Executive Function In Older Adults Research Articles

Effects of an individual cognitive stimulation intervention on global cognition, memory, and executive function in older adults with mild to moderate Alzheimer's disease.

To determine the efficacy of a 12-week individual cognitive stimulation (iCS) intervention on global cognition, memory, and executive function of older adults with mild to moderate Alzheimer's disease (AD). Protocolized analysis using data from a multicenter, single-blind, randomized, parallel two-arm RCT of iCS for older adults with probable AD. A sample of 142 people with probable Alzheimer's disease attending 13 Portuguese institutions providing care and support services for older adults were selected. Intervention group (n = 72) received 24 iCS sessions, twice a week for 12 weeks. Control group (n = 70) maintained their activities as usual. Outcomes included global cognitive function (Mini-Mental State Examination, and Alzheimer's Disease Assessment Scale-Cognitive Subscale), memory (Memory Alteration Test, and Free and Cued Selective Reminding Test), and executive functioning (Frontal Assessment Battery). All participants were assessed at baseline (T0), after the intervention (T1), and 12 weeks follow-up (T2). The results showed significant improvements in memory performance at follow-up for the intervention group and greater stability in global cognition in the intervention relative to the control group. The current iCS protocol shows effectiveness in cognitive functioning in older adults with probable AD, particularly for memory upon completion of the intervention and at follow-up, adding further support to previous iCS studies showing similar results and to the effectiveness of the current intervention.

Executive functions in older adults with generalised anxiety disorder and healthy controls: Associations with heart rate variability, brain-derived neurotrophic factor, and physical fitness

Executive functions (EF) decline with age and this decline in older adults with generalised anxiety disorder (GAD) may be influenced by heart rate variability (HRV), brain-derived neurotrophic factor (BDNF), and physical fitness. Understanding these relationships is important for tailored treatments in this population. In this study, 51 adults with GAD (M age = 66.46, SD = 4.08) and 51 healthy controls (M age = 67.67, SD = 4.04) were assessed on cognitive inhibition (Stroop task), shifting (Trails part 4), flexibility (Wisconsin Card Sorting Test – Perseverative errors), working memory (Digit Span Backwards), IQ (Wechsler Abbreviated Scale of Intelligence), high frequency HRV, serum mature BDNF levels, and VO2 max. Results indicated that participants with GAD exhibited better cognitive inhibition compared to controls, with no general reduction in EF. Cognitive inhibition was predicted by gender, HRV, and BDNF levels, while cognitive shifting was predicted by gender and IQ, and cognitive flexibility and working memory by IQ. The enhanced cognitive inhibition in GAD participants might stem from maladaptive use of this function, characteristic of GAD, or protection from EF decline due to normal HRV. Increased BDNF levels, possibly due to good fitness, or compensatory mechanisms related to the disorder, might also play a role. These findings highlight the complexity of EF and related mechanisms in GAD, highlighting the need for interventions that consider both cognitive and physiological factors for optimal outcomes.

Impact Of A Medical Student Led Walk With A Future Doc Program On Executive Function In Older Adults

Impact Of A Medical Student Led Walk With A Future Doc Program On Executive Function In Older Adults

Influence of auditory-based cognitive training on auditory resolution, executive function, and working memory skills in individuals with mild cognitive impairment – a pilot randomized controlled study

Background Age-related central auditory processing disorder and mild cognitive impairment (MCI) can be concomitant in older adults, making it difficult to communicate, especially in challenging listening conditions. This preliminary study investigated the efficacy of auditory-based cognitive training on the auditory processing abilities and cognitive functions of older adults with MCI. Methods In this randomized controlled trial twenty-two older adults with mild cognitive impairment (MCI) were randomly assigned to either an experimental (n=11) or a control group (n=11). The experimental group received 15 cognitive training sessions through tasks involving the auditory domain. The outcome measures of this study included auditory resolution (Temporal gap detection, frequency discrimination, and modulation detection) and cognitive measures (Trail making tests and digit recall), which were administered at three-time points (before training, post-training, and follow-up). The linear mixed model computed the effects of training on the outcome measures. Results A significant improvement was observed in the modulation detection threshold between baseline and follow-up and between post-training and follow-up sessions. However, GDT and FD thresholds did not reveal any statistically significant difference. In the trail making test, Part B showed consistent significance across the time points, whereas Part A and the delayed recall task showed no significant difference. Conclusion Auditory-based cognitive training may improve auditory processing and executive function in older adults with mild cognitive impairment (MCI). Trial registration CTRI/2019/01/017073, registered on 14.01.2019

Effects of Information and Communication Technology Use on the Executive Function of Older Adults Without Dementia: A Longitudinal Fixed-effect Analysis.

Impaired executive function is common in older adults. This study examined the causal relationship between the use of information and communication technology (ICT) and executive function in older adults over time. This study performed a secondary analysis of data from four waves (2016-2019) of the National Health and Aging Trends Study (NHATS). A fixed-effect analysis was conducted to examine the effects of ICT on the executive function of older adults without dementia aged ≥65 years. This study analyzed data from 3,334 respondents. We observed significant positive effects of ICT use on executive function over time (standardized β = 0.043-0.045, 95% confidence interval [CI] = 0.001-0.043, p < 0.05). The current findings support the use of ICT as a protective approach to prevent decline in executive function in community-dwelling older adults.

Executive functions in male and female older adults with aligned levels of VO2max.

Studies have shown a positive relationship between cardiorespiratory fitness (CRF) and executive functioning in older adults. Although this relationship has been well established, there seems to be a gap in the literature on the role of sex differences concerning CRF and executive functions. The current study aimed to assess the effect of sex in the relationship between CRF and cognition in older adults by stratifying the results to examine effects in males and females. Ninety-six older adults (61 females) gave their written, informed consent to participate in this cross-sectional study. All participants underwent a maximal continuous graded exercise test on a cycle ergometer to assess their maximal oxygen uptake (VO<inf>2max</inf>) and a computerized Stroop task (naming, inhibition, and switching) to assess their executive functions. According to VO<inf>2max</inf> test results and the American College of Sports Medicine's guidelines, females and males were classified into higher-fit and lower-fit groups. A general linear model and estimated marginal means analyses were applied. Results showed no significant differences in the naming, inhibition and switching performance tests between male and female older adults (P>0.05). Based on the observed positive relationship between CRF and executive functioning, the data of the current study supports the idea that aerobic exercise, which typically increases CRF, is well-situated to improve executive functioning in older adults, irrespective of sex.

Identifying exercise and cognitive intervention parameters to optimize executive function in older adults with mild cognitive impairment and dementia: a systematic review and meta-analyses of randomized controlled trials

Physical exercise is recognized for its beneficial effects on brain health and executive function, particularly through the careful manipulation of key exercise parameters, including type, intensity, and duration. The aim of this systematic review and meta-analysis was to delineate the optimal types, intensities, and durations of exercise that improve cognitive functions in older adults with mild cognitive impairment (MCI) or dementia. A comprehensive search was conducted in Scopus, Web of Science, and PubMed from their inception until December 2023. The methodological quality and publication bias of the included studies were assessed using the PEDro scale and Egger’s regression test, respectively. Separate meta-analyses were performed to assess the overall impact of exercise on cognitive assessments and to explore the effects of different exercise types (i.e., aerobic, resistance, dual-task, mind-body, and multi-component exercises) and intensities (i.e., low, moderate, and high) on executive function. Results were presented as standardized mean differences (SMD) and 95% confidence intervals (95% CI). A meta-regression analysis was conducted to examine the correlation between exercise duration and mean effects. In total, 15,087 articles were retrieved from three databases, of which 35 studies were included in our final analyses. The results indicated high overall methodological quality (PEDro score = 8) but a potential for publication bias (t = 2.08, p = 0.045). Meta-analyses revealed that all types of exercise (SMD = 0.691, CI [0.498 to 0.885], p < 0.001) and intensities (SMD = 0.694, CI [0.485 to 0.903], p < 0.001) show significant effects favoring exercise. Notably, dual-task exercises (SMD = 1.136, CI [0.236 to 2.035], p < 0.001) and moderate-intensity exercises (SMD = 0.876, CI [0.533 to 1.219], p < 0.001) exhibited the greatest effect. No significant correlation was observed between exercise duration and SMD (R² = 0.038, p = 0.313). Overall, our meta-analyses support the role of physical exercise in enhancing executive function in older adults with MCI or dementia. It is essential to carefully tailor exercise parameters, particularly type and intensity, to meet the specific needs of older adults with MCI or dementia. Such customization is crucial for optimizing executive function outcomes and improving overall brain health.

The role of cognitive reserve and depression on executive function in older adults: A 10-year study from the Wisconsin Registry for Alzheimer’s Prevention

Objective: The current study examined the longitudinal relationship between cognitive reserve (CR), depression, and executive function (EF) in a cohort of older adults. Methods: 416 participants were selected from the Wisconsin Registry for Alzheimer’s Prevention. They were native English speakers, aged ≥50+, and cognitively unimpaired at baseline, with no history of neurological or other psychiatric disorders aside from depression. Depression was assessed with the 20-item Center for Epidemiologic Studies Depression Scale (CES-D). A composite score, based on the premorbid IQ (WRAT-3 Reading subtest) and years of education was used to estimate CR. Another composite score from four cognitive tests was used to estimate EF. A moderation analysis was performed to evaluate the effects of CR and Depression on EF at follow-up after controlling for age, gender, and APOE risk score. Moreover, a multinomial logistic regression was used to predict conversion to Mild Cognitive Impairment (MCI) from the healthy baseline. Results: The negative relationship between depression and EF was stronger in individuals with higher CR levels, suggesting a possible floor effect at lower CR levels. In the multinomial regression, the interaction between CR and depression predicted conversion to MCI status, indicating that lower CR paired with more severe depression at baseline was associated with a higher risk of subsequent impairment. Conclusions: This study sheds light on the intricate relationship between depression and EF over time, suggesting that the association may be influenced by varying levels of CR. Further studies may replicate these findings in clinical populations.

Effects of Second Language Acquisition on Executive Functioning in Older Adults in France

Purpose: The aim of the study was to analyze the effects of second language acquisition on executive functioning in older adults in France. Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: Research on second language acquisition in older adults in France indicates that learning a new language can boost cognitive abilities like problem-solving and multitasking. It enhances memory retention and cognitive flexibility, vital for maintaining mental acuity. Language learning stimulates brain regions linked to executive functions, potentially reducing cognitive decline and offering protective benefits against neurodegenerative diseases in aging populations. These findings highlight the cognitive advantages of bilingualism among older adults in France. Unique Contribution to Theory, Practice and Policy: Bilingual advantage hypothesis, cognitive reserve theory &amp; neuroplasticity theory may be used to anchor future studies on the effects of second language acquisition on executive functioning in older adults in France. Encourage lifelong learning programs that include SLA courses for older adults in France. Advocate for the inclusion of SLA programs in public health initiatives aimed at promoting cognitive health among older adults. Policy frameworks should support funding and infrastructure for community-based language learning initiatives.

Moderate intensity intermittent lifestyle physical activity is associated with better executive function in older adults.

Executive functions are among the first cognitive abilities to decline with age and age-related executive function slowing predisposes older adults to cognitive disorders and disease. Intermittent Lifestyle Physical Activity (ILPA) reflects brief, unplanned activity that occurs during routine daily activities and is operationalized as activity bouts <60s. Our understanding of short bouts of habitual physical activity and executive functions is limited. We tested the hypothesis that greater amounts of ILPA in moderate and vigorous intensity domains would be associated with better executive function in older adults. Forty older adults (26 females, 68 ± 6, >55 years; body mass index: 26.6 ± 4.3 kg/m2) completed a Trail-Making-Task and wore an activPAL 24-hr/day for 6.2 ± 1.8-days. For each intensity, total time and time spent in bouts <60 s were determined. Trail A (processing speed) and Trail B (cognitive flexibility) were completed in 25.8 ± 8.2 s and 63.2 ± 26.2 s, respectively. Non-parametric Spearman's rank correlations report that moderate ILPA (3.2 ± 3.2 min/day) and total-moderate physical activity (20.1 ± 16.0 min/day) were associated with faster Trail A (total-moderate physical activity: ρ=-0.48; moderate-ILPA: ρ = -0.50; both, p < 0.003) and Trail B time (total-moderate physical activity: ρ = 0.36; moderate-ILPA: ρ = -0.46; both, p < 0.020). However, the results show no evidence of an association with either vigorous physical activity or light physical activity (total time or ILPA bouts: all, p > 0.180). Moderate physical activity accumulated in longer bouts (>60 s) was not associated with Trail B time (p = 0.201). Therefore, more total moderate physical activity and shorter bouts (<60 s) may result in better executive functions in older adults.

Clinical Utility of the Neuropsychological Assessment Battery Judgment Subtest in the Evaluation of Older Adults.

The purpose of this retrospective archival study was to explore the clinical utility of the Judgment subtest of the Neuropsychological Assessment Battery (NAB) in older adults who were referred because of cognitive concerns. Specifically, we were interested in how NAB Judgment covaried with other measures of executive functioning. 226 adults, aged 61-89years (48% dementia, 35% mild cognitive impairment, 18% cognitively intact) completed NAB Judgment. They also completed Trail Making Test (TMT) A and B. In addition, Behavior Rating Inventory of Executive Function (BRIEF-A) informant and self-reports were obtained to measure executive functioning in daily life. Scores on NAB Judgment did not correlate significantly with BRIEF-A informant ratings. However, there was a statistically significant correlation between BRIEF-A informant ratings and TMT B. Better performance on TMT B was associated with fewer informant concerns. Furthermore, subgroups with versus without informant BRIEF-A Metacognition indices in the range of impairment demonstrated a statistically significant difference on TMT B but not on Judgment. Executive functioning in older adults should not be assessed using NAB Judgment alone. Such an evaluation should be supplemented with other in-person tests as well as informant ratings of daily functioning.

Effects of different types of physical exercise on executive function of older adults: a scoping review.

This scoping review examined the impact of physical exercise on executive function (EF) in older adults and investigated the moderating effects of exercise types. We systematically searched four electronic databases for randomized controlled trials (RCTs) investigating the effects of exercise on EF, published until November 26, 2023. The proportions of positive and null/negative effects across all studies were calculated. In total, 91 studies were included in the analysis. Among these, 27 (29.7%) studies employed aerobic exercise interventions for older adults' EF, with 19 (70.4%) studies reporting positive effects. Additionally, 18 (19.8%) studies utilized strength exercise interventions for older adults' EF, with 15 (83.3%) studies demonstrating positive benefits. Furthermore, 32 (35.2%) studies employed coordination exercise interventions for older adults' EF, with 25 (78.1%) studies showing positive benefits. Similarly, 30 (33%) studies applied mixed exercise interventions for older adults' EF, with 25 (83.3%) studies indicating positive benefits. Overall, all four types of physical exercise enhance EF in older adults, with mixed exercises being the most effective.

The Combined Impact of Physical Activity and Sedentary Behavior on Executive Functions in Older Adults: A Cross-Sectional Study.

The interplay between physical activity (PA) and sedentary behavior (SB) significantly influences cognitive health in older adults, with executive functions (EFs) being particularly vulnerable to lifestyle factors. However, previous research on older adults focused mainly on PA and is limited due to the lack of comprehensive consideration of other factors that influence EFs. Current guidelines suggest an association between sedentary behavior (SB) and EFs, yet few studies have examined the combined effects of PA and SB on EFs. This cross-sectional study aimed to explore the relationship between PA, SB, and EFs in older adults. A total of 116healthy older adults aged ≥65 years were recruited and categorized into four groups based on activity lifestyles: higher PA and higher SB (PHSH); higher PA and lower SB (PHSL); lower PA and higher SB (PLSH); and lower PA and lower SB (PLSL). EFs were assessed using the Tower of London (TOL) task and the Stroop test, which measure high-order EFs (planning and problem-solving) and core EFs (inhibitory control), respectively. The PHSL group performed better on the TOL task, with lower total move scores and shorter total problem-solving times, compared to the PLSH group. The total move score of the PLSL group was better, and the total problem-solving time of the PHSH group was shorter than those of the PLSH group. However, the Stroop test scores did not differ between the four groups. These findings suggest that increasing PA or reducing SB selectively enhances executive functions, particularly in planning and problem-solving, while less impacting inhibitory control in older adults. This highlights the importance of considering the nuanced effects of PA and SB on different aspects of executing functioning in older adults.

Neural mechanisms and digital promotion of executive function in older adults with amnestic mild cognitive impairment

Neural mechanisms and digital promotion of executive function in older adults with amnestic mild cognitive impairment

Effect of Baduanjin exercise on executive function in older adults with cognitive frailty: A randomized controlled trial

Objective To investigate the effectiveness of Baduanjin exercise on executive function in community-dwelling older adults with cognitive frailty. Design Randomized controlled trial. Setting Community residential centers. Subjects 120 eligible older adults. Interventions Baduanjin training group received supervised Baduanjin training, 60 min sessions three times per week for 24 weeks. The control group did not receive any exercise intervention. Main measures Primary outcome was executive function, assessed using Clock Drawing Test. Secondary outcomes included the subcomponents of executive function (working memory, inhibitory control and cognitive flexibility), attention and cognitive frailty (global cognitive function, physical frailty) assessed using Verbal Fluency Test, Trail Making Test-A/B, Stroop Test, Montreal Cognitive Assessment and Edmonton Frailty Scale, respectively, at baseline and 24 weeks after intervention. Results After the 24-week intervention, the scores of Clock Drawing Test and Verbal Fluency Test, the Trail Making Test-B time and the Card correct numbers of Stroop Test in Baduanjin training group showed significant improvement compared with control group (all P < 0.05) with small to moderate effect sizes and the significant interaction effect of group by time in the Clock Drawing Test and Trail Making Test-B test (P = 0.003 and P = 0.043); cognitive frailty variables, including Montreal Cognitive Assessment and Edmonton Frail Scale scores, also showed significant improvement (P = 0.002 and P = 0.004) with a moderate effect sizes and a significant interaction effect (P < 0.001, P = 0.013). No adverse events were reported. Conclusion Regular Baduanjin training may be an effective and safe intervention to improve cognitive frailty and executive function in community-dwelling older adults with cognitive frailty. Trial registration Chinese Clinical Trial Registry, ChiCTR2100050857. Data of registration: 8/5/2020, https://www.chictr.org.cn/showproj.html?proj = 133037.

Exercise training mitigates the deleterious effects of experimental bed rest on intraindividual variability of executive functioning in older adults: A randomised controlled trial

AbstractBackgroundIn older adults, bed rest can occur because of chronic conditions, injury, surgery, or hospitalization. Extreme levels of physical inactivity due to bed rest initiate a downward spiral in several body systems. Exercise is a countermeasure to many of these changes; nonetheless, little is known about the effect of exercise on older adults’ cognition during bed rest. We thus examined the effects of exercise on the intraindividual variability (IIV) of cognitive performance in older adults exposed to 14 days of experimental 6° head‐down bed rest (HDBR) and whether sex moderates its effects. We chose IIV as our outcome measure because it is more sensitive than traditional summary scores of cognitive performance, albeit no studies have explored exercise effects on older adults’ IIV submitted to bed rest.MethodA non‐blinded, parallel‐group, randomised controlled trial. Twenty‐three healthy older adults aged 55‐65 were randomised to: 1) 14 days of HDBR (CON); or 2) 14 days of HDBR with daily aerobic and strength exercise (EX). Data were collected at baseline, HDBR completion, and end of seven‐day‐recovery. The National Institutes of Health Toolbox Cognitive Battery assessed executive function (Flanker Incongruent and Congruent and Dimensional Change Card Sort) and processing speed (Pattern Comparison). IIV was indexed by intraindividual coefficient of variation (ICV) and residual intraindividual standard deviation (R‐ISD), with R‐ISD as our primary measure of interest. Linear mixed models assessed group differences and the moderator role of sex.ResultAt HDBR completion, EX had significantly lower (better) Flanker incongruent ICV (Estimated mean difference = ‐0.10, 95%CI ‐0.19;‐0.003, p = 0.022) and R‐ISD (Estimated mean difference = ‐3.63, 95%CI ‐6.10;‐1.17, p = 0.005) vs. CON. Sex moderated the effect of exercise; females in EX had significantly lower Flanker incongruent ICV vs. CON (Estimated mean difference = ‐0.23; 95%CI ‐0.34;‐0.12, p&lt;0.001). At the end of the seven‐day recovery, EX had significantly lower Flanker incongruent R‐ISD vs. CON (Estimated mean difference = ‐3.11, 95%CI ‐5.70;‐0.052, p = 0.019). Summary scores and processing speed IIV changes were not statistically significant (ps&gt;0.05).ConclusionExercise during HDBR preserved executive functioning, especially in females. Our findings support the delivery of exercises to older adults during bed rest to preserve their cognitive function.

SARS-CoV-2 infection and cognition in community-dwelling and nursing home residents in southern Switzerland

BackgroundCOVID-19 patients can report ‘brain fog’ and may exhibit cognitive symptoms for months after recovery (Cognitive COVID). However, evidence on whether and the extent to which SARS-CoV-2 infection impacts cognition irrespective of COVID-19 course and severity is limited to clinical samples and mainly comes from prognostic studies. We aimed to explore the association between serologically confirmed SARS-CoV-2 infection and cognitive functioning in community-based and institutionalized older adults, irrespective of COVID-19 symptoms. MethodsWe conducted a case-control study nested into two cohorts in Southern Switzerland. Eligible subjects were Italian speaking older adults, without a previous diagnosis of dementia, who underwent serological testing for anti-SARS-CoV-2 antibodies between November 2020 and July 2021. We manually selected age-, sex- and education-matched cases (i.e., individuals with a serologically confirmed SARS-CoV-2 infection), with seronegative controls, and we conducted in-person neuropsychological assessments using validated, highly sensitive cognitive tests. ResultsWe completed 38 neuropsychological assessments in a mostly female sample of older adults (Mean age: 83.13 ± 8.95; 86.8% women). 17 were community dwelling individuals while 21 lived in a nursing home. As expected, socio-demographic characteristics of age, gender and educational level were similarly distributed between cases (n = 14) and controls (n = 24). In linear regression models, cases had significantly lower scores in cognitive tasks of memory (β = −0.367, p = 0.023), attention (β = 0.428, p = 0.008) and executive functions (β = 0.326, p = 0.046). We found no significant difference in tests of language and spatial-temporal orientation (all p values > 0.05). ConclusionsSARS-CoV-2 infection was associated with cognitive impairment in memory, attention, and executive functions in older adults. Our findings are consistent with mechanistic evidence of the neurotropism of the virus and provide empirical support for the “Cognitive COVID” construct also in non-clinical samples. With nearly 800 million COVID-19 cases (in April 2023), and many more infections worldwide, the clinical and public health implications of Cognitive COVID due to SARS-CoV-2 infection may be massive and warrant further epidemiological investigations.

32 Elevated Plasma pTau-181 is Associated with Lower Global Cognition and Executive Function in Older Adults

Objective:Aggregation of phosphorylated tau (pTau) is a hallmark feature of Alzheimer’s disease (AD). Novel assays now allow pTau to be measured in plasma. Elevated plasma pTau predicts subsequent development of AD, cortical atrophy and AD-related pathologies in the brain. We aimed to determine whether elevated pTau is associated with cognitive functioning in older adults prior to the development of dementia.Participants and Methods:Independently living older adults (N = 48, mean age = 70.0 years; SD = 7.7; age range 55-88 years; 35.4% male) free of dementia or clinical stroke were recruited from the community and underwent blood draw and neuropsychological assessment. Plasma was assayed using the Quanterix Simoa® pTau-181 V2 Advantage Kit to quantify pTau-181 levels and APOE genotyping was conducted on the blood cell pellet fraction obtained from plasma separation. Global cognition was assessed using the Dementia Rating Scale-2 (DRS-2) and executive function was assessed using the Stroop, D-KEFS-2 Fluency, and Trails Making Test. Diagnosis of mild cognitive impairment (MCI) was determined based on overall neuropsychological performance. Participants were diagnosed as MCI if they scored &gt;1 SD below norm-referenced values on 2 or more tests within a domain (language, executive, memory) or on 3 tests across domains.Results:Multiple linear regression analysis revealed a significant negative association between plasma pTau-181 levels and DRS-2 (B = -2.57, 95% CI (-3.68, -1.47), p &lt;.001), Stroop Color-Word score (B = -2.64, 95% CI (-4.56, - 0.71), p = .009) and Fruits and Vegetables Fluency (B = -1.67, 95% CI (-2.84, -0.49), p = .007), adjusting for age, sex, education and APOE4 status. MCI diagnosis was determined for 43 participants, of which 8 (18.6%) met criteria. Logistic regression analysis revealed that pTau-181 levels are associated with increased odds of MCI diagnosis (OR = 2.18, 95% CI (1.01, 4.68), p = .046), after accounting for age, sex, education and APOE4 status.Conclusions:Elevated plasma pTau-181 is associated with worse cognition, particularly executive function, and predicts MCI diagnosis in older adults. Higher plasma pTau-181 was associated with increased odds of MCI diagnosis. Detection of pTau-181 in plasma allows a novel, non-invasive method to detect burden of one form of AD pathology. These findings lend support to the use of plasma pTau-181 as a valuable marker in detecting even early cognitive changes prior to the development of AD. Additional longitudinal studies are warranted to explore the prognostic value of plasma pTau-181 over time.

29 Vascular Burden Mediates the Relationship Between ADHD and Cognition in Older Adults

Objective:Accumulating evidence from case-control and population studies suggests attention-deficit/hyperactivity disorder (ADHD) confers a 2- to 5-fold risk of all-cause dementia later in life. Here, we investigate vascular burden as a potential mediator of this relationship, because vascular integrity is well known to be compromised in ADHD (due to chronic obesity, diabetes, and hypertension) and is also a robust risk factor for neurodegeneration (due to reduced cerebral blood flow). We use brain white matter hyperintensities (WMH) as a measure of vascular burden.Participants and Methods:Thirty-nine adults aged 48-81 years with clinical ADHD, and 37 matched controls, completed neuropsychological testing and 1.5 T structural neuroimaging. None had stroke. Cognitive tests were demographically-adjusted to Z scores using regression-based norms generated from the control group, and averaged across tests within domains of short- and long-term verbal memory (forward digit span, California Verbal Learning Test, Logical Memory), visual memory (Visual Recognition, Rey Complex Figure), processing speed (coding, trails A, Stroop word-reading and color-naming), language (Boston Naming Test, semantic fluency), visuoconstruction (clock drawing, Rey Complex Figure copy), and executive function (backward digit span, trails B, phonemic fluency, Stroop inhibition, Wisconsin Card Sorting Test). Total WMH volumes (i.e., combined periventricular and deep) within subcortical, temporal, frontal, parietal, and occipital regions were individually divided by regional volumes to produce a proportion of each region representing WMH, then log-transformed to correct for skew. Age-corrected linear regression quantified total effects of ADHD on cognition; when these were significant, mediation models quantified the direct effects of ADHD on WMH volumes and the direct effect of WMH volumes on cognition. Sobel’s test estimated indirect effects of ADHD on cognition via WMH.Results:Group had a significant total effect on Processing Speed (ß=-1.154, p&lt;.001) and on Executive Functioning (ß=-0.587, p=.004), where ADHD participants had lower composite scores (M=-1.10, SD=1.76 and M=-0.54, SD=1.14 respectively) than controls (M=0.02, SD=0.74; M=0.00, SD=0.49). Only frontal-lobe WMH had direct effects on Processing Speed (ß=-0.315, p=.012) and Executive Functioning (ß=-0.273, p&lt;.001). The direct effect of ADHD on frontal WMH was significant (ß=-0.734, p=.016), and Sobel’s tests supported an indirect effect of ADHD on Executive Functioning (z=2.079, p=.038) but not Processing Speed (z=1.785, p=.074) via WMH. Because the effect of ADHD on WMH was negative (i.e., fewer WMH in ADHD) despite worse cognition than controls, we tested the a posteriori hypothesis that WMH burden may be relatively more deleterious for ADHD than controls. We found considerably stronger negative correlations between total WMH volumes and Processing Speed (r=-.423, p=.009) and Executive Functioning (r=-.528, p&lt;.001) in the ADHD group than in controls (r=-.231, p=.175 and r=-.162, p=.346, respectively), even though total whole-brain proportion of WMH (M=0.15%, SD=0.27; Mann-Whitney l/=430.0, p=.002) and frontal-lobe proportion of WMH volumes (M=0.33%, SD=0.51; Mann-Whitney U=464.0, p=.007) were lower in ADHD than in controls (M=0.29%, SD=0.42 and M=0.66%, SD=0.88, respectively).Conclusions:WMH burden contributes significantly to the relationship between ADHD and cognition, but ADHD remains an independent contributor to worse processing speed and executive functioning in older adults. Vascular burden may have relatively more deleterious effects on cognition in ADHD, potentially due to decades of accumulated allostatic load, whereas healthy controls can accumulate greater amounts of WMH before cognition is impacted.

90 Self-Rated Executive Dysfunction in Older Adults with Subjective Cognitive Dysfunction and Mild Cognitive Impairment

Objective:Mild cognitive impairment (MCI) is characterized by subjective and objective memory concerns, though additional cognitive concerns are commonly reported, including changes in executive functions (EF). Rabin et al. (2006) showed that a sample of research participants with MCI endorsed problems with their EFs, especially working memory. Similarly, those with subjective cognitive dysfunction (SCD) also reported greater difficulty with aspects of their EF than a healthy comparison sample of older adults (HC). In the present study, we investigated subjective EF in clinical samples of older adults with MCI or SCD, which represents a more naturalistic sample relative to a research sample. Furthermore, we evaluated whether subjective EF varied in these groups depending on whether patients were "young-old" versus "old-old" given prior research indicating objective cognitive differences between these age groups.Participants and Methods:Participants were 135 older adults (53 MCI, 52 SCD, and 30 HC) matched for age (p = .116) and education (p = .863). Dichotomous categorization of age used the sample median (72 years) as cutoff score with 72 participants in the young-old group (mean age = 65.8 ± 4.7 years) and 63 in the old-old group (mean age = 78.1 ± 3.7 years). Participants completed the Behavior Rating Inventory of Executive Function-Adult (BRIEF-A), assessing executive functions in everyday life over the past month. The BRIEF-A yields an overall score (Global Executive Composite [GEC]) composed of two index scores (Behavioral Regulation Index [BRI] and Metacognition Index [MI]) and nine clinical scales (Inhibit, Shift, Emotional Control, Self-Monitor, Initiate, Working Memory, Plan/Organize, Task Monitor, and Organization of Materials). A diagnosis by age-group multivariate analysis of variance (MANOVA) with post-hoc comparisons for diagnosis using a Tukey HSD correction was conducted using SPSS Version 24.Results:MCI and SCD groups endorsed worse EF on all three index scores (ps &lt; .005) and all nine clinical scales (ps &lt; .05) relative to the HC group, and the MCI group reported worse initiation relative to the SCD group. Additionally, worse executive functions on all three index scores (ps &lt; .05) and four clinical scales (ps &lt; .05; emotional control, self-monitoring, planning/organization, and task monitoring) were reported by the young-old group relative to the old-old group. No diagnosis by age-group interactions were observed.Conclusions:Problems with aspects of EF were endorsed by older adults with MCI and SCD compared to HCs across all indices and clinical scales; however, only initiation was reported to be worse in MCI than those with SCD. Additionally, the young-old group endorsed having worse EF than the old-old group across BRIEF-A indices and several more specific aspects of EF, without a moderating effect of diagnosis. These findings highlight the importance of assessing subjective EF in older adults, as they may be early indicators of cognitive change, prior to objective evidence of cognitive decline. Furthermore, results also point to differences in how the young-old and old-old perceive their EF in everyday life.