Depression and risk of cognitive decline and Alzheimer's disease. Results of two prospective community-based studies in The Netherlands

Long-Term Depressive Symptom Trajectories and Midlife Cognition: The CARDIA Study

BACKGROUND AND OBJECTIVES

The nature of associations between depressive symptoms and cognition early in the life course remains unclear, and racial differences in these associations are not well characterized. The aim of this study was to examine the relationship between trajectories of depressive symptom over 20 years, beginning in young adulthood, and cognitive functions in middle-age among Black and White adults.

METHODS

We used prospective data from participants of the Coronary Artery Risk Development in Young Adults Study. Depressive symptoms were measured at 5 study visits between 1990 and 2010 using the Center for Epidemiologic Studies Depression scale. We used latent class group-based modeling to identify 4 trajectories: "persistently low," "persistently medium," "medium decreasing," and "high increasing" depressive symptoms. In 2015, cognitive function was measured using the Digit Symbol Substitution Test (DSST), Stroop test (reverse coded), and Rey Auditory-Verbal Learning Test (RAVLT).We excluded participants who missed the cognitive battery or had no depressive symptoms measurements, resulting in a total of 3,117 participants. All cognitive tests were standardized, and linear regression was used to relate depressive trajectories with 2015 cognitive functions.

RESULTS

The mean [SD] baseline age was 30.1 [3.6] years, and 57% were female. The associations between depressive symptoms and cognition significantly differed by race (p < 0.05). Among Black individuals, compared with having "persistently low," having "medium decreasing," "persistently medium," or "high increasing" depressive symptoms were associated with worse verbal memory, processing speed, and executive function scores (RAVLT persistently medium vs low: β = -0.30, 95% CI -0.48 to -0.12; and high increasing vs low: β = -0.49, 95% CI -0.70 to -0.27; DSST persistently medium vs low: β = -0.28, 95% CI -0.47 to -0.09; and high increasing vs low: β = -0.64, 95% CI -0.87 to -0.42; Stroop persistently medium vs low: β = -0.46, 95% CI -0.70 to -0.23; and high increasing vs low: β = -0.76, 95% CI -1.04 to -0.47). Associations were slightly weaker among White individuals, but we still found that having 'high increasing' depressive symptoms was associated with worse verbal memory and processing speed scores (high increasing vs low: β = -0.38, 95% CI -0.61 to -0.15; and β = -0.40, 95% CI -0.63 to -0.18, respectively).

DISCUSSION

Prolonged exposure to elevated depressive symptoms beginning in young adulthood may result in worse cognitive function over midlife. This association was stronger among Black adults.

Common mental health disorders and cognitive decline in a longitudinal Down syndrome cohort

BACKGROUND

Down syndrome is the most common genetic cause of intellectual disability and Alzheimer's disease. In the general population, common mental disorders (CMDs), including anxiety, depression and obsessive-compulsive disorder, are linked to cognitive decline and higher risk for dementia. It is not known how CMDs affect longer-term cognitive outcomes in Down syndrome, and there is often diagnostic uncertainty in older people with Down syndrome and psychiatric comorbidity.

AIMS

To study the influence of CMDs on cognitive ability and whether they are related longitudinally to development of clinical signs of Alzheimer's disease in Down syndrome.

METHOD

We followed 115 individuals with Down syndrome, 27 of whom were diagnosed with a CMD, over approximately 3 years. Changes in cognitive and behavioural outcomes between baseline and follow-up assessment were analysed, with comparisons made between those with and without a comorbid CMD. Age, gender, apolipoprotein E status and level of intellectual disability were included as covariates.

RESULTS

No significant association between presence of a CMD and poorer performance on cognitive tasks or informant-rated decline over time was observed (P > 0.05).

CONCLUSIONS

Our results suggest that a diagnosis of a CMD does not have a significant negative effect on long-term cognitive or behavioural outcomes in individuals with Down syndrome. In individuals with stable or treated CMD, subsequent cognitive decline is likely indicative of Alzheimer's disease rather than a consequence of mental disorder.

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.

An Investigation of Affective Personality Traits in Alzheimer's Disease: SEEKING as a Possible Predictor for Early-Stage Alzheimer's Dementia

OBJECTIVE

The aim of the current study was to investigate affective personality traits in Alzheimer's disease, a neurodegenerative condition mainly characterized by episodic memory impairment.

METHOD

The sample included 69 participants from 3 diagnostic categories. Twenty-five participants were diagnosed with subjective cognitive impairment (SCI), 26 participants were diagnosed with mild cognitive impairment of the amnestic type (aMCI), and the remaining 18 participants were diagnosed with early-stage Alzheimer's dementia (ADD). Diagnostic labels were given as a result of detailed neurological, neuropsychological, and neuroradiological assessment. Affective personality traits were assessed via Affective Neuroscience Personality Scales (ANPS).

RESULTS

The only significant intergroup difference was obtained for the SEEKING subscale of ANPS. Here, ADD group scored significantly lower compared to the SCI group. The results of logistic regression analysis also indicated that SEEKING score successfully predicted early-stage ADD diagnosis.

CONCLUSION

The results suggest that a specific personality constellation characterized by reduced investment in the outside world might be associated with Alzheimer's disease, either as a risk factor or a byproduct of the neurodegenerative process initiated by AD pathology.

Reduced body cell mass and functions in lower extremities are associated with mild cognitive impairment and Alzheimer's dementia

This study examined the alterations of segmental body composition in individuals with Alzheimer's pathology (AD), including mild cognitive impairment (MCI) and dementia. A multifrequency bioimpedance analysis (BIA) was used to provide segmental water and impedance variables from 365 cognitively normal (CN), 123 MCI due to AD, and 30 AD dementia participants. We compared the BIA variables between the three groups, examined their correlations with neuropsychological screening test scores, and illustrate their 95% confidence RXc graphs. AD dementia participants were older, more depressive, and had worse cognitive abilities than MCI due to AD and CN participants. Although the BIA variables showed weak partial correlations with the cognitive test scores, we found patterns of an increasing water content in lean mass, increasing extra to intracellular water ratio, and decreasing reactance and phase angle in the lower extremities with effect sizes ranging from 0.26 to 0.51 in the groups of MCI and dementia due to AD compared with CN individuals. The RXc graphs upheld the findings with a significant displacement downward and toward the right, dominantly in the lower extremities. Individuals with AD pathology exhibit a reduced body cell mass or cell strength, an abnormal cellular water distribution, and an overhydration status in lean mass, especially in the lower extremities.

Putative pathological mechanisms of late-life depression and Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disorder that is characterized by progressive impairment in cognition and memory. AD is accompanied by several neuropsychiatric symptoms, with depression being the most prominent. Although depression has long been known to be associated with AD, controversial findings from preclinical and clinical studies have obscured the precise nature of this association. However recent evidence suggests that depression could be a prodrome or harbinger of AD. Evidence indicates that the major central serotonergic nucleus-the dorsal raphe nucleus (DRN)-shows very early AD pathology: neurofibrillary tangles made of hyperphosphorylated tau protein and degenerated neurites. AD and depression share common pathophysiologies, including functional deficits of the serotonin (5-HT) system. 5-HT receptors have modulatory effects on the progression of AD pathology i.e., reduction in Aβ load, increased hyper-phosphorylation of tau, decreased oxidative stress etc. Moreover, preclinical models show a role for specific channelopathies that result in abnormal regional activational and neuroplasticity patterns. One of these concerns the pathological upregulation of the small conductance calcium-activated potassium (SK) channel in corticolimbic structure. This has also been observed in the DRN in both diseases. The SKC is a key regulator of cell excitability and long-term potentiation (LTP). SKC over-expression is positively correlated with aging and cognitive decline, and is evident in AD. Pharmacological blockade of SKCs has been reported to reverse symptoms of depression and AD. Thus, aberrant SKC functioning could be related to depression pathophysiology and diverts its late-life progression towards the development of AD. We summarize findings from preclinical and clinical studies suggesting a molecular linkage between depression and AD pathology. We also provide a rationale for considering SKCs as a novel pharmacological target for the treatment of AD-associated symptoms.

