.

Selective breeding for physical inactivity produces cognitive deficits via altered hippocampal mitochondrial and synaptic function

Physical inactivity is the 4th leading cause of death globally and has been shown to significantly increase the risk for developing Alzheimer's Disease (AD). Recent work has demonstrated that exercise prior to breeding produces heritable benefits to the brains of offspring, suggesting that the physical activity status of previous generations could play an important role in one's brain health and their subsequent risk for neurodegenerative diseases. Thus, our study aimed to test the hypothesis that selective breeding for physical inactivity, or for high physical activity, preference produces heritable deficits and enhancements to brain health, respectively. To evaluate this hypothesis, male and female sedentary Low Voluntary Runners (LVR), wild type (WT), and High Voluntary Runner (HVR) rats underwent cognitive behavioral testing, analysis of hippocampal neurogenesis and mitochondrial respiration, and molecular analysis of the dentate gyrus. These analyses revealed that selecting for physical inactivity preference has produced major detriments to cognition, brain mitochondrial respiration, and neurogenesis in female LVR while female HVR display enhancements in brain glucose metabolism and hippocampal size. On the contrary, male LVR and HVR showed very few differences in these parameters relative to WT. Overall, we provide evidence that selective breeding for physical inactivity has a heritable and detrimental effect on brain health and that the female brain appears to be more susceptible to these effects. This emphasizes the importance of remaining physically active as chronic intergenerational physical inactivity likely increases susceptibility to neurodegenerative diseases for both the inactive individual and their offspring.

Turning Back the Clock: A Retrospective Single-Blind Study on Brain Age Change in Response to Nutraceuticals Supplementation vs. Lifestyle Modifications

BACKGROUND

There is a growing consensus that chronological age (CA) is not an accurate indicator of the aging process and that biological age (BA) instead is a better measure of an individual's risk of age-related outcomes and a more accurate predictor of mortality than actual CA. In this context, BA measures the "true" age, which is an integrated result of an individual's level of damage accumulation across all levels of biological organization, along with preserved resources. The BA is plastic and depends upon epigenetics. Brain state is an important factor contributing to health- and lifespan.

METHODS AND OBJECTIVE

Quantitative electroencephalography (qEEG)-derived brain BA (BBA) is a suitable and promising measure of brain aging. In the present study, we aimed to show that BBA can be decelerated or even reversed in humans (N = 89) by using customized programs of nutraceutical compounds or lifestyle changes (mean duration = 13 months).

RESULTS

We observed that BBA was younger than CA in both groups at the end of the intervention. Furthermore, the BBA of the participants in the nutraceuticals group was 2.83 years younger at the endpoint of the intervention compared with their BBA score at the beginning of the intervention, while the BBA of the participants in the lifestyle group was only 0.02 years younger at the end of the intervention. These results were accompanied by improvements in mental-physical health comorbidities in both groups. The pre-intervention BBA score and the sex of the participants were considered confounding factors and analyzed separately.

CONCLUSIONS

Overall, the obtained results support the feasibility of the goal of this study and also provide the first robust evidence that halting and reversal of brain aging are possible in humans within a reasonable (practical) timeframe of approximately one year.

Neuropsychiatric Symptoms and Trajectories of Dependence and Cognition in a Sample of Community-dwelling Older Adults with Dementia

BACKGROUND AND OBJECTIVES

Neuropsychiatric symptoms (NPS), including psychotic symptoms (hallucinations, illusions, delusions), agitation/aggression, and depressed mood, are common in individuals with Alzheimer's disease (AD) and predict poorer outcomes, including faster disease progression. We aimed to evaluate associations between NPS and cognition and dependence in a multi-ethnic sample of community-dwelling older adults with AD.

