The Relationships Between Cognitive Reserve and Psychological Symptoms: A Cross-Sectional Study in Healthy Individuals

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

INTRODUCTION

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

METHODS

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

RESULTS

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

DISCUSSION

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

The impact of adverse childhood experiences on cognitive function among middle-aged and older Chinese adults: Multiple mediators of cognitive reserve and depressive symptoms

BACKGROUND

Adverse childhood experiences (ACEs) are associated with later cognitive decline. However, the mechanisms underlying the effects of different types of ACEs are unclear. This study examined how ACEs impact cognitive function, specifically deprivation-related ACEs (DrACEs) and threat-related ACEs (TrACEs). Additionally, we explored the potential role of cognitive reserve (CR) and depression in these relationships.

METHODS

Data were taken from the China Health and Retirement Longitudinal Study (CHARLS) of 2014 and 2020. CR, depressive symptoms and cognitive function measures were collected from 2020. ACEs were assessed at the 2014 Life Course Survey. The main analyses included 7113 participants aged 45 years or older. To explore potential associations, linear regression and SPSS Macro PROCESS were employed.

RESULTS

Among middle-aged and older adults, only exposure to DrACEs was associated with cognitive function ((β = -0.101 [95%CI: -0.150, -0.052]) for DrACEs = 1; (β = -0.250 [95%CI: -0.333, -0.167]) for DrACEs ≥ 2). The indirect effects mediated by CR and depressive symptoms were statistically significant.

LIMITATIONS

The use of retrospective self-reported data for ACEs may introduce recall bias.

CONCLUSIONS

Chinese middle-aged and older adults who have experienced DrACEs exhibit poorer cognitive function, while the association between TrACEs and cognitive function was not significant. And the impact of DrACEs on cognitive function was mediated by CR and depressive symptoms. Further research is necessary to validate our findings, establish causal links, and uncover the underlying mechanisms involved.

Cognitive engagement may slow clinical progression and brain atrophy in Huntington's disease

Lifelong cognitive engagement conveys benefits in Huntington's disease (HD) and may positively affect non-cognitive domains in other populations. However, the effect of lifelong cognitive engagement on the progression of motor and psychiatric domains in HD remains unknown, as is its neurobiological basis. Forty-five HD individuals completed the Cognitive Reserve Questionnaire (CRQ) and longitudinal clinical evaluation (maximum total of six visits, mean inter-assessment duration of 13.53 ± 4.1 months). Of these, thirty-three underwent longitudinal neuroimaging (18 ± 6 months follow-up). Generalized linear mixed-effects models were executed to predict the effect of individual differences in lifelong cognitive engagement on HD clinical progression and voxel-based morphometry to explore the impact of lifelong cognitive engagement on whole-brain gray matter volume atrophy. Controlling for age, disease stage, and sex, higher CRQ scores were associated with reduced overall severity and longitudinal progression across cognitive, motor, and psychiatric domains. Those with higher CRQ scores demonstrated reduced gray matter volume loss in the middle frontal gyrus, supplementary motor area, and middle cingulate. This putative impact on HD clinical progression may be conferred by preservation of brain volume in neural hubs that integrate executive function with action initiation and behavioral regulation, providing support for early cognitive engagement, even prior to diagnosis.

Apathy in persons living with HIV disease: A systematic narrative review

BACKGROUND

Apathy was identified as a feature of HIV early in the epidemic; however, there are no systematic reviews of the diverse literature on the sociodemographic and clinical correlates of apathy in HIV disease.

METHODS

The current study adopted a hybrid systematic-narrative review methodology in which we used PRISMA guidelines to identify, summarize, and critique peer-reviewed, empirical studies of apathy in HIV disease in the era of combination antiretroviral therapy.

RESULTS

A total of 34 studies of apathy in persons living with HIV (PLWH) were identified. Findings across these studies showed that apathy was reliably related to the structure of grey and white matter pathways commonly implicated in apathy, poorer everyday functioning, education, and other neuropsychiatric symptoms (e.g., depression). Apathy was not reliably associated with age, sex, race/ethnicity, cognition, and clinical markers of HIV disease.

LIMITATIONS

The current review does not provide rigorous quantitative estimates of clinical correlates of apathy, and the exclusion criteria of non-English and non-peer reviewed publications introduces risk of bias and Type I error.

