Relation of cognitive activity to risk of developing Alzheimer disease

Promoting Successful Cognitive Aging: A Ten-Year Update

A decade has passed since we published a comprehensive review in this journal addressing the topic of promoting successful cognitive aging, making this a good time to take stock of the field. Because there have been limited large-scale, randomized controlled trials, especially following individuals from middle age to late life, some experts have questioned whether recommendations can be legitimately offered about reducing the risk of cognitive decline and dementia. Despite uncertainties, clinicians often need to at least make provisional recommendations to patients based on the highest quality data available. Converging lines of evidence from epidemiological/cohort studies, animal/basic science studies, human proof-of-concept studies, and human intervention studies can provide guidance, highlighting strategies for enhancing cognitive reserve and preventing loss of cognitive capacity. Many of the suggestions made in 2010 have been supported by additional research. Importantly, there is a growing consensus among major health organizations about recommendations to mitigate cognitive decline and promote healthy cognitive aging. Regular physical activity and treatment of cardiovascular risk factors have been supported by all of these organizations. Most organizations have also embraced cognitively stimulating activities, a heart-healthy diet, smoking cessation, and countering metabolic syndrome. Other behaviors like regular social engagement, limiting alcohol use, stress management, getting adequate sleep, avoiding anticholinergic medications, addressing sensory deficits, and protecting the brain against physical and toxic damage also have been endorsed, although less consistently. In this update, we review the evidence for each of these recommendations and offer practical advice about behavior-change techniques to help patients adopt brain-healthy behaviors.

Increases in Cognitive Activity Reduce Aging-Related Declines in Executive Functioning

Declines in cognitive functioning are commonly experienced with aging, yet there is wide variation in the nature and extent of these changes. Previous research has shown associations between the frequency of engaging in stimulating cognitive activities and performance on cognitive tests. However, it is not known whether it is important to increase the amount of cognitive activity as one gets older in order to curtail cognitive declines. We examined cognitive activities and cognition in a national sample of 2,130 community-dwelling middle-aged and older adults from the Midlife in the United States longitudinal study. Participants completed cognitive assessments of episodic memory (EM) and executive functioning (EF) on two occasions, ~9 years apart. At the first assessment, participants ranged in age between 33 and 83 years (M = 55.76, SD = 11.09), with 56.1% women. Multilevel models were tested to examine educational level and change in cognitive activity as predictors of change in EM and EF, controlling for initial level of cognitive activity and key correlates of cognitive decline. Results indicated that increases in cognitive activity were important over and above earlier levels of cognitive activity for reducing declines in EF. Further analysis also showed differential results by educational level. Increased cognitive activity was not associated with changes in EF among individuals with a college degree. In contrast, individuals without a college degree who increased their cognitive activity showed significantly less decline in EF compared to those without a college degree who decreased or maintained their cognitive activity across the 9 years. Thus, the results suggest that increased engagement in cognitive activity makes more of a difference for EF declines among those without a college degree. The results have particular relevance given that aging-related changes in domains such as work status, health, or social relationships can lead to reductions in stimulating cognitive activities. The findings emphasize the importance of increasing cognitive activities especially among those with lower educational attainment.

Components of an indirect cognitive reserve: a longitudinal assessment of community-dwelling older adults

Cognitive reserve enables individuals to preserve their cognition, despite a possible underlying brain pathology. The objective was to verify which components contribute to an indirect measurement of cognitive reserve in older adults, assessed longitudinally within a four-year interval. The sample was comprised of 64 older adults from the community. The following instruments were used: sociodemographic form; Mini-Mental State Examination; subtests from the Wechsler Adult Intelligence Scale - Third Edition; Trail Making Test; Verbal Fluency Test (animal category); Rey Auditory-Verbal Learning Test; Beck Anxiety Inventory; and the Geriatric Depression Scale 15-item version. Multiple linear regression analyses were performed for the data analysis. The sample was predominantly composed of women (81.3%) and the mean age of the sample was 73.19 years (SD = 6.12). With respect to the variables related to cognitive reserve, it was found that anxiety was the predictor variable of more cognitive components: It was found that poorer cognitive performance is associated with anxiety, and this variable is negatively related to cognitive reserve, as well as to the age variable. Engaging in cognitively stimulating activities, education level and living with someone were deemed to be factors that help build cognitive reserve in older adults. Keywords: cognitive reserve; older adults; longitudinal.

Leisure activity participation and risk of dementia: An 18-year follow-up of the Whitehall II Study

OBJECTIVE

To test the hypothesis that leisure activity participation is associated with lower dementia risk, we examined the association between participation in leisure activities and incident dementia in a large longitudinal study with average 18-year follow-up.

METHODS

We used data from 8,280 participants of the Whitehall II prospective cohort study. A 13-item scale assessed leisure activity participation in 1997-1999, 2002-2004, and 2007-2009, and incidence of dementia (n cases = 360, mean age at diagnosis 76.2 years, incidence rate 2.4 per 1,000 person-years) was ascertained from 3 comprehensive national registers with follow-up until March 2017. Primary analyses were based on complete cases (n = 6,050, n cases = 247) and sensitivity analyses used multiple imputation for missing data.

RESULTS

Participation in leisure activities at mean age 55.8 (1997-1999 assessment), with 18.0-year follow-up, was not associated with dementia (hazard ratio [HR] 0.92 [95% confidence interval 0.79-1.06]), but those with higher participation at mean age 65.7 (2007-2009 assessment) were less likely to develop dementia with 8.3-year follow-up (HR 0.82 [0.69-0.98]). No specific type of leisure activity was consistently associated with dementia risk. Decline in participation between 1997-1999 and 2007-2009 was associated with subsequent dementia risk.

CONCLUSION

Our findings suggest that participation in leisure activities declines in the preclinical phase of dementia; there was no robust evidence for a protective association between leisure activity participation and dementia. Future research should investigate the sociobehavioral, cognitive, and neurobiological drivers of decline in leisure activity participation to determine potential approaches to improving social participation of those developing dementia.

An Internet-Based Intervention Augmented With a Diet and Physical Activity Consultation to Decrease the Risk of Dementia in At-Risk Adults in a Primary Care Setting: Pragmatic Randomized Controlled Trial

BACKGROUND

There is a need to develop interventions to reduce the risk of dementia in the community by addressing lifestyle factors and chronic diseases over the adult life course.

OBJECTIVE

This study aims to evaluate a multidomain dementia risk reduction intervention, Body Brain Life in General Practice (BBL-GP), targeting at-risk adults in primary care.

METHODS

A pragmatic, parallel, three-arm randomized trial involving 125 adults aged 18 years or older (86/125, 68.8% female) with a BMI of ≥25 kg/m² or a chronic health condition recruited from general practices was conducted. The arms included (1) BBL-GP, a web-based intervention augmented with an in-person diet and physical activity consultation; (2) a single clinician-led group, Lifestyle Modification Program (LMP); and (3) a web-based control. The primary outcome was the Australian National University Alzheimer Disease Risk Index Short Form (ANU-ADRI-SF).