METHODS

Predictors 3 (P3) is a cohort study of AD disease courses recruiting older adults aged 65 and above residing in upper Manhattan. A total of 138 of 293 participants had probable AD at the study baseline. We fit linear mixed models to examine longitudinal associations of time-varying NPS (psychotic symptoms, agitation/aggression, and depressed mood) with dependence and cognition, adjusted for race-ethnicity, sex, education, age, clinical dementia rating score, APOE-ε4, and comorbidity burden; separate interaction models were fit for age, Hispanic ethnicity, and sex.

RESULTS

Psychotic symptoms were associated with faster rates of increasing dependence and declining cognition over time, agitation/aggression with faster rates of declining cognition, and depressed mood with faster rates of increasing dependence. Among psychotic symptoms, delusions, but not hallucinations or illusions, were associated with worse outcome trajectories. Depressed mood predicted an accelerated increase in dependence in males but not females.

CONCLUSION

Our results confirm and extend prior results in clinic-based samples. The presence of NPS was associated with worse trajectories of dependence and cognition in this muti-ethnic sample of older adults with AD. Importantly, sex modified the association between depressed mood and dependence. Our results on NPS as predictors of differential AD progression in a community-dwelling, ethnically diverse sample serve to better inform the clinical care of patients and the future development of AD therapies.

Cognitive reserve profiles are associated with outcome in schizophrenia

Cognitive reserve (CR), the brain's ability to cope with brain pathology to minimize symptoms, could explain the heterogeneity of outcomes in neuropsychiatric disorders, however it is still rarely investigated in schizophrenia. Indeed, this study aims to classify CR in this disorder and evaluate its impact on neurocognitive and socio-cognitive performance and daily functioning. A group of 106 patients diagnosed with schizophrenia was enrolled and assessed in these aereas: neurocognition, Theory of Mind (ToM) and daily functioning. A composite CR score was determined through an integration of the intelligence quotient and education and leisure activities. CR profiles were classified with a two-step cluster analysis and differences among clusters were determined with an analysis of variance (ANOVA). The cluster analysis was identified with three CR profiles characterized, respectively, by high, medium and low CR. ANOVA analysis showed significant differences on neurocognition, ToM and daily functioning between the clusters: people with higher CR reached significantly superior scores. This study suggests that greater general cognitive resources could act as a buffer against the effect of brain pathology, allowing patients to have a better cognitive performance, social outcome and quality of life.

Are Adverse Childhood Experiences Associated with Worse Cognitive Function in Older Adults?

OBJECTIVES

Adverse childhood experiences (ACE) are associated with an increased risk for dementia, but this relationship and modifying factors are poorly understood. This study is the first to our knowledge to comprehensively examine the effect of ACE on specific cognitive functions and measures associated with greater risk and resiliency to cognitive decline in independent community-dwelling older adults.

METHODS

Verbal/nonverbal intelligence, verbal memory, visual memory, and executive attention were assessed. Self-report measures examined depression, self-efficacy, and subjective cognitive concerns (SCC). The ACE questionnaire measured childhood experiences of abuse, neglect, and household dysfunction.

RESULTS

Over 56% of older adults reported an adverse childhood event. ACE scores were negatively associated with income and years of education and positively associated with depressive symptoms and SCC. ACE scores were a significant predictor of intellectual function and executive attention; however, these relationships were no longer significant after adjusting for education. Follow-up analyses using the PROCESS macro revealed that relationships among higher ACE scores with intellectual function and executive attention were mediated by education.

CONCLUSIONS

Greater childhood adversity may increase vulnerability for cognitive impairment by impacting early education, socioeconomic status, and mental health. These findings have clinical implications for enhancing levels of cognitive reserve and addressing modifiable risk factors to prevent or attenuate cognitive decline in older adults.

