Temporal Relationship Between Depressive Symptoms and Cognition in Mid and Late Life: A Longitudinal Cohort Study

Longitudinal relationships between depressive symptoms, functional impairment, and physical activity in later late life

The purpose of this study was to investigate relationships between depressive symptoms, functional disability, and physical activity over time in community-dwelling older adults. The Religious Order Study and Rush Memory and Aging Project are longitudinal cohort studies based in the United States which began recruitment in 1994 and 1997, respectively. This analysis included 1611 participants (27.4% male, 92.9% White, 74.7% cognitively normal) who were included at age 80 and followed until age 90. Depressive symptoms were assessed using the modified Center for Epidemiologic Studies Depression scale. Functional disability was assessed using the Instrumental Activities of Daily Living (IADL) scale. Physical activity was self-reported hours of weekly exercise. Reciprocal temporal relationships between these variables were investigated using a random intercept cross-lagged panel model, which decomposes observed variables into stable between-person ('trait') and variable within-person ('state') components to estimate the directional effects between variables over time. Traits for depressive symptoms, IADL disability, and physical activity were correlated. IADL disability showed autoregressive effects; disability starting at age 82 strongly predicted subsequent disability. Consistent autoregressive effects were not observed for depressive symptoms nor physical activity. Several small cross-lagged effects between states were observed for IADL disability and physical activity, as well as for IADL disability and depressive symptoms. There were no direct effects between depressive symptoms and physical activity, but several paths through IADL disability were observed between ages 82 and 88. Functional disability played an important role in octogenarians, highlighting the importance of maintaining functional independence later in life.

Is the change in longitudinal cognitive function in older adults with diabetes affected by trajectory classes of depressive symptoms?

OBJECTIVE

This study aims to identify classes based on the trajectory of depressive symptoms and to examine the impact of trajectory classes of depressive symptoms on longitudinal changes in cognitive function in older adults with diabetes.

METHODS

This is a secondary data analysis of 572 older adults with diabetes using data from the 5th (2014) to 8th (2020) wave of the Korean longitudinal study of aging. Analysis of latent class growth and the effect of trajectories of depressive symptoms on cognitive function was examined using a latent growth curve model. This analysis has been found to be functional in change trajectories and in describing the direction of the trajectory.

RESULTS

The trajectory of depressive symptoms was classified into four classes: low-stable (36.89%), high-decreasing (20.28%), low-increasing (18.71%), and high-persistent (24.13%). Compared with the high-persistent class, higher initial levels of cognitive function were observed in the high-decreasing and low-stable classes. Compared with the high-persistent class, a slower rate of cognitive decline was observed in the low-stable class (B = 0.410, p = .021).

CONCLUSIONS

Continuous monitoring of depressive symptoms and early management of depressive symptoms for community-dwelling older adults with diabetes can help prevent the cognitive decline and delay the deterioration of cognitive function.

Cardiovascular and lifestyle risk factors of mild cognitive impairment in UK veterans and non-veterans

BACKGROUND

The link between poor cardiovascular health (CVH), lifestyle and mild cognitive impairment (MCI) has been well established in the general population. However, there is limited research exploring these associations in ageing UK veterans.

AIMS

This study explored the risk of MCI and its association with nine CVH and lifestyle risk factors (including diabetes, heart disease, high cholesterol, high blood pressure, obesity, stroke, physical inactivity, the frequency of alcohol consumption and smoking) in UK veterans and non-veterans.

METHODS

This prospective cohort study comprised data from the PROTECT study between 2014 and 2022. Participants comprised of UK military veterans and non-veterans aged ≥50 years at baseline. Veteran status was defined using the Military Service History Questionnaire. CVH and lifestyle risk factors were defined using a combination of self-report measures, medication history or physical measurements. MCI was defined as the presence of subjective and objective cognitive impairment.

RESULTS

Based on a sample of 9378 veterans (n = 488) and non-veterans (n = 8890), the findings showed the risk of MCI significantly reduced in veterans with obesity, those who frequently consumed alcohol and were physically inactive compared to non-veterans. The risk of MCI significantly increased in veterans with diabetes (hazards ratio [HR] = 2.22, 95% confidence interval [CI] 1.04-4.75, P ≤ 0.05) or high cholesterol (HR = 3.11, 95% CI 1.64-5.87, P ≤ 0.05) compared to veterans without.