Cognitive Decline in Early and Premature Menopause

Early and premature menopause, or premature ovarian insufficiency (POI), affects 1% of women under the age of 40 years. This paper reviews the main aspects of early and premature menopause and their impact on cognitive decline. Based on the literature, cognitive complaints are more common near menopause: a phase marked by a decrease in hormone levels, especially estrogen. A premature reduction in estrogen puts women at a higher risk for cardiovascular disease, parkinsonism, depression, osteoporosis, hypertension, weight gain, midlife diabetes, as well as cognitive disorders and dementia, such as Alzheimer's disease (AD). Experimental and epidemiological studies suggest that female sex hormones have long-lasting neuroprotective and anti-aging properties. Estrogens seem to prevent cognitive disorders arising from a cholinergic deficit in women and female animals in middle age premature menopause that affects the central nervous system (CNS) directly and indirectly, both transiently and in the long term, leads to cognitive impairment or even dementia, mainly due to the decrease in estrogen levels and comorbidity with cardiovascular risk factors, autoimmune diseases, and aging. Menopausal hormone therapy from menopause to the age of 60 years may provide a "window of opportunity" to reduce the risk of mild cognitive impairment (MCI) and AD in later life. Women with earlier menopause should be taken care of by various specialists such as gynecologists, endocrinologists, neurologists, and psychiatrists in order to maintain their mental health at the highest possible level.

Managers' and Administrators' Perspectives on Digital Technology Use in Regional Long-Term Care Homes During the COVID-19 Pandemic

In this paper, we explore managers' and administrators' perspectives on digital technology use for residents during province-wide lockdowns (June-August 2021) during the COVID-19 pandemic in seven regional long-term care homes (LTC) in Niagara, Canada. Fifteen semi-structured interviews were conducted with participants representing operational, financial, and recreational departments where we discussed their needs and factors influencing the use of digital technology during the phases of increased restrictions on visitors and social isolation. Our findings indicate extensive use of cellular devices including smartphones, however additional iPads were needed to meet the ever-rising demand for virtual connections. Almost all participants revealed supportive leadership, redeployed staff, and community donations as main facilitators for technology use. Barriers related to managing varying elderly cognitive capacities and technical issues affected technology use. Based on our findings, we conclude that financial commitment and community support are integral for future-proofing LTC homes with technological innovations.

Association of Global Cognitive Function With Psychological Distress and Adherence to Public Health Recommendations During the Coronavirus Disease 2019 Pandemic: The Women's Health Initiative

BACKGROUND

The association of cognitive function with symptoms of psychological distress during the coronavirus disease 2019 (COVID-19) pandemic or adherence to COVID-19 protective health behaviors is not well-understood.

METHODS

We examined 2 890 older women from the Women's Health Initiative cohort. Prepandemic (ie, within 12 months prior to pandemic onset) and peripandemic global cognitive function scores were assessed with the modified Telephone Interview for Cognitive Status (TICS-m). Anxiety, stress, and depressive symptom severity during the pandemic were assessed using validated questionnaires. We examined adherence to protective behaviors that included safe hygiene, social distancing, mask wearing, and staying home. Multivariable models were adjusted for age, race, ethnicity, education, region of residence, alcohol intake, and comorbidities.

RESULTS

Every 5-point lower prepandemic TICS-m score was associated with 0.33-point mean higher (95% confidence interval [CI], 0.20, 0.45) perceived stress and 0.20-point mean higher (95% CI, 0.07, 0.32) depressive symptom severity during the pandemic. Higher depressive symptom severity, but not anxiety or perceived stress, was associated with a 0.69-point (95% CI, -1.13, -0.25) mean decline in TICS-m from the prepandemic to peripandemic period. Every 5-point lower peripandemic TICS-m score was associated with 12% lower odds ratio (OR, 0.88; 95% CI, 0.80, 0.97) of practicing safe hygiene.

CONCLUSIONS

Among older women, we observed that: (a) lower prepandemic global cognitive function was associated with higher stress and depressive symptom severity during the pandemic; (b) higher depressive symptom severity during the pandemic was associated with cognitive decline; and (c) lower global cognitive function during the pandemic was associated with lower odds of practicing safe hygiene.

Hormone therapy and the decreased risk of dementia in women with depression: a population-based cohort study

Background

The literature has shown depression to be associated with an increased risk of dementia. In addition, hormone therapy can be a responsive treatment option for a certain type of depression. In this study, we examined the association between hormone therapy, including lifetime oral contraceptive (OC) use, and hormone replacement therapy (HRT) after menopause with the occurrence of dementia among female patients with depression.

Methods

The South Korean national claims data from January 1, 2005, to December 31, 2018, was used. Female subjects aged 40 years or older with depression were included in the analyses. Information on hormone therapy was identified from health examination data and followed up for the occurrence of dementia during the average follow-up period of 7.72 years.

Results

Among 209,588 subjects, 23,555 were diagnosed with Alzheimer’s disease (AD) and 3023 with vascular dementia (VD). Lifetime OC usage was associated with a decreased risk of AD (OC use for < 1 year: HR, 0.92 [95% CI, 0.88–0.97]; OC use for ≥ 1 year: HR, 0.89 [95% CI, 0.84–0.94]), and HRT after menopause was associated with a decreased risk of AD (HRT for < 2 years: HR, 0.84 [95% CI, 0.79–0.89]; HRT for 2–5 years: HR, 0.80 [95% CI, 0.74–0.88]; and HRT for ≥ 5 years : HR, 0.78 [95% CI, 0.71–0.85]) and VD (HRT < 2 years: HR, 0.82 [95% CI, 0.71–0.96]; HRT for 2–5 years: HR, 0.81 [95% CI, 0.64–1.02]; and HRT for ≥ 5 years: HR, 0.61 [95% CI, 0.47–0.79]).

Conclusions

In this nationwide cohort study, lifetime OC use was associated with a decreased risk of AD, and HRT after menopause was associated with a decreased risk of AD and VD among female patients with depression. However, further studies are needed to establish causality.

Fractional order epidemiological model of SARS-CoV-2 dynamism involving Alzheimer’s disease

In this paper, we study a Caputo–Fabrizio fractional order epidemiological model for the transmission dynamism of the severe acute respiratory syndrome coronavirus 2 pandemic and its relationship with Alzheimer’s disease. Alzheimer’s disease is incorporated into the model by evaluating its relevance to the quarantine strategy. We use functional techniques to demonstrate the proposed model stability under the Ulam–Hyres condition. The Adams–Bashforth method is used to determine the numerical solution for our proposed model. According to our numerical results, we notice that an increase in the quarantine parameter has minimal effect on the Alzheimer’s disease compartment.

Association between a history of clinical depression and dementia, and the role of sociodemographic factors: population-based cohort study

BACKGROUND

Depression is associated with an increased dementia risk, but the nature of the association in the long-term remains unresolved, and the role of sociodemographic factors mainly unexplored.

AIMS

To assess whether a history of clinical depression is associated with dementia in later life, controlling for observed sociodemographic factors and unobserved factors shared by siblings, and to test whether gender, educational level and marital status modify the association.

METHOD

We conducted a national cohort study of 1 616 321 individuals aged 65 years or older between 2001 and 2018 using administrative healthcare data. A history of depression was ascertained from the national hospital register in the period 15-30 years prior to dementia follow-up. We used conventional and sibling fixed-effects Cox regression models to analyse the association between a history of depression, sociodemographic factors and dementia.

RESULTS

A history of depression was related to an adjusted hazard ratio of 1.27 (95% CI 1.23-1.31) for dementia in the conventional Cox model and of 1.55 (95% CI 1.09-2.20) in the sibling fixed-effects model. Depression was related to an elevated dementia risk similarly across all levels of education (test for interaction, P = 0.84), but the association was weaker for the widowed than for the married (P = 0.003), and stronger for men than women (P = 0.006). The excess risk among men attenuated following covariate adjustment (P = 0.10).

DISCUSSION

This study shows that a history of depression is consistently associated with later-life dementia risk. The results support the hypothesis that depression is an aetiological risk factor for dementia.