RESULTS

Baseline assessments were conducted on 128 participants. A total of 125 participants were randomized to 3 groups (BBL-GP=42, LMP=41, and control=42). At immediate, week 18, week 36, and week 62 follow-ups, the completion rates were 43% (18/42), 57% (24/42), 48% (20/42), and 48% (20/42), respectively, for the BBL-GP group; 71% (29/41), 68% (28/41), 68% (28/41), and 51% (21/41), respectively, for the LMP group; and 62% (26/42), 69% (29/42), 60% (25/42), and 60% (25/42), respectively, for the control group. The primary outcome of the ANU-ADRI-SF score was lower for the BBL-GP group than the control group at all follow-ups. These comparisons were all significant at the 5% level for estimates adjusted for baseline differences (immediate: difference in means -3.86, 95% CI -6.81 to -0.90, P=.01; week 18: difference in means -4.05, 95% CI -6.81 to -1.28, P<.001; week 36: difference in means -4.99, 95% CI -8.04 to -1.94, P<.001; and week 62: difference in means -4.62, 95% CI -7.62 to -1.62, P<.001).

CONCLUSIONS

A web-based multidomain dementia risk reduction program augmented with allied health consultations administered within the general practice context can reduce dementia risk exposure for at least 15 months. This study was limited by a small sample size, and replication on a larger sample with longer follow-up will strengthen the results.

TRIAL REGISTRATION

Australian clinical trials registration number (ACTRN): 12616000868482; https://anzctr.org.au/ACTRN12616000868482.aspx.

Acculturation in Context: The Relationship Between Acculturation and Socioenvironmental Factors With Level of and Change in Cognition in Older Latinos

OBJECTIVES

Latinos are 1.5 times as likely to develop Alzheimer's dementia as non-Latino Whites. This health disparity may arise from multiple influences with culturally relevant factors receiving increasing attention. Models of acculturation stress the importance of considering acculturation-related factors within the context of socioenvironmental factors to better capture the Latino experience in the United States.

METHODS

We measured 10 acculturation and contextually-related variables in 199 Latinos (age 69.7 years) without dementia participating in Rush Alzheimer's Disease Center studies. We tested the relationship between these variables via Principal Component Analysis (PCA), then investigated how resulting components associated with level of and longitudinal change in global and domain-specific cognition using separate linear mixed-effects models adjusted for relevant confounders and their interactions with time.

RESULTS

The PCA revealed a 3-factor unrotated solution (variance explained ~70%). Factor 1, representing acculturation-related aspects of nativity, language- and social-based acculturation, was positively associated with level, but not change, in global cognition, semantic memory, and perceptual speed. Factor 2, representing contextually-related socioenvironmental experiences of discrimination, social isolation, and social networks, was negatively associated with level of global cognition, episodic and working memory, and faster longitudinal decline in visuospatial ability. Factor 3 (familism only) did not associate with level or change in any cognitive outcome.

DISCUSSION

Acculturation- and contextually-related factors differentiated from each other and differentially contributed to cognition and cognitive decline in older Latinos. Providers should query acculturation and lived experiences when evaluating cognition in older Latinos.

Longitudinal Associations Between Contact Frequency with Friends and with Family, Activity Engagement, and Cognitive Functioning

OBJECTIVES

Social engagement may be an important protective resource for cognitive aging. Some evidence suggests that time spent with friends may be more beneficial for cognition than time spent with family. Because maintaining friendships has been demonstrated to require more active maintenance and engagement in shared activities, activity engagement may be one underlying pathway that explains the distinct associations between contact frequency with friends versus family and cognition.

METHODS

Using two waves of data from the national survey of Midlife in the United States (n = 3707, Mage = 55.80, 51% female at baseline), we examined longitudinal associations between contact frequency with friends and family, activity engagement (cognitive and physical activities), and cognition (episodic memory and executive functioning) to determine whether activity engagement mediates the relationship between contact frequency and cognition.

RESULTS

The longitudinal mediation model revealed that more frequent contact with friends, but not family, was associated with greater concurrent engagement in physical and cognitive activities, which were both associated with better episodic memory and executive functioning.

CONCLUSION

These findings suggest that time spent with friends may promote both cognitively and physically stimulating activities that could help to preserve not only these social relationships but also cognitive functioning.

Risk for Alzheimer's disease: A review of long-term episodic memory encoding and retrieval fMRI studies

Many risk factors have been identified that predict future progression to Alzheimer's disease (AD). However, clear links have yet to be made between these risk factors and how they affect brain functioning in early stages of AD. We conducted a narrative review and a quantitative analysis to better understand the relationship between nine categories of AD risk (i.e., brain pathology, genetics/family history, vascular health, head trauma, cognitive decline, engagement in daily life, late-life depression, sex/gender, and ethnoracial group) and task-evoked fMRI activity during episodic memory in cognitively-normal older adults. Our narrative review revealed widespread regional alterations of both greater and lower brain activity with AD risk. Nevertheless, our quantitative analysis revealed that a subset of studies converged on two patterns: AD risk was associated with (1) greater brain activity in frontal and parietal regions, but (2) reduced brain activity in hippocampal and occipital regions. The brain regions affected depended on the assessed memory stage (encoding or retrieval). Although the results clearly indicate that AD risks impact brain activity, we caution against using fMRI as a diagnostic tool for AD at the current time because the above consistencies were present among much variability, even among the same risk factor.

Lifestyle intervention to prevent Alzheimer's disease

Alzheimer's disease (AD) is the most common neurodegenerative disease that leads to significant morbidities in elderly. The major pathological hallmark of AD is beta-amyloid plaques (Aβ) and intracellular neurofibrillary tangles (NFTs) deposition in hippocampus of the brain. These abnormal protein deposition damages neuronal cells resulting in neurodegeneration and cognitive decline. As a result of limited treatment options available for this disease, there is huge economic burden for patients and social health care system. Thus, alternative approaches (lifestyle intervention) to prevent this disease are extremely important. In this systemic review, we summarized epidemiological evidence of lifestyle intervention and the mechanisms involved in delaying and/or preventing AD. Lifestyle interventions include education, social engagement and cognitive stimulation, smoking, exercise, depression and psychological stress, cerebrovascular disease (CVD), hypertension (HTN), dyslipidaemia, diabetes mellitus (DM), obesity and diet. The methods are based on a literature review of available sources found on the research topic in four acknowledged databases: Web of Science, Scopus, Medline and PubMed. Results of the identified original studies revealed that lifestyle interventions have significant effects and our conclusion is that combination of early lifestyle interventions can decrease the risk of developing AD.

Healthy lifestyle and the risk of Alzheimer dementia: Findings from 2 longitudinal studies

OBJECTIVE

To quantify the impact of a healthy lifestyle on the risk of Alzheimer dementia.

METHODS

Using data from the Chicago Health and Aging Project (CHAP; n = 1,845) and the Rush Memory and Aging Project (MAP; n = 920), we defined a healthy lifestyle score on the basis of nonsmoking, ≥150 min/wk moderate/vigorous-intensity physical activity, light to moderate alcohol consumption, high-quality Mediterranean-DASH Diet Intervention for Neurodegenerative Delay diet (upper 40%), and engagement in late-life cognitive activities (upper 40%), giving an overall score ranging from 0 to 5. Cox proportional hazard models were used for each cohort to estimate the hazard ratio (HR) and 95% confidence interval (CI) of the lifestyle score with Alzheimer dementia, and a random-effect meta-analysis was used to pool the results.

RESULTS

During a median follow-up of 5.8 years in CHAP and 6.0 years in MAP, 379 and 229 participants, respectively, had incident Alzheimer dementia. In multivariable-adjusted models, the pooled HR (95% CI) of Alzheimer dementia across 2 cohorts was 0.73 (95% CI 0.66-0.80) per each additional healthy lifestyle factor. Compared to participants with 0 to 1 healthy lifestyle factor, the risk of Alzheimer dementia was 37% lower (pooled HR 0.63, 95% CI 0.47-0.84) in those with 2 to 3 healthy lifestyle factors and 60% lower (pooled HR 0.40, 95% CI 0.28-0.56) in those with 4 to 5 healthy lifestyle factors.

