Stress, depression, and risk of dementia - a cohort study in the total population between 18 and 65 years old in Region Stockholm

No causal relationship between serum urate and neurodegenerative diseases: A Mendelian randomization study

OBJECTIVE

Observational studies have shown that increased serum urate is associated with a lower risk of neurodegenerative diseases (NDs), but the causality remains unclear. We employed a two-sample Mendelian randomization (MR) approach to assess the causal relationship between serum urate and four common subtypes of NDs, including Parkinson's disease (PD), Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS).

METHODS

Serum urate data came from the CKDGen Consortium. GWAS data for PD, AD, ALS, and MS were obtained from four databases in the primary analysis and then acquired statistics from the FinnGen consortium for replication and meta-analysis. Inverse variance weighted (IVW), weighted median (WM), and MR-Egger regression methods were applied in the MR analyses. Pleiotropic effects, heterogeneity, and leave-one-out analyses were evaluated to validate the results.

RESULTS

There was no evidence for the effect of serum urate on PD (OR: 1.00, 95 % CI: 0.90-1.11, P = 0.97), AD (OR: 1.02, 95 % CI: 1.00-1.04, P = 0.06), ALS (OR: 1.05, 95 % CI: 0.97-1.13, P = 0.22), and MS (OR: 1.01, 95 % CI: 0.89-1.14, P = 0.90) risk when combined with the FinnGen consortium, neither was any evidence of pleiotropy detected between the instrumental variables (IVs).

CONCLUSION

The MR analysis suggested that serum urate may not be causally associated with a risk of PD, AD, ALS, and MS.

Neuroticism personality, social contact, and dementia risk: A prospective cohort study

BACKGROUND

Personality traits, especially neuroticism, can influence susceptibility to dementia. Social contact mitigates stress and risk of dementia, the extent to which social contact can mitigate excess risk associated with neuroticism remains unclear. We aim to investigate whether active social contact is associated with lower neuroticism-associated excess risk of dementia.

METHODS

This prospective cohort study examined 393,939 UK Biobank participants (mean [SD] age: 56.4 [8.1] years; 53.7 % female) assessed from 2006 to 2010 and followed up until December 2022. Neuroticism was measured using the Revised Eysenck Personality Questionnaire. Social contact levels were assessed based on household size, contact with family or friends, and group participation. Dementia was determined using linked electronic health records.

RESULTS

High neuroticism was associated with increased all-cause dementia risk and cause-specific dementia. Among high neuroticism participants, excess risk of all-cause dementia showed a stepwise decrease with increasing social contact (low: hazard ratios (HR) = 1.27, 95 % confidence interval (CI) = 1.15-1.40; intermediate: HR = 1.20, 95 % CI = 1.12-1.28; high: HR = 1.07, 95 % CI = 1.00-1.15). High social contact similarly decreased excess risk of cause-specific dementia, comparable to those with low neuroticism.

LIMITATIONS

Neuroticism and social contact information relied on self-report questionnaires at baseline, with a potential temporal relationship between these factors.

CONCLUSION

Active social contact is associated with a stepwise reduction in excess dementia risk and potentially eliminate excess risk of dementia with high neuroticism individuals, supporting social contact as a preventive strategy to attenuate excess risks of dementia from neuroticism personality trait.

Relevance and Premises of Values-Based Practice for Decision Making in Brain Health

Brain health is a complex concept, shaped by a plethora of determinants related to physical health, healthy environments, safety and security, learning and social connection, as well as access to quality healthcare services. Decision-making in this complex field is characterized by diverse values, potentially conflicting interests, and asymmetrically influential stakeholders. Values-based practice (VBP) is a toolkit for balancing values in a democratic and inclusive way, so that every stakeholder feels a sense of ownership over the decision made. In VBP, the emphasis is on good process rather than on pre-determined 'correct' outcomes. Based on two case vignettes, we highlight the relevance of the ten principles of VBP for balancing different values to the satisfaction of those directly concerned, in a given decision-making process. In addition, we argue that the successful implementation of VBP in the complex area of brain health, as well as in other fields, is premised on higher order values (meta-values), beyond mutual respect and the legal, regulatory, and bioethical framework. These include mutual regard, reciprocity, autonomy, and an egalitarian attitude towards VBP procedures and involved stakeholders.