Depression and bone loss as risk factors for cognitive decline: A systematic review and meta-analysis

BACKGROUND

Depression is linked to Alzheimer's disease (AD) but it is unclear whether depression is also associated with cognitive decline in the preclinical phase and mild cognitive impairment (MCI). Previous meta-analyses have only investigated AD as an outcome without accounting for individuals showing cognitive decline that does not meet the diagnostic criteria for AD. Other potentially modifiable risk factors such as bone loss have also been less explored and there remains uncertainty around their temporal relationship with cognitive decline.

AIMS

To conduct a systematic review and meta-analysis investigating depression and bone loss as risk factors for subsequent cognitive decline.

METHODS

A comprehensive search strategy was developed and applied using four databases; MEDLINE Complete, Embase, PsycINFO and CINAHL Complete. The pooled summary effects were estimated as odds ratios with 95% confidence intervals using a random-effects model. The study protocol was registered with PROSPERO (ID: CRD42020159369).

RESULTS

A total of 75 longitudinal cohort studies were identified for meta-analysis, of which 70 examined the impact of depression on cognitive decline and five examined the impact of bone loss. Prior exposure to depression was found to be associated with cognitive score reduction (OR 1.33 95% CI 1.17, 1.51), MCI incidence (OR 1.52 95% CI 1.28, 1.79) and AD incidence (OR 1.79 95% CI 1.46, 2.2). Bone loss was also associated with the incidence of AD (OR=1.81 95% CI 1.28, 2.55).

CONCLUSIONS

Overall, the results support the hypothesis that depression is associated with subsequent cognitive decline. Bone loss was also found to be associated with AD incidence; however, due to the small number of studies, the results should be viewed with caution.

Negative and Positive Psychosocial Factors in Relation to Cognitive Health in Older African Americans

Background and Objectives

Identifying potential intervention strategies to reduce cognitive decline, particularly among older African Americans at high risk for Alzheimer’s dementia, is critical. This study aimed to investigate whether depressive symptoms, purpose in life, and their interrelations are associated with cognitive decline in older African Americans.

Research Design and Methods

We included older African Americans from the Minority Aging Research Study (n = 748) and Rush Memory and Aging Project (n = 109), without dementia at baseline. We assessed associations of depressive symptoms, purpose in life, and their interrelations, with baseline levels and change in global cognition using linear mixed-effects models.

Results

At baseline, each unit increment in depressive symptoms was related to worse initial global cognition (mean difference = −0.03 standard unit; p = .003), while higher purpose in life was related to better cognition (mean difference = 0.12; p = .002). Further, participants with ≥1 depressive symptom who had a purpose in life score above the median appeared to have better global cognition (mean difference = 0.10; p = .01), compared to those with depressive symptoms but lower levels of purpose in life. However, we did not find relations of depressive symptoms or purpose in life with rates of cognitive decline over time, likely due to the modest follow-up.

Discussion and Implications

In older African Americans, we found that lower depressive symptoms and greater purpose in life were independently related to higher initial levels of global cognition, but not cognitive decline. Preliminary findings of higher global cognition in individuals with depressive symptoms but greater purpose in life merit further investigation if purpose may eventually be considered as an intervention.

Associations between Air Pollution and Psychiatric Symptoms in The Normative Aging Study

BACKGROUND

Environmental risk factors for psychiatric health are poorly identified. We examined the association between air pollution and psychiatric symptoms, which are often precursors to the development of psychiatric disorders.

METHODS

This study included 570 participants in the US Veterans Administration (VA) Normative Aging Study and 1,114 visits (defined as an onsite follow-up at the VA with physical examination and questionnaires) from 2000-2014 with information on the Brief Symptom Inventory (BSI) to assess their psychiatric symptom levels. Differences in the three BSI global measures (Global Severity Index - GSI, Positive Symptom Distress Index - PSDI and Positive Symptom Total - PST) were reported per interquartile (IQR) increase of residential address-specific air pollutants levels (fine particulate matter - PM_2.5, ozone - O₃, nitrogen dioxide - NO₂) at averages of 1 week, 4 weeks, 8 weeks and 1 year prior to the visit using generalized additive mixed effects models. We also evaluated modification by neighborhood factors.

RESULTS

On average, among the NAS sample (average age, 72.4 yrs. (standard deviation: 6.7 yrs.)), an IQR increase in 1- and 4- week averages of NO₂ before visit was associated with a PSDI T score (indicator for psychiatric symptom intensity) increase of 1.60 (95% Confidence Interval (CI): 0.31, 2.89), 1.71 (95% CI: 0.18, 3.23), respectively. Similarly, for each IQR increase in 1- and 4-week averages of ozone before visit, PSDI T-score increased by 1.66 (95% CI: 0.68, 2.65), and 1.36 (95% CI: 0.23, 2.49), respectively. Stronger associations were observed for ozone and PSDI in low house value and low household income areas. No associations were found for PM_2.5.

CONCLUSIONS

Exposure to gaseous air pollutants was associated with higher intensity of psychiatric symptoms among a cohort of older men, particularly in communities with lower socio-economic or housing conditions.

C-Reactive Protein as a Biomarker for Major Depressive Disorder?

The etiopathogenesis of depression is not entirely understood. Several studies have investigated the role of inflammation in major depressive disorder. The present work aims to review the literature on the association between C-Reactive Protein (CRP) and depression. A systematic review was performed for the topics of ‘CRP’ and ‘depression’ using the PubMed database from inception to December 2021. Fifty-six studies were identified and included in the review. Evidence suggested the presence of dysregulation in the inflammation system in individuals with depression. In most studies, higher blood CRP levels were associated with greater symptom severity, a specific pattern of depressive symptoms, and a worse response to treatment. Moreover, about one-third of depressed patients showed a low-grade inflammatory state, suggesting the presence of a different major depressive disorder (MDD) subgroup with a distinct etiopathogenesis, clinical course, treatment response, and prognosis, which could benefit from monitoring of CRP levels and might potentially respond to anti-inflammatory treatments. This work provides robust evidence about the potential role of CRP and its blood levels in depressive disorders. These findings can be relevant to developing new therapeutic strategies and better understanding if CRP may be considered a valuable biomarker for depression.

Recognizing Depression in the Elderly: Practical Guidance and Challenges for Clinical Management

Depression is one of the most common mood disorders in the late-life population and is associated with poor quality of life and increased morbidity, disability and mortality. Nevertheless, in older adults, it often remains undetected and untreated. This narrative review aims at giving an overview on the main definitions, clinical manifestations, risk and protective factors for depression in the elderly, and at discussing the main reasons for its under/misdiagnosis, such as cognitive decline and their overlapping symptomatology. A practical approach for the global and multidisciplinary care of the older adult with depression, derived from cross-checking evidence emerging from the literature with everyday clinical experience, is thus provided, as a short and flexible "pocket" guide to orient clinicians in recognizing, diagnosing and treating depression in the elderly.

Validating a Genomic Convergence and Network Analysis Approach Using Association Analysis of Identified Candidate Genes in Alzheimer's Disease

Previously, we demonstrated an integrated genomic convergence and network analysis approach to identify the candidate genes associated with the complex neurodegenerative disorder, Alzheimer's disease (AD). Here, we performed a pilot study to validate the in silico approach by studying the association of genetic variants from three identified critical genes, APOE, EGFR, and ACTB, with AD. A total of 103 patients with AD and 146 healthy controls were recruited. A total of 46 single-nucleotide polymorphisms (SNPs) spanning the three genes were genotyped, of which only 19 SNPs were included in the final analyses after excluding non-polymorphic and Hardy-Weinberg equilibrium-violating SNPs. Apart from our previously reported APOE ε4, four other SNPs in APOE (rs405509, rs7259620, -rs769449, and rs7256173), one in EGFR (rs6970262), and one in ACTB (rs852423) showed a significant association with AD (p < 0.05). Our results validate the reliability of genomic convergence and network analysis approach in identifying the AD-associated candidate genes.