Validation of one-year reliable change in the RBANS for community-dwelling older adults with amnestic mild cognitive impairment

Objective: The current study sought to externally validate previously published standardized regression-based (SRB) equations for the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Indexes administered twice over a one-year period. Method: Hammers and colleagues' SRB prediction equations were applied to two independent samples of community-dwelling older adults with amnestic Mild Cognitive Impairment (MCI), including those recruited from the community (n = 64) and those recruited from a memory disorders clinic (n = 58). Results: While Observed Baseline and Observed Follow-up performances were generally comparable for both MCI samples over one year, both samples possessed significantly lower Observed One-Year Follow-up scores than were predicted based on Hammers and colleagues' development sample across many RBANS Indexes. Relatedly, both amnestic MCI samples possessed a greater percentage of participants either "declining" or failing to exhibit a long-term practice effect over one year relative to expectation across most Indexes. Further, the clinic-recruited amnestic MCI sample displayed worse baseline performances, smaller long-term practice effects, and greater proportions of individual participants exhibiting a decline across one year relative to the community amnestic MCI sample. Conclusions: These findings validate Hammers and colleagues' SRB prediction equations by (1) indicating their ability to identify clinically meaningful change across RBANS Indexes in independent samples, and (2) discriminating rates of cognitive change among cognitively nuanced samples.

The relationship between cognition, education, and employment in multiple sclerosis patients

Background

Processing speed decline is a common manifestation of multiple sclerosis (MS). The processing speed test (PST) is a validated electronic cognitive assessment based on the Symbol–Digit Modalities Test, which is routinely administered as part of the multi-institutional Multiple Sclerosis Partners Advancing Technology and Health Solutions (MS PATHS) initiative. The longitudinal relationship between education, processing speed, and employment is unclear.

Objectives

Determine the longitudinal impact of educational attainment on processing speed and employment.

Methods

MS PATHS data through March 2020 were analyzed. Repeat PST assessments at 1, 2, and 3 years were classified as improved, worsened, or stable. Linear regression was used to evaluate the relationship between education and baseline PST performance and logistic regression was used to determine the odds of PST worsening by educational attainment. Employment outcomes were analyzed by PST status and educational level.

Results

There were 13,732 patients analyzed. Education impacted baseline PST scores, but had a limited effect on PST performance over time. Education was protective with respect to employment in the setting of both PST worsening and improvement.

Conclusion

Greater education results in better baseline processing speed and is protective with respect to employment status. Its impact on processing speed over time is marginal.

Factors Influencing Post-Stroke Cognitive Impairment in Patients with Type 2 Diabetes Mellitus

Objective

Type 2 diabetes mellitus (T2DM) and ischemic stroke, which are common diseases among older people, are closely related to cognitive impairment. This study aims to investigate the influencing factors of post-stroke cognitive impairment (PSCI) in patients with T2DM.

Methods

We enrolled 161 patients with T2DM who experienced acute ischemic stroke and were hospitalized in the Department of Neurology, Jinan Central Hospital, Shandong, China. Cognitive function was evaluated with the Montreal Cognitive Assessment scale. According to the results, patients were divided into three groups-the cognitively normal group, mild cognitive impairment group, and severe cognitive impairment group. We analyzed general demographic data, laboratory information, imaging data, the results of neuropsychological evaluation, and clinical features as well as influencing factors of PSCI in these patients and established a prediction model.

Results

The three groups of patients were significantly different in terms of age, education level, course of diabetes mellitus (DM), recurrent cerebral infarction (RCI), and other factors. RCI, course of DM, and glycated hemoglobin (HbA1c) were independent risk factors of PSCI in patients with T2DM, with odds ratio (95% confidence interval): 7.17 (2.09, 30.37), 5.39 (2.40, 14.59), and 3.89 (1.66, 10.04), respectively, whereas female, senior high school, serum albumin were protective factors: 0.28 (0.07, 0.95), 0.05 (0.01, 0.21), 0.20 (0.08, 0.42), respectively. Furthermore, we constructed a prediction model using sex, age, education level, RCI, DM course, HbA1c and serum albumin and obtained a receiver operating characteristic (ROC) curve. The area under the ROC curve is 0.966, suggesting the significant association of these influencing factors with PSCI in patients with T2DM.