Midlife stress-related exhaustion and dementia incidence: a longitudinal study over 50 years in women

BACKGROUNDS

Cognitive problems are common symptoms among individuals with stress-related exhaustion. It is still unknown whether these individuals are at a higher risk of developing dementia later. This study aims to examine the relationship between midlife stress-related exhaustion and dementia incidence.

METHODS

A population sample of 777 women (aged 38, 46, 50 and 54 years) without dementia at baseline was followed over 50 years, from 1968 to 2019. Stress-related exhaustion was based on information from the psychiatric examination in 1968/69. Information on dementia incidence between 1968 and 2019 was obtained from neuropsychiatric examinations, key-informant interviews, and hospital registry. Dementia was diagnosed according to the DSM-III-R criteria. A subgroup of non-demented women (n = 284) was examined for cognitive functions by the Gottfries-Bråne-Steen scale 24 years after baseline.

RESULTS

Stress-related exhaustion in midlife was associated with higher risk for development of dementia before age 75 (Hazard ratio and 95% confidence interval: 2.95 and 1.35-6.44). The association remained after adjustment for age, major depression, and anxiety disorder. Mean age of dementia onset was younger for women with stress-related exhaustion than women without stress (mean ± SD, 76 ± 9 vs. 82 ± 8 . p = 0.009). Women with stress-related exhaustion in midlife still showed more cognitive impairments 24 years later compared with women without stress (Odds ratio and 95% confidence interval: 2.64 and 1.15-6.06).

CONCLUSIONS

We found that women with stress-related exhaustion in midlife were at a higher risk to develop dementia at relatively younger age. These women showed persistently lower cognitive functions over years even without dementia. Present study results need to be interpreted with caution due to small sample size and should be confirmed in future studies with larger sample size. Our study findings may imply the importance of long-term follow-up regarding cognitive function among individuals with stress-related exhaustion.

The risk of Alzheimer's disease and cognitive impairment characteristics in eight mental disorders: A UK Biobank observational study and Mendelian randomization analysis

INTRODUCTION

The cognitive impairment patterns and the association with Alzheimer's disease (AD) in mental disorders remain poorly understood.

METHODS

We analyzed data from 486,297 UK Biobank participants, categorizing them by mental disorder history to identify the risk of AD and the cognitive impairment characteristics. Causation was further assessed using Mendelian randomization (MR).

RESULTS

AD risk was higher in individuals with bipolar disorder (BD; hazard ratio [HR] = 2.37, P < 0.01) and major depressive disorder (MDD; HR = 1.63, P < 0.001). MR confirmed a causal link between BD and AD (ORIVW = 1.098), as well as obsessive-compulsive disorder (OCD) and AD (ORIVW = 1.050). Cognitive impairments varied, with BD and schizophrenia showing widespread deficits, and OCD affecting complex task performance.

DISCUSSION

Observational study and MR provide consistent evidence that mental disorders are independent risk factors for AD. Mental disorders exhibit distinct cognitive impairment prior to dementia, indicating the potential different mechanisms in AD pathogenesis. Early detection of these impairments in mental disorders is crucial for AD prevention.

HIGHLIGHTS

This is the most comprehensive study that investigates the risk and causal relationships between a history of mental disorders and the development of Alzheimer's disease (AD), alongside exploring the cognitive impairment characteristics associated with different mental disorders. Individuals with bipolar disorder (BD) exhibited the highest risk of developing AD (hazard ratio [HR] = 2.37, P < 0.01), followed by those with major depressive disorder (MDD; HR = 1.63, P < 0.001). Individuals with schizophrenia (SCZ) showed a borderline higher risk of AD (HR = 2.36, P = 0.056). Two-sample Mendelian randomization (MR) confirmed a causal association between BD and AD (ORIVW = 1.098, P < 0.05), as well as AD family history (proxy-AD, ORIVW = 1.098, P < 0.001), and kept significant after false discovery rate correction. MR also identified a nominal significant causal relationship between the obsessive-compulsive disorder (OCD) spectrum and AD (ORIVW = 1.050, P < 0.05). Individuals with SCZ, BD, and MDD exhibited impairments in multiple cognitive domains with distinct patterns, whereas those with OCD showed only slight declines in complex tasks.