Assessment of Social Behavior Using a Passive Monitoring App in Cognitively Normal and Cognitive Impaired Older Adults: an Observational Study (Preprint)

Background

In people with cognitive impairment, loss of social interactions has a major impact on well-being. Therefore, patients would benefit from early detection of symptoms of social withdrawal. Current measurement techniques such as questionnaires are subjective and rely on recall, in contradiction to smartphone apps, which measure social behavior passively and objectively.

Objective

This study uses the remote monitoring smartphone app Behapp to assess social behavior, and aims to investigate (1) the association between social behavior, demographic characteristics, and neuropsychiatric symptoms in cognitively normal (CN) older adults, and (2) if social behavior is altered in cognitively impaired (CI) participants. In addition, we explored in a subset of individuals the association between Behapp outcomes and neuropsychiatric symptoms.

Methods

CN, subjective cognitive decline (SCD), and CI older adults installed the Behapp app on their own Android smartphone for 7 to 42 days. CI participants had a clinical diagnosis of mild cognitive impairment (MCI) or Alzheimer-type dementia. The app continuously measured communication events, app use and location. Neuropsychiatric Inventory (NPI) total scores were available for 20 SCD and 22 CI participants. Linear models were used to assess group differences on Behapp outcomes and to assess the association of Behapp outcomes with the NPI.

Results

We included CN (n=209), SCD (n=55) and CI (n=22) participants. Older cognitively normal participants called less frequently and made less use of apps (P<.05). No sex effects were found. Compared to the CN and SCD groups, CI individuals called less unique contacts (β=–0.7 [SE 0.29], P=.049) and contacted the same contacts relatively more often (β=0.8 [SE 0.25], P=.004). They also made less use of apps (β=–0.83 [SE 0.25], P=.004). Higher total NPI scores were associated with further traveling (β=0.042 [SE 0.015], P=.03).

Conclusions

CI individuals show reduced social activity, especially those activities that are related to repeated and unique behavior, as measured by the smartphone app Behapp. Neuropsychiatric symptoms seemed only marginally associated with social behavior as measured with Behapp. This research shows that the Behapp app is able to objectively and passively measure altered social behavior in a cognitively impaired population.

Cognitive impairment and depression: Meta-analysis of structural magnetic resonance imaging studies

Longitudinal comorbidity of depression and cognitive impairment has been reported by number of epidemiological studies but the underlying mechanisms explaining the link between affective problems and cognitive decline are not very well understood. Imaging studies have typically investigated patients with major depressive disorder (MDD) and mild cognitive impairment (MCI) separately and thus have not identified a structural brain signature common to these conditions that may illuminate potentially targetable shared biological mechanisms. We performed a meta-analysis of. 48 voxel-based morphometry (VBM) studies of individuals with MDD, MCI, and age-matched controls and demonstrated that MDD and MCI patients had shared volumetric reductions in a number of regions including the insula, superior temporal gyrus (STG), inferior frontal gyrus, amygdala, hippocampus, and thalamus. We suggest that the shared volumetric reductions in the insula and STG might reflect communication deficits and infrequent participation in mentally or socially stimulating activities, which have been described as risk factors for both MCI and MDD. We also suggest that the disease-specific structural changes might reflect the disease-specific symptoms such as poor integration of emotional information, feelings of helplessness and worthlessness, and anhedonia in MDD. These findings could contribute to better understanding of the origins of MDD-MCI comorbidity and facilitate development of early interventions.

Educational level as a protective factor against the influence of depressive symptoms on cognition in older adults: implications for functional independence during a 10-year follow-up

OBJECTIVES

To examine whether the educational level moderates the relationship between baseline depressive symptoms and cognitive functioning at 5- and 10-year follow-ups in older adults, considering the association between cognitive functioning and difficulty with activities of daily living (ADL).

DESIGN

Using a prospective design, a path analysis was performed.

SETTING

In-home, face-to-face interviews and self-administered questionnaires, within the National Social Life, Health, and Aging Project.

PARTICIPANTS

In total, 1,461 participants (mean age = 66.62) were followed up from Wave 1 (baseline) to Wave 2 (at 5 years) and Wave 3 (at 10 years).

MEASUREMENTS

Depressive symptoms were assessed at baseline. Cognitive functioning and difficulty with ADL were assessed at baseline and at 5 and 10 years.

RESULTS

Educational level moderates the relationship between depressive symptoms and cognitive functioning at 5 years (β = 0.07, SE = 0.03, p = 0.04, Cohen's f2 = 0.02), being depressive symptoms related to poor cognitive functioning only at low educational levels. Cognitive functioning predicts difficulty with ADL at 5 and 10 years (β = -0.08, SE = 0.03, p = 0.008, Cohen's f2 = 0.01; β = -0.09, SE = 0.03, p = 0.006, Cohen's f2 = 0.02). The proposed model yielded excellent fit (CFI = 1.00, RMSEA = 0.0001, 90% CI 0.0001-0.03, SRMR = 0.004, and χ2(8) = 7.16, p = 0.52).

CONCLUSIONS

Cognitive reserve may act as a protective factor against the effect of depressive symptoms on cognition in older adults, which, in turn, is relevant to their functional independence.

Sex differences in risk factors for cognitive decline and dementia, including death as a competing risk, in individuals with diabetes: Results from the ADVANCE trial

AIM

To estimate the associations between risk factors and cognitive decline (CD)/dementia, and the sex differences in these risk factors in individuals with type 2 diabetes, while accounting for the competing risk of death.

MATERIALS AND METHODS

The Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) trial of 11,140 individuals with type 2 diabetes was used to estimate the odds of CD/dementia using multinomial logistic regression.

RESULTS

During a median 5-year follow-up, 1827 participants (43.2% women) had CD/dementia (1718 with CD only; 21 with dementia only; 88 with CD and dementia), and 929 (31.0% women) died without CD/dementia. Women had lower odds of CD/dementia than men (odds ratio [OR] [95% confidence interval], 0.88 [0.77, 1.00]); older age, higher total cholesterol, HbA1c, waist circumference, waist-to-height ratio, moderately increased albumin-creatinine ratio, stroke/transient ischaemic attack and retinal disease were each associated with greater odds of CD/dementia; higher years at education completion, baseline cognitive function, taller stature and current alcohol use were inversely associated. Higher waist circumference (women-to-men ratio of ORs [ROR], 1.05 [1.00, 1.10] per 5 cm) and presence of anxiety/depression (ROR, 1.28 [1.01, 1.63]) were associated with greater ORs for CD/dementia in women than men.

CONCLUSIONS

Several risk factors were associated with CD/dementia. Higher waist circumference and mental health symptoms were more strongly associated with CD/dementia in women than men. Further studies should examine the mechanisms that underlie these sex differences.

Does the application of acetylcholinesterase inhibitors in the treatment of Alzheimer's disease lead to depression?

Introduction: Alzheimer's disease and depression are health conditions affecting millions of people around the world. Both are strongly related to the level of the neurotransmitter acetylcholine. Since cholinergic deficit is characteristic of Alzheimer's disease, acetylcholinesterase inhibitors are applied as relevant drugs for the treatment of this disease, elevating the level of acetylcholine. On the other hand, a high level of acetylcholine is found to be associated with the symptoms of clinical depression.Areas covered: This article aims to discuss if acetylcholinesterase inhibitors used as anti-Alzheimer's drugs could be the cause of the symptoms of clinical depression often linked to this neurological disorder. Emphasis will be put on drugs currently in use and on newly investigated natural products, which can inhibit AChE activity.Expert opinion: Currently, it is not proven that the patient treated for Alzheimer's disease is prone to increased risk for depression due to the acetylcholinesterase inhibition, but there are strong indications. The level of acetylcholine is not the only factor in highly complicated diseases like AD and depression. Still, it needs to be considered isolated, keeping in mind the nature of presently available therapy, especially during a rational drug design process.

Is there a combined effect of depression and cognitive reserve on cognitive function? Findings from a population-based study

OBJECTIVE

To analyse the combined effect of depression and cognitive reserve (CR) on cognition over a three-year follow-up period; and to explore this relationship specifically in individuals aged 65+ years.