Conclusion

In this study, the occurrence of PSCI in patients with T2DM was related to RCI, course of DM, and HbA1c, among other factors. Attention to influencing factors is needed in these patients for early diagnosis and timely intervention of cognitive impairment.

Bridging patterns of neurocognitive aging across the older adult lifespan

Magnetic resonance imaging (MRI) studies of brain and neurocognitive aging rarely include oldest-old adults (ages 80 +). But predictions of neurocognitive aging theories derived from MRI findings in younger-old adults (ages ~55-80) may not generalize into advanced age, particularly given the increased prevalence of cognitive impairment/dementia in the oldest-old. Here, we reviewed the MRI literature in oldest-old adults and interpreted findings within the context of regional variation, compensation, brain maintenance, and reserve theories. Structural MRI studies revealed regional variation in brain aging as larger age effects on medial temporal and posterior regions for oldest-old than younger-old adults. They also revealed that brain maintenance explained preserved cognitive functioning into the tenth decade of life. Very few functional MRI studies examined compensatory activity in oldest-old adults who perform as well as younger groups, although there was evidence that higher brain reserve in oldest-old adults may mediate effects of brain aging on cognition. Despite some continuity, different cognitive and neural profiles across the older adult lifespan should be addressed in modern neurocognitive aging theories.

The Assessment of Cognitive Reserve: A Systematic Review of the Most Used Quantitative Measurement Methods of Cognitive Reserve for Aging

The cognitive reserve (CR) is widely accepted as the active ability to cope with brain damage, using preexisting cognitive and compensatory processes. The common CR proxies used are the number of formal years of education, intelligence quotient (IQ) or premorbid functioning, occupation attainment, and participation in leisure activities. More recently, it has employed the level of literacy and engagement in high-level cognitive demand of professional activities. This study aims to identify and summarize published methodologies to assess the CR quantitatively. We searched for published studies on PubMed, ScienceDirect, and Web of Science between September 2018 and September 2021. We only included those studies that characterized the CR assessment methodology. The search strategy identified 1,285 publications, of which 25 were included. Most of the instruments targeted proxies individually. The lack of a gold standard tool that incorporates all proxies and cognitive tests highlights the need to develop a more holistic battery for the quantitative assessment of CR. Further studies should focus on a quantitative methodology that includes all these proxies supported by normative data to improve the use of CR as a valid measure in clinical contexts.

The role of cognitive and brain reserve in memory decline and atrophy rate in mid and late-life: The SMART-MR study

OBJECTIVE

Investigate associations of cognitive and brain reserve with trajectories of memory decline in mid-life and late-life, and whether the relationship of memory decline with atrophy differs as a function of reserve.

METHODS

Participants were 989 Dutch middle-aged to older adults from the SMART-MR prospective cohort, followed up to 12 years with up to 3 measurements of memory and brain MRI. Education and Dutch National Adult Reading Test (DART) were used as proxies of cognitive reserve, and intracranial volume (ICV) and baseline brain parenchymal fraction (BPF) for brain reserve. Univariate growth curve models analyzed associations of reserve with memory decline, and multiple-group bivariate growth curve models tested the longitudinal brain-memory relationship as a function of reserve. Models were additionally stratified by mid-life and late-life.

RESULTS

Higher DART, education, and BPF were related to a slower rate of memory decline, particularly in late-life, but ICV was not. A positive covariance indicated that an individual who undergoes atrophy also undergoes memory decline-this relationship did not differ across cognitive or brain reserve, but was not present in mid-life. Memory declined slower than brain volume, yet rates were more similar in the low DART, education, and BPF groups.

DISCUSSION

Higher cognitive (DART, education) and brain reserve (BPF) work protectively in longitudinal memory change. ICV is an inappropriate proxy of brain reserve, failing to show any association with memory performance at baseline or over time. Deconstructing relationships of reserve capacities with longitudinal cognitive and brain outcomes may identify focus areas with potential for intervention.