CONCLUSIONS

This study identified CVH and lifestyle factors of MCI in UK veterans and non-veterans. Further work is needed to understand these associations and the underpinning mechanisms which could determine intervention strategies to reduce the risk of MCI.

Exploring the chain mediating roles of frailty and depressive symptoms in the relationship between pain and cognitive function among nursing home older adults

BACKGROUND

The prevalence of cognitive decline is high among nursing home older adults. Pain is a vital factor in cognitive function. Furthermore, the current literature lacks the complex association between pain, frailty, depressive symptoms, and cognitive function. The aim of this study was to explore the chain mediating roles of frailty and depressive symptoms in the association between pain and cognitive function among nursing home older adults.

METHODS

This is a population-based cross-sectional study, conducted in China, of 210 nursing home older adults aged 64-98 years old, who completed the measurements of sociodemographic information, pain, frailty, depressive symptoms, and cognitive function. Mediation analyses tested the indirect effect of frailty and depressive symptoms in the relationship between pain and cognitive function by PROCESS macro.

RESULTS

Pain, frailty, as well as depressive symptoms, were negatively related to cognitive function. Frailty mediated the association between pain and cognitive function. Importantly, mediation analyses showed that frailty and depressive symptoms acted as sequential mediators of pain and cognitive function.

CONCLUSIONS

These findings have crucial clinical implications, as they suggest targeting physiological and psychological factors in older adults with chronic pain to alleviate cognitive decline.

Sequential link in depression, sleep and cognition: Longitudinal evidence from a serial multiple mediation analysis of older adults in China

BACKGROUND

A growing body of literature examines the link between depression, sleep and cognition, but little is known regarding the extent to which this relationship holds among older adults over time.

OBJECTIVE

This study examines how sleep duration mediates the relationship between depressive symptoms and cognitive performance, by utilizing partial least squares structural equation modelling (PLS-SEM) estimation.

METHODS

This study utilizes the 2013-18 China Health and Retirement Longitudinal Study (CHARLS) dataset, of which 3557 participants over the age of 50 satisfied inclusion criteria. Depressive symptoms and cognitive performance are measured by the Center for Epidemiological Studies Depression Scale (CESD) and the Mini-Mental State Examination (MMSE); sleep duration is assessed using the adapted Pittsburgh Sleep Quality Index (PSQI). A serial multiple mediation model was built to assess how depressive symptoms in 2013 and in 2018 are related, in addition to assessing their links with sleep duration and cognitive performance.

FINDINGS

Results indicate that early depression positively predicts depression progression (std.β = 0.564, 95 % Confidence Interval: 0.534, 0.594), but negatively predicts sleep duration (std.β = -0.081, 95 % CI: -0.128, -0.034) and cognitive performance (std.β = -0.118, 95 % CI: -0.165, -0.072). The sequential indirect effect of early depression operating via depression progression and sleep duration is evaluated to be -0.083 (95 % CI: -0.110, -0.056), representing as much as 41.29 % of the total effect.

CONCLUSIONS

Early depressive symptoms are directly associated with increased depressive symptoms and shortened sleep, which are identified as key channels through which early depression is linked with worsened cognition.

CLINICAL IMPLICATIONS

Many older adults may underestimate the adverse costs of early depression, since its net effects on cognition could be channeled indirectly and discretely via depression progression and sleep, which is worth highlighting in health guidelines and clinical recommendations.

Is lifetime traumatic brain injury a risk factor for mild cognitive impairment in veterans compared to non-veterans?