CONCLUSIONS

Apathy occurs at higher rates in PLWH and is linked to neuroanatomical differences, as well as negative outcomes for everyday functions, aspects of neurocognition, and neuropsychiatric symptoms. As such, apathy is an important component to consider in the clinical assessment, diagnosis, and management of neurocognitive disorders in PLWH. Future work is needed to replicate existing findings with larger sample sizes and longitudinal designs, examine apathy as a multi-dimensional construct, and develop evidence-based treatments for apathy in PLWH.

Acute effects of a chewable beetroot-based supplement on cognitive performance: a double-blind randomized placebo-controlled crossover clinical trial

BACKGROUND

Dietary nitrate (NO3-) has been shown to be useful as an ergogenic aid with potential applications in health and disease (e.g., blood pressure control). However, there is no consensus about the effects of dietary NO3- or beetroot (BR) juice supplementation on cognitive function.

OBJECTIVE

The aim of this study was to evaluate the effects of a single dose of a chewable BR-based supplement on cognitive performance.

METHODS

A double-blind randomized placebo-controlled two-period crossover clinical trial was carried out based on the extension of the CONSORT guidelines for randomized crossover trials. A total of 44 participants (24 F; 20 M; 32.7 [12.5] years; 66.3 [9.0] kg; 170 [9.2] cm; 22.8 [1.4] kg/m2) were randomly allocated to receive first either four BR-based chewable tablets (BR-CT) containing 3 g of a Beta vulgaris extract (RedNite®) or four tablets of a placebo (maltodextrin). A 4-day washout period was used before crossover. Ninety minutes after ingestion of the treatments, a neuropsychological testing battery was administered in each period. The trial was registered at clinicaltrials.gov NCT05509075.

RESULTS

Significant improvements with moderate effect size were found on memory consolidation at the short and long term only after BR-CT supplementation via the Rey Auditory Verbal Learning Test immediate (+ 20.69%) and delayed (+ 12.34%) recalls. Likewise, enhancement on both frontal lobe functions (+ 2.57%) and cognitive flexibility (+ 11.16%) were detected after BR-CT. There was no significant change (p < 0.05) on verbal memory of short-term digits, working memory and information processing speed. Mixed results were found on mood and anxiety through the Beck Depression Inventory-II (BDI-II) and the State-Trait Anxiety Inventory (STAI-Y1 and STAI-Y2); however, sequence and period effects were seen on STAI-Y2.

CONCLUSIONS

The acute administration of a chewable BR-based supplement improves certain aspects of cognitive function in healthy females and males, particularly memory capacity and frontal skills.

Evaluation of apathy in non-clinical populations: validation, psychometric properties, and normative data of the Italian version of Apathy-Motivation Index (AMI)

INTRODUCTION

Evaluation of apathy in non-clinical populations is relevant to identify individuals at risk for developing cognitive decline in later stages of life, and it should be performed with questionnaires specifically designed for healthy individuals, such as the Apathy-Motivation Index (AMI); therefore, the aim of the present study was to validate the AMI in a healthy Italian population, and to provide normative data of the scale.

MATERIALS AND METHODS

Data collection was performed using a survey completed by 500 healthy participants; DAS, MMQ-A, BIS-15, PHQ-9, and GAD-7 were used to investigate convergent and divergent validity. Internal consistency and factorial structure were also evaluated. A regression-based procedure and receiver operating characteristics (ROC) analyses were used to evaluate the influence of socio-demographic variables on AMI scores and to provide adjusting factors and three cut-offs for the detection of mild, moderate, and severe apathy.

RESULTS

The Italian version of the AMI included 17 items (one item was removed because it was not internally consistent) and demonstrated good psychometric properties. The three-factor structure of AMI was confirmed. Multiple regression analysis revealed no effect of sociodemographic variables on the total AMI score. ROC analyses revealed three cut-offs of 1.5, 1.66, and 2.06 through the Youden's J statistic to detect mild, moderate, and severe apathy, respectively.

CONCLUSION

The Italian version of the AMI reported similar psychometric properties, factorial structure, and cut-offs to the original scale. This may help researchers and clinicians to identify people at risk and address them in specific interventions to lower their apathy levels.

The role of cognitive and brain reserve in late-life depressive events: The Rotterdam Study

BACKGROUND

Cognitive and brain reserve aim to explain individual differences in susceptibility to dementia and may also affect the risk of late-life depressive events. We assessed whether higher cognitive and brain reserve are associated with lower risk of a late-life depressive event.

METHODS

This study included 4509 participants from the population-based Rotterdam Study (mean age: 63.4 ± 10.2 years, 55 % women) between 2005 and 2019. Participants completed cognitive testing and brain-MRI at baseline. Cognitive reserve was defined as the common variance across cognitive tests, while adjusting for demographic factors and brain MRI-markers. Brain reserve was defined as total brain volume divided by intracranial volume. Depressive events (depressive symptoms/depressive syndrome/major depressive disorder) were repeatedly measured (follow-up: 6.6 ± 3.9 years) with validated questionnaires, clinical interviews, and follow-up of medical records. Hazard ratios (HR) with 95 % confidence intervals (CI) were estimated using Cox-regressions.

RESULTS

Higher cognitive (HR: 0.91/SD, 95%CI: 0.84; 1.00) and brain reserve (HR: 0.88/SD, 95%CI: 0.77; 1.00) were associated with a lower risk of a depressive event after adjustment for baseline depressive symptoms. These associations attenuated when participants with clinically relevant depressive symptoms at baseline were excluded (HR: 0.95/SD, 95%CI: 0.86; 1.05, HR: 0.89/SD, 95%CI: 0.76; 1.03, respectively).

LIMITATIONS

No data was available on depression in early-life and the number of participants with major depressive disorder was relatively low (n = 105).

CONCLUSIONS

Higher cognitive and brain reserve may be protective factors for late-life depressive events, particularly in those who have experienced clinical relevant depressive symptoms before. Further research is needed to determine whether cognitive and brain reserve could be used as targets for the prevention of late-life depression.

Semiology and determinants of apathy across neurodegenerative motor disorders: A comparison between amyotrophic lateral sclerosis, Parkinson’s and Huntington’s disease

Background

The semiology and determinants of apathy are largely unknown across amyotrophic lateral sclerosis (ALS), Parkinson’s disease (PD), and Huntington’s disease (HD), due to both motor and non-motor confounders. This study thus aimed at (1) profiling apathy in ALS, PD, and HD and (2) exploring its clinical determinants.

Materials

Consecutive ALS (N = 99), PD (N = 73), and HD (N = 25) patients underwent a motor-free assessment of apathy (Dimensional Apathy Scale, DAS), global cognition, anxiety and depression. Function was assessed through disease-specific scales. The DAS was also completed by N = 101 healthy controls (HCs). Between-group comparisons on DAS scores were implemented by covarying for all applicable confounders. Predictive models on DAS scores were built through multiple, stepwise regressions.

Results

Parkinson’s disease and HD, but not ALS, patients were more apathetic than HCs—with HD patients also selectively showing lower initiation and poorer goal-directed planning than HCs. Higher apathetic features were detected in PD and HD as compared to ALS. Education was a protective factor against apathy in ALS. Anxiety was a risk factor for global apathy in ALS, HD, and to a lesser extent, in PD, whereas, protective only toward affective disintegration in PD and ALS. Cognitive inefficiency was a risk factor toward apathy in both PD and ALS. Depression was a risk factor for executive-related apathy in PD.

Discussion

This study provides unprecedented insights into the heterogeneous semiology and determinants of apathy across ALS, PD, and HD via the DAS, in turn informing clinical practice and research.

The relationship between cognitive reserve and cognition in healthy adults: a systematic review

The concept of Cognitive Reserve (CR) refers to the individual differences allowing some people to cope better with brain pathology. The aim of the present review was to explore the relationship between CR and cognition in adulthood. This association has been addressed in several neuro(psycho)logical disorders and in healthy elderly people. However, few studies explored this issue in adulthood (age range 18–65), when individuals might take advantage the most from psychoeducational approaches aimed at increasing CR. For our systematic review, we selected studies assessing CR and adopting neuropsychological and experimental tasks for evaluation of cognitive functioning in healthy individuals. In the selected articles, we examined the relationship of singular proxies, composite indexes or standardized scales of CR with measures of general cognition, attention, inhibitory control, verbal fluency, constructional abilities, and verbal and spatial memory. The results suggested a positive relationship between singular CR proxies, composite indexes or standardized scales, and almost all the explored cognitive domains. No clear conclusion could be made on constructional abilities due to the scarcity of available studies. CR seems associated with better cognitive performance in adulthood, but definite methodological improvements and the use of standardized scales for CR are necessary to reduce inconsistencies among studies.

Cognitive reserve and coping strategies predict the level of perceived stress during COVID-19 pandemic: A cross-sectional study

The COVID-19 pandemic and the measures to avert contagion heavily impacted individuals' mental health. In the present cross-sectional study, we investigate the relationship between cognitive reserve, coping modalities and the perceived stress during a chronic stage of COVID-19 pandemic by online administration of three standardized questionnaires in a sample of healthy volunteers covering a large lifespan (18–85 years). We found that positive orientation to problems and higher levels of cognitive reserve were associated with lower levels of stress. Conversely, coping strategies involving negation, substance consumption, and appeal to other people and religion to face everyday life, together with higher education, were associated with higher levels of stress. These results shade light on the long-term psychological consequences of COVID-19 and call for the development of psychological interventions improving coping and cognitive reserve, to preserve and restore mental health following the pandemic.

Quantifying and Examining Reserve in Symptomatic Former National Football League Players

BACKGROUND

Repetitive head impacts (RHI) from contact sports have been associated with cognitive and neuropsychiatric disorders. However, not all individuals exposed to RHI develop such disorders. This may be explained by the reserve hypothesis. It remains unclear if the reserve hypothesis accounts for the heterogenous symptom presentation in RHI-exposed individuals. Moreover, optimal measurement of reserve in this population is unclear and likely unique from non-athlete populations.

OBJECTIVE

We examined the association between metrics of reserve and cognitive and neuropsychiatric functioning in 89 symptomatic former National Football League players.

METHODS

Individual-level proxies (e.g., education) defined reserve. We additionally quantified reserve as remaining residual variance in 1) episodic memory and 2) executive functioning performance, after accounting for demographics and brain pathology. Associations between reserve metrics and cognitive and neuropsychiatric functioning were examined.

RESULTS

Higher reading ability was associated with better attention/information processing (β=0.25; 95% CI, 0.05-0.46), episodic memory (β=0.27; 95% CI, 0.06-0.48), semantic and phonemic fluency (β=0.24; 95% CI, 0.02-0.46; β=0.38; 95% CI, 0.17-0.59), and behavioral regulation (β=-0.26; 95% CI, -0.48, -0.03) performance. There were no effects for other individual-level proxies. Residual episodic memory variance was associated with better attention/information processing (β=0.45; 95% CI, 0.25, 0.65), executive functioning (β=0.36; 95% CI, 0.15, 0.57), and semantic fluency (β=0.38; 95% CI, 0.17, 0.59) performance. Residual executive functioning variance was associated with better attention/information processing (β=0.44; 95% CI, 0.24, 0.64) and episodic memory (β=0.37; 95% CI, 0.16, 0.58) performance.

CONCLUSION

Traditional reserve proxies (e.g., years of education, occupational attainment) have limitations and may be unsuitable for use in elite athlete samples. Alternative approaches of reserve quantification may prove more suitable for this population.

Neuropsychological assessment could distinguish among different clinical phenotypes of progressive supranuclear palsy: A Machine Learning approach

Progressive supranuclear palsy (PSP) is a rare, rapidly progressive neurodegenerative disease. Richardson's syndrome (PSP-RS) and predominant parkinsonism (PSP-P) are characterized by wide range of cognitive and behavioural disturbances, but these variants show similar cognitive pattern of alterations, leading difficult differential diagnosis. For this reason, we explored with an Artificial Intelligence approach, whether cognitive impairment could differentiate the phenotypes. Forty Parkinson's disease (PD) patients, 25 PSP-P, 40 PSP-RS, and 34 controls were enrolled following the consensus criteria diagnosis. Participants were evaluated with neuropsychological battery for cognitive domains. Random Forest models were used for exploring the discriminant power of the cognitive tests in distinguishing among the four groups. The classifiers for distinguishing diseases from controls reached high accuracies (86% for PD, 95% for PSP-P, 99% for PSP-RS). Regarding the differential diagnosis, PD was discriminated from PSP-P with 91% (important variables: HAMA, MMSE, JLO, RAVLT_I, BDI-II) and from PSP-RS with 92% (important variables: COWAT, JLO, FAB). PSP-P was distinguished from PSP-RS with 84% (important variables: JLO, WCFST, RAVLT_I, Digit span_F). This study revealed that PSP-P, PSP-RS and PD had peculiar cognitive deficits compared with healthy subjects, from which they were discriminated with optimal accuracies. Moreover, high accuracies were reached also in differential diagnosis. Most importantly, Machine Learning resulted to be useful to the clinical neuropsychologist in choosing the most appropriate neuropsychological tests for the cognitive evaluation of PSP patients.