Laptop-Administered NIH Toolbox and Cogstate Brief Battery in Community-Dwelling Black Adults: Unexpected Pattern of Cognitive Performance between MCI and Healthy Controls

OBJECTIVE

Black adults are approximately twice as likely to develop Alzheimer's disease (AD) than non-Hispanic Whites and access diagnostic services later in their illness. This dictates the need to develop assessments that are cost-effective, easily administered, and sensitive to preclinical stages of AD, such as mild cognitive impairment (MCI). Two computerized cognitive batteries, NIH Toolbox-Cognition and Cogstate Brief Battery, have been developed. However, utility of these measures for clinical characterization remains only partially determined. We sought to determine the convergent validity of these computerized measures in relation to consensus diagnosis in a sample of MCI and healthy controls (HC).

METHOD

Participants were community-dwelling Black adults who completed the neuropsychological battery and other Uniform Data Set (UDS) forms from the AD centers program for consensus diagnosis (HC = 61; MCI = 43) and the NIH Toolbox-Cognition and Cogstate batteries. Discriminant function analysis was used to determine which cognitive tests best differentiated the groups.

RESULTS

NIH Toolbox crystallized measures, Oral Reading and Picture Vocabulary, were the most sensitive in identifying MCI apart from HC. Secondarily, deficits in memory and executive subtests were also predictive. UDS neuropsychological test analyses showed the expected pattern of memory and executive functioning tests differentiating MCI from HC.

CONCLUSIONS

Contrary to expectation, NIH Toolbox crystallized abilities appeared preferentially sensitive to diagnostic group differences. This study highlights the importance of further research into the validity and clinical utility of computerized neuropsychological tests within ethnic minority populations.

Pleiotropic predisposition to Alzheimer's disease and educational attainment: insights from the summary statistics analysis

Epidemiological studies report beneficial associations of higher educational attainment (EDU) with Alzheimer's disease (AD). Prior genome-wide association studies (GWAS) also reported variants associated with AD and EDU separately. The analysis of pleiotropic associations with these phenotypes may shed light on EDU-related protection against AD. We performed pleiotropic meta-analyses using Fisher's method and omnibus test applied to summary statistics for single nucleotide polymorphisms (SNPs) associated with AD and EDU in large-scale univariate GWAS at suggestive-effect (5 × 10-8 < p < 0.1) and genome-wide (p ≤ 5 × 10-8) significance levels. We report 53 SNPs that attained p ≤ 5 × 10-8 at least in one of the pleiotropic meta-analyses and were reported in the univariate GWAS at 5 × 10-8 < p < 0.1. Of them, there were 46 pleiotropic SNPs according to Fisher's method. Additionally, Fisher's method identified 25 of 206 SNPs with pleiotropic effects, which attained p ≤ 5 × 10-8 in the univariate GWAS. We showed that a large fraction of the pleiotropic associations was affected by a counterintuitive phenomenon of antagonistic genetic heterogeneity, which explains the increase, rather than decrease, of the significance of the pleiotropic associations in the omnibus test. Functional enrichment analysis showed that apart from cancers, gene set harboring the non-pleiotropic SNPs was characterized by late-onset AD and neurodevelopmental disorders. The pleiotropic gene set was characterized by a broad spectrum of progressive neurological and neuromuscular diseases and immune-mediated conditions, including progressive motor neuropathy, multiple sclerosis, Parkinson's disease, and severe AD. Our results suggest that disentangling genes harboring variants with and without pleiotropic associations with AD and EDU is promising for dissecting heterogeneity in biological mechanisms of AD.