DESIGN

Data from the 'Edad con Salud' project were analysed (n = 1,144; 50+ years).

MAIN OUTCOME MEASURES

The Composite International Diagnostic Interview was used to evaluate depression. CR was assessed with the Cognitive Reserve Questionnaire. Episodic memory was assessed with the word list memory and recall. Verbal fluency was measured through the animal naming task. Random coefficient regression analyses were performed.

RESULTS

Depression was associated with lower scores in episodic memory, whereas increased levels of CR were related with higher scores across all the cognitive tests. Among older-aged individuals, cognition decreased at lower levels of CR regardless of depression, while participants with depression exhibited decreased values in both measures of memory at higher levels of CR.

CONCLUSION

Depression and CR were related with cognitive performance. Among older individuals, those with low levels of CR may constitute a vulnerable group with poor cognitive prognosis, whilst a harmful effect of depression on memory performance was observed among individuals with greater CR. Further evidence needs to be gathered to understand these associations.

Gut microbiota in mental health and depression: role of pre/pro/synbiotics in their modulation

The microbiome residing in the human gut performs a wide range of biological functions. Recently, it has been elucidated that a change in dietary habits is associated with alteration in the gut microflora which results in increased health risks and vulnerability towards various diseases. Falling in line with the same concept, depression has also been shown to increase its prevalence around the globe, especially in the western world. Various research studies have suggested that changes in the gut microbiome profile further result in decreased tolerance of stress. Although currently available medications help in relieving the symptoms of depressive disorders briefly, these drugs are not able to completely reverse the multifactorial pathology of depression. The discovery of the communication pathway between gut microbes and the brain, i.e. the Gut-Brain Axis, has led to new areas of research to find more effective and safer alternatives to current antidepressants. The use of probiotics and prebiotics has been suggested as being effective in various preclinical studies and clinical trials for depression. Therefore, in the present review, we address the new antidepressant mechanisms via gut microbe alterations and provide insight into how these can provide an alternative to antidepressant therapy without the side effects and risk of adverse drug reactions.

Sublingual AKBA Exerts Antidepressant Effects in the Aβ-Treated Mouse Model

The 3-O-acetyl-11-keto-β-boswellic acid (AKBA) is the most active compound of Boswellia serrata proposed for treating neurodegenerative disorders, including Alzheimer’s disease (AD), characterized in its early phase by alteration in mood. Accordingly, we have previously demonstrated that an intracerebroventricular injection of soluble amyloid beta _1-42 (Aβ) peptide evokes a depressive-like phenotype in rats. We tested the protective effects of AKBA in the mouse model of an Aβ-induced depressive-like phenotype. We evaluated the depressive-like behavior by using the tail suspension test (TST) and the splash test (ST). Behavioral analyses were accompanied by neurochemical quantifications, such as glutamate (GLU), kynurenine (KYN) and monoamines, and by biochemical measurements, such as glial fibrillary acid protein (GFAP), CD11b and nuclear factor kappa B (NF-kB), in mice prefrontal cortex (PFC) and hippocampus (HIPP). AKBA prevented the depressive-like behaviors induced by Aβ administration, since we recorded a reduction in latency to initiate self-care and total time spent to perform self-care in the ST and reduced time of immobility in the TST. Likewise, the increase in GLU and KYN levels in PFC and HIPP induced by the peptide injection were reverted by AKBA administration, as well as the displayed increase in levels of GFAP and NF-kB in both PFC and HIPP, but not in CD11b. Therefore, AKBA might represent a food supplement suitable as an adjuvant for therapy of depression in early-stage AD.

Depression as a Risk Factor for Alzheimer's Disease: A Systematic Review of Longitudinal Meta-Analyses

Alzheimer’s disease (AD) is the most frequent cause of dementia, linked to morbidity and mortality among elderly patients. Recently, several clinical studies suggested that depression is a potential risk factor for cognitive decline and AD. A review of meta-analyses was performed, calculating pooled odds ratios to estimate the risk of AD in people with a prior diagnosis (or clinically significant symptoms) of depression. A total of six meta-analyses which represented 28 individual studies were analyzed. A significant association between depression and AD was found (OR = 1.54, 95% CI [1.02–2.31]; p = 0.038). The results showed that heterogeneity across studies was substantial. We found a significant positive effect size for clinical measures of depression, but not for symptomatic rating scales, in the association of depression with risk of AD. The type of rating scale used to assess depression and the cut-off criteria selected also moderated the relationship between depression and AD risk. We found that studies that used clinically significant criteria for diagnosis of depression had more consistent and significant results than studies that used symptomatic scales.

Depression and the Diagnosis of MCI in a Culturally Diverse Sample in the United States

OBJECTIVE

To analyze (1) whether there are ethnic differences in the severity of depressive symptoms between groups of elders classified as cognitively normal (CN) or amnestic mild cognitive impairment (aMCI) and (2) the influence of depressive symptoms on specific cognitive performance by ethnicity across diagnoses, controlling for covariates.

METHODS

164 Hispanics residing in the United States (HAs) and European Americans (EAs) (100 women; Mage = 72.1, SD = 8.0) were diagnosed as either CN or aMCI. Depressive symptoms were measured with the Geriatric Depression Scale (GDS-15). Cognition was assessed using the Loewenstein-Acevedo Scales for Semantic Interference and Learning (semantic memory), Multilingual Naming Test (confrontation naming), and the Stroop Test (Color-Word condition; executive function). A 2 × 2 univariate ANCOVA as well as linear and logistic regressions explored differences in depressive symptoms among diagnostic and ethnic groups.

RESULTS

Higher depression was seen in aMCI compared to the CN group for both ethnicities, after controlling for age, education, gender, and Mini-Mental State Examination score. Greater levels of depression also predicted lower scores in confrontation naming and semantic memory for only the EA group and marginally in scores of executive function for HA participants. GDS-15 scores of ≤ 4 also predicted less likelihood of aMCI diagnosis.

CONCLUSIONS

Severity of depressive symptoms was associated with greater cognitive impairment, independent of ethnicity. Significant results suggest detrimental effects of depression on clinical diagnoses most evidently for subjects from the EA group.

The Effects of COVID-19 Among the Elderly Population: A Case for Closing the Digital Divide

The COVID-19 pandemic has had huge effects on the daily lives of most individuals in the first half of 2020. Widespread lockdown and preventative measures have isolated individuals, affected the world economy, and limited access to physical and mental healthcare. While these measures may be necessary to minimize the spread of the virus, the negative physical, psychological, and social effects are evident. In response, technology has been adapted to try and mitigate these effects, offering individuals digital alternatives to many of the day-to-day activities which can no longer be completed normally. However, the elderly population, which has been worst affected by both the virus, and the lockdown measures, has seen the least benefits from these digital solutions. The age based digital divide describes a longstanding inequality in the access to, and skills to make use of, new technology. While this problem is not new, during the COVID-19 pandemic it has created a large portion of the population suffering from the negative effects of the crisis, and unable to make use of many of the digital measures put in place to help. This paper aims to explore the increased negative effects the digital divide is having in the elderly population during the COVID-19 pandemic. It also aims to highlight the need for increased attention and resources to go toward improving digital literacy in the elderly, and the need to put in place measures to offer immediate solutions during the COVID-19 crisis, and solutions to close the digital divide for good in the long-term.

Positive Affect Is Associated With Less Memory Decline: Evidence From a 9-Year Longitudinal Study

Memory decline is a concern for aging populations across the globe. Positive affect plays an important role in healthy aging, but its link with memory decline has remained unclear. In the present study, we examined associations between positive affect (i.e., feeling enthusiastic, attentive, proud, active) and memory (i.e., immediate and delayed recall), drawing from a 9-year longitudinal study of a national sample of 991 middle-age and older U.S. adults. Results revealed that positive affect was associated with less memory decline across 9 years when analyses controlled for age, gender, education, depression, negative affect, and extraversion. Findings generalized across another measure that assessed additional facets of positive affect, across different (but not all) facets of positive affect and memory, and across age, gender, and education; findings did not emerge for negative affect. Reverse longitudinal associations between memory and positive affect were not significant. Possible pathways linking positive affect and memory functioning are discussed.

Association of Late Life Depression, (Non-) Modifiable Risk and Protective Factors with Dementia and Alzheimer's Disease: Literature Review on Current Evidences, Preventive Interventions and Possible Future Trends in Prevention and Treatment of Dementia

The number of people living with dementia and Alzheimer’s disease is growing rapidly, making dementia one of the biggest challenges for this century. Many studies have indicated that depression plays an important role in development of dementia, including Alzheimer’s disease; depression, especially, during the late life may either increase the risk of dementia or even being its prodromal stage. Despite a notably large number of carried observational studies and/or clinical trials, the association between the late life depression and dementia remains, due to the complexity of their relationship, still unclear. Moreover, during past two decades multiple other (non-)modifiable risk and possibly protective factors such as the hypertension, social engagement, obesity, level of education or physical (in)activity have been identified and their relationship with the risk for development of dementia and Alzheimer’s disease has been extensively studied. It has been proposed that to understand mechanisms of dementia and Alzheimer’s disease pathogeneses require their multifactorial nature represented by these multiple factors to be considered. In this review, we first summarize the recent literature findings on roles of the late life depression and the other known (non-)modifiable risk and possibly protective factors in development of dementia and Alzheimer’s disease. Then, we provide evidences supporting hypotheses that (i) depressive syndromes in late life may indicate the prodromal stage of dementia (Alzheimer’s disease) and, (ii) the interplay among the multiple (non-)modifiable risk and protective factors should be considered to gain a better understanding of dementia and Alzheimer’s disease pathogeneses. We also discuss the evidences of recently established interventions considered to prevent or delay the prodromes of dementia and provide the prospective future directions in prevention and treatment of dementia and Alzheimer’s disease using both the single-domain and multidomain interventions.

Modifiable Risk Factors for Poor Cognitive Function in Former American-Style Football Players: Findings from the Harvard Football Players Health Study

Recent attention to consequences of head trauma among former professional American-style football players has increased the likelihood that former players and their healthcare providers attribute neurocognitive effects to these exposures. In addition to head trauma, however, many potentially modifiable risk factors are associated with cognitive impairment. We examined the association of self-reported risk factors for cognitive impairment (e.g., cardiovascular health, sleep, pain, depression, anxiety, smoking, physical impairment, and physical activity) with cognition-related quality of life, measured by the Quality of Life in Neurological Disorders, Applied Cognition-General Concerns (Neuro-QOL) among 3803 former National Football League (NFL) players. We examined the prevalence of risk factors among men who had experienced a high number of concussion symptoms during playing years, comparing men with good current cognition-related QOL, the "healthy concussed," to men with poor cognition-related QOL, the "unhealthy concussed." Physical functioning, pain, depression, and anxiety were very strongly associated with poor cognitive-related QOL (risk ratio range, 2.21-2.70, p < 0.0001 for all). Short sleep duration and low physical activity were also strongly associated (RR = 1.69 and 1.57, respectively, p < 0.0001 for both). The largest differences between healthy and unhealthy concussed were in chronic pain (72.0% vs. 21.2%), depressive symptoms (50.3% vs. 6.3%), anxiety symptoms (53.4% vs. 11.6%), and physical impairment (52.4% vs. 12.5%). Substantial differences also existed in prevalence of sleep apnea, short sleep duration, high-intensity exercise, weight training, high blood pressure, and body mass index ≥35 kg/m² (all differences >10 percentage points). We identified cognitive risk factors, including chronic pain, mood problems, sleep problems, obesity, and lack of exercise, that were commonly present in former football players with cognition-related impairment. Better treatment for these factors may reduce cognitive problems in this population.

Effects of Process-Based Cognitive Training on Memory in the Healthy Elderly and Patients with Mild Cognitive Impairment: A Randomized Controlled Trial

OBJECTIVE

This study investigated the effects of process-based cognitive training that targets working memory and cognitive control on memory improvement in healthy elderly individuals and patients with mild cognitive impairment (MCI).

METHODS

Forty healthy subjects and 40 patients with MCI were randomly assigned to either the intervention or control group. The intervention group received 12 sessions of designated cognitive training. The control group did not receive cognitive training. A memory test was administered pre-intervention, post-intervention, and 4 weeks after the intervention. Additional comprehensive neuropsychological tests were also administered including a depression scale questionnaire.

RESULTS

Performance in attention and working memory, which are directly related to the training domains, and global cognitive function were improved in the intervention group after training. In memory tests, interference by irrelevant stimuli was reduced and recognition memory was improved after the intervention. Furthermore, cognitive training ameliorated depressive symptoms. These training effects were not dependent on MCI status.

CONCLUSION

Process-based cognitive training that targets working memory and cognitive control effectively improves memory processes including retrograde interference and recognition, as well as depressive symptoms associated with aging in healthy elderly individuals and patients with MCI.

Transcranial sonography imaging of brainstem raphe, substantia nigra and cerebral ventricles in patients with geriatric depression

OBJECTIVES

Geriatric depression is a special condition associated with a chronic course, treatment resistance and vascular processes. However, its neurobiology has not been fully elucidated. There is no study in geriatric depression evaluating deep brain structures with transcranial sonography (TCS) which is a low-cost, non-invasive and practical tool. The present study aimed to evaluate the changes in the echogenicity of brainstem raphe (BR), substantia nigra (SN) and ventricular diameters by TCS in association with cognitive dysfunctions in patients with geriatric depression.

METHODS

Echogenicity of BR and SN were assessed and transverse diameters of the third ventricle and frontal horns of the lateral ventricles were measured by TCS in 34 patients with DSM-5 major depression and 31 healthy volunteers aged 60 and older. Cognitive functions were evaluated by using Mini Mental State Examination, Montreal Cognitive Assessment Tool, Clock Drawing Test and Subjective Memory Complaints Questionnaire.

RESULTS

Although depressed patients had more subjective memory complaints than controls, they had similar cognitive performances. Reduced echogenicity (interrupted/invisible echogenic line) of BR was found to be significantly higher and the ventricular diameters were larger in the depressed group. There was no difference between the groups in terms of SN echogenicity. There was no correlation between ventricular diameters and depression severity or cognitive functions.

CONCLUSIONS

Results of the present study are important in terms of pointing out neurobiological changes related to geriatric depression which are in parallel with the results of the studies in younger patients with depression. However, long-term follow-up studies are required for accurate differentiation of neurocognitive disorders.

Association between Shift Work and Neurocognitive Function among Firefighters in South Korea: A Prospective Before-After Study

Background: Recent research indicates that shift work is associated with neurocognitive function. However, studies that examine the association between shift work and neurocognitive function in firefighters have not yet been performed. We examined the effect of shift work on neurocognitive function in firefighters by measuring and comparing neurocognitive function before and after night shift. Methods: 352 firefighters from eight fire stations in South Korea were included in this study. We performed neurocognitive function test using central nervous system vital signs (CNSVS) during daytime work and on the next day after night work. We performed paired t-tests to assess differences between neurocognitive function before and after night work. We also compared neurocognitive function in insomnia and depression. We used a general linear model to analyze the associations between shiftwork schedule and the changes in neurocognitive function. Results: The neurocognitive function significantly decreased in six domains (composite memory, verbal memory, visual memory, complex attention, psychomotor speed, and motor speed) as did the neurocognitive index on the next day after night work compared with during day work. These decreased domains were the same following night work regardless of the type of shift work. Conclusion: Night work in firefighters may cause neurocognitive decline.

Association of depressive symptoms with decline of cognitive function-Rugao longevity and ageing study

Cognitive decline is a central feature in the aging process. Previous studies have indicated an association between depressive symptoms and cognitive decline in Caucasian populations. However, few studies have examined the effect of changes in depression on the trajectory of cognitive decline. Here, we included 580 participants with normal cognitive ability and complete cognitive and depression data from the Rugao Longevity and Ageing Study (RuLAS). We explored the relationship between depressive symptoms and cognitive decline in these participants. We examined how the change in depressive symptoms affected the trajectory in the HDS-R (the Revised Hasegawa Dementia Scale) scores by comparing cognition function in both the depression deterioration group and the depression steady group by using a linear mixed model. The results indicated that those with deteriorating depression tended to have faster cognitive declines than those with steady depression, indicated by the significance of the interaction term of GDS (Geriatric Depression Scale) groups and time (unadjusted model, β = - 0.673, p < 0.001). The results remained significant after adding demographic covariates. Moreover, we found that those with the worst depressive symptoms at baseline had the worst cognition in subsequent years (GDS = 0 group vs. GDS ≥ group in the unadjusted model: β = - 1.522, p < 0.003), while the slope of change was not significantly different among groups (GDS = 0 group × time vs. GDS > =4 group × time in the unadjusted model: β = - 0.045, p = 0.857). Therefore, we found that depressive symptom deterioration was significantly associated with faster cognitive decline. Medical interventions for depression may decrease the number of older Chinese individuals who experience early-stage cognitive decline.

Depressive Symptoms in the Elderly-An Early Symptom of Dementia? A Systematic Review

Background

Depression and dementia are common incapacitating diseases in old age. The exact nature of the relationship between these conditions remains unclear, and multiple explanations have been suggested: depressive symptoms may be a risk factor for, a prodromal symptom of, or a coincidental finding in dementia. They may even be unrelated or only connected through common risk factors. Multiple studies so far have provided conflicting results.

Objectives

To determine whether a systematic literature review can clarify the nature of the relation between depressive symptoms and dementia.

Methods

Using the Patient/Problem/Population, Intervention, Comparator, Outcome or PICO paradigm, a known framework for framing healthcare and evidence questions, we formulated the question “whether depressive symptoms in cognitively intact older adults are associated with a diagnosis of dementia later in life.” We performed a systematic literature review of MEDLINE and PsycINFO in November 2018, looking for prospective cohort studies examining the aforementioned question.

Results

We critically analyzed and listed 31 relevant papers out of 1,656 and grouped them according to the main hypothesis they support: depressive symptoms as a risk factor, not a risk factor, a prodromal symptom, both, or some specific other hypothesis. All but three studies used clinical diagnostic criteria for dementia alone (i.e., no biomarkers or autopsy confirmation). Several studies contain solid arguments for the hypotheses they support, yet they do not formally contradict other findings or suggested explanations and are heterogeneous.

Conclusions

The exact nature of the relationship between depressive symptoms and dementia in the elderly remains inconclusive, with multiple studies supporting both the risk factor and prodromal hypotheses. Some provide arguments for common risk factors. It seems unlikely that there is no connection at all. We conclude that at least in a significant part of the patients, depressive symptoms and dementia are related. This may be due to common risk factors and/or depressive symptoms being a prodromal symptom of dementia and/or depression being a risk factor for dementia. These causal associations possibly overlap in some patients. Further research is warranted to develop predictive biomarkers and to develop interventions that may attenuate the risk of “conversion” from depressive symptoms to dementia in the elderly.

Monoaminergic System Modulation in Depression and Alzheimer's Disease: A New Standpoint?

The prevalence of depression has dramatically increased, and it has been estimated that over 300 million people suffer from depression all over the world. Depression is highly comorbid with many central and peripheral disorders. In this regard, depressive states have been associated with the development of neurological disorders such as Alzheimer's disease (AD). Accordingly, depression is a risk factor for AD and depressive symptomatology is common in pre-clinical AD, representing an early manifestation of this disease. Neuropsychiatric symptoms may represent prodromal symptoms of dementia deriving from neurobiological changes in specific cerebral regions; thus, the search for common biological substrates is becoming an imperative and intriguing field of research. Soluble forms of beta amyloid peptide (Aβ) have been implicated both in the development of early memory deficits and neuropsychiatric symptoms. Indeed, soluble Aβ species have been shown to induce a depressive-like phenotype in AD animal models. Alterations in monoamine content are a common feature of these neuropathologies. Interestingly, serotonergic system modulation has been implicated in alteration of Aβ production. In addition, noradrenaline is considered crucially involved in compensatory mechanisms, leading to increased Aβ degradation via several mechanisms, including microglia modulation. In further agreement, antidepressant drugs have also been shown to potentially modulate cognitive symptoms in AD and depression. Thus, the present review summarizes the main knowledge about biological and pathological substrates, such as monoamine and related molecules, commonly involved in AD and depression pathology, thus shading light on new therapeutic approaches.

Affective problems and decline in cognitive state in older adults: a systematic review and meta-analysis

Evidence suggests that affective problems, such as depression and anxiety, increase risk for late-life dementia. However, the extent to which affective problems influence cognitive decline, even many years prior to clinical diagnosis of dementia, is not clear. The present study systematically reviews and synthesises the evidence for the association between affective problems and decline in cognitive state (i.e., decline in non-specific cognitive function) in older adults. An electronic search of PubMed, PsycInfo, Cochrane, and ScienceDirect was conducted to identify studies of the association between depression and anxiety separately and decline in cognitive state. Key inclusion criteria were prospective, longitudinal designs with a minimum follow-up period of 1 year. Data extraction and methodological quality assessment using the STROBE checklist were conducted independently by two raters. A total of 34 studies (n = 71 244) met eligibility criteria, with 32 studies measuring depression (n = 68 793), and five measuring anxiety (n = 4698). A multi-level meta-analysis revealed that depression assessed as a binary predictor (OR 1.36, 95% CI 1.05-1.76, p = 0.02) or a continuous predictor (B = -0.008, 95% CI -0.015 to -0.002, p = 0.012; OR 0.992, 95% CI 0.985-0.998) was significantly associated with decline in cognitive state. The number of anxiety studies was insufficient for meta-analysis, and they are described in a narrative review. Results of the present study improve current understanding of the temporal nature of the association between affective problems and decline in cognitive state. They also suggest that cognitive function may need to be monitored closely in individuals with affective disorders, as these individuals may be at particular risk of greater cognitive decline.

The moderating effect of subjective age on the association between depressive symptoms and cognitive functioning in Korean older adults

OBJECTIVES

Depressive symptoms are greatly associated with cognitive impairment in older adults. Recent growing body of literature has reported that the subjective perception of one's own age (subjective age) predicts both cognitive performance and mental well-being in old age. This study aims to examine whether subjective age moderates the association between depressive symptoms and cognitive functioning in a representative sample of Korean older adults. To address this research question, we employed the Stereotype-Embodiment Theory as a theoretical guide.

METHOD

Data are from the 2016 Dementia Literacy Survey collected by Kyung Hee University, and 526 community-dwelling Korean older adults (ages 60-79) completed the questionnaire about depressive symptoms, cognitive functioning, and subjective age.

RESULTS

According to the hierarchical regression analysis, both higher levels of depressive symptoms and older subjective age were associated with poorer cognitive functioning. Further analyses showed that subjective age attenuated the effect of depressive symptoms on cognitive functioning: when older adults have a higher level of depression, those with younger subjective age reported a higher level of cognitive functioning than those with older subjective age.

CONCLUSION

Based on the findings from this study, both theoretical and practical implications were discussed.

Aberrant Default Mode Network Underlying the Cognitive Deficits in the Patients With Late-Onset Depression

Late-onset depression (LOD) is regarded as a risk factor or a prodrome of Alzheimer’s disease (AD). Moreover, LOD patients with cognitive deficits have the higher risk of subsequent AD. Thus, it is necessary to understand the neural underpinnings of cognitive deficits and its pathological implications in LOD. Consistent findings show that the default mode network (DMN) is an important and potentially useful brain network for the cognitive deficits in LOD patients. In recent years, genetics has been actively researched as a possible risk factor in the pathogenesis of LOD. So, in this review, we discuss the current research progress on the cognitive deficits and DMN in LOD through a combined view of brain network and genetics. We find that different structural and functional impairments of the DMN might be involved in the etiological mechanisms of different cognitive impairments in LOD patients.

The Role of Physical Exercise and Omega-3 Fatty Acids in Depressive Illness in the Elderly

Background:

In adulthood, depression is the most common type of mental illness and will be the second leading cause of disease by 2020. Major depression dramatically affects the function of the central nervous system and degrades the quality of life, especially in old age.

Several mechanisms underlie the pathophysiology of depressive illness, since it has a multifactorial etiology. Human and an-imal studies have demonstrated that depression is mainly associated with imbalances in neurotransmitters and neurotrophins, hypothalamic-pituitary-adrenal axis alterations, brain volume changes, neurogenesis dysfunction, and dysregulation of in-flammatory pathways. Also the gut microbiota may influence mental health outcomes.

Although depression is not a consequence of normal aging, depressive disorders are common in later life, even if often undi-agnosed or mis-diagnosed in old age. When untreated, depression reduces life expectancy, worsens medical illnesses, en-hances health care costs and is the primary cause of suicide among older people. To date, the underpinnings of depression in the elderly are still to be understood, and the pharmacological treatment is the most commonly used therapy.

Objective:

Since a sedentary lifestyle and poor eating habits have recently emerged as crucial contributors to the genesis and course of depression, in the present review, we have focused on the effects of physical activity and omega-3 fatty acids on depressive illness in the elderly.

Results:

A growing literature indicates that both exercise and dietary interventions can promote mental health throughout one’s lifespan.

Conclusion:

There thus emerges the awareness that an active lifestyle and a balanced diet may constitute valid low-cost pre-vention strategies to counteract depressive illness in the elderly.

A Remote Intervention to Prevent or Delay Cognitive Impairment in Older Adults: Design, Recruitment, and Baseline Characteristics of the Virtual Cognitive Health (VC Health) Study

Background

A growing body of evidence supports the use of lifestyle interventions for preventing or delaying the onset of Alzheimer disease and other forms of dementia in at-risk individuals. The development of internet-delivered programs would increase the scalability and reach of these interventions, but requires validation to ensure similar effectiveness to brick-and-mortar options.

Objective

We describe the study design, recruitment process, and baseline participant characteristics of the sample in the Virtual Cognitive Health (VC Health) study. Future analyses will assess the impact of the remotely delivered lifestyle intervention on (1) cognitive function, (2) depression and anxiety, and (3) various lifestyle behaviors, including diet, exercise, and sleep, in a cohort of older adults with subjective memory decline. Additional analyses will explore feasibility outcomes, as well as the participants’ engagement patterns with the program.

Methods

Older adults (aged 60-75 years) with subjective memory decline as measured by the Subjective Cognitive Decline 9-item (SCD-9) questionnaire, and who reported feeling worried about their memory decline, were eligible to participate in this single-arm pre-post study. All participants enrolled in the yearlong digital intervention, which consists of health coach-guided lifestyle change for improving diet, exercise, sleep, stress, and cognition. All components of this study were conducted remotely, including the collection of data and the administration of the intervention. We assessed participants at baseline, 12 weeks, 24 weeks, and 52 weeks with online surveys and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) test. We will conduct intention-to-treat analysis on all outcomes.

Results

A total of 85 participants enrolled in the intervention and 82 are included in the study sample (3 participants withdrew). The study cohort of 82 participants comprises 61 (74%) female, 72 (88%) white, and 64 (78%) overweight or obese participants, and 55 (67%) have at least a college degree. The average baseline RBANS score was 95.9 (SD 11.1), which is within age-adjusted norms. The average SCD-9 score was 6.0 (SD 2.0), indicating minor subjective cognitive impairment at the beginning of the study. The average baseline Generalized Anxiety Disorder 7-item scale score was 6.2 (SD 4.5), and the average Patient Health Questionnaire 9-item score was 8.5 (SD 4.9), indicating mild levels of anxiety and depression at baseline.

Conclusions

Internet-delivered lifestyle interventions are a scalable solution for the prevention or delay of Alzheimer disease. The results of this study will provide the first evidence for the effectiveness of a fully remote intervention and lay the groundwork for future investigations.

Trial Registration

ClinicalTrials.gov NCT02969460; http://clinicaltrials.gov/ct2/show/NCT02969460 (Archived by WebCite at http://www.webcitation.org/71LkYAkSh)

Registered Report Identifier

RR1-10.2196/11368

Pharmacotherapy for the treatment of depression in patients with alzheimer's disease: a treatment-resistant depressive disorder

INTRODUCTION

Pharmacotherapy for the treatment of depressive disorders in Alzheimer's Disease (AD) represents a clinical challenge. pharmacological options are often attempted after a period of watchful waiting (8-12 weeks). monoaminergic antidepressant drugs have shown only modest or null clinical benefits, maybe because the etiology of depressive symptoms in ad patients is fundamentally different from that of nondemented subjects.

AREAS COVERED

The following article looks at the selective serotonin reuptake inhibitor sertraline, which is one of the most frequently studied antidepressant medications in randomized controlled trials (RCTs). It also discusses many other pharmacological approaches that have proven to be inadequate (antipsychotics, acetylcholinesterase inhibitors, anticonvulsants, hormone replacement therapy) and new drug classes (mainly affecting glutamate transmission) that are being studied for treating depression in AD. It also gives discussion to the phase II RCT on the alternative drug S47445 and the potential effect on cognition of the multimodal antidepressant vortioxetine in older depressed patients. Finally, it discusses the N-methyl-D-aspartate antagonist ketamine.

EXPERT OPINION

The present RCT methodologies are too disparate to draw firm conclusions. Future studies are required to identify effective and multimodal pharmacological treatments that efficiently treat depression in AD. Genotyping may boost antidepressant treatment success.

Design, synthesis and evaluation of vilazodone-tacrine hybrids as multitarget-directed ligands against depression with cognitive impairment

Depression, a severe mental disease, is greatly difficult to treat and easy to induce other neuropsychiatric symptoms, the most frequent one is cognitive impairment. In this study, a series of novel vilazodone-tacrine hybrids were designed, synthesized and evaluated as multitarget agents against depression with cognitive impairment. Most compounds exhibited good multitarget activities and appropriate blood-brain barrier permeability. Specifically, compounds 1d and 2a exhibited excellent 5-HT_1A agonist activities (1d, EC₅₀ = 0.36 ± 0.08 nM; 2a, EC₅₀ = 0.58 ± 0.14 nM) and 5-HT reuptake inhibitory activities (1d, IC₅₀ = 20.42 ± 6.60 nM; 2a, IC₅₀ = 22.10 ± 5.80 nM). In addition, they showed moderate ChE inhibitory activities (1d, AChE IC₅₀ = 1.72 ± 0.217 μM, BuChE IC₅₀ = 0.34 ± 0.03 μM; 2a, AChE IC₅₀ = 2.36 ± 0.34 μM, BuChE IC₅₀ = 0.10 ± 0.01 μM). Good multitarget activities with goodt blood-brain barrier permeability of 1d and 2a make them good lead compounds for the further study of depression with cognitive impairment.

Reducing Depressive Symptoms in Nursing Home Residents: Evaluation of the Pennsylvania Depression Collaborative Quality Improvement Program

Depression reduces quality of life for nursing home (NH) residents and places them at greater risk for disability, medical morbidity, and mortality. However, accumulating evidence suggests that interventions for early detection and treatment can mitigate symptoms of clinical and subclinical levels of depression. The Promoting Positive Well-Being (PPW) program is a quality improvement (QI) intervention that features tools and strategies to assist NHs in early identification, assessment, treatment, and monitoring of residents with depressive symptoms. The PPW was evaluated in 40 NHs through an 8-month QI collaborative that provided participants with tools, webinar training, and technical support. Results showed a significant group by time interaction effect with facility quality rating as a covariate; the active group (n = 18 NHs) outperformed the waitlist control group (n = 19 NHs). In all, there was a 58% relative reduction in the percentage of residents with self-reported moderate-to-severe depressive symptoms. Most NHs reported that they were satisfied with the collaborative (97%) and would recommend it to others (86%); only 15% reported significant challenges. The rate of webinar attendance and data submission compliance was 92%. Results suggest that PPW is a promising approach that should be further evaluated in larger NH initiatives and other settings.