Background: Traumatic brain injury (TBI) is prevalent in veterans and may occur at any stages of their life (before, during, or after military service). This is of particular concern, as previous evidence in the general population has identified TBI as a strong risk factor for mild cognitive impairment (MCI), a known precursor of dementia.Objectives: This study aimed to investigate whether exposure to at least one TBI across the lifetime was a risk factor for MCI in ageing UK veterans compared to non-veterans.Method: This cross-sectional study comprised of data from PROTECT, a cohort study comprising UK veterans and non-veterans aged ≥ 50 years at baseline. Veteran and TBI status were self-reported using the Military Service History Questionnaire (MSHQ) and the Brain Injury Screening Questionnaire (BISQ), respectively. MCI was the outcome of interest, and was defined as subjective cognitive impairment and objective cognitive impairment.Results: The sample population comprised of veterans (n = 701) and non-veterans (n = 12,389). TBI was a significant risk factor for MCI in the overall sample (OR = 1.21, 95% CI 1.11-1.31) compared to individuals without TBI. The prevalence of TBI was significantly higher in veterans compared to non-veterans (69.9% vs 59.5%, p < .001). There was no significant difference in the risk of MCI between veterans with TBI and non-veterans with TBI (OR = 1.19, 95% CI 0.98-1.45).Conclusion: TBI remains an important risk factor for MCI, irrespective of veteran status. The clinical implications indicate the need for early intervention for MCI prevention after TBI.

Bidirectional associations between hearing difficulty and cognitive function in Chinese adults: a longitudinal study

Background

Middle-aged and older adults frequently experience hearing loss and a decline in cognitive function. Although an association between hearing difficulty and cognitive function has been demonstrated, its temporal sequence remains unclear. Therefore, we investigated whether there are bidirectional relationships between hearing difficulty and cognitive function and explored the mediating role of depressive symptoms in this relationship.

Method

We used the cross-lagged panel model and the random-intercept cross-lagged panel model to look for any possible two-way link between self-reported hearing difficulty and cognitive function. To investigate depressive symptoms' role in this association, a mediation analysis was conducted. The sample was made up of 4,363 adults aged 45 and above from the China Health and Retirement Longitudinal Study (CHARLS; 2011-2018; 44.83% were women; mean age was 56.16 years). One question was used to determine whether someone had a hearing impairment. The tests of cognitive function included episodic memory and intelligence. The Center for Epidemiologic Studies Depression Scale, which consists of 10 items, was used to measure depressive symptoms.

Results

A bidirectional association between hearing and cognition was observed, with cognition predominating (Wald χ2 (1) = 7.241, p < 0.01). At the between-person level, after controlling for potential confounders, worse hearing in 2011 predicted worse cognitive function in 2013 (β = -0.039, p < 0.01) and vice versa (β = -0.041, p < 0.01) at the between-person level. Additionally, there was no corresponding cross-lagged effect of cognitive function on hearing difficulty; rather, the more hearing difficulty, the greater the cognitive decline at the within-person level. According to the cross-lagged mediation model, depressive symptoms partially mediates the impact of cognitive function on subsequent hearing difficulty (indirect effect: -0.003, bootstrap 95% confidence interval: -0.005, -0.001, p < 0.05), but not the other way around.

Conclusion

These results showed that within-person relationships between hearing impairment and cognitive function were unidirectional, while between-person relationships were reciprocal. Setting mental health first may be able to break the vicious cycle that relates hearing loss to cognitive decline. Comprehensive long-term care requires services that address depressive symptoms and cognitive decline to be integrated with the hearing management.

Cognitive decline in older adults in the UK during and after the COVID-19 pandemic: a longitudinal analysis of PROTECT study data

BACKGROUND

Although the long-term health effects of COVID-19 are increasingly recognised, the societal restrictions during the COVID-19 pandemic hold the potential for considerable detriment to cognitive and mental health, particularly because major dementia risk factors-such as those related to exercise and dietary habits-were affected during this period. We used longitudinal data from the PROTECT study to evaluate the effect of the pandemic on cognition in older adults in the UK.

METHODS

For this longitudinal analysis, we used computerised neuropsychology data from individuals aged 50 years and older participating in the PROTECT study in the UK. Data were collected from the same participants before the COVID-19 pandemic (March 1, 2019-Feb 29, 2020) and during its first (March 1, 2020-Feb 28, 2021) and second (March 1, 2021-Feb 28, 2022) years. We compared cognition across the three time periods using a linear mixed-effects model. Subgroup analyses were conducted in people with mild cognitive impairment and in people who reported a history of COVID-19, and an exploratory regression analysis identified factors associated with changes in cognitive trajectory.