Trends in Dementia Prevalence, Incidence, and Mortality in the United States (2000-2016)

Objectives: The prevalence of dementia has declined in the United States; how this parallels to changes in incidence and mortality, and how improvements in educational attainment may have influences these trends, is not known. Methods: Using the Health and Retirement Study (2000-2016), we estimated logistic regression models to examine trends in dementia prevalence and incidence, and mortality for those with and without dementia. Results: The relative decline was about 2.4% per year for dementia prevalence and 1.9% for dementia incidence. Mortality declined similarly for those with and without dementia. Improved educational attainment accounted for decline in incidence, some of the decline in prevalence, and had a negligible role in mortality. Discussion: The declines in dementia incidence provide evidence that dementia prevalence should continue to decline in the near future. These declines are most likely largely driven by continued improvements in older adult education.

Comparing Psychometric Properties of the NIH Toolbox Cognition Battery to Gold-Standard Measures in Socioeconomically Diverse Older Adults

OBJECTIVE

The National Institutes of Health Toolbox-Cognition Battery (NIHTB-CB) is an efficient computerized neuropsychological battery. This study investigated its psychometric properties in terms of sociodemographic characteristics and technology use in adults aged 57-87 (with an average age of 70).

METHODS

Community-based participatory research procedures were used to enhance enrollment of adults with lower education and income backgrounds. Study procedures replicated work that compared the NIHTB-CB Crystallized and Fluid composites to analogous gold-standard (GS) measures and extended it by investigation of socioeconomic status and technology use-related differences in performance.

RESULTS

The high correlations among the NIHTB-CB and GS analogous Crystallized and Fluid composites suggested good convergent validity. There was no evidence of significant education- or economic-related group differences in these associations. However, caution is needed as Cronbach's alpha that indicated the NIHTB-CB Fluid composite had questionable internal item consistency. The NIHTB-CB and GS measures demonstrated poor discriminant validity in the high school but not college-educated groups. Regression analyses found that comfort with technology use, income, education, and age predicted better cognitive test performance on the computerized and paper-pencil measures.

CONCLUSIONS

There is an urgent need to improve the understanding of socioeconomic disparities influence on test scores and brain health. Lack of discriminant validity in the cognitive tests indicates that these measures could result in diagnostic errors within noncollege-educated older adults. These findings reduce confidence in the use of the NIHTB-CB Fluid composite in older adults and support that there is a significant socioeconomic-related digital divide in comfort with technology use.

Two Sides of the Same Coin: Fluid Intelligence and Crystallized Intelligence as Cognitive Reserve Predictors of Social Cognition and Executive Functions Among Vulnerable Elderly People

The concept of cognitive reserve -CR- postulates two forms that prevent cognitive impairment: neural reserve and neural compensation. Both have been primarily linked to the protective role played by genetic factors, educational level, occupation or socioeconomic status. Though it is true that it has been related to executive functions, so far very little attention has been paid to its predictive capacity with other variables more related to social cognition and psychosocial adaptation. Considering socially vulnerable contexts with reduced cultural capital and educational levels, the neural reserve function would be the most relevant and best predictor of aspects related to social cognition and executive functions. We suggest that variables such as fluid and crystallized intelligence influence social cognition and executive functions. This study included a sample of 27 participants over 60 years old from varied contexts of social vulnerability. The procedure included data collection using various cognitive measures. Results show that elderly people with high intelligence-mainly fluid intelligence-have better executive functions, emotional recognition and theory of mind. These results focus on cognitive reserve and its importance because they show that elderly people in vulnerable contexts who strengthen these aspects protect themselves against the deterioration of cognitive skills. This study is the first preliminary research to present a relationship between cognitive reserve and social cognition factors in elderly subjects. Fluid intelligence functions as a highly related factor to protect the performance of executive functions, along with other social-cognitive factors relevant to facilitating the conditions of social adaptation.

Relationship between neuropsychiatric symptoms and cognitive functions in patients with cognitive impairment

BACKGROUND

Cognitive decline and neuropsychiatric symptoms (NPS) are main clinical manifestations in Alzheimer disease (AD). It is unclear whether the link between specific NPS and cognitive domains exists in AD or mild cognitive impairment (MCI). Our study aimed to examine the association between specific cognitive domain and NPS in AD and MCI, and to evaluate whether this association showed variety in different stages of cognitive impairment.

METHODS

A total of 458 patients diagnosed as AD or MCI were included in this study. Neuropsychological batteries were applied in the study. The association between NPS and cognitive function were evaluated by multiple linear regression, and its correlation was evaluated by Spearman correlation coefficient.

RESULTS

The prevalence of NPS increased with the severity of cognitive impairment, and there were significant differences between MCI and AD. NPS were predominantly associated with cognitive domains, including memory, language, attention, and executive function. Both regression liner analysis and correlation analysis showed delusion, hallucination, and aberrant motor behaviour (AMB) were linked to language and attention. In addition, regression liner analysis illustrated depression, anxiety, and apathy were related to learning and episodic memory. Generally, the delusion, hallucination, and AMB have the broadest impact on cognition.

CONCLUSION

Specific NPS was predominantly associated with different cognitive domains. Symptoms of agitation, delusion and irritability indicate worse cognitive performance. Therefore, cognitive improvement should be a therapeutic strategy in managing NPS in AD.

Social Networks and Cognitive Function: An Evaluation of Social Bridging and Bonding Mechanisms

BACKGROUND AND OBJECTIVES

Social connectedness has been linked prospectively to cognitive aging, but there is little agreement about the social mechanisms driving this relationship. This study evaluated nine measures of social connectedness, focusing on two forms of social enrichment - access to an expansive and diverse set of loosely connected individuals (i.e., social bridging) and integration in a supportive network of close ties (i.e., social bonding).

RESEARCH DESIGN AND METHODS

This study used egocentric network and cognitive data from 311 older adults in the Social Networks in Alzheimer Disease (SNAD) study. Linear regressions were used to estimate the association between social connectedness and global cognitive function, episodic memory, and executive function.

RESULTS

Measures indicative of social bridging (larger network size, lower density, presence of weak ties, and proportion non-kin) were consistently associated with better cognitive outcomes, while measures of social bonding (close ties, multiplex support, higher frequency of contact, better relationship quality, and being married) largely produced null effects.

DISCUSSION AND IMPLICATIONS

These findings suggest that the protective benefits of social connectedness for cognitive function and memory may operate primarily through a cognitive reserve mechanism that is driven by irregular contact with a larger and more diverse group of peripheral others.

Interactive effects of the APOE and BDNF polymorphisms on functional brain connectivity: the Tasmanian Healthy Brain Project

Resting-state functional magnetic resonance imaging measures pathological alterations in neurodegenerative diseases, including Alzheimer’s disease. Disruption in functional connectivity may be a potential biomarker of ageing and early brain changes associated with AD-related genes, such as APOE and BDNF. The objective of this study was to identify group differences in resting-state networks between individuals with BDNF Val66Met and APOE polymorphisms in cognitively healthy older persons. Dual regression following Independent Components Analysis were performed to examine differences associated with these polymorphisms. APOE ε3 homozygotes showed stronger functional connectivity than APOE ε4 carriers. Males showed stronger functional connectivity between the Default Mode Network (DMN) and grey matter premotor cortex, while females showed stronger functional connectivity between the executive network and lateral occipital cortex and parahippocampal gyrus. Additionally, we found that with increasing cognitive reserve, functional connectivity increased within the Dorsal Attention Network (DAN), but decreased within the DMN. Interaction effects indicated stronger functional connectivity in Met/ε3 carriers than in Met/ε4 and Val/ε4 within both the DMN and DAN. APOE/BDNF interactions may therefore influence the integrity of functional brain connections in older adults, and may underlie a vulnerable phenotype for subsequent Alzheimer’s-type dementia.