Dissecting the Association Between Inflammation, Metabolic Dysregulation, and Specific Depressive Symptoms: A Genetic Correlation and 2-Sample Mendelian Randomization Study

Genome-wide Mendelian randomization mapping the influence of plasma proteome on major depressive disorder

Plasma proteins play critical roles in a series of biological processes and represent a major source of translational biomarkers and drug targets. In this study, we performed Mendelian randomization (MR) to explore potential causal associations of protein quantitative trait loci (pQTL, n = 54,219) with major depressive disorder (MDD) using summary statistics from the PGC (n = 143,265) and further replicated in FinnGen cohort (n = 406,986). Subsequently, gene expression quantitative trait loci (eQTL) of identified proteins were leveraged to validate the primary findings in both PGC and FinnGen cohorts. We implemented reverse causality detection using bidirectional MR analysis, Steiger test, Bayesian co-localization and phenotype scanning to further strengthen the MR findings. In primary analyses, MR analysis revealed 2 plasma protein significantly associated with MDD risk at Bonferroni correction (P < 3.720 × 10-5), including butyrophilin subfamily 2 member A1 (BTN2A1, OR = 0.860; 95 % CI, 0.825-0.895; P = 1.79 × 10-5) and butyrophilin subfamily 3 member A2 (BTN3A2, OR = 1.071; 95 % CI, 1.056-1.086; P = 3.89 × 10-6). Both the identified proteins had no reverse causality. Bayesian co-localization indicated that BTN2A1 (coloc.abf-PPH4 = 0.620) and BTN3A2 (coloc.abf-PPH4 = 0.872) exhibited a shared variant with MDD, a finding that was subsequently validated by HEIDI test. In the replication stage, BTN2A1 and BTN3A2 were successfully validated in the FinnGen cohort. This study genetically determined BTN2A1 and BTN3A2 were associated with MDD and these findings may have clinical implications for MDD prevention.

Combined influence of healthy lifestyles, nutritional and inflammatory status on mortality among US adults with depression

OBJECTIVE

Healthy lifestyles, nutritional and inflammatory status are interrelated and influence mortality. This study aimed to evaluate their separate and combined effects on all-cause and cause-specific mortality in individuals exhibiting depression.

METHODS

6143 individuals with depression (median age 47) were recruited from the US National Health and Nutrition Examination Survey (NHANES 2005-2018), with mortality followed up through December 31, 2019. A healthy lifestyle score (0-5) was constructed based on current non-smoking, low-to-moderate alcohol consumption, adequate sleep, sufficient physical activity and healthy diet. Higher scores indicated healthier lifestyles. The Advanced Lung Cancer Inflammation Index (ALI), a composite marker of inflammation and nutritional status, was calculated as Body Mass Index (BMI) (kg/m2) × albumin (g/dl)/Neutrophil-to-Lymphocyte Ratio (NLR). Higher ALI values denoted lower inflammation and better nutrition. Weighted Cox proportional-hazards models were used to estimate mortality hazard ratios.

RESULTS

Healthier lifestyles significantly lowered all-cause (hazard ratio [HR] 0.72, 95 % confidence interval [CI] 0.66-0.78), cardiovascular (HR 0.70, 95 % CI 0.58-0.83), and non-cardiovascular mortality (HR 0.72, 95 % CI 0.64-0.81). High ALI reduced all-cause (HR 0.70, 95 % CI 0.54-0.91) and cardiovascular mortality (HR 0.46, 95 % CI 0.28-0.77) compared with low ALI. Joint analyses showed that individuals with both healthy lifestyle scores ≥3 and high ALI had the lowest risk of all-cause, cardiovascular, and non-cardiovascular mortality (HR 0.44, 95 % CI 0.33-0.60; 0.32, 95 % CI 0.16-0.63; 0.49, 95 % CI 0.35-0.68).

CONCLUSION

The joint presence of healthy lifestyles and high ALI was significantly associated with lower risk of mortality among individuals with depression.

Association between peripheral inflammation and body mass index on white matter integrity and free water in bipolar II depression

Immuno-metabolic dysregulation is implicated in mood disorders and elucidating non-invasive brain correlates may aid clinical translation of pathomechanism. This study aims to investigate the interrelationship between peripheral inflammation and body mass index (BMI) and their effects on white matter (WM) microstructure and free water (FW) in bipolar II depression (BDII-D). Voxel-wise FW and FW-corrected fractional anisotropy (FAt) were compared between 146 BDII-D and 151 healthy controls (HCs) using FSL Randomise. Partial correlations were used to explore associations between BMI, peripheral inflammation, FW measures, and psychiatric symptoms. Moderation analysis examined the interrelationships among BMI, peripheral inflammation, and FW measures. BDII-D showed lower FAt in the genu of the corpus callosum (CC) and bilateral anterior corona radiata, and higher FW in the body of the CC compared with HCs. Higher BMI was linked to lower global FAt (q < 0.001), while higher peripheral inflammation was associated with higher global FW (q ≤ 0.01) in BDII-D. Lower FAt in the genu of the CC and higher FW in the body of CC were significantly related to higher BMI, inflammation, and greater depressive symptoms (q < 0.05). Low-grade Inflammation moderated the relationship between higher BMI and lower FAt in the genu of the CC in BDII-D (B = -3.094e-05, p < 0.001). We found evidence for a mechanistic link between immune-metabolic dysregulation and altered connection in BDII-D. Next to mediating BMI effects on WM integrity, there seems to exist specific relationships between inflammation and BMI with different MR-based tract markers that need further investigation.

Protein associations and protein-metabolite interactions with depressive symptoms and the p-factor

Despite increasing mental health problems among young people, few studies have examined associations between plasma proteins and mental health. Interactions between proteins and metabolites in association with mental health problems remain underexplored. In 730 twins, we quantified associations between plasma proteins measured at age 22 with 21 indicators of either depressive symptoms or the p-factor and tested for interactions with metabolites. Symptoms were collected from questionnaires and interviews completed by different raters (e.g., self-report, teachers) through adolescence to young adulthood (12 to 22 years). We found 47 proteins associated with depressive symptoms or the p-factor (FDR < 0.2), 9 being associated with both. Two proteins, contactin-1 and mast/stem cell growth factor receptor kit, positively interacted with valine levels in explaining p-factor variability. Our study demonstrates strong associations between plasma proteins and mental health and provides evidence for proteome-metabolome interactions in explaining higher levels of mental health problems.

Immunometabolic Blood Biomarkers of Developmental Trajectories of Depressive Symptoms: Findings from the ALSPAC Birth Cohort

Depression is associated with immunological and metabolic alterations, but immunometabolic characteristics of developmental trajectories of depressive symptoms remain unclear. Studies of longitudinal trends of depressive symptoms in young people could provide insight into aetiological mechanisms and heterogeneity behind depression, and origins of possible common cardiometabolic comorbidities for depression. Using depressive symptoms scores measured on 10 occasions between ages 10 and 25 years in the Avon Longitudinal Study of Parents and Children (n=7302), we identified four distinct trajectories: low-stable (70% of the sample), adolescent-limited (13%), adulthood-onset (10%) and adolescent-persistent (7%). We examined associations of these trajectories with: i) anthropometric, cardiometabolic and psychiatric phenotypes using multivariable regression (n=1709-3410); ii) 67 blood immunological proteins and 57 metabolomic features using empirical Bayes moderated linear models (n=2059 and n=2240 respectively); and iii) 28 blood cell counts and biochemical measures using multivariable regression (n=2256). Relative to the low-stable group, risk of depression and anxiety in adulthood was higher for all other groups, especially in the adolescent-persistent (RR depression =13.11, 95% CI 9.59-17.90; RR GAD =11.77, 95% CI 8.58-16.14) and adulthood-onset (RR depression =6.25, 95% CI 4.50-8.68; RR GAD =4.66, 95% CI 3.29-6.60) groups. The three depression-related trajectories vary in their immunometabolic profile, with evidence of little or no alterations in the adolescent-limited group. The adulthood-onset group shows widespread classical immunometabolic changes (e.g., increased immune cell counts and insulin resistance), while the adolescent-persistent group is characterised by higher BMI both in childhood and adulthood with few other immunometabolic changes. These findings point to distinct mechanisms and prevention opportunities for adverse cardiometabolic profile in different groups of young people with depression.

