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Background and objectivesThe existing literature highlights the importance of reading books in middle-to-older adulthood for cognitive functioning; very few studies, however, have examined the importance of childhood cognitive resources for cognitive outcomes later in life.Research design and methodsUsing data from 11 countries included in the Survey of Health, Ageing, and Retirement in Europe (SHARE) data set (N = 32,783), multistate survival models (MSMs) were fit to examine the importance of access to reading material in childhood on transitions through cognitive status categories (no cognitive impairment and impaired cognitive functioning) and death. Additionally, using the transition probabilities estimated by the MSMs, we estimated the remaining years of life without cognitive impairment and total longevity. All models were fit individually in each country, as well as within the pooled SHARE sample.ResultsAdjusting for age, sex, education, and childhood socioeconomic status, the overall pooled estimate indicated that access to more books at age 10 was associated with a decreased risk of developing cognitive impairment (adjusted hazard ratio = 0.79, confidence interval: 0.76-0.82). Access to childhood books was not associated with risk of transitioning from normal cognitive functioning to death, or from cognitive impairment to death. Total longevity was similar between participants reporting high (+1 standard deviation [SD]) and low (-1 SD) number of books in the childhood home; however, individuals with more access to childhood books lived a greater proportion of this time without cognitive impairment.Discussion and implicationsFindings suggest that access to cognitive resources in childhood is protective for cognitive aging processes in older adulthood.

Global initiatives call for further understanding of the impact of inequity on aging across underserved populations. Previous research in low- and middle-income countries (LMICs) presents limitations in assessing combined sources of inequity and outcomes (i.e., cognition and functionality). In this study, we assessed how social determinants of health (SDH), cardiometabolic factors (CMFs), and other medical/social factors predict cognition and functionality in an aging Colombian population. We ran a cross-sectional study that combined theory- (structural equation models) and data-driven (machine learning) approaches in a population-based study (N = 23,694; M = 69.8 years) to assess the best predictors of cognition and functionality. We found that a combination of SDH and CMF accurately predicted cognition and functionality, although SDH was the stronger predictor. Cognition was predicted with the highest accuracy by SDH, followed by demographics, CMF, and other factors. A combination of SDH, age, CMF, and additional physical/psychological factors were the best predictors of functional status. Results highlight the role of inequity in predicting brain health and advancing solutions to reduce the cognitive and functional decline in LMICs.

BackgroundThe existing literature suggests that impaired olfaction may be an early marker for cognitive decline. Tracking the earliest stages of the progression to dementia is paramount, and yet the importance of olfactory ability throughout cognitive states and death remains unclear.MethodsDrawing data from the Rush Memory and Aging Project (N = 1 501; 74% female), olfactory ability was assessed using the Brief Smell Identification Test (range = 0-16), while cognitive states (unimpaired, mild cognitive impairment [MCI], and dementia) were determined using a 3-step neuropsychological diagnostic protocol at up to 15 annual occasions. Multistate survival models simultaneously estimated the association of olfactory ability on transitions through cognitive states and death, while multinomial regression models estimated cognitively unimpaired and total life expectancies.ResultsHigher olfactory scores were associated with a reduced risk of transitioning from unimpaired cognition to MCI (hazard ratio [HR] = 0.86, 95% confidence interval [CI] = 0.82-0.88) and from MCI to dementia (HR = 0.89, 95% CI = 0.86-0.93), indicating that 1-unit increase in olfactory scores was associated with an approximate 14% and 11% reduction in risk, respectively. Additionally, higher olfactory scores were associated with a greater likelihood of transitioning backward from MCI to unimpaired cognition (HR = 1.07, 95% CI = 1.02-1.12). Furthermore, higher baseline olfactory scores were associated with more years of longevity without cognitive impairment. However, olfaction was not associated with the transition to death when accounting for transitions through cognitive states.ConclusionsFindings suggest that higher olfactory identification scores are associated with a decreased risk of transitioning to impaired cognitive states and that associations between olfaction and mortality may occur primarily through the pathway of neurodegeneration.

Research suggests that personality traits are associated with mild cognitive impairment (MCI), dementia, and mortality risk, but the timing of when traits are most important in the progression to dementia and the extent to which they are associated with years of cognitive health span are unclear. This project applied secondary data analysis to the Rush Memory and Aging Project (N = 1954; baseline Mage = 80 years; 74% female) over up to 23 annual assessments. Multistate survival modeling examined the extent to which conscientiousness, neuroticism, and extraversion, assessed using the NEO Five Factor Inventory, were associated with transitions between cognitive status categories and death. Additionally, multinomial regression models estimated cognitive health span and total survival based on standard deviation units of personality traits. Adjusting for demographics, depressive symptoms, and apolipoprotein (APOE) ε4, personality traits were most important in the transition from no cognitive impairment (NCI) to MCI. For instance, higher conscientiousness was associated with a decreased risk of transitioning from NCI to MCI, hazard ratio (HR) = 0.78, 95% CI [0.72, 0.85] and higher neuroticism was associated with an increased risk of transitioning from NCI to MCI, HR = 1.12, 95% CI [1.04, 1.21]. Additional significant and nonsignificant results are discussed in the context of the existing literature. While personality traits were not associated with total longevity, individuals higher in conscientiousness and extraversion, and lower in neuroticism, had more years of cognitive health span, particularly female participants. These findings provide novel understanding of the simultaneous associations between personality traits and transitions between cognitive status categories and death, as well as cognitive health span and total longevity. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

ObjectivesDispersion in cognitive test performance within a single testing session is proposed as an early marker of poor brain health. Existing research, however, has not investigated factors that may explain individual differences in cognitive dispersion. We investigate the extent to which the Big Five personality traits are associated with cognitive dispersion in older adulthood.MethodTo promote transparency and reliability, we applied preregistration and conceptual replication via coordinated analysis. Drawing data from seven longitudinal studies of aging (Ntotal = 33,581; Mage range = 56.4-71.2), cognitive dispersion scores were derived from cognitive test results. Independent linear regression models were fit in each study to examine personality traits as predictors of dispersion scores, adjusting for mean cognitive performance and sociodemographics (age, sex, education). Results from individual studies were synthesized using random effects meta-analyses.ResultsSynthesized results revealed that openness was positively associated with cognitive dispersion, 0.028, 95% CI [0.003, 0.054]. There was minimal evidence for associations between cognitive dispersion and the other personality traits in independent analyses or meta-analyses. Mean cognitive scores were negatively associated with cognitive dispersion across the majority of studies, while sociodemographic variables were not consistently associated with cognitive dispersion.ConclusionHigher levels of openness were associated with greater cognitive dispersion across seven independent samples, indicating that individuals higher in openness had more dispersion across cognitive tests. Further research is needed to investigate mechanisms that may help to explain the link between openness and cognitive dispersion, as well as to identify additional individual factors, beyond personality traits, that may be associated with cognitive dispersion. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Executive functions (EF), either conceptualized as skills involved in regulation of cognition and emotion in service of goal-oriented behavior, or reductively as working memory, flexibility and inhibitory control, are commonly invoked constructs in developmental science. Two main traditions on EFs measurement prevail, one consisting of ratings obtained through questionnaires that inquire on behavior in common situations, the other based on performance in laboratory tasks. Whether both types of assessment actually refer to the same constructs is not consensual. Further, the role of school context in the degree of correspondence between both types of measures remains largely unexplored. Here, we show in a sample of over 220 children (age M = 5.6, SD = 0.4 years), by means of multilevel models, that whether EF tasks can predict BRIEF-P ratings and vice-versa, depends on the process considered and on the school SES. Inhibitory control, planning, and global executive functioning are associated with BRIEF-P ratings in all schools. In contrast, we found no association among measures of flexibility independently of school SES. For working memory, we found that questionnaire rating predicts span only in high SES schools, but span predicts behaviors across schools. Our findings contribute to a growing body of literature that proposes constructs assessed by questionnaires and tasks only partially overlap and suggests that school SES may be a relevant factor to consider when questionnaires are answered by teachers.

Background: The Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) questionnaires are commonly used to measure global cognition in clinical trials. Because these scales are discrete and bounded with ceiling and floor effects and highly skewed, their analysis as continuous outcomes presents challenges. Normality assumptions of linear regression models are usually violated, which may result in failure to detect associations with variables of interest. Methods: Alternative approaches to analyzing the results of these cognitive batteries include transformations (standardization, square root, or log transformation) of the scores in the multivariate linear regression (MLR) model, the use of nonlinear beta-binomial regression (which is not dependent on the assumption of normality), or Tobit regression, which adds a latent variable to account for bounded data. We aim to empirically compare the model performance of all proposed approaches using four large randomized controlled trials (ORIGIN, TRANSCEND, COMPASS, and NAVIGATE-ESUS), and using as metrics the Akaike information criterion (AIC). We also compared the treatment effects for the methods that have the same unit of measure (i.e., untransformed MLR, beta-binomial, and Tobit). Results: The beta-binomial consistently demonstrated superior model performance, with the lowest AIC values among nearly all the approaches considered, followed by the MLR with square root and log transformations across all four studies. Notably, in ORIGIN, a substantial AIC reduction was observed when comparing the untransformed MLR to the beta-binomial, whereas other studies had relatively small AIC reductions. The beta-binomial model also resulted in a significant treatment effect in ORIGIN, while the untransformed MLR and Tobit regression showed no significance. The other three studies had similar and insignificant treatment effects among the three approaches. Conclusion: When analyzing discrete and bounded outcomes, such as cognitive scores, as continuous variables, a beta-binomial regression model improves model performance, avoids spurious significance, and allows for a direct interpretation of the actual cognitive measure. Trials registration: ORIGIN (NCT00069784). Registered on October 1, 2003; TRANSCEND (NCT00153101). Registered on September 9, 2005; COMPASS (NCT01776424). Registered on January 24, 2013; NAVIGATE-ESUS (NCT02313909). Registered on December 8, 2014. [ABSTRACT FROM AUTHOR]

Background: The pathophysiology of Alzheimer's disease (AD) may begin developing years or even decades prior to the manifestation of its first symptoms. The APOE ε4 genotype is a prominent genetic risk for AD that has been found to be associated with brain changes across the lifespan since early adulthood. Thus, studying brain changes that may occur in young adults with an APOE ε4 status is highly relevant. Objective: Examine potential differences in grey matter (GM) and functional connectivity (FC) in brains of cognitively healthy young APOE ε4 carriers and non-carriers, denoted here as ε4(+) and ε4(−), respectively. Methods: Three Tesla magnetic resonance imaging (MRI) brain scans were acquired from cognitively healthy young participants aged approximately 20 years (n = 151). Voxel-based morphometry (VBM) analysis was employed to identify potential structural differences in GM between ε4(+) and ε4(−). In a subsequent seed-based connectivity (SBC) analysis, brain regions that structurally differed in the VBM analysis were considered as seeds and correlated with all the remaining voxels across the brains to then measure the differences in FC between groups. Results: The VBM analysis suggested that ε4(+) (n = 28) had greater GM densities relative to ε4(−) (n = 123) in the left hippocampus and the left posterior insula (puncorr < 0.001). However, the effect did not survive the correction for multiple comparisons, suggesting minimal structural differences in this age range. In contrast, the SBC analysis indicated that ε4(+) exhibited significantly decreased FC between the left hippocampus and areas of the left middle temporal gyrus (n = 27) compared to ε4(−) (n = 102). These results remained significant after multiple comparisons (pFDR < 0.05). Lastly, no statistically significant differences in FC between groups were observed for the left insular seed (pFDR > 0.05). Discussion: These results suggest early structural and functional brain changes associated with the APOE ε4 genotype on young adults. Yet, they must be cautiously interpreted and contrasted with both older adults with genetic risk for AD and patients diagnosed with AD. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the availability of Alzheimer's Centers (ACs) in US hospitals. Methods: Utilizing the American Hospital Association Annual Survey, Area Health Resource File, and US Census (n = 3251), we employed multivariable logistic regression to examine hospital, county, and regional predictors of AC availability. Results: Large hospitals (>399 beds) had approximately 14 times higher odds of having an AC than small hospitals (<50 beds; OR = 14.0; 95% CI = 6.44 – 30.46). Counties with a higher proportion of Latino residents, relative to non-Latino Whites, had lower odds of having an AC (OR =.05; 95% CI =.01 –.41). Northeastern (OR = 1.92; 95% CI = 1.15 – 3.22) and Midwestern (OR = 2.12; 95% CI = 1.34 – 3.37) hospitals had higher odds of having an AC than Southern hospitals. Discussion: To address dementia needs and disparities, investment in a national infrastructure is critical. [ABSTRACT FROM AUTHOR]

Brain atrophy and cortical thinning are typically observed in people with Alzheimer's disease (AD) and, to a lesser extent, in those with mild cognitive impairment. In asymptomatic middle‐aged apolipoprotein ε4 (ΑPOE4) carriers, who are at higher risk of future AD, study reports are discordant with limited evidence of brain structural differences between carriers and non‐carriers of the ε4 allele. Alternative imaging markers with higher sensitivity at the presymptomatic stage, ideally quantified using typically acquired structural MRI scans, would thus be of great benefit for the detection of early disease, disease monitoring and subject stratification. In the present cross‐sectional study, we investigated textural properties of T1‐weighted 3T MRI scans in relation to APOE4 genotype, age and sex. We pooled together data from the PREVENT‐Dementia and ALFA studies focused on midlife healthy populations with dementia risk factors (analysable cohort: 1585 participants; mean age 56.2 ± 7.4 years). Voxel‐based and texture (examined features: contrast, entropy, energy, homogeneity) based morphometry was used to identify areas of volumetric and textural differences between APOE4 carriers and non‐carriers. Textural maps were generated and were subsequently harmonised using voxel‐wise COMBAT. For all analyses, APOE4, sex, age and years of education were used as model predictors. Interactions between APOE4 and age were further examined. There were no group differences in regional brain volume or texture based on APOE4 carriership or when age × APOE4 interactions were examined. Older people tended to have a less homogeneous textural profile in grey and white matter and a more homogeneous profile in the ventricles. A more heterogeneous textural profile was observed for females in areas such as the ventricles, frontal and parietal lobes and for males in the brainstem, cerebellum, precuneus and cingulate. Overall, we have shown the absence of volumetric and textural differences between APOE4 carriers and non‐carriers at midlife and have established associations of textural features with ageing and sex. [ABSTRACT FROM AUTHOR]

The prevalence of informal caregiving is increasing as populations across the world age. Caregiving has been found to be associated with poor mental health outcomes including depressive symptoms. The purpose of this study is to examine the mean trajectory of depressive symptomatology in older caregivers in a large European sample over an eight-year period, the effects of time-varying and time-invariant covariates on this trajectory, and the mean trajectory of depressive symptomatology according to pattern of caregiving. The results suggest that depressive symptoms in the full sample of caregivers follow a nonlinear trajectory characterized by an initial decrease which decelerates over time. Caregiver status and depressive symptoms were significantly associated such that depressive symptoms increased as a function of caregiver status. The trajectory in caregivers who report intermittent or consecutive occasions of caregiving remained stable over time. Significant associations were found between sociodemographic, health and caregiving characteristics and the initial levels and rates of change of these trajectories. While these results point to the resilience of caregivers, they also highlight the factors that are related to caregivers' adaptation over time. This can help in identifying individuals who may require greater supports and, in turn, ensuring that caregivers preserve their well-being. [ABSTRACT FROM AUTHOR]