CONCLUSION

A healthy lifestyle as a composite score is associated with a substantially lower risk of Alzheimer's dementia.

Floor Maze Test as a predictor of cognitive decline in older adults living in nursing homes

ABSTRACT Objective Long-term care facilities (LTCF) are associated with an increased risk of cognitive decline and impairment in spatial navigation abilities. Recent studies have demonstrated that spatial navigation as a complex skill, involving cognitive and motor functions, emerging as a new marker for the progression of dementia. The present study aims to compare spatial navigation in healthy, institutionalized, and AD elderly subjects. Methods In a cross-sectional study, we evaluated 78 elderly individuals (healthy = 37, AD = 22, institutionalized = 19) using the Mini-Mental State Examination (MMSE), Floor Maze Test (FMT) and 8-foot-up-and-gotest (8UG) to assess global cognitive function, spatial navigation and motor function, respectively. Results In the FMT, the immediate maze time (IMT) and delay maze time (DMT) were significantly shorter in the healthy group than those of the institutionalized and AD groups ( X 2 = 31.23; p < 0.01) and ( X 2 = 41.21; p < 0.01), while there were no significant differences between the AD and institutionalized groups in terms of the DMT and MMSE results. However, the institutionalized group showed worse results in terms of IMT (p < 0.01) and 8UG (p < 0.01) than those in the dementia group. Conclusion Our results indicate that both institutionalized older people and patients with Dementia have a deficit in the spatial navigation ability, cognitive functions and motor skills. We should consider that there might be a possibility of underdiagnosis in institutionalized older people.

Association of lifespan cognitive reserve indicator with the risk of mild cognitive impairment and its progression to dementia

INTRODUCTION

The association of lifespan cognitive reserve (CR) with mild cognitive impairment (MCI) remains controversial. We aimed to examine the association of lifespan CR indicator with the risk of MCI and its progression to dementia, taking brain pathologies into account.

METHODS

In a community-based cohort study (mean age, 79 years) with annual follow-up (median, 5.16 years; maximum, 20 years), a cognitively intact group (n = 1182) and an MCI group (n = 420) were identified at baseline. During the follow-up, 611 participants died and underwent autopsies. CR indicator encompassing education, early life to late-life cognitive and social activities were obtained and tertiled.

RESULTS

The multi-adjusted hazard ratio (HR) of MCI was 0.72 (95% confidence interval [CI] 0.58 to 0.90) in the cognitively intact group, and the HR of dementia was 0.66 (95% CI 0.45 to 0.97) in the MCI group for participants with the highest CR indicator (reference: the lowest CR indicator). Among MCI participants with brain pathologies, dementia incidence was about 50% lower in people with the highest CR indicator than the lowest CR indicator.

DISCUSSION

High lifespan CR indicator reduces risk of MCI, and delays its progression to dementia.

Association of Physical Activity and Cognitive Activity With Disability: A 2-Year Prospective Cohort Study

OBJECTIVE

Engaging in physical activity (PA) and/or cognitive activity (CA) retains function in older adults, but whether the combination of these activities is associated with disability onset is still unknown. This study aimed to examine the prospective association of PA and/or CA with disability onset in older adults.

METHODS

This was an ongoing prospective community-based cohort study. Data collection was conducted through a health check. An analyzable sample of 2668 participants (mean age = 75.5 years; 51.6% female) were categorized into 4 groups based on quartile 1 (low) and 2 to 4 (high) values of accelerometer-measured moderate-to-vigorous PA and CA scale scores based on the frequency of 6 activities including reading, writing for pleasure, doing crossword puzzles, and playing board games or cards. Disability onset was monitored through long-term care insurance certification for at least 2 years.

RESULTS

A log-rank test showed significantly lower incidence of disability in the high PA and low CA group and the high PA and high CA group compared with the low PA and low CA group. Cox-proportional hazards models (referring to the low PA and low CA group) showed that only the high PA and high CA group was significantly associated with a lowered hazard ratio for disability onset (0.51; 95% CI = 0.29-0.90) after adjusting for covariates.

CONCLUSIONS

Engaging in both PA and CA is effective for reducing risk of disability onset, but engaging in either PA or CA is not effective.

IMPACT

Physical therapists can be guided by this research to design intervention strategies for people at risk of disability.

Cognitive reserve and working memory in cognitive performance of adults with subjective cognitive complaints: longitudinal structural equation modeling

OBJECTIVE

To study the influence of cognitive reserve (CR) on cognitive performance of individuals with subjective cognitive complaints (SCCs) within a period of 36 months.

DESIGN

We used a general linear model repeated measures procedure to analyze the differences in performance between three assessments. We used a longitudinal structural equation modeling to analyze the relationship between CR and cognitive performance at baseline and at two follow-up assessments.

SETTING

Participants with SCCs were recruited and assessed in primary care health centers.

PARTICIPANTS

A total of 212 participants older than 50 years with SCCs.

MEASUREMENTS

Cognitive reserve data were collected with an ad hoc questionnaire administered to the subjects in an interview. General cognitive performance (GCP), episodic memory (EM), and working memory (WM) have been evaluated. The Mini-Mental State Examination and the total score of Spanish version of the Cambridge Cognitive Examination evaluated the GCP. Episodic memory was assessed with the Spanish version of the California Verbal Learning. Working memory was evaluated by the counting span task and the listening span task.

RESULTS

The satisfactory fit of the proposed model confirmed the direct effects of CR on WM and GCP at baseline, as well as indirect effects on EM and WM at first and second follow-up. Indirect effects of CR on other cognitive constructs via WM were observed over time.

CONCLUSION

The proposed model is useful for measuring the influence of CR on cognitive performance over time. Cognitive response acquired throughout life may influence cognitive performance in old age and prevent cognitive deterioration, thus increasing processing resources via WM.

Self-reported Lifestyle Activities in Relation to Longitudinal Cognitive Trajectories

BACKGROUND

Few studies have examined the relationship between lifestyle activity engagement and cognitive trajectories among individuals who were cognitively normal at baseline.

OBJECTIVE

To examine the relationship of current engagement in lifestyle activities to previous cognitive performance among individuals who were cognitively normal at baseline, and whether this relationship differed for individuals who subsequently developed mild cognitive impairment (MCI), or by APOE-4 genotype, age, and level of cognitive reserve.

METHODS

Participants (N=189) were primarily middle-aged (M=56.6 y) at baseline and have been prospectively followed with annual assessments (M follow-up=14.3 y). Engagement in physical, cognitive, and social activities was measured by the CHAMPS activity questionnaire. Longitudinal cognitive performance was measured by a global composite score.

RESULTS

Among individuals who progressed to MCI (n=27), higher lifestyle activity engagement was associated with less decline in prior cognitive performance. In contrast, among individuals who remained cognitively normal, lifestyle activity engagement was not associated with prior cognitive trajectories. These effects were largely independent of APOE-4 genotype, age, and cognitive reserve.

CONCLUSIONS

Greater engagement in lifestyle activities may modify the rate of cognitive decline among those who develop symptoms of MCI, but these findings need to be confirmed in prospective studies.

Does Treating Hearing Loss in Older Adults Improve Cognitive Outcomes? A Review

Hearing loss is the third most prevalent health condition in older age. In recent years, research has consistently reported an association between hearing loss and mental health outcomes, including poorer cognitive performances. Whether treating hearing loss in elders improves cognition has been directly or indirectly addressed by several studies. This review aims at providing a synthesis of those results. Regarding the literature on hearing aids’ use and cognition, although the lack of interventional studies has to be underlined, observational data suggest that hearing aids positively impact long-term cognition, even though more research is necessary to ascertain this statement and provide information on the length or frequency of use required in order to observe benefits. Regarding cochlear implants in elders experiencing more severe auditory deprivation, the literature is scarcer. The available studies have many limitations and do not allow the drawing of clear conclusions. Taken together, the results are encouraging. Nevertheless, because hearing loss is suspected to account for 9% of dementia cases, and also because hearing loss is one of the few potentially modifiable factors from a dementia prevention perspective, the need to stimulate research to have clearer knowledge of the benefits of treating hearing loss on cognitive outcomes is urgent.

A Combined Treatment Approach to Support Everyday Function and Promote Brain Health in Older Adults: A Pilot Study

Objective: Subtle changes in functional abilities are an early indicator of cognitive impairment. Early intervention may be key to prolonging independence. This study describes the development and program evaluation of an intervention designed to (1) bolster the use of compensation strategies that support everyday executive and memory functioning and (2) utilize these strategies to promote engagement in brain health activities.Method: Older adults (n = 35) with subjective cognitive complaints completed an eight-week group program targeting compensation strategies (e.g., calendars) and brain health activities (e.g., physical exercise). Participants completed outcome measures at first, last, and 3 month follow-up sessions.Results: Compensation strategy use can be successfully taught to and implemented by older adults, and increasing engagement in brain health behaviors is possible, although particular lifestyle changes are challenging to implement.Conclusion: Findings support the use of interventions aimed at increased engagement in compensation strategies to aid everyday memory and executive functioning.Clinical Implications: Early intervention may help to promote prolonged functional independence.

Impact of modifiable risk factors on Alzheimer's disease: A two-sample Mendelian randomization study

With the steadily increasing prevalence of Alzheimer's disease (AD) and great difficulties encountered for AD drug development presently, much interest has been devoted to identifying modifiable risk factors to lower the risk of AD, while the causal associations between risk factors and AD remain inconclusive. The present study conducted a comprehensive evaluation of the causal associations between risk factors and AD development by taking the recent advancements of Mendelian randomization (MR). Inverse variance weighted (IVW), MR-Egger, weighted median, and weighted mode were used for complementary calculation. A total of 45 risk factors and corresponding studies were covered in the study. This two-sample MR (2SMR) analysis provided a suggestive association between genetically predicted higher years of schooling and reduced risks of AD, and each standard deviation (3.71 years) increased in years of schooling was associated with a 41% reduction in the risk of AD (IVW, OR: 0.59, 95% CI: 0.45-0.77). At the same time, it was genetically predicted that urate might be a risk factor in AD, and it was found that each standard deviation increase in urate levels (1.33 mg/dL) was associated with a 0.09-fold increase in the risk of AD (IVW, OR: 1.09, 95% CI: 1.01-1.18). To summarize, the 2SMR analysis indicated a suggestive association between genetically predicted higher years of schooling and reduced risks of AD, and between genetically predicted higher urate levels and increased risks of AD. The findings provide useful clues to help combat AD and warrants future studies.

The effects of different proxies of cognitive reserve on episodic memory performance: aging study in Iran

OBJECTIVE

The main aim of the present study is to investigate the association between different measures of cognitive reserve including bilingualism, mental activities, type of education (continuous versus distributed), age, educational level, and episodic memory in a healthy aging sample.

METHODS

Four hundred and fifteen participants aged between 50 and 83 years participated in this cross-sectional study and were assessed with the Psychology Experimental Building Language Test battery tapping episodic memory. Demographic variables were collected from a questionnaire designed by the research team.

RESULTS

Compared to participants with continuous type of education, those with distributed type performed better in tests of episodic memory, while no differences were found between bilingual and monolingual participants. We additionally found that age negatively predicts episodic memory, whereas playing mind teasers and educational level have positive relationships with episodic memory.

CONCLUSIONS

Our results indicate that higher cognitive reserve, as measured by distributed educational training, higher level of education, and doing regular mental activities, is associated with better performance on episodic memory tasks in older adults. These results were discussed in connection with successful aging and protection against memory decline with aging.

How do we validate approaches that aim to harness reserve to improve the aging brain?

An accurate assessment of the impact of reserve on cognitive functioning in older individuals with brain pathology requires careful measurement of each and an assessment of the extent to which each influences the other. Studies to integrate information about molecular biology, neuropathology, behavioral aspects of cognitive decline, and cognitive resilience will be of particular importance. In addition, more work is needed to improve our understanding of the effect of systemic factors on brain health and function. It seems likely that, even in later life, the brain's plasticity may allow for a positive response to stimulation. The ultimate goal of this research is to create a validated set of variables and interventions-and to understand the biology underlying them-that are useful not only in describing an individual's cognitive state but also in identifying promising paths for treatment and prevention of cognitive decline.

Coffee intake and decreased amyloid pathology in human brain

Several epidemiological and preclinical studies supported the protective effect of coffee on Alzheimer's disease (AD). However, it is still unknown whether coffee is specifically related with reduced brain AD pathologies in human. Hence, this study aims to investigate relationships between coffee intake and in vivo AD pathologies, including cerebral beta-amyloid (Aβ) deposition, the neurodegeneration of AD-signature regions, and cerebral white matter hyperintensities (WMH). A total of 411 non-demented older adults were included. Participants underwent comprehensive clinical assessment and multimodal neuroimaging including [¹¹C] Pittsburgh compound B-positron emission tomography (PET), [¹⁸F] fluorodeoxyglucose PET, and magnetic resonance imaging scans. Lifetime and current coffee intake were categorized as follows: no coffee or <2 cups/day (reference category) and ≥2 cups/day (higher coffee intake). Lifetime coffee intake of ≥2 cups/day was significantly associated with a lower Aβ positivity compared to coffee intake of <2 cups/day, even after controlling for potential confounders. In contrast, neither lifetime nor current coffee intake was not related to hypometabolism, atrophy of AD-signature region, and WMH volume. The findings suggest that higher lifetime coffee intake may contribute to lowering the risk of AD or related cognitive decline by reducing pathological cerebral amyloid deposition.

Association of Lifespan Cognitive Reserve Indicator With Dementia Risk in the Presence of Brain Pathologies

Importance

Evidence on the association of lifespan cognitive reserve (CR) with dementia is limited, and the strength of this association in the presence of brain pathologies is unknown.

Objective

To examine the association of lifespan CR with dementia risk, taking brain pathologies into account.

Design, Setting, and Participants

This study used data from 2022 participants in the Rush Memory and Aging Project, an ongoing community-based cohort study with annual follow-up from 1997 to 2018 (mean follow-up, 6 years; maximum follow-up, 20 years). After excluding 420 individuals who had prevalent dementia, missing data on CR, or dropped out, 1602 dementia-free adults were identified at baseline and evaluated to detect incident dementia. During follow-up, 611 died and underwent autopsies. Data were analyzed from May to September 2018.

Exposures

Information on CR factors (education; early-life, midlife, and late-life cognitive activities; and social activities in late life) was obtained at baseline. Based on these factors, lifespan CR scores were captured using a latent variable from a structural equation model and was divided into tertiles (lowest, middle, and highest).

Main Outcomes and Measures

Dementia was diagnosed following international criteria. Neuropathologic evaluations for Alzheimer disease and other brain pathologies were performed in autopsied participants. The association of lifespan CR with dementia or brain pathologies was estimated using Cox regression models or logistic regression.

Results

Of the 1602 included participants, 1216 (75.9%) were women, and the mean (SD) age was 79.6 (7.5) years. During follow-up, 386 participants developed dementia (24.1%), including 357 participants with Alzheimer disease-related dementia (22.3%). The multiadjusted hazards ratios (HRs) of dementia were 0.77 (95% CI, 0.59-0.99) for participants in the middle CR score tertile and 0.61 (95% CI, 0.47-0.81) for those in the highest CR score tertile compared with those in the lowest CR score tertile. In autopsied participants, CR was not associated with most brain pathologies, and the association of CR with dementia remained significant after additional adjustment for brain pathologies (HR, 0.60; 95% CI, 0.42-0.86). The highest CR score tertile was associated with a reduction in dementia risk, even among participants with high Alzheimer disease pathology (HR, 0.57; 95% CI, 0.37-0.87) and any gross infarcts (HR, 0.34; 95% CI, 0.18-0.62).

Conclusions and Relevance

High lifespan CR is associated with a reduction in dementia risk, even in the presence of high brain pathologies. Our findings highlight the importance of lifespan CR accumulation in dementia prevention.

Change in Engagement in Cognitive Activity and Risk for Mild Cognitive Impairment in a Cohort of Older Adults: The Monongahela-Youghiogheny Healthy Aging Team (MYHAT) Study

Engagement in cognitively stimulating activities is gaining prominence as a potential strategy to maintain cognitive functioning in old age. In a population-based cohort of individuals aged 65+ years, we examined patterns of change in frequency of engagement in total cognitive activity (TCA), higher cognitive activity (HCA), and frequent cognitive activity (FCA) based on the Florida Cognitive Activities Scale over an average of 3.62 years, and whether these patterns were associated with incident mild cognitive impairment (MCI) during this same period. Among 867 cognitively normal participants, 129 (15%) progressed to MCI. Latent class trajectory modeling identified high and stable, slowly, and quickly declining patterns for TCA; high and stable, slowly declining, and slowing increasing patterns for FCA; and high and stable, and slowly declining patterns for HCA. Separate, adjusted Cox proportional hazard models, revealed that compared with the high, stable pattern, both slow decline [hazard ratio (HR), 2.5; 95% confidence interval (CI), 1.5-4.0] and quick decline (HR, 11.0; 95% CI, 6.3-19.2) in TCA, and slow decline in the FCA (HR, 8.7; 95% CI, 5.3-14.3) and HCA (HR, 3.4; 95% CI, 2.0-5.6) subscales increased risk for incident MCI. Maintaining engagement in cognitive activities may be protective against progression to MCI, alternatively, declining engagement may be a marker for impending cognitive impairment.

Brain-Derived Neurotrophic Factor: A Key Molecule for Memory in the Healthy and the Pathological Brain

Brain Derived Neurotrophic Factor (BDNF) is a key molecule involved in plastic changes related to learning and memory. The expression of BDNF is highly regulated, and can lead to great variability in BDNF levels in healthy subjects. Changes in BDNF expression are associated with both normal and pathological aging and also psychiatric disease, in particular in structures important for memory processes such as the hippocampus and parahippocampal areas. Some interventions like exercise or antidepressant administration enhance the expression of BDNF in normal and pathological conditions. In this review, we will describe studies from rodents and humans to bring together research on how BDNF expression is regulated, how this expression changes in the pathological brain and also exciting work on how interventions known to enhance this neurotrophin could have clinical relevance. We propose that, although BDNF may not be a valid biomarker for neurodegenerative/neuropsychiatric diseases because of its disregulation common to many pathological conditions, it could be thought of as a marker that specifically relates to the occurrence and/or progression of the mnemonic symptoms that are common to many pathological conditions.

Quantity and quality of mental activities and the risk of incident mild cognitive impairment

OBJECTIVE

To investigate whether timing, number, and frequency of mentally stimulating activities in midlife and late life are associated with the risk of incident mild cognitive impairment (MCI).

METHODS

We conducted a prospective cohort study in the setting of the population-based Mayo Clinic Study of Aging in Olmsted County, Minnesota, including 2,000 individuals aged ≥70 years who were cognitively unimpaired at baseline and were followed for a median of 5.0 years. Participants completed a self-reported survey on timing, number, and frequency of engagement in 5 mentally stimulating activities (reading books, computer use, social activities, playing games, craft activities) at baseline.

RESULTS

The risk of incident MCI was significantly reduced for participants who engaged in social activities (hazard ratio [95% confidence interval] 0.80 [0.64-0.99]) and playing games (0.80 [0.66-0.98]) in both late life and midlife combined. Using a computer was associated with a decreased risk regardless of timing (not late life but midlife: 0.52 [0.31-0.88]; late life but not midlife: 0.70 [0.56-0.88]; late life and midlife: 0.63 [0.51-0.79]). Craft activities were associated with a reduced risk of incident MCI only when carried out in late life but not midlife (0.58 [0.34-0.97]). Furthermore, engaging in a higher number of activities in late life was associated with a significantly reduced risk of incident MCI (any 2 activities: 0.72 [0.53-0.99], any 3: 0.55 [0.40-0.77], any 4: 0.44 [0.30-0.65], all 5: 0.57 [0.34-0.96]).

CONCLUSION

Engaging in a higher number of mentally stimulating activities, particularly in late life, is associated with a decreased risk of MCI among community-dwelling older persons.

Linking late life depression and Alzheimer's disease: mechanisms and resilience

Purpose of Review

This review summarizes recent literature linking Alzheimer's disease (AD) and late life depression (LLD). It describes shared neurobiological features associated with both conditions, as well as factors that may increase resilience to onset and severity of cognitive decline and AD. Finally, we pose a number of future research directions toward improving detection, management, and treatment of both conditions.

Recent Findings

Epidemiological studies have consistently shown a significant relationship between LLD and AD, with support for depression as a prodromal feature of AD, a risk factor for AD, and observation of some shared risk factors underlying both disease processes. Three major neurobiological features shared by LLD and AD include neurodegeneration, disruption to cerebrovascular functioning, and increased levels of neuroinflammation. There are also potentially modifiable factors that can increase resilience to AD and LLD, including social support, physical and cognitive engagement, and cognitive reserve.

Summary

We propose that, in the context of depression, neurobiological events, such as neurodegeneration, cerebrovascular disease, and neuroinflammation result in a brain that is more vulnerable to the consequences of the pathophysiological features of AD, lowering the threshold for the onset of the behavioral presentation of AD (i.e., cognitive decline and dementia). We discuss factors that can increase resilience to AD and LLD, including social support, physical and cognitive engagement, and cognitive reserve. We conclude with a discussion of future research directions.

Continuing education for the prevention of mild cognitive impairment and Alzheimer's-type dementia: a systematic review and overview of systematic reviews

OBJECTIVE

To summarise evidence on the preventive effects of continuing education on mild cognitive impairment and Alzheimer's-type dementia in adults 45 years or older.

DESIGN

Systematic review and overview of systematic reviews.

DATA SOURCES

We systematically searched MEDLINE, PsycINFO, EMBASE, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, and Scopus for published studies and grey literature databases for unpublished studies from January 1990 to April 2018.

METHODS

To assess evidence directly addressing our objectives, we conducted a systematic review. Because we were aware of a dearth of direct evidence, we also performed an overview of systematic reviews on leisure activities that mimic formal continuing education. We a priori established the inclusion and exclusion criteria. Two authors independently assessed inclusion and exclusion at the abstract and full-text level, rated the risk of bias, and determined the certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation. We resolved all discrepancies by consensus. We synthesised the available evidence narratively.

RESULTS

Our searches identified 4933 citations. For the systematic review, only two publications on the same prospective cohort study (Tasmanian Healthy Brain Project) met the inclusion criteria; for the overview of reviews, we included five systematic reviews. Based on 459 participants, preliminary data of the ongoing cohort study indicated that cognitive reserve statistically significantly increased in persons attending university classes compared with the control group (92.5% vs 55.7%, p<0.01). Likewise, language processing capacities statistically significantly improved (p<0.01). Episodic memory, working memory and executive function did not differ significantly between groups. Systematic reviews consistently reported a positive association between participation in cognitively stimulating leisure activities and reduced incidence of dementia and improved cognitive test performance.

CONCLUSION

Available results demonstrate that cognitive reserve increases through continuing education and show a positive association of cognitive leisure activities with both improved cognitive function and lower dementia incidence.

PROSPERO REGISTRATION NUMBER

CRD42017063944.

Leisure Activity, Brain β-amyloid, and Episodic Memory in Adults with Down Syndrome

The present study provided an investigation of associations between leisure activity and early Alzheimer's disease neuropathology (i.e., brain β-amyloid) and episodic memory in a sample of 65 adults with Down syndrome (aged 30-53 years), at baseline and follow-up, approximately three years apart. Findings indicated that leisure activity at baseline was not associated with brain β-amyloid at baseline or change in brain β-amyloid from baseline to follow-up. Greater cognitively stimulating leisure activity at baseline was associated with better episodic memory at baseline, and greater social leisure activity at baseline was associated with less decline in episodic memory from baseline to follow-up. High (as opposed to low) levels of social and overall leisure activity at baseline moderated the association between increase in brain β-amyloid and decline in episodic memory, from baseline to follow-up. Findings suggest that cognitively stimulating and social leisure activity could protect against the effect of Alzheimer's disease neuropathology on episodic memory in adults with Down syndrome.

Non-drug therapies for cognitive impairment

The review considers basic methods for non-drug correction of cognitive disorders, as well as a combined approach, including the use of drugs and cognitive-motor training in the rehabilitation of patients with impaired cognitive functions. The authors present their own data on the efficiency of non-drug therapies in patients with Alzheimer’s disease.

Chess Practice as a Protective Factor in Dementia

BACKGROUND

dementia is one of the main causes of disability and dependency among the older population worldwide, producing physical, psychological, social and economic impact in those affected, caregivers, families and societies. However, little is known about dementia protective factors and their potential benefits against disease decline in the diagnosed population. Cognitive stimulating activities seem to be protective factors against dementia, though there is paucity in the scientific evidence confirming this, with most publications focusing on prevention in non-diagnosed people. A scoping review was conducted to explore whether chess practice could mitigate signs, deliver benefits, or improve cognitive capacities of individuals diagnosed with dementia through the available literature, and therefore act as a protective factor.

METHODS

twenty-one articles were selected after applying inclusion and exclusion criteria.

RESULTS

the overall findings stress that chess could lead to prevention in non-diagnosed populations, while little has been shown with respect to individuals already diagnosed. However, some authors suggest its capacity as a protective factor due to its benefits, and the evidence related to the cognitive functions associated with the game.

CONCLUSION

although chess is indirectly assumed to be a protective factor due to its cognitive benefits, more studies are required to demonstrate, with strong evidence, whether chess could be a protective factor against dementia within the diagnosed population.

Social networks and social activities promote cognitive functioning in both concurrent and prospective time: evidence from the SHARE survey

The study aimed to investigate the role of social activities, social networks as well as socioeconomic status (SES) in influencing some aspects of cognitive functioning (immediate and delayed verbal recall tests and semantic verbal fluency) in elderly people over time. This analysis was conducted on a sample of 31,954 healthy elderly people (58% female, mean age 65.54 ± 9.74) interviewed in both the fourth and sixth waves of the Survey on Health, Aging and Retirement in Europe (SHARE), in 2011 and 2015. A structural equation model with measurement component was used to assess the relationship between cognitive function, social life and SES over time. Multilevel ordinal logistic regression was applied to explain satisfaction with social network in relation to different types of social network across countries. Being equipped with good cognitive skills did not seem to be predictive of their maintenance over time (latent coefficient = 0.24, p value = 0.34). On the contrary, the subject's social and participatory life, understood as satisfying one's social network and engaging in diversified non-professional social activities, seemed to play a crucial role in the maintenance of cognitive functions in the elderly (latent coefficient = 3.5, p value = 0.03). This research suggests that a socially active and participatory lifestyle mitigates the effects of the physiological process of brain aging.

Cognitive trajectories and spectrum of neuropathology in SuperAgers: The first 10 cases

On average, memory capacity is significantly higher in populations of 50-60 year olds than in populations of 80 year olds. We define SuperAgers as individuals 80 or older whose episodic memory capacity is at least as good as that of cognitively average individuals in their 50s and 60s. SuperAgers therefore have memory capacity that is superior for age. Previous work showed that SuperAgers have greater cortical volumes and greater resistance to age-related cortical atrophy than "cognitively average" individuals of the same age. Here we report on the cognitive, personality, and neuropathologic characteristics of the first 10 autopsy cases in the Northwestern SuperAging Program. During the follow-up period, seven SuperAgers maintained episodic memory performance within or above the average range for 50-65 year-old norms and all 10 SuperAgers maintained episodic memory scores within normal limits for their own age. Extraversion scores tended to be high on the NEO-PI-R measure of personality. The 10 autopsy specimens showed variable findings within the spectrum of Alzheimer pathology. The hippocampus and entorhinal cortex contained neurofibrillary degeneration mostly in the Braak II-III stages. However, even these limbic areas contained many healthy appearing neurons and the neocortex was generally free of neurofibrillary degeneration. In contrast, neocortical areas in at least five of the cases contained moderate to high densities of neuritic plaques. These findings need to be placed in context by comparing them to the neuropathology of cognitively average individuals of the same age. Future research on SuperAgers is likely to offer insights into factors that either prevent the emergence of involutional changes in the brain or that makes cognitive function more resistant to their consequences.

Card playing enhances speech perception among aging adults: comparison with aging musicians

Speech perception and auditory processing have been shown to be enhanced among aging musicians as compared to non-musicians. In the present study, the aim was to test whether these functions are also enhanced among those who are engaged in a non-musical mentally challenging leisure activity (card playing). Three groups of 23 aging adults, aged 60-80 years, were recruited for the study: Musicians, Card players, and Controls. Participants were matched for age, gender, Wechsler Adult Intelligence Scale-III Matrix Reasoning, and Digit Span scores. Their performance was measured using auditory spectral and spatial temporal order judgment tests, and four tasks of speech perception in conditions of: no background noise, background noise of speech frequencies, background noise of white noise, and 60% compressed speech. Musicians were better in auditory and speech perception than the other two groups. Card players were similar to Controls in auditory perception tasks, but were better in the speech perception tasks. Non-musician aging adults may be able to improve their speech perception ability by engaging in leisure activity requiring cognitive effort.

Defining Cognitive Reserve and Implications for Cognitive Aging

PURPOSE OF REVIEW

The aim of this review is to summarize current conceptual models of cognitive reserve (CR) and related concepts and to discuss evidence for these concepts within the context of aging and Alzheimer's disease.

RECENT FINDINGS

Evidence to date supports the notion that higher levels of CR, as measured by proxy variables reflective of lifetime experiences, are associated with better cognitive performance, and with a reduced risk of incident mild cognitive impairment/dementia. However, the impact of CR on longitudinal cognitive trajectories is unclear and may be influenced by a number of factors. Although there is promising evidence that some proxy measures of CR may influence structural brain measures, more research is needed. The protective effects of CR may provide an important mechanism for preserving cognitive function and cognitive well-being with age, in part because it can be enhanced throughout the lifespan. However, more research on the mechanisms by which CR is protective is needed.

Is Alzheimer's Disease Risk Modifiable?

Population-based clinic-pathological studies have established that the most common pathological substrate of dementia in community-dwelling elderly people is mixed, especially Alzheimer's disease (AD) and cerebrovascular ischemic disease (CVID), rather than pure AD. While these could be just two frequent unrelated comorbidities in the elderly, epidemiological research has reinforced the idea that mid-life (age <65 years) vascular risk factors increase the risk of late-onset (age ≥ 65 years) dementia, and specifically AD. By contrast, healthy lifestyle choices such as leisure activities, physical exercise, and Mediterranean diet are considered protective against AD. Remarkably, several large population-based longitudinal epidemiological studies have recently indicated that the incidence and prevalence of dementia might be decreasing in Western countries. Although it remains unclear whether these positive trends are attributable to neuropathologically definite AD versus CVID, based on these epidemiological data it has been estimated that a sizable proportion of AD cases could be preventable. In this review, we discuss the current evidence about modifiable risk factors for AD derived from epidemiological, preclinical, and interventional studies, and analyze the opportunities for therapeutic and preventative interventions.

Association Between Later Life Lifestyle Factors and Alzheimer's Disease Biomarkers in Non-Demented Individuals: A Longitudinal Descriptive Cohort Study

BACKGROUND

Lifestyle factors have been associated with the risk of dementia, but the association with Alzheimer's disease (AD) remains unclear.

OBJECTIVE

To examine the association between later life lifestyle factors and AD biomarkers (i.e., amyloid-β 1-42 (Aβ42) and tau in cerebrospinal fluid (CSF), and hippocampal volume) in individuals with subjective cognitive decline (SCD) and mild cognitive impairment (MCI). In addition, to examine the effect of later life lifestyle factors on developing AD-type dementia in individuals with MCI.

METHODS

We selected individuals with SCD (n = 111) and MCI (n = 353) from the DESCRIPA and Kuopio Longitudinal MCI studies. CSF Aβ42 and tau concentrations were assessed with ELISA assay and hippocampal volume with multi-atlas segmentation. Lifestyle was assessed by clinical interview at baseline for: social activity, physical activity, cognitive activity, smoking, alcohol consumption, and sleep. We performed logistic and Cox regression analyses adjusted for study site, age, gender, education, and diagnosis. Prediction for AD-type dementia was performed in individuals with MCI only.

RESULTS

Later life lifestyle factors were not associated with AD biomarkers or with conversion to AD-type dementia. AD biomarkers were strongly associated with conversion to AD-type dementia, but these relations were not modulated by lifestyle factors. Apolipoprotein E (APOE) genotype did not influence the results.

CONCLUSIONS

Later life lifestyle factors had no impact on key AD biomarkers in individuals with SCD and MCI or on conversion to AD-type dementia in MCI.

Development of the Broad Learning Adult Questionnaire

Infants and children experience an intense form of intellectual engagement associated with learning a variety of new skills. A recent theory proposes that such broad learning experiences may be the key to maximal cognitive development not just during infancy and childhood but also during adulthood. To begin investigating this possibility, the present questionnaire on broad learning in adulthood builds on prior research on need for cognition, intellectual engagement, personal growth, and leisure activities. After several rounds with preliminary versions of the questionnaire, the final version consists of 28 items. Responses were gathered from two mTurk samples to measure scale reliability and to assess model fit. In the end, we obtained a satisfactory measure of broad learning that consists of six separate reliable scales. Once this questionnaire is validated in future studies, perhaps it could be used as a predictor for cognitive development during adulthood and for interventions inducing broad learning.

Protective Role of Recent and Past Long-Term Physical Activity on Age-Related Cognitive Decline: The Moderating Effect of Sex

This study aimed to investigate if the impact of both recent and long-term physical activity on age-related cognitive decline would be modified by sex. One-hundred thirty-five men (N = 67) and women (N = 68) aged 18 to 80 years completed the Modifiable Activity Questionnaire and the Historical Leisure Activity Questionnaire. A composite score of cognitive functions was computed from five experimental tasks. Hierarchical regression analyses performed to test the moderating effect of recent physical activity on age-cognition relationship had not revealed significant result regardless of sex. Conversely, past long-term physical activity was found to slow down the age-related cognitive decline among women (β = 0.22,p = .03), but not men. The findings support a lifecourse approach in identifying determinants of cognitive aging and the importance of taking into account the moderating role of sex. This article presented potential explanations for these moderators and future avenues to explore.

Neuroplasticity across the lifespan and aging effects in bilinguals and monolinguals

Evidence that bilingualism protects against age-related neurocognitive decline is mixed. One relatively consistent finding is that bilingual seniors have greater grey matter volume (GMV) in regions implicated in executive control (EC) and language processing. Here, we compare the neuroplastic effects of bilingual experience on the EC network of young and aging populations directly, and for the first time we evaluate the extent to which such effects may predict executive control performance across age. We used GMV as an index of neural reserve and response time (RT) performance on the Flanker task for measuring EC efficiency. In the presence of age-related widespread GM deterioration, bilinguals had greater GMV than monolinguals in key regions of interest across age. Moreover, whereas EC performance in monolingual seniors was strictly related to GMV, this was not observed for bilingual seniors or younger participants in either group. Interactions between expected effects-of-age and language group on the relationships between GMV and RT suggested that bilingualism affords differential benefits across the lifespan. In younger participants, greater GMV offered no behavioral benefit on EC performance, whilst it did for seniors. It thus appears that age-related cognitive decline following GMV loss in the EC network is delayed in bilinguals.

Effects of Cognitive Reserve on Cognitive Performance in a Follow-Up Study in Older Adults With Subjective Cognitive Complaints. The Role of Working Memory

Objective: Analyze the effects of CR on cognitive performance in adults with subjective cognitive complaints at follow-up. Method: We analyzed the factorial structure of the three constructs defined in cognitive performance (Episodic memory, Working memory, and General cognitive performance) separately to search for evidence of the invariance of the measurement model. We then developed four structural nested models to analyze the relationship between CR and cognitive performance, measured at baseline and after approximately 18 months, in 266 participants older than 50 years with subjective cognitive complaints. Results: The nested models revealed the following main results: direct effects of CR on all cognitive constructs at baseline and also indirect effects on the same constructs at follow-up, and indirect effects of CR on other cognitive constructs at follow-up via working memory at follow-up. Conclusion: The findings show that the proposed model is useful for measuring the influence of CR on cognitive performance in follow-up studies and that CR has a positive influence on cognitive performance at follow-up via working memory. CR may enhance mechanisms of information processing, favoring performance of tasks involving other cognitive constructs in older adults with subjective cognitive complaints.

DUPLICATE: The effectiveness of a cognitive training program in people with mild cognitive impairment: A study in urban community

OBJECTIVE

To assess the effectiveness of a cognitive training program on global cognition among people with mild cognitive impairment.

METHODS

In this experimental study, using purposive sampling, 60 participants age 50 years and over who complained of subjective memory impairment were screened in their communities by public health volunteers with the Abbreviated Mental Test. Those with dementia were excluded as well as those with depression, which were screened out by the Thai Geriatric Depression Scale (TGDS-15). Mild cognitive impairment was diagnosed and confirmed by the Montreal Cognitive Assessment (MoCA) and joint agreement between a psychiatrist and a neurologist. The participants were alternately assigned to receive a cognitive training program (intervention group) while the other half received their normal usual therapy (control group). The program involved training of 4 aspects of cognition through 6 sessions; 2 sessions per month for 3 months. The MoCA and TGDS-15 scales were given at baseline and again at week 13, and at months 6 and 9. Independent t-tests were used to compare changes in global cognition among the two groups.

RESULTS

MoCA scores at 9 months were significantly higher than at baseline in both groups. However, the mean difference in intervention group was significantly higher than control group. TGDS-15 scores at 6 months was significantly lower than at baseline among the intervention group but not the control group.

CONCLUSION

This cognitive training program helped to improve global cognition and reduce depressive symptoms.

The effectiveness of a cognitive training program in people with mild cognitive impairment: A study in urban community

OBJECTIVE

To assess the effectiveness of a cognitive training program on global cognition among people with mild cognitive impairment.

METHODS

In this experimental study, using purposive sampling, 60 participants age 50 years and over who complained of subjective memory impairment were screened in their communities by public health volunteers with the Abbreviated Mental Test. Those with dementia were excluded as well as those with depression, which were screened out by the Thai Geriatric Depression Scale (TGDS-15). Mild cognitive impairment was diagnosed and confirmed by the Montreal Cognitive Assessment (MoCA) and joint agreement between a psychiatrist and a neurologist. The participants were alternately assigned to receive a cognitive training program (intervention group) while the other half received their normal usual therapy (control group). The program involved training of 4 aspects of cognition through 6 sessions; 2 sessions per month for 3 months. The MoCA and TGDS-15 scales were given at baseline and again at week 13, and at months 6 and 9. Independent t-tests were used to compare changes in global cognition among the two groups.

RESULTS

MoCA scores at 9 months were significantly higher than at baseline in both groups. However, the mean difference in intervention group was significantly higher than control group. TGDS-15 scores at 6 months was significantly lower than at baseline among the intervention group but not the control group.

CONCLUSION

This cognitive training program helped to improve global cognition and reduce depressive symptoms.

Early-Life Cognitive Activity Is Related to Reduced Neurodegeneration in Alzheimer Signature Regions in Late Life

Background: Although increased cognitive activity (CA), both current and past, is known to be associated with a decreased occurrence of Alzheimer’s disease (AD) dementia in older adults, the exact neural mechanisms underlying the association between CA during different stages of life and human dementia remain unclear. Therefore, we investigated whether CA during different life stages is associated with cerebral amyloid-beta (Aβ) pathology and AD-related neurodegeneration in non-demented older adults.

Methods: Cross-sectional analyses of data collected between April 2014 and March 2016 from the Korean Brain Aging Study for Early Diagnosis and Prediction of Alzheimer’s Disease (KBASE), an ongoing prospective cohort. In total, 321 community-dwelling, non-demented older adults were involved in this study. Cerebral Aβ deposition and Aβ positivity were measured using ¹¹C-Pittsburgh compound B (PiB)-positron emission tomography (PET). AD-signature region cerebral glucose metabolism (AD-CMglu) and AD-signature region neurodegeneration (AD-ND) positivity were measured using ¹⁸F-fluorodeoxyglucose (FDG)-PET. In addition, CA in early, mid, and late life was systematically evaluated using a structured questionnaire.

Results: Of the 321 participants, 254 were cognitively normal (CN) and 67 had mild cognitive impairment (MCI). The mean age of participants was 69.6 years old [standard deviation (SD) = 8.0]. Higher early-life CA (CA_early) was associated with significantly increased AD-CMglu (B = 0.035, SE = 0.013, P = 0.009) and a decreasing trend of AD-ND positivity (OR = 0.65, 95% CI 0.43–0.98, P = 0.04) but was not associated with Aβ deposition or positivity. We observed no association between midlife CA (CA_mid) and any AD-related brain changes. Late-life CA (CA_late) showed an association with both global Aβ deposition and AD-CMglu, although it was not statistically significant. Sensitivity analyses controlling for current depression or conducted only for CN individuals revealed similar results.

Conclusion: Our results suggest that CA in early life may be protective against late-life AD-related neurodegeneration, independently of cerebral Aβ pathology.

Effect of a Comprehensive Intervention on Plasma BDNF in Patients with Alzheimer's Disease

A comprehensive intervention (CI) on patients with Alzheimer’s disease was assessed by measuring plasmabrain-derived neurotrophic factor (pBDNF) and ADAS-Cog score (ADAS-Cog_score) before, immediately after (FU1), and 6 (FU2) and 24 months (FU3) after the CI. Baseline pBDNF was higher in patients with moderate AD (but not mild AD) than in healthy controls. At FU1, pBDNF and ADAS-Cog_score decreased significantly. At FU2 and FU3, patients’ cognitive status worsened and pBDNF further increased versus baseline, suggesting that CI interruption may be a stress event that prevents return to homeostasis. CI exerted positive short-term effects, but more information is needed on long-term consequences.

Late-life Cognitive Activity and Dementia: A Systematic Review and Bias Analysis

BACKGROUND

Engaging in late-life cognitive activity is often proposed as a strategy to delay or prevent Alzheimer's disease (AD) and other dementias. However, it is unclear to what extent the available evidence supports a causal effect of cognitive activity in dementia prevention.

METHODS

We systematically searched PubMed and EMBASE through June 2014 to identify peer-reviewed epidemiologic studies of cognitive activity and incidence of AD or all-cause dementia. Eligible articles analyzed data from cohort or nested case-control studies, explicitly defined cognitive activity, evaluated participants for AD or all-cause dementia using clearly defined criteria, and provided effect estimates adjusted for at least age and sex. We describe methodologic issues and biases relevant to interpretation of these studies, and quantify the degree of bias due to confounding and reverse causation required to nullify typically observed associations.

RESULTS

We reviewed 12 studies involving 13,939 participants and 1,663 dementia cases, of which 565 were specifically evaluated as AD. Most studies found associations between late-life cognitive activity and lower AD and/or all-cause dementia incidence. Differences in cognitive activity operationalization across studies precluded meta-analysis of effect estimates. Our bias analysis indicated that the observed inverse associations are probably robust to unmeasured confounding, and likely only partially explained by reverse causation.

CONCLUSION

Our systematic review and bias analyses provide support for the hypothesis that late-life cognitive activity offers some reduction in AD and all-cause dementia risk. However, more data are needed to confirm this relationship and on the optimal type, duration, intensity, and timing of that activity.