Multi-omic studies on the pathogenesis of Sepsis

BACKGROUND

Sepsis is a life-threatening inflammatory condition, and its underlying genetic mechanisms are not yet fully elucidated. We applied methods such as Mendelian randomization (MR), genetic correlation analysis, and colocalization analysis to integrate multi-omics data and explore the relationship between genetically associated genes and sepsis, as well as sepsis-related mortality, with the goal of identifying key genetic factors and their potential mechanistic pathways.

METHODS

To identify therapeutic targets for sepsis and sepsis-related mortality, we conducted an MR analysis on 11,643 sepsis cases and 1,896 cases of 28-day sepsis mortality from the UK Biobank cohort. The exposure data consisted of 15,944 potential druggable genes (expression quantitative trait loci, eQTL) and 4,907 plasma proteins (protein quantitative trait loci, pQTL). We then performed sensitivity analysis, SMR analysis, reverse MR analysis, genetic correlation analysis, colocalization analysis, enrichment analysis, and protein-protein interaction network analysis on the overlapping genes. Validation was conducted using 17,133 sepsis cases from FinnGen R12. Drug prediction and molecular docking were subsequently used to further assess the therapeutic potential of the identified drug targets, while PheWAS was used to evaluate potential side effects. Finally, mediation analysis was conducted to identify the mediating role of related metabolites.

RESULTS

The MR analysis results identified a significant causal relationship between 24 genes and sepsis. The robustness of these causal associations was further strengthened by SMR analysis, sensitivity analysis, and reverse MR analysis. Genetic correlation analysis revealed that only two of these genes were genetically correlated with sepsis. Colocalization analysis showed that only one gene was closely associated with sepsis, while validation using the FinnGen dataset identified three genes. In the MR analysis of 28-day sepsis mortality, seven genes were found to have significant associations, with reverse MR analysis excluding one gene. The remaining genes passed sensitivity analysis, with no significant genes identified in genetic correlation and colocalization analyses. Molecular docking demonstrated excellent binding affinity between drugs and proteins with available structural data. PheWAS at the gene level did not reveal any potential side effects of the related drugs.

CONCLUSIONS

The identified drug targets, associated pathways, and metabolites have enhanced our understanding of the complex relationships between genes and sepsis. These genes and metabolites can serve as effective targets for sepsis treatment, paving new pathways in this field and laying a foundation for future research.

Psychiatric morbidity in people with autoimmune arthritides as a model of inflammatory mechanisms in mental disorders

BACKGROUND

Rheumatoid arthritis (RA) and axial spondyloarthritis (axSpA) are autoimmune illnesses characterised by chronic inflammation demonstrating differential associations with psychiatric conditions.

OBJECTIVE

In this matched-cohort study, we aimed to investigate whether the associations between these inflammatory illnesses and mental disorders are predominantly the consequence of the burden of the former or whether common causes might underpin the susceptibility to both.

METHODS

Using Czech national inpatient care data, we identified individuals with RA or axSpA during the years 1999-2012. We investigated the occurrence of psychiatric outcomes up to 2017 using stratified Cox proportional hazards models. In evidence triangulation, we assessed the potential moderation by age at inflammatory illness, the associations relative to counterparts with other similarly burdensome chronic illnesses and the temporal ordering of conditions.

FINDINGS

Both RA and axSpA were associated with mood and anxiety disorders and behavioural syndromes. In evidence triangulation, the associations with depression showed a decreasing age-at-inflammatory-illness gradient in RA; the association between RA and depression was stronger than that between other chronic illnesses and depression; and excluding prevalent depression attenuated the RA-depression association. RA showed consistent inverse associations with schizophrenia and Alzheimer's disease.

CONCLUSIONS

Common aetiologies might be involved in increasing the risk of developing both RA and depression. The consistent inverse associations between RA and schizophrenia and between RA and Alzheimer's disease suggest that at least part of these associations might also be a consequence of shared aetiologies as well as potential medication effects.

CLINICAL IMPLICATIONS

People with autoimmune arthritides are more likely to experience mood and anxiety disorders, even relative to counterparts with other similarly burdensome chronic illnesses.

Unveiling circulating targets in pancreatic cancer: Insights from proteogenomic evidence and clinical cohorts

Pancreatic cancer (PC), characterized by the absence of effective biomarkers and therapies, remains highly fatal. Data regarding the correlations between PC risk and individual plasma proteome known for minimally invasive biomarkers are scarce. Here, we analyzed 1,345 human plasma proteins using proteome-wide association studies, identifying 78 proteins significantly associated with PC risk. Of these, four proteins (ROR1, FN1, APOA5, and ABO) showed the most substantial causal link to PC, confirmed through Mendelian randomization and colocalization analyses. Data from two clinical cohorts further demonstrated that FN1 and ABO were notably overexpressed in both blood and tumor samples from PC patients, compared to healthy controls or para-tumor tissues. Additionally, elevated FN1 and ABO levels correlated with shorter median survival in patients. Multiple drugs targeting FN1 or ROR1 are available or in clinical trials. These findings suggest that plasma protein FN1 associated with PC holds potential as both prognostic biomarkers and therapeutic targets.

Curvilinear association between cardiometabolic index and depressive symptoms in individuals aged 45 and older: a cross-sectional study of CHARLS

Objective

This research is aimed at investigating the association between the cardiometabolic index (CMI) and depressive symptoms in Chinese population of middle and older age, using data derived from the CHARLS study.

Methods

Using data from 7,800 participants in the 2011-2012 wave of the CHARLS cohort, this cross-sectional analysis concentrated on examining the association between CMI and depressive symptoms, assessed through CESD-10 scores. The study utilized multivariate logistic regression, multiple linear regression, and restricted cubic spline (RCS) models to investigate the link between CMI and depression, with subgroup analyses offering further insights. Sensitivity analyses included propensity score matching and data from 8,457 participants in the 2015-2016 CHARLS wave.

Results

In fully adjusted models, higher CMI was significantly associated with an elevated risk of depression, with participants having a CMI ≥ 0.594 showing a 162% higher risk compared to those with lower CMI. The RCS analysis identified a threshold at CMI = 0.594, where participants with CMI ≥ 0.594 had a 162% elevated possibility of depression in comparison to those with CMI < 0.594 [OR = 2.62, 95% CI: 2.36-2.91]. Sensitivity analyses, including propensity score matching and data from the 2015-2016 CHARLS wave, confirmed the robustness of the findings.

Conclusion

Our analysis demonstrates that elevated CMI levels are independently correlated with a heightened likelihood of experiencing depressive symptoms, highlighting the significance of metabolic interventions in mitigating depressive tendencies in middle-aged and older individuals.