Experimental laboratory models as tools for understanding modifiable dementia risk

Experimental laboratory research has an important role to play in dementia prevention. Mechanisms underlying modifiable risk factors for dementia are promising targets for dementia prevention but are difficult to investigate in human populations due to technological constraints and confounds. Therefore, controlled laboratory experiments in models such as transgenic rodents, invertebrates and in vitro cultured cells are increasingly used to investigate dementia risk factors and test strategies which target them to prevent dementia. This review provides an overview of experimental research into 15 established and putative modifiable dementia risk factors: less early-life education, hearing loss, depression, social isolation, life stress, hypertension, obesity, diabetes, physical inactivity, heavy alcohol use, smoking, air pollution, anesthetic exposure, traumatic brain injury, and disordered sleep. It explores how experimental models have been, and can be, used to address questions about modifiable dementia risk and prevention that cannot readily be addressed in human studies. HIGHLIGHTS: Modifiable dementia risk factors are promising targets for dementia prevention. Interrogation of mechanisms underlying dementia risk is difficult in human populations. Studies using diverse experimental models are revealing modifiable dementia risk mechanisms. We review experimental research into 15 modifiable dementia risk factors. Laboratory science can contribute uniquely to dementia prevention.

Epigenetic modifications of DNA and RNA in Alzheimer's disease

Alzheimer's disease (AD) is a complex neurodegenerative disorder and the most common form of dementia. There are two main types of AD: familial and sporadic. Familial AD is linked to mutations in amyloid precursor protein (APP), presenilin-1 (PSEN1), and presenilin-2 (PSEN2). On the other hand, sporadic AD is the more common form of the disease and has genetic, epigenetic, and environmental components that influence disease onset and progression. Investigating the epigenetic mechanisms associated with AD is essential for increasing understanding of pathology and identifying biomarkers for diagnosis and treatment. Chemical covalent modifications on DNA and RNA can epigenetically regulate gene expression at transcriptional and post-transcriptional levels and play protective or pathological roles in AD and other neurodegenerative diseases.

Differences in psychiatric comorbidity patterns in patients diagnosed with chronic stress-induced exhaustion disorder and depression - A cohort study in the total population of Region Stockholm

The high prevalence of stress-related disorders and depression underscores the urgent need to unravel their impact on individual well-being. This study aim to investigate common psychiatric and stress-related diagnoses, along with postviral fatigue, in individuals with prior stress-induced exhaustion disorder (SED) and prior depression compared to those without prior SED or depression, and to study whether the psychiatric comorbidity patterns differ. The study includes individuals in Region Stockholm who, in 2011, did not have a diagnosis of SED or depression. ICD-10 diagnosis of SED, depression, or both, recorded in 2012-2013, were compared to individuals without prior SED or depression in a cohort (n = 1,362,886), aged 18 to 65. Odds ratios (OR) with 99 % confidence intervals, adjusted for age and neighborhood socioeconomic status, were calculated for psychiatric disorders and post-viral fatigue in 2014-2022. Patients with prior SED showed associations primarily with stress related diagnoses, including acute stress reaction, reaction to severe stress, as well as post-COVID-19 and post-viral fatigue syndrome. These ORs were all larger for SED than depression. Depression was primarily associated with post-traumatic stress disorder (PTSD), alcohol related and substance use disorders, schizophrenia, schizotypal disorders, delusional disorders, manic episode, bipolar affective disorder, persistent mood disorder, neurotic disorder, borderline personality disorder, autistic disorder, Asperger's syndrome, attention -deficit hyperactivity disorder, attention-deficit disorders ADHD/ADD), and suicide attempt. These ORs were all higher for depression, although autistic disorders, ADHD/ADD and PTSD were also highly associated with prior SED (OR > 3.5). The divergent psychiatric comorbidity patterns suggest different underlying mechanisms and clinical prognosis.

The association between religious beliefs and values with inflammation among Middle-age and older adults

Objectives: Dimensions of religion and spirituality are associated with better emotional, physical, and cognitive health. However, the underlying physiological mechanisms are not well known. We investigated the relationship between dimensions of religion and spirituality with levels of C-reactive protein (CRP), a biomarker of systematic inflammation, in middle-aged and older adults in the United States.Methods: In this descriptive longitudinal study using secondary data, we used proportional odds models of the generalized estimating equation (GEE) to assess the association between religious beliefs and values and religious service attendance with CRP levels from respondents (n = 2,385) aged 50 years and older in the Health and Retirement Study from 2006 to 2014.Results: Middle-aged to older adults who reported higher religious beliefs and values had lower levels of CRP, controlling for age, sex, education, marital status, race, household income, and health, such as hypertension, diabetes, cancer, and body mass index (BMI).Conclusion: Religious beliefs and values are associated with lower CRP levels among middle-aged and older adults in the U.S. This study adds to the understanding of biological processes underlying the relationship between dimensions of religion and spirituality with better cognitive and physical health, potentially through inflammation.

Immediate-Early Genes as Influencers in Genetic Networks and their Role in Alzheimer's Disease

Immediate-early genes (IEGs) are a class of activity-regulated genes (ARGs) that are transiently and rapidly activated in the absence of de novo protein synthesis in response to neuronal activity. We explored the role of IEGs in genetic networks to pinpoint potential drug targets for Alzheimer's disease (AD). Using a combination of network analysis and genome-wide association study (GWAS) summary statistics we show that (1) IEGs exert greater topological influence across different human and mouse gene networks compared to other ARGs, (2) ARGs are sparsely involved in diseases and significantly more mutational constrained compared to non-ARGs, (3) Many AD-linked variants are in ARGs gene regions, mainly in MARK4 near FOSB, with an AD risk eQTL that increases MARK4 expression in cortical areas, (4) MARK4 holds an influential place in a dense AD multi-omic network and a high AD druggability score. Our work on IEGs' influential network role is a valuable contribution to guiding interventions for diseases marked by dysregulation of their downstream targets and highlights MARK4 as a promising underexplored AD-target.

Mild Behavioral Impairment and Cerebrovascular Profiles Are Associated with Early Cognitive Impairment in a Community-Based Southeast Asian Cohort

Background

Mild behavioral impairment (MBI) is one of the earliest observable changes when a person experiences cognitive decline and could be an early manifestation of underlying Alzheimer's disease neuropathology. Limited attention has been given to investigating the clinical applicability of behavioral biomarkers for detection of prodromal dementia.

Objective

This study compared the prevalence of self-reported MBI and vascular risk factors in Southeast Asian adults to identify early indicators of cognitive impairment and dementia.

Methods

This cohort study utilized baseline data from the Biomarkers and Cognition Study, Singapore (BIOCIS). 607 participants were recruited and classified into three groups: cognitively normal (CN), subjective cognitive decline (SCD), and mild cognitive impairment (MCI). Group comparisons of cognitive-behavioral, neuroimaging, and blood biomarkers data were applied using univariate analyses. Multivariate logistic regression analyses were conducted to investigate the association between cerebrovascular disease, vascular profiles, and cognitive impairment.

Results

SCD had significantly higher depression scores and poorer quality of life (QOL) compared to CN. MCI had significantly higher depression scores; total MBI symptoms, MBI-interest, MBI-mood, and MBI-beliefs; poorer sleep quality; and poorer QOL compared to CN. Higher Staals scores, glucose levels, and systolic blood pressure were significantly associated with MCI classification. Fasting glucose levels were significantly correlated with depression, anxiety, MBI-social, and poorer sleep quality.

Conclusions

The results reflect current research that behavioral changes are among the first symptoms noticeable to the person themselves as they begin to experience cognitive decline. Self-reported questionnaires may aid in early diagnoses of prodromal dementia. Behavioral changes and diabetes could be potential targets for preventative healthcare for dementia.