FINDINGS

Pre-pandemic data were included for 3142 participants, of whom 1696 (54·0%) were women and 1446 (46·0%) were men, with a mean age of 67·5 years (SD 9·6, range 50-96). Significant worsening of executive function and working memory was observed in the first year of the pandemic across the whole cohort (effect size 0·15 [95% CI 0·12-0·17] for executive function and 0·51 [0·49-0·53] for working memory), in people with mild cognitive impairment (0·13 [0·07-0·20] and 0·40 [0·36-0·47]), and in people with a history of COVID-19 (0·24 [0·16-0·31] and 0·46 [0·39-0·53]). Worsening of working memory was sustained across the whole cohort in the second year of the pandemic (0·47; 0·44-0·49). Regression analysis indicated that cognitive decline was significantly associated with reduced exercise (p=0·0049; executive function) and increased alcohol use (p=0·049; working memory) across the whole cohort, as well as depression (p=0·011; working memory) in those with a history of COVID-19 and loneliness (p=0·0038; working memory) in those with mild cognitive impairment. In the second year of the pandemic, reduced exercise continued to affect executive function across the whole cohort, and associations were sustained between worsening working memory and increased alcohol use (p=0·0040), loneliness (p=0·042), and depression (p=0·014) in those with mild cognitive impairment, and reduced exercise (p=0·0029), loneliness (p=0·031) and depression (p=0·036) in those with a history of COVID-19.

INTERPRETATION

The COVID-19 pandemic resulted in a significant worsening of cognition in older adults, associated with changes in known dementia risk factors. The sustained decline in cognition highlights the need for public health interventions to mitigate the risk of dementia-particularly in people with mild cognitive impairment, in whom conversion to dementia within 5 years is a substantial risk. Long-term intervention for people with a history of COVID-19 should be considered to support cognitive health.

FUNDING

National Institute for Health and Care Research.

Temporal relationship between depression and cognitive decline in the elderly: a two-wave cross-lagged study in a Chinese sample

Objectives: Less information is available about the temporal relationship between depression in the elderly and cognitive decline. In the current study, we (1) evaluated the temporal association between depression and cognitive decline in older adults over a 4-year period; (2) indicated which cognitive domains have a strong temporal relationship with depression.Methods: Using data from China Family Panel Studies, we examined the relationship between depression and cognition among adults aged 65 and older with a cross-lagged design.Results: The results showed that initial depression affected subsequent cognitive function, especially immediate and delayed recall, but that cognition decline did not predict depression over time.Conclusion: The findings suggest that depression precedes cognitive decline in older adults, which is of great significance for the future research of mild cognitive impairment and dementia in the elderly.

Longitudinal relationships between depressive symptoms and cognitive function after stroke: A cross-lagged panel design

OBJECTIVE

Stroke is a leading cause of mortality and disability. This study aimed to investigate the temporal and directional relationships between post-stroke depressive symptoms and cognitive impairment using a cross-lagged panel design. Depressive symptoms and cognitive impairment are two common post-stroke complications. However, the precise underlying mechanism remains unclear despite their close relationship. Therefore, elucidating the causal relationship between these two issues is of great clinical significance for improving the poor prognosis of stroke.

METHODS

This study employed a hospital-based multicenter prospective cohort design. A total of 610 patients with ischemic stroke were eligible. Depressive symptoms (measured using the seventeen-item Hamilton Rating Scale for Depression) and cognitive function (measured using the Montreal Cognitive Assessment) were assessed at baseline and the 12-month follow-up. Spearman's correlation was used to examine the correlation between cognitive function and depressive symptoms. Additionally, a cross-lagged panel analysis was employed to elucidate the causal relationship between these factors after adjusting for potential covariates.

RESULTS

The results of a four-iteration cross-lagged panel analysis substantiated a bidirectional relationship between post-stroke depressive symptoms and cognitive function over time. Specifically, higher scores for early depressive symptoms were associated with lower scores for later cognitive function; additionally, higher baseline cognitive function scores were associated with lower depressive symptom scores at a later point.

CONCLUSION

This study establishes a reciprocally causal long-term relationship between depressive symptoms and cognitive function after an ischemic stroke. Therefore, interventions aimed at improving cognitive function and ameliorating depressive symptoms may positively affect both cognition and mood.

TRIAL REGISTRATION

ChiCTR-ROC-17013993.

Bidirectional association between depressive symptoms and mild cognitive impairment over 20 years: Evidence from the Health and Retirement Study in the United States

BACKGROUND

Research examining the association between depressive symptoms and mild cognitive impairment (MCI) has yielded conflicting results. This study aimed to examine the bidirectional association between depressive symptoms and MCI, and the extent to which this bidirectional association is moderated by gender and education.

METHODS

Data come from the US Health and Retirement Study over a 20-year period (older adults aged ≥50 years). Competing-risks regression is employed to examine the association between baseline high-risk depressive symptoms and subsequent MCI (N = 9317), and baseline MCI and subsequent high-risk depressive symptoms (N = 9428). Interactions of baseline exposures with gender and education are tested.

RESULTS

After full adjustment, baseline high-risk depressive symptoms were significantly associated with subsequent MCI (SHR = 1.20, 95%CI 1.08-1.34). Participants with baseline MCI are more likely to develop subsequent high-risk depressive symptoms than those without baseline MCI (SHR = 1.16, 95%CI 1.01-1.33). Although gender and education are risk factors for subsequent depression and MCI, neither moderates the bidirectional association.

LIMITATIONS

Items used to construct the composite cognitive measure are limited; selection bias due to missing data; and residual confounding.

CONCLUSIONS

Our study found a bidirectional association between depressive symptoms and MCI. High-risk depressive symptoms are related to a higher risk of subsequent MCI; and MCI predicts subsequent high-risk depression. Though neither gender nor education moderated the bidirectional association, public health interventions crafted to reduce the risk of depression and MCI should pivot attention to older women and those with less formal education.

Between-person and within-person effects in the temporal relationship between depressive symptoms and cognitive function

BACKGROUND

e aimed to disentangle within-person and between-person effects in the temporal relationship between depressive symptoms and cognitive function.

METHODS

We performed a prospective population-based cohort study on participants of the Survey of Health, Ageing and Retirement in Europe. Cognitive function was assessed by tests on verbal fluency, immediate recall and delayed recall. Depressive symptoms were measured with EURO-D scale. To determine the temporal order of the association between cognitive function and depressive symptoms, we employed the fully saturated cross-lagged panel model (between-person effects), and random intercept cross-lagged panel model (within-person effects).

RESULTS

In 59,311 participants (mean age 65, ranging 46-100), between-person effects showed a bi-directional relationship that could be seen in three stages: First, the effect of cognitive function on depressive symptoms was initially slightly stronger than vice versa. Second, the effect of depressive symptoms on cognitive function became stronger during the follow-up. Third, all effects were small and no direction dominated. Within-person effects, however, revealed a dominant effect from depressive symptoms on cognitive function. Some effects from cognitive function on depressive symptoms were apparent only in older adults, in particular men. All effects were small and strongest for individuals aged 65 years and above.

LIMITATIONS

The sample is healthier than general population and thus not fully representative. A comprehensive cognitive battery was not available.

CONCLUSIONS

Long-term relationship between depressive symptoms and cognitive function is bi-directional. However, to achieve improvement in an individual in the short-term, the focus should be on decreasing depressive symptoms to improve cognitive function.

Disentangling the relationship of subjective cognitive decline and depressive symptoms in the development of cognitive decline and dementia

INTRODUCTION

Subjective cognitive decline (SCD) and depressive symptoms (DS) frequently co-occur prior to dementia. However, the temporal sequence of their emergence and their combined prognostic value for cognitive decline and dementia is unclear.

METHODS

Temporal relationships of SCD, DS and memory decline were examined by latent difference score modeling in a high-aged, population-based cohort (N = 3217) and validated using Cox-regression of dementia-conversion. In 334 cognitively unimpaired SCD-patients from memory-clinics, we examined the association of DS with cognitive decline and with cerebrospinal fluid (CSF) Alzheimer's disease (AD) biomarkers.

RESULTS

In the population-based cohort, SCD preceded DS. High DS were associated with increased risk of dementia conversion in individuals with SCD. In SCD-patients from memory-clinics, high DS were associated with greater cognitive decline. CSF Aß42 predicted increasing DS.

DISCUSSION

SCD typically precedes DS in the evolution to dementia. SCD-patients from memory-clinics with DS may constitute a high-risk group for cognitive decline.

HIGHLIGHTS

Subjective cognitive decline (SCD) precedes depressive symptoms (DS) as memory declines. Emerging or persistent DS after SCD reports predict dementia. In SCD patients, more amyloid pathology relates to increasing DS. SCD patients with DS are at high risk for symptomatic progression.

The Relationship between Alternative Healthy Diet Index and Cognitive Function in the Older Adults: The Mediating Effect of Depressive Symptoms

This study aimed to investigate the association between the alternative healthy eating index-2010 (AHEI-2010) with cognitive function and the mediating role of depressive symptoms in older adults using the data from the 2011–2014 National Health and Nutrition Examination Survey (NHANES). The AHEI-2010 was calculated from NHANES individual food data and Food Patterns Equivalents Database (FPED) diet data. Cognitive function was assessed by the Consortium to Establish a Registry for Alzheimer’s disease (CERAD, memory function indicator), Word Learning sub-test, digital symbol substitution test (DSST, processing speed indicator), animal fluency test (AFT, executive function indicator), and the comprehensive z-score (global cognition indicator). A weighted multiple linear regression model was used to explore the relationship between AHEI-2010 and cognitive function, and Karlson–Holm–Breen (KHB) method was used to explore the mediating effect of depressive symptoms. A total of 2644 participants were included in this study. Participants with higher AHEI-2010 scores were more likely to have higher scores in DSST, AFT, and comprehensive z-score compared with the lowest quartile. Depressive symptoms play a significant mediating role between AHEI-2010 and cognitive function. The proportion of mediating in CERAD, DSST, AFT, and comprehensive z-score was 14.14%, 9.10%, 9.15%, and 10.47%, respectively. This study found that higher dietary quality was associated with better cognitive function. In addition, depressive symptoms may be an important pathway linking diet and cognitive function.

Sex-Influenced Risk Factors for Cognitive Impairment Among Community-Dwelling Older Adults

The current study aimed to explore sex-influenced risk factors for cognitive impairment among community-dwelling older adults in Taiwan. This cross-sectional study was a secondary analysis using a population-based design. We accessed and analyzed data from the Taiwan Longitudinal Study on Aging survey of 2011. Participants were older adults aged ≥55 years living in non-indigenous townships. A total of 3,392 community-dwelling older adults were included. Results showed that the prevalence of cognitive impairment in females and males was 15.3% and 5.7%, respectively. Having a low educational level and being single (i.e., single, widowed, or divorced) were risk factors for cognitive impairment in both sexes. Males who had more than two chronic diseases had a higher risk of cognitive impairment. Self-reported hearing loss and depression increased risk of cognitive impairment in older females. Older age, lower educational level, and single marital status were associated with cognitive impairment among community-dwelling older adults in Taiwan. The effects of self-reported hearing loss, depression, and chronic disease on cognitive impairment were influenced by sex. [Journal of Gerontological Nursing, 48(6), 19-25.].

Impairment in activities of daily living and cognitive decline mediate the association between depressive symptoms and incident hip fractures in Chinese older adults

BACKGROUND

The presence of depressive symptoms is associated with increasing risks of hip fractures (HFs). However, few studies investigated the longitudinal relationship between depressive symptoms and incident HFs among Chinese older adults, and the underlying mechanisms remain unclear.

OBJECTIVES

To investigate the association between depressive symptoms and incident HFs, and the mediating role of cognitive function and impairment in activities of daily living (ADL) in the association among the older adults in China.

METHODS

This population-based cohort study included 6336 Chinese older adults (age range, 60-101 years) without the history of HFs at baseline and with complete data during the follow-up. Discrete-time Cox regression was used to evaluate the relationship between depressive symptoms and incident HFs, and bootstrapped multiple mediation analyses were conducted to examine the effects of cognitive function and ADL impairment on the association.

RESULTS

Among 6336 participants (3172 women [50.1%]; mean [SD] age, 67.9 [6.6] years), 264 (4.2%) subjects had HFs onset. After adjusting for age, sex, education, marital status, current residence, smoking status, drinking status, body mass index, number of chronic conditions, and falls history, elevated depressive symptoms were independently associated with increasing risks of HFs (adjusted hazard ratio [aHR]: 1.42; 95% CI: 1.07 to 1.88). However, this association was no longer significant (aHR: 1.09; 95% CI: 0.78 to 1.53) after adjusting for cognitive function and ADL impairment. When mortality and incident HFs were modeled as a composite outcome, the association between depressive symptoms and combined outcomes also remained non-significant after adjusting for cognitive function and ADL impairment. Furthermore, the mediation model demonstrated that cognitive decline (indirect effect: β = 0.002, 95% CI: 0.001 to 0.003) and ADL impairment (indirect effect: β = 0.002, 95% CI: 0.000 to 0.003) fully mediated the association between depressive symptoms and incident HFs after adjusting for age, sex, falls history, and number of chronic conditions.

CONCLUSIONS

The positive association between depressive symptoms and incident HFs was confirmed among Chinese older adults, which was fully mediated by cognitive decline and ADL impairment. This study shed new light on the potential role played by depressive symptoms in incident HFs.

Gender/Sex Differences in the Association of Mild Behavioral Impairment with Cognitive Aging

BACKGROUND

While the gender/sex differences in neuropsychiatric symptoms in dementia population are well described, gender/sex differences in mild behavioral impairment (MBI) in dementia-free populations and the relationship to cognitive performance and to subsequent cognitive decline have not been studied.

OBJECTIVE

We aimed to explore gender/sex differences in the association of MBI with the level of cognitive performance and its rate of decline in a dementia-free cohort.

METHODS

We studied 8,181 older adults enrolled in the online PROTECT UK Study. MBI was assessed using the MBI Checklist and cognition was measured by digit span, paired associate learning, spatial working memory, and verbal reasoning. Statistical analysis was conducted using linear regression models and linear mixed-effects models.

RESULTS

Out of 8,181 individuals (median age 63 years, 73% females), 11% of females and 14% of males had MBI syndrome. Females exhibited less often symptoms of decreased motivation (45% versus 36% in males), impulse dyscontrol (40% versus 44% in males; p = 0.001) and social inappropriateness (12% versus 15% ; p <  0.001), while they showed more often symptoms of emotional dysregulation (45% versus 36% ; p <  0.001). The associations of MBI domains with some measures of cognitive performance and decline were stronger in males than females, with the exception of the association of emotional dysregulation with the rate of cognitive decline in verbal reasoning, which was present exclusively in females.

CONCLUSION

MBI may influence cognition to a greater extent in males than in females. We propose that predictors and biomarkers of dementia should consider gender/sex as an effect modifier.

Differences in verbal and spatial working memory in patients with bipolar II and unipolar depression: an MSI study

BACKGROUND

Depressive symptoms could be similarly expressed in bipolar and unipolar disorder. However, changes in cognition and brain networks might be quite distinct. We aimed to find out the difference in the neural mechanism of impaired working memory in patients with bipolar and unipolar disorder.

METHOD

According to diagnostic criteria of bipolar II disorder of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) and assessments, 13 bipolar II depression (BP II), 8 unipolar depression (UD) patients and 15 healthy controls (HC) were recruited in the study. We used 2-back tasks and magnetic source imaging (MSI) to test working memory functions and get the brain reactions of the participants.

RESULTS

Compared with HC, only spatial working memory tasks accuracy was significantly worse in both UD and BP II (p = 0.001). Pearson correlation showed that the stronger the FCs' strength of MFG-IPL and IPL-preSMA, the higher accuracy of SWM task within left FPN in patients with UD (r = 0.860, p = 0.006; r = 0.752, p = 0.031). However, the FC strength of IFG-IPL was negatively correlated with the accuracy of SWM task within left FPN in patients with BP II (r = - 0.591, p = 0.033).

CONCLUSIONS

Our study showed that the spatial working memory of patients with whether UD or BP II was impaired. The patterns of FCs within these two groups of patients were different when performing working memory tasks.

Interaction between Subjective Memory Decline and Depression Symptom Intensity in Older People. Results of the Second Wave of Cognition of Older People, Education, Recreational Activities, Nutrition, Comorbidities, and Functional Capacity Studies (COPERNICUS)

Background: Prevalence of subjective memory impairment (SMC), with or without objective memory impairment, and the mediating role of depression symptom intensity was examined in older people. Methods: n = 205 subjects (60 years old and older) were examined and followed up at two years. Cognitive function was examined using the Montreal Cognitive Assessment (MoCA) Delayed Recall (DR) subtest. Geriatric Depression Scale (GDS) was used as a screening tool for depression. Statistical analysis was performed using linear mixed models. Results: A total of 144 subjects (70.24%) had SMC. MoCA Delayed Recall scores were not significantly changed in relation to time and SMC. Dynamics of SMC significantly influenced changes in GDS score (p = 0.008). Conclusions: SMC and objective memory impairment do not fully overlap each other. Subjects without SMC for longer than two years noted less intensity of depression symptoms in comparison to subgroup with SMC. However, occurrence of SMC in subjects who were previously free of SMC, was not related to increase in depression symptom intensity.

Longitudinal Association Between Cognition and Depression in Patients With Late-Life Depression: A Cross-Lagged Design Study

Objectives: Although previous studies have extensively confirmed the cross-sectional relationship between cognitive impairment and depression in depressed elderly patients, the findings of their longitudinal associations are still mixed. The purpose of this study was to explore the two-way causal relationship between depression symptoms and cognition in patients with late-life depression (LLD). Methods: A total of 90 patients with LLD were assessed across two time points (baseline and 1-year follow up) on measures of 3 aspects of cognition and depressive symptoms. The data were then fitted to a structural equation model to examine two cross-lagged effects. Results: Depressive symptoms predicted a decline in executive function (β = 0.864, p = 0.049) but not vice versa. Moreover, depressive symptoms were predicted by a decline in scores of working memory test (β = -0.406, p = 0.023), respectively. None of the relationships between the two factors was bidirectional. Conclusion: These results provide robust evidence that the relationship between cognition and depressive symptoms is unidirectional. Depressive symptoms may be a risk factor for cognitive decline. The decrease of information processing speed predicts depressive symptoms.

Trajectories of depressive symptoms and associated patterns of cognitive decline

The aim was to investigate the pattern and rate of cognitive decline across distinctive trajectories of depressive symptoms in older adults. In this prospective multinational cohort study on 69,066 participants (on average 64 years at baseline, 55% women), assessments of cognitive functions (immediate recall, delayed recall, verbal fluency) and depressive symptoms (EURO-D scale) were conducted at 2-year intervals. The trajectories of depressive symptoms were obtained using latent growth mixture modelling, cognitive decline was assessed using smoothing splines and linear mixed effects models. Four distinct trajectories of depressive symptoms were identified: constantly low (n = 49,660), constantly high (n = 2999), increasing (n = 6828) and decreasing (n = 9579). Individuals with increasing and constantly high depressive symptoms showed linear cognitive decline, while those with constantly low and decreasing depressive symptoms had fluctuating cognition. Participants with increasing depressive symptoms had the fastest decline, while those with decreasing symptoms were spared from decline in cognition. This study suggests that the pattern as well as the rate of cognitive decline co-occurs with specific patterns of changes in depressive symptoms over time. The most pronounced cognitive decline is present in individuals, in whom depressive symptoms increase late in life. Unique mechanisms of cognitive decline may exist for subgroups of the population, and are associated with the trajectory of depressive symptoms.