Exploring metabolite-mediated links between lipidome and deep vein thrombosis: Insights from Mendelian randomization analysis

The aim was to investigate the causal relationship between the lipidome and deep vein thrombosis (DVT) while identifying and quantifying the role of metabolites as potential mediators. Two-sample Mendelian randomization (MR) analysis of lipid species (n = 7174) and DVT (6767 cases and 330,392 controls) was performed using pooled data from genome-wide association studies. In addition, we quantified the proportion of metabolite-mediated lipidomic effects on DVT using 2-step MR. Phosphatidylcholine (18:0_18:2) levels mined from 179 lipids using MR analysis reduced the risk of DVT (odds ratio [OR]: 0.997; 95% CI: 0.996-0.999; P = 4.25 × 10-4; false discovery rate [FDR] = 0.013). Octadecadienedioate (C18:2-DC) levels increased with the increasing phosphatidylcholine (18:0_18:2) levels (OR: 1.087, 95% confidence interval [CI]: [1.024, 1.154], P = .006). Octadecadienedioate (C18:2-DC) levels mined from 1400 metabolites using MR analysis reduced the DVT risk (OR: 0.997; 95% CI: [0.996, 0.999], P = 6.11 × 10-6; FDR = 8.55 × 10-3). The proportion of the predicted genes for phosphatidylcholine (18:0_18:2) levels mediated by octadecadienedioate (C18:2-DC) levels was 7.8%. This study identified octadecadienedioate (C18:2-DC) levels as a potential mediator of the causal relationship between phosphatidylcholine (18:0_18:2) levels and DVT, which provides direction for the future investigation of DVT; however, further research on other potential mediators is still needed.

Causality of blood metabolites on hepatocellular carcinoma and cholangiocarcinoma: a metabolome-wide mendelian randomization study

BACKGROUND

Reportedly, there is an association between body metabolites and the risk of Hepatocellular Carcinoma (HCC) & Cholangiocarcinoma (CCA), possibly due to disrupted metabolic pathways leading to oxidative stress and an imbalance in cell proliferation and apoptosis, thereby increasing the risk of cancer. However, whether metabolites play a role in the onset of HCC or CCA remains inconclusive.

OBJECTIVE

The aim of our study is to explore the potential causal relationship between metabolites and the risk of HCC&CCA.

METHODS

Our study investigated the causal relationship between 1400 metabolites and HCC&CCA using publicly available genome-wide association study data. Single nucleotide polymorphisms (SNPs) associated with both metabolites and HCC&CCA were chosen as instrumental variables (IVs). The main approaches employed include inverse variance weighted (IVW), MR-Egger regression, and weighted median estimator (WME), with odds ratios (OR) used as the assessment criterion. Heterogeneity testing and sensitivity analyses were conducted to validate the results. We also conducted a reverse MR analysis to further validate the relationship between exposure and disease outcomes.

RESULTS

This Mendelian Randomization (MR) study indicates a significant causal relationship between 19 metabolites and the risk of HCC&CCA. Among them, the risk factors include "Bilirubin (E, Z or Z, E) levels," "Bilirubin (Z, Z) to taurocholate ratio," "Dimethylarginine (sdma + adma) levels," "N-methyltaurine levels," "4-vinylguaiacol sulfate levels," "Cholate to adenosine 3',5'-cyclic monophosphate (cAMP) ratio," "Glycohyocholate levels," "Cholesterol levels," and "4-methylguaiacol sulfate levels." The incidence risk of HCC and CCA increases with the elevation of these metabolites. Protective factors include "Ursodeoxycholate levels," "3-hydroxybutyroylglycine levels," "Linoleoylcholine levels," "Nonanoylcarnitine (C9) levels," "Pristanate levels," "Heptenedioate (C7:1-DC) levels," "Mannonate levels," "N-acetyl-L-glutamine levels," "Sphinganine levels," and "N-lactoyl isoleucine levels." The incidence risk of HCC and CCA potentially decreases as the levels of these metabolites increase. Heterogeneity tests show that most instrumental variables do not exhibit inter-gene heterogeneity, and the possibility of pleiotropy in the analysis is very low according to the sensitivity analysis. The reverse MR analysis did not yield positive results.

CONCLUSION

Our study has unveiled the intricate causal relationships between metabolites and the risk of HCC&CCA. Through our analysis, we identified nine metabolites, including "Bilirubin (E, Z or Z, E) levels," "Dimethylarginine (sdma + adma) levels," "Cholesterol levels,"ect, as risk factors for HCC&CCA. The incidence risk of HCC and CCA increases with their elevation. On the other hand, ten metabolites, such as "Ursodeoxycholate levels," "Linoleoylcholine levels," "Pristanate levels," ect, were identified as protective factors for HCC&CCA. The risk of developing HCC and CCA decreases with an increase in these metabolites. In conclusion, these findings further explore the physiological metabolic pathways underlying the pathogenesis of HCC and CCA, emphasizing future research directions. They pave the way for researchers to delve into the biological mechanisms of these diseases, facilitating early intervention and treatment strategies for these conditions.

Decoding and reconstructing disease relations between dry eye and depression: a multimodal investigation comprising meta-analysis, genetic pathways and Mendelian randomization

INTRODUCTION

The clinical presentations of dry eye disease (DED) and depression (DEP) often comanifest. However, the robustness and the mechanisms underlying this association were undetermined.

OBJECTIVES

To this end, we set up a three-segment study that employed multimodality results (meta-analysis, genome-wide association study [GWAS] and Mendelian randomization [MR]) to elucidate the association, common pathways and causality between DED and DEP.

METHODS

A meta-analysis comprising 26 case-control studies was first conducted to confirm the DED-DEP association. Next, we performed a linkage disequilibrium (LD)-adjusted GWAS and targeted phenotype association study (PheWAS) in East Asian TW Biobank (TWB) and European UK Biobank (UKB) populations. Single-nucleotide polymorphisms (SNPs) were further screened for molecular interactions and common pathways at the functional gene level. To further elucidate the activated pathways in DED and DEP, a systemic transcriptome review was conducted on RNA sequencing samples from the Gene Expression Omnibus. Finally, 48 MR experiments were implemented to examine the bidirectional causation between DED and DEP.

RESULTS

Our meta-analysis showed that DED patients are associated with an increased DEP prevalence (OR = 1.83), while DEP patients have a concurrent higher risk of DED (OR = 2.34). Notably, cross-disease GWAS analysis revealed that similar genetic architecture (rG = 0.19) and pleiotropic functional genes contributed to phenotypes in both diseases. Through protein-protein interaction and ontology convergence, we summarized the pleiotropic functional genes under the ontology of immune activation, which was further validated by a transcriptome systemic review. Importantly, the inverse variance-weighted (IVW)-MR experiments in both TWB and UKB populations (p value <0.001) supported the bidirectional exposure-outcome causation for DED-to-DEP and DEP-to-DED. Despite stringent LD-corrected instrumental variable re-selection, the bidirectional causation between DED and DEP remained.

CONCLUSION

With the multi-modal evidence combined, we consolidated the association and causation between DED and DEP.

Mendelian randomization and colocalization analysis reveal the role of IL-6 signaling pathway in psoriasis and potential therapeutic targets

IL-6 signaling is critical in the pathogenesis of several autoimmune diseases, including psoriasis and psoriatic arthritis. This study utilized Mendelian randomization (MR) analysis to investigate the genetic associations between IL-6 signaling, soluble IL-6 receptor (sIL-6R) levels, and psoriasis and its arthritis. Additionally, the therapeutic potential of IL-6R inhibitors was evaluated. The study methodology was validated through positive and negative control analysis, with further confirmation of genetic associations via Bayesian factor colocalization analysis. The MR results indicated that upregulation of IL-6 signaling was positively associated with psoriasis (PIVW = 0.008, 95% CI: 1.16-2.66), whereas elevated sIL-6R levels were negatively associated with psoriasis (PIVW < 0.001, 95% CI: 0.95-0.99). Positive control analysis showed that IL-6R inhibitors effectively reduced the risk of rheumatoid arthritis but increased the risk of atopic dermatitis. In contrast, negative control analysis revealed no significant therapeutic effect on seborrheic dermatitis. Using GWAS data from multiple databases, IL-6R inhibitors were identified as being associated with a reduced risk of psoriasis and psoriatic arthritis. Colocalization analysis highlighted the rs4129267 genetic variant as strongly linked to the therapeutic effects of IL-6R inhibitors on psoriasis (P < 0.001, 95% CI: 0.37-0.74). These findings underscore the crucial role of IL-6 signaling in the development of psoriasis and psoriatic arthritis and provide robust genetic evidence supporting the therapeutic potential of IL-6R inhibitors. By identifying genetic determinants of disease susceptibility and potential biomarkers of treatment response, this study provides valuable clinical insights and guidance for optimizing treatment strategies for psoriasis.

Bidirectional Mendelian randomization reveals causal immune cell phenotypes in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by persistent inflammation in synovial joints and influenced by genetic and environmental factors. The immune system, comprising various cells that either exacerbate or reduce inflammation, plays a central role in RA pathogenesis. Despite extensive research, the causal relationships between immune cell phenotypes and RA remain unclear. We employed a two-sample Mendelian randomization (MR) approach to investigate the causal associations between 731 immune cell phenotypes and RA. Genetic variants, carefully selected based on rigorous criteria, served as instrumental variables to ensure analytical validity. Data on RA were derived from the FinnGen database, whereas immune cell phenotype data were obtained from the genome-wide association studies catalog. We employed 5 MR methods, including inverse variance weighted and MR Egger, to ensure robust causal inference. We assessed for pleiotropy and heterogeneity and adjusted findings using the False Discovery Rate. After False Discovery Rate adjustment (threshold < 0.05), inverse variance weighted analysis revealed potential causal relationships between 4 immune cell types and RA: CD62L- dendritic cells %dendritic cells (P = 3.88E-05; 95% confidence interval [CI] = 1.056), CD19 on IgD+ CD38- naive cells (P = 1.75E-04; 95% CI = 0.969), CD45RA on TD CD8br (P = 5.59E-04; 95% CI = 0.919), and HLA DR on CD33- HLA DR+ (P = 8.13E-05; 95% CI = 1.422). In reverse Mendelian studies, specific immune cell phenotypes were found to be associated with RA risk and progression: the percentage of memory B cells among lymphocytes (P = 2.74E-04; 95% CI = 0.861), IgD+ CD24+ cells among lymphocytes (P = 6.93E-04; 95% CI = 0.867), CD4+ CD8dim cells among lymphocytes (P = 2.92E-04; 95% CI = 0.802), CD4+ CD8dim cells among leukocytes (P = 4.37E-04; 95% CI = 0.814), and CD24 expression on IgD+CD24+ cells (P = 1.05E-04; 95% CI = 0.857). These results identify immune cell phenotypes closely linked to RA susceptibility and progression. The findings suggest that specific immune cell phenotypes are not only influenced by RA but may also contribute to its development and progression. These results offer new insights into the immunological underpinnings of RA and highlight potential targets for therapeutic intervention. Future research should focus on validating these causal relationships in diverse populations and exploring the molecular mechanisms involved.

Long-term exposure to low-concentration sulfur dioxide and mental disorders in middle-aged and older urban adults

The World Health Organization loosened the air quality guideline for daily sulfur dioxide (SO2) concentrations from 20 μg/m3 to 40 μg/m3. However, the guideline for SO2 concentrations in 2021 raised public concerns since there was no sufficient evidence that low-concentration SO2 exposure is harmless to the population's health, including mental health. We analyzed the associations between low-concentration SO2 exposure and incidence risks of total and cause-specific mental disorders, including depressive disorder, anxiety disorder, bipolar disorder, and schizophrenia spectrum disorder. 245,820 urban participants with low-concentration SO2 exposure (<8 μg/m3) at baseline were involved in the analyses from the UK Biobank. SO2 exposure (2006-2022) was estimated using high-resolution annual mean concentration maps from the Department for Environment, Food and Rural Affairs. Mental disorders and corresponding symptoms were identified using healthcare records and an online questionnaire, respectively. Associations were examined using both time-independent (2006-2010) and time-dependent (from 2006 to 2022) Cox regression models and logistic regression models with full adjustments for potential confounders. Stratification analyses were further conducted to identify vulnerable populations. Long-term exposure to low-concentration SO2 (per 1.36 μg/m3) was associated with increased risks of mental disorders, depressive disorder, and anxiety disorder with hazard ratios of 1.02 (95% confidence interval [CI]: 1.00, 1.03), 1.11 (95% CI: 1.07, 1.16), and 1.10 (95% CI: 1.06, 1.14) in the time-independent model, respectively. Associations were stronger for younger individuals. Additionally, the low-concentration SO2 exposure was linked to several psychiatric symptoms, such as trouble concentrating and restlessness, with odds ratios of 1.07 (95% CI: 1.04, 1.10) and 1.11 (95% CI: 1.07, 1.14), respectively. This study demonstrated significant associations of long-term exposure to low-concentration SO2 with mental disorders, highlighting the need for stricter regulations for SO2 to better protect public health and improve air quality in urban areas, in support of the Sustainable Development Goals.

Associations between IL-6 and trajectories of depressive symptoms across the life course: Evidence from ALSPAC and UK Biobank cohorts

BACKGROUND

Peripheral inflammatory markers, including serum interleukin 6 (IL-6), are associated with depression, but less is known about how these markers associate with depression at different stages of the life course.

METHODS

We examined the associations between serum IL-6 levels at baseline and subsequent depression symptom trajectories in two longitudinal cohorts: ALSPAC (age 10-28 years; N = 4,835) and UK Biobank (39-86 years; N = 39,613) using multilevel growth curve modeling. Models were adjusted for sex, BMI, and socioeconomic factors. Depressive symptoms were measured using the Short Moods and Feelings Questionnaire in ALSPAC (max time points = 11) and the Patient Health Questionnaire-2 in UK Biobank (max time points = 8).

RESULTS

Higher baseline IL-6 was associated with worse depression symptom trajectories in both cohorts (largest effect size: 0.046 [ALSPAC, age 16 years]). These associations were stronger in the younger ALSPAC cohort, where additionally higher IL-6 levels at age 9 years was associated with worse depression symptoms trajectories in females compared to males. Weaker sex differences were observed in the older cohort, UK Biobank. However, statistically significant associations (pFDR <0.05) were of smaller effect sizes, typical of large cohort studies.

CONCLUSIONS

These findings suggest that systemic inflammation may influence the severity and course of depressive symptoms across the life course, which is apparent regardless of age and differences in measures and number of time points between these large, population-based cohorts.

The immunological perspective of major depressive disorder: unveiling the interactions between central and peripheral immune mechanisms

Major depressive disorder is a prevalent mental disorder, yet its pathogenesis remains poorly understood. Accumulating evidence implicates dysregulated immune mechanisms as key contributors to depressive disorders. This review elucidates the complex interplay between peripheral and central immune components underlying depressive disorder pathology. Peripherally, systemic inflammation, gut immune dysregulation, and immune dysfunction in organs including gut, liver, spleen and adipose tissue influence brain function through neural and molecular pathways. Within the central nervous system, aberrant microglial and astrocytes activation, cytokine imbalances, and compromised blood-brain barrier integrity propagate neuroinflammation, disrupting neurotransmission, impairing neuroplasticity, and promoting neuronal injury. The crosstalk between peripheral and central immunity creates a vicious cycle exacerbating depressive neuropathology. Unraveling these multifaceted immune-mediated mechanisms provides insights into major depressive disorder's pathogenic basis and potential biomarkers and targets. Modulating both peripheral and central immune responses represent a promising multidimensional therapeutic strategy.

Associations of pro-inflammatory factors and IL-10 levels with degree of suicide risk in adolescents with depression

Background

Depression and suicidal behavior are associated with pro-inflammatory status in adults. However, differences in inflammatory levels among adolescents with depression at different suicide risk levels are unclear, and the connection between anti-inflammatory factors, which serve as vital for the immune system, and suicide needs to be explored.

Methods

This study recruited 111 adolescent patients with depression aged 13-18 and 23 healthy controls. Patients were divided into three subgroups according to suicidal ideation within the past week and history of suicide attempts. Severity of depression, suicidal ideation, and suicide risk were assessed using the Hamilton Depression Scale-17 (HAMD-17) and the Chinese version of the Beck Suicide Ideation Scale (BSI-CV). Plasma levels of IL-6, TNF-α, IFN-γ, IL-1β, and IL-10 in all participants were measured.

Results

Plasma levels of IL-6, TNF-α, IFN-γ, and IL-10 differed between the suicide risk subgroups, and the differences remained significant after controlling for severity of depressive symptoms using covariance analysis. Pairwise comparison indicated that plasma levels of these four cytokines in the high suicide risk group were higher than those in the low suicide risk group (all p<0.05), among which the level of IL-10 was significantly higher than that in the medium and low risk groups. IL-10 was positively correlated with the total score of the HAMD-17, BSI-CV, and suicidal ideation; the other four cytokines were also somewhat correlated with suicidal ideation (all p<0.05). IL-10 correlated positively with these four pro-inflammatory factors. Multiple linear regression analysis showed that IL-10 levels significant were associated with BSI-CV (β = 0.270, t = 2.897, p = 0.005) and HAMA-17 (β = 0.285, t = 3.041, p = 0.003) total scores. In binary logistic regression, after controlling for depressive symptoms, gender, age, BMI, and duration of illness: IL-10 level remained a risk factor for suicidal behavior (OR = 3.224, 95% CI 1.571-6.619 p = 0.001).

Conclusion

Adolescents with different suicide risk levels differed in plasma levels of pro-inflammatory factors and the anti-inflammatory factor IL-10. These differences were independent of depressive symptoms; high IL-10 levels may be a risk factor for suicidal behavior in depressed patients. Further research is needed to explore the relationship between anti-inflammatory factors and suicide.

The genomic architecture of circulating cytokine levels points to drug targets for immune-related diseases

Circulating cytokines orchestrate immune reactions and are promising drug targets for immune-mediated and inflammatory diseases. Exploring the genetic architecture of circulating cytokine levels could yield key insights into causal mediators of human disease. Here, we performed genome-wide association studies (GWAS) for 40 circulating cytokines in meta-analyses of 74,783 individuals. We detected 359 significant associations between cytokine levels and variants in 169 independent loci, including 150 trans- and 19 cis-acting loci. Integration with transcriptomic data point to key regulatory mechanisms, such as the buffering function of the Atypical Chemokine Receptor 1 (ACKR1) acting as scavenger for multiple chemokines and the role of tumor necrosis factor receptor-associated factor 1 (TRAFD1) in modulating the cytokine storm triggered by TNF signaling. Applying Mendelian randomization (MR), we detected a network of complex cytokine interconnections with TNF-b, VEGF, and IL-1ra exhibiting pleiotropic downstream effects on multiple cytokines. Drug target cis-MR using 2 independent proteomics datasets paired with colocalization revealed G-CSF/CSF-3 and CXCL9/MIG as potential causal mediators of asthma and Crohn's disease, respectively, but also a potentially protective role of TNF-b in multiple sclerosis. Our results provide an overview of the genetic architecture of circulating cytokines and could guide the development of targeted immunotherapies.

Casual correlation between overweight, obesity, and severe COVID-19 infection with respiratory failure: A two-sample Mendelian randomization

This study aimed to detect the causal association of overweight and obesity on severe COVID-19 infection with respiratory failure through a two-sample Mendelian randomization (MR) method based on the genome-wide association studies datasets. All genome-wide association studies summary data of exposures and outcome used in this study were obtained from the IEU database derived from Europeans. The study mainly used the inverse variance weighted method to test causal relationship. Simultaneously, MR-PRESSO and MR-EGGER were used to detect the pleiotropy, and sensitivity analysis was performed using leave-one-out analysis. In the inverse variance weighted analyses, we found no causal association between obesity (e.g., OR = 1.15, 95% CIs = 0.96-1.37, P = .13 for obesity-ebi-a-GCST90000255), obesity subtypes (e.g., OR = 1.93, 95% CIs = 0.90-4.14, P = .10 for obesity and other hyperalimentation) as well as overweight (OR = 0.90, 95% CIs = 0.64-1.27, P = .54) and severe COVID-19 infection with respiratory failure. The findings showed no causal association between obesity or overweight and severe COVID-19 infection with respiratory failure. Further validation is needed regarding whether obesity or overweight is a risk factor for it.

Immuno-metabolic depression: from concept to implementation

Major depressive disorder is a common, disabling mental disorder characterized by extensive etiological and phenotypic heterogeneity. This heterogeneity makes treatment approaches imprecise and often ineffective. Insight into the underlying biological mechanisms underpinning depression and its subtypes may enable more personalized treatments. In this review, we provide an overview of immuno-metabolic depression and illustrate that significant immuno-metabolic dysregulations are present in about 20-30% of people with depression. Such immuno-metabolic depression is characterized by the clustering of 1) atypical, energy-related depressive symptoms such as hypersomnia, fatigue, hyperphagia, and possibly anhedonia, 2) systemic low-grade inflammation with elevated levels of e.g., C-reactive protein, cytokines and glycoprotein acetyls, and 3) metabolic abnormalities involving e.g., obesity, dyslipidaemia, insulin and leptin resistance. Persons with immuno-metabolic depression are at a higher risk for cardiometabolic diseases and seem to respond less well to standard antidepressant treatment. Interventions targeting inflammation, metabolism or lifestyle may be more effective treatment options for individuals with immuno-metabolic depression, in line with principles of precision psychiatry.

Relationship among depressive symptoms, dyspnea-related fear and sarcopenia in patients with chronic obstructive pulmonary disease: The mediating effect of physical activity

Objectives: Sarcopenia is influenced by multiple factors, including psychological aspects. This study aimed to explore the relationships among depressive symptoms, dyspnea-related fear, and sarcopenia, with a focus on the mediating role of physical activity. Methods: A cross-sectional study was conducted among 348 COPD patients at a tertiary hospital in Western China from July 2023 to July 2024. Sarcopenia was assessed according to the 2019 AWGS criteria, including hand bioelectrical impedance analysis (BIA), and grip strength testing. Depressive symptoms, dyspnea-related fear, and physical activity were evaluated through self-reported measures using the depression subscale of the Hospital Anxiety and Depression Scale (HADS), the Breathlessness Beliefs Questionnaire (BBQ), and the International Physical Activity Questionnaire Short Form (IPAQ-SF), respectively. Logistic regressions analyses explored associations among depressive symptoms, dyspnea-related fear, and sarcopenia. Maximum Likelihood (ML) estimation was employed using Mplus software to evaluate the mediating effect of physical activity on the relationships. Results: The prevalence of sarcopenia among COPD patients was 60.3%. In the logistic regression analysis with sarcopenia as the dependent variable, physical activity levels (OR = 0.508, p = 0.019) and depressive symptoms (OR = 1.079, p = 0.029) were statistically significant, while BBQ scores were not (OR = 1.031, p = 0.070). Mediating analyses revealed that depressive symptoms directly increased the risk of sarcopenia (β = 0.076, p = 0.042) but did not do so indirectly via physical activity (β = 0.056, p = 0.146). Conversely, dyspnea-related fear had an indirect effect on sarcopenia through physical activity, with a borderline statistical significance (β = 0.053, p = 0.049). Conclusions: This study highlights the critical role of psychological factors in sarcopenia development among COPD patients, with physical activity serving as a significant mediator. These findings underscore the need for integrated rehabilitation strategies addressing both psychological and physical activity barriers to improve outcomes for COPD patients.

Genetic prediction of blood metabolites mediating the relationship between gut microbiota and postpartum depression: A mendelian randomization study

BACKGROUND

Observational studies have suggested an association between gut microbiota(GM) and postpartum depression (PPD). However, the causal relationship remains unclear, and the role of blood metabolites in this association remains elusive.

METHODS

This study firstly elucidated the causal relationship among 196 GM taxa, 224 blood metabolites, and PPD from a genetic perspective, employing two-sample Mendelian randomization (MR). Subsequently, a two-step mediation MR approach was employed to explore the role of blood metabolites as potential mediators. To validate the relevant findings, we further selected other data (GM and blood metabolites) from the IEU Open GWAS and GWAS Catalog for analysis. Our primary analysis utilized the inverse variance weighted method. To enhance the robustness of our results, we also applied MR-Egger method, weighted median method, Cochran's Q test, MR-Egger regression, and MR-PRESSO.

RESULTS

MR analysis results revealed a nominal association (p < 0.05) between 13 GM taxa, 6 blood metabolites, and PPD. After multiple-testing correction (PFDR < 0.1), Bifidobacteriales (PFDR = 0.034), Bifidobacteriaceae (PFDR = 0.055) and Guanosine (PFDR = 0.081) showed significant causal relationships with PPD. In our validation results, the higher level of Alphaproteobacteria (OR: 1.057, 95% CI: 1.024-1.091; p = 0.0006) retained a causal relationship with a higher risk of PPD. Finally, mediation analysis revealed that the impact of Odoribacter on PPD was mediated indirectly through Hyodeoxycholate, with a mediation proportion of 16.8%.

CONCLUSION

Our findings elucidated the underlying mechanisms between the GM, blood metabolites, and PPD. These findings contribute to the prevention and diagnosis of PPD, offering novel insights into microbiome-based therapies and metabolite-targeted interventions for the treatment of PPD.

Dissecting depression symptoms: Multi-omics clustering uncovers immune-related subgroups and cell-type specific dysregulation

In a subset of patients with mental disorders, such as depression, low-grade inflammation and altered immune marker concentrations are observed. However, these immune alterations are often assessed by only one data type and small marker panels. Here, we used a transdiagnostic approach and combined data from two cohorts to define subgroups of depression symptoms across the diagnostic spectrum through a large-scale multi-omics clustering approach in 237 individuals. The method incorporated age, body mass index (BMI), 43 plasma immune markers and RNA-seq data from peripheral mononuclear blood cells (PBMCs). Our initial clustering revealed four clusters, including two immune-related depression symptom clusters characterized by elevated BMI, higher depression severity and elevated levels of immune markers such as interleukin-1 receptor antagonist (IL-1RA), C-reactive protein (CRP) and C-C motif chemokine 2 (CCL2 or MCP-1). In contrast, the RNA-seq data mostly differentiated a cluster with low depression severity, enriched in brain related gene sets. This cluster was also distinguished by electrocardiography data, while structural imaging data revealed differences in ventricle volumes across the clusters. Incorporating predicted cell type proportions into the clustering resulted in three clusters, with one showing elevated immune marker concentrations. The cell type proportion and genes related to cell types were most pronounced in an intermediate depression symptoms cluster, suggesting that RNA-seq and immune markers measure different aspects of immune dysregulation. Lastly, we found a dysregulation of the SERPINF1/VEGF-A pathway that was specific to dendritic cells by integrating immune marker and RNA-seq data. This shows the advantages of combining different data modalities and highlights possible markers for further stratification research of depression symptoms.

Association of dietary inflammatory index and systemic inflammatory markers with mortality risk in depressed adults: a mediation analysis of NHANES data

Background

Previous research has linked systemic inflammatory markers and the Dietary Inflammatory Index (DII) with depression. However, the relationship between DII and these markers, and their impact on mortality risk among depressed adults, remains underexplored. This study aims to explore the association between DII and systemic inflammatory markers and their mediating effect on mortality risk in adults with depression.

Methods

This study analyzed data from 4,981 adults with depression in the National Health and Nutrition Examination Survey (NHANES). This study quantified dietary inflammatory potential with the DII and systemic inflammation with the Systemic Immune-Inflammation Index (SII) and Systemic Inflammation Response Index (SIRI). Cox proportional hazards regression and inverse probability weighting evaluated the impact of DII, SII, and SIRI on mortality risk in depressed adults, as well as their mediating effects. Multiple linear regression analyzed the associations between DII and SII/SIRI. Restricted cubic spline analysis explored the non-linear relationship between DII and mortality risk.

Results

In adjusted regression models, DII, SII, and SIRI were significantly associated with all-cause mortality risk in depressed adults, with hazard ratios (HRs) (95% CIs) from 1.333 to 1.497 (1.051-1.233, 1.689-1.832). DII was linearly related to SII, with βs (95% CIs) from 0.001 to 0.121 (0.001-0.017, 0.001-0.224). SII significantly mediated the DII-mortality risk link, especially in males (8.07%). The DII-mortality relationship was linear (P non-linear = 0.174), with a beneficial threshold at 1.62.

Conclusion

DII and SII are associated with increased all-cause mortality risk in depressed adults. The DII-related mortality risk in depression can be partially mediated by SII, with a more pronounced effect in males.

Associations between uric acid and depressive symptoms, and the mediating role of immunoinflammatory: Findings from rural older adults

Background

In the low-resource rural areas, older adults may experience prolonged and severe depressive symptoms. This study aimed to investigate the relationship between uric acid, depressive symptoms and immunoinflammatory among rural older adults.

Method

This case-control study was conducted in 17 rural villages in Hunan Province, China, between January 2023 and April 2024. This study included 180 participants: (1) Rural Older Adults with Depressive Symptoms group:90 patients with first-time diagnosed with depressive symptoms (Geriatric Depression Scale-15, GDS-15 ≥ 5 scores); (2) Control group: 90 individually matched (age and sex) healthy subjects (GDS-15 < 5 scores) who were aged ≥60 years.

Results

Both males and females, depressive symptoms were associated with higher uric acid levels and C-reactive protein levels (All P < 0.05). Whereas in females, depressive symptoms were also linked to higher procalcitonin (P = 0.005) and serum amyloid A (P = 0.008) levels. In addition, C-reactive protein plays a significant mediating role between uric acid and depressive symptoms in males.

Conclusion

Further investigation is necessary to clarify the underlying mechanisms, examine gender-specific disparities, and assess potential therapeutic interventions targeting uric acid and inflammation levels to mitigate mental disorders risk.

Mendelian randomization analysis revealed that albuminuria is the key factor affecting socioeconomic status in CKD patients

Previous studies indicate a strong correlation between the incidence of chronic kidney disease (CKD) and lower economic status. However, these studies often struggle to delineate a clear cause-effect relationship, leaving healthcare providers uncertain about how to manage kidney disease in a way that improves patients' financial outcomes. Our study aimed to explore and establish a causal relationship between CKD and socioeconomic status, identifying critical influencing factors. We utilized summary meta-analysis data from the CKDGen Consortium and UK Biobank. Genetic variants identified from these sources served as instrumental variables (IVs) to estimate the association between CKD and socioeconomic status. The presence or absence of CKD, estimated glomerular filtration rate (eGFR), and albuminuria were used as exposures, while income and regional deprivation were analyzed as outcomes. We employed the R packages 'TwoSampleMR' and 'Mendelianrandomization' to conduct both univariable and multivariable Mendelian randomization (MR) analyses, assessing for potential pleiotropy and heterogeneity. Our univariable MR analysis revealed a significant causal relationship between high levels of albuminuria and lower income (OR = 0.84, 95% CI: 0.73-0.96, p = 0.013), with no significant pleiotropy detected. In the multivariable MR analysis, both CKD (OR = 0.867, 95% CI: 0.786-0.957, p = 0.0045) and eGFR (OR = 0.065, 95% CI: 0.010-0.437, p = 0.0049) exhibited significant effects on income. This study underscores that higher albuminuria levels in CKD patients are associated with decreased income and emphasizes the importance of effective management and treatment of albuminuria in CKD patients to mitigate both social and personal economic burdens.

Aspirin may be more suitable for patients with major depression: Evidence from two-sample Mendelian randomization analysis

OBJECTIVE

Utilizing two-sample Mendelian randomization (TSMR) analysis, this study aims to explore the potential bidirectional causal relationship between common nonsteroidal anti-inflammatory drugs (paracetamol, ibuprofen, aspirin) and major depression (MD) from a genetic standpoint.

METHODS

We employed summarized data from a Genome-Wide Association Study (GWAS) of European populations. The inverse variance weighted (IVW) method was used for TSMR analysis; outcomes were evaluated based on p-value, OR (Odds Ratio), and 95% confidence interval (95% CI).

RESULTS

From a genetic perspective, the study found that the use of paracetamol and ibuprofen increased the risk of MD (IVW (MRE): OR = 2.314, 95% CI: 1.609-3.327; p = 6.07E-06) and (IVW (MRE): OR = 2.308, 95% CI: 1.780-3.653; p = 0.002), respectively. No significant causal relationship was found between aspirin and MD (p > 0.05). Reverse TSMR analysis found that MD increased the genetic predisposition to use paracetamol, ibuprofen, and aspirin (IVW (MRE): OR = 1.042, 95% CI: 1.030-1.054, p = 3.07E-12), (IVW (FE): OR = 1.015, 95% CI: 1.007-1.023, p = 1.13E-04), (IVW (MRE): OR = 1.019, 95% CI: 1.009-1.030, p = 4.22E-04), respectively. Other analytical methods and sensitivity analyses further supported the robustness and reliability of these findings.

CONCLUSION

This study provides preliminary genetic evidence through bidirectional TSMR analysis that MD increases the genetic predisposition to use paracetamol, ibuprofen, and aspirin, aiding clinicians in devising preventive strategies against the misuse of non-steroidal anti-inflammatory drugs. Moreover, we found that the use of paracetamol and ibuprofen increases the risk of MD, whereas aspirin did not. This suggests a crucial clinical implication: clinicians treating MD patients could opt for the relatively safer aspirin over paracetamol and ibuprofen.

Evidence of symptom specificity for depression in multiple sclerosis: A two sample Mendelian randomization study

BACKGROUND

Depression is common and phenotypically heterogenous in multiple sclerosis (MS). MS may increase risk of some but not all affective symptoms or certain symptoms may predispose individuals to higher MS risk.

OBJECTIVE

To assess the existence and direction of causality between distinct depressive symptoms and MS using two-sample Mendelian randomization (MR).

METHODS

Using summary data from genome-wide association studies, we selected genetic instrument variables (IV) for MS (n = 115,776) and IVs for depressive symptoms (average n = 117,713): anhedonia, altered appetite, concentration, depressed mood, fatigue, inadequacy, psychomotor changes, sleeping problems and suicidality. We performed two-sample MR in either direction using inverse-variance models. Sensitivity analyses included weighted-median and MR-Egger regression. Obesity is a known risk factor for MS and depression; we adjusted for body mass index in multivariable-MR.

RESULTS

Genetic liability to MS was associated with anhedonia (IVW estimate per 102: 0.69; 95 % CI: 0.24-1.13; p = 0.002), concentration difficulty (0.66; 0.19-1.13; p = 0.006) and psychomotor changes (0.37; 0.08-0.65; p = 0.01). Results were similar in sensitivity analyses. In the opposite direction, we found no evidence of a causal relationship for any affective symptom on MS risk.

CONCLUSIONS

Genetic susceptibility to MS was associated with anhedonia, concentration, and psychomotor-related symptoms, suggesting a specific phenotype of depression in MS.

Balancing the mind: Toward a complete picture of the interplay between gut microbiota, inflammation and major depressive disorder

The intricate interplay existing between gut microbiota and homeostasis extends to the realm of the brain, where emerging research underscores the significant impact of the microbiota on mood regulation and overall neurological well-being and vice-versa, with inflammation playing a pivotal role in mediating these complex interactions. This comprehensive review explores the complex interplay between inflammation, alterations in gut microbiota, and their impact on major depressive disorder (MDD). It provides a cohesive framework for the puzzle pieces of this triad, emphasizing recent advancements in understanding the gut microbiota and inflammatory states' contribution to the depressive features. Two directions of communication between the gut and the brain in depression are discussed, with inflammation serving as a potential modulator. Therapeutic implications were discussed as well, drawing insights from interventional studies on the effects of probiotics on gut bacterial composition and depressive symptoms. Ultimately, this review will attempt to provide a complete and valuable framework for future research and therapeutic interventions in MDD.

Eight-year total, cognitive-affective, and somatic depressive symptoms trajectories and risks of cardiac events

In this study, we analyzed pooled data from two prospective population-based cohorts-the Health Retirement Study (HRS) and the English Longitudinal Study of Ageing (ELSA)-to explore the association between trajectories of depressive symptoms and the risk of cardiac events. Depressive symptoms were assessed using the 8-item CES-D scale and categorized into somatic and cognitive-affective subtypes. Trajectories were tracked for four surveys from baseline. Heart disease was identified based on self-reported physician-diagnosed conditions. Hazard ratios and 95% confidence intervals were calculated with Cox proportional risk models that adjusted for potential confounders. In total, 17,787 subjects (59.7% female, median age 63 years) were enrolled at baseline. During a 10-year follow-up, 2409 cases of heart disease were identified. Participants with fluctuating (HR = 1.13, 95% CI: 1.06-1.20), increasing (HR = 1.43, 95% CI: 1.25-1.64), and consistently high (HR = 1.64, 95% CI: 1.45-1.84) depressive symptom trajectories exhibited an increased risk of heart disease compared to those with consistently low depressive symptoms, while a decreasing (HR = 1.07, 95% CI: 0.96-1.19) depressive symptom trajectory did not significantly affect the risk of heart disease. Moreover, the association between heart disease and somatic depressive symptoms was found to be stronger than with cognitive-affective symptoms. These findings suggest a significant link between depressive symptom trajectories and heart disease, with particular emphasis on stronger associations with somatic symptoms. It is recommended that the identification and management of depressive symptoms be incorporated into heart disease prevention strategies.

Exploring the role of interleukin-6 receptor blockade in epilepsy and associated neuropsychiatric conditions through a mendelian randomization study

BACKGROUND

The interplay between inflammation, immune dysregulation, and the onset of neurological disorders, including epilepsy, has become increasingly recognized. Interleukin (IL)-6, a pro-inflammatory cytokine, is suspected to not only mediate traditional inflammatory pathways but also contribute to neuroinflammatory responses that could underpin neuropsychiatric symptoms and broader psychiatric disorders in epilepsy patients. The role of IL-6 receptor (IL6R) blockade presents an intriguing target for therapeutic intervention due to its potential to attenuate these processes.

AIM

To explore the potential of IL6R blockade in reducing the risk of epilepsy and investigate whether this pathway might also influence associated psychiatric and neuropsychiatric conditions due to neuroinflammation.

METHODS

Mendelian randomization (MR) analysis employing single nucleotide polymorphisms (SNPs) in the vicinity of the IL6R gene (total individuals = 408225) was used to evaluate the putative causal relationship between IL6R blockade and epilepsy (total cases/controls = 12891/312803), focal epilepsy (cases/controls = 7526/399290), and generalized epilepsy (cases/controls = 1413/399287). SNP weights were determined by their effect on C-reactive protein (CRP) levels and integrated using inverse variance-weighted meta-analysis as surrogates for IL6R effects. To address potential outlier and pleiotropic influences, sensitivity analyses were conducted employing a variety of MR methods under different modeling assumptions.

RESULTS

The genetic simulation targeting IL6R blockade revealed a modest but significant reduction in overall epilepsy risk [inverse variance weighting: Odds ratio (OR): 0.827; 95% confidence interval (CI): 0.685-1.000; P = 0.05]. Subtype analysis showed variability, with no significant effect observed in generalized, focal, or specific childhood and juvenile epilepsy forms. Beyond the primary inflammatory marker CRP, the findings also suggested potential non-inflammatory pathways mediated by IL-6 signaling contributing to the neurobiological landscape of epilepsy, hinting at possible links to neuroinflammation, psychiatric symptoms, and associated mental disorders.

CONCLUSION

The investigation underscored a tentative causal relationship between IL6R blockade and decreased epilepsy incidence, likely mediated via complex neuroinflammatory pathways. These results encouraged further in-depth studies involving larger cohorts and multifaceted psychiatric assessments to corroborate these findings and more thoroughly delineate the neuro-psychiatric implications of IL-6 signaling in epilepsy. The exploration of IL6R blockade could herald a novel therapeutic avenue not just for seizure management but also for addressing the broader psychiatric and cognitive disturbances often associated with epilepsy.

Advances in biosensors for major depressive disorder diagnostic biomarkers

Depression is one of the most common mental disorders and is mainly characterized by low mood or lack of interest and pleasure. It can be accompanied by varying degrees of cognitive and behavioral changes and may lead to suicide risk in severe cases. Due to the subjectivity of diagnostic methods and the complexity of patients' conditions, the diagnosis of major depressive disorder (MDD) has always been a difficult problem in psychiatry. With the discovery of more diagnostic biomarkers associated with MDD in recent years, especially emerging non-coding RNAs (ncRNAs), it is possible to quantify the condition of patients with mental illness based on biomarker levels. Point-of-care biosensors have emerged due to their advantages of convenient sampling, rapid detection, miniaturization, and portability. After summarizing the pathogenesis of MDD, representative biomarkers, including proteins, hormones, and RNAs, are discussed. Furthermore, we analyzed recent advances in biosensors for detecting various types of biomarkers of MDD, highlighting representative electrochemical sensors. Future trends in terms of new biomarkers, new sample processing methods, and new detection modalities are expected to provide a complete reference for psychiatrists and biomedical engineers.

The interplay between cytokines and stroke: a bi-directional Mendelian randomization study

Stroke, the second leading cause of death and disability, causes massive cell death in the brain followed by secondary inflammatory injury initiated by disease associated molecular patterns released from dead cells. Nonetheless, the evidence regarding the causal relationship between inflammatory cytokines and stroke subtypes is obscure. To leverage large scale genetic association data to investigate the interplay between circulating cytokines and stroke, we adopted a two-sample bi-directional Mendelian randomization (MR) analysis. Firstly, we performed a forward MR analysis to examine the associations of genetically determined 31 cytokines with 6 stroke subtypes. Secondly, we conducted a reverse MR analysis to check the associations of 6 stroke subtypes with 31 cytokines. In the forward MR analysis, genetic evidence suggests that 21 cytokines were significantly associated with certain stroke subtype risk with |β| ranging from 1.90 × 10-4 to 0.74. In the reverse MR analysis, our results found that five stroke subtypes (intracerebral hemorrhage (ICH), large artery atherosclerosis ischemic stroke (LAAS), lacunar stroke (LS), cardioembolic ischemic stroke (CEI), small-vessel ischemic stroke (SV)) caused significantly changes in 16 cytokines with |β| ranging from 1.08 × 10-4 to 0.69. In particular, those five stroke subtypes were statistically significantly associated with C-reactive protein (CRP). In addition, ICH, LAAS, LS and SV were significantly correlated with vascular endothelial growth factor (VEGF), while LAAS, LS, CEI and SV were significantly related to fibroblast growth factor (FGF). Moreover, integrated bi-directional MR analysis, these factors (IL-3Rα, IL-6R, IL-6Rα, IL-1Ra, insulin-like growth factor-1(IGF-1), IL-12Rβ2) can be used as predictors of some specific stroke subtypes. As well as, IL-16 and C-C motif chemokine receptor 7 (CCR7) can be used as prognostic factors of stroke. Our findings prognostic identify potential pharmacological opportunities, including perturbation of circulating cytokines for both predicting stroke risk and post stroke treatment effects. As we conducted a comprehensive search and analysis of stroke subtype and cytokines in the existing publicly available GWAS database, the results have good population-generalizability.

A parametric bootstrap approach for computing confidence intervals for genetic correlations with application to genetically determined protein-protein networks

Genetic correlation refers to the correlation between genetic determinants of a pair of traits. When using individual-level data, it is typically estimated based on a bivariate model specification where the correlation between the two variables is identifiable and can be estimated from a covariance model that incorporates the genetic relationship between individuals, e.g., using a pre-specified kinship matrix. Inference relying on asymptotic normality of the genetic correlation parameter estimates may be inaccurate when the sample size is low, when the genetic correlation is close to the boundary of the parameter space, and when the heritability of at least one of the traits is low. We address this problem by developing a parametric bootstrap procedure to construct confidence intervals for genetic correlation estimates. The procedure simulates paired traits under a range of heritability and genetic correlation parameters, and it uses the population structure encapsulated by the kinship matrix. Heritabilities and genetic correlations are estimated using the close-form, method of moment, Haseman-Elston regression estimators. The proposed parametric bootstrap procedure is especially useful when genetic correlations are computed on pairs of thousands of traits measured on the same exact set of individuals. We demonstrate the parametric bootstrap approach on a proteomics dataset from the Jackson Heart Study.

Inflammation as a mediator between adverse childhood experiences and adult depression: A meta-analytic structural equation model

Exposure to adverse childhood experiences (ACEs) confers a higher risk of developing depression in adulthood, yet the mediation of inflammation remains under debate. To test this model, we conducted a systematic review and two-stage structural equation modelling meta-analysis of studies reporting correlations between ACEs before age 18, inflammatory markers and depression severity in adulthood. Scopus, Pubmed, Medline, PsycInfo, and CINAHL were searched up to 2 October 2023. Twenty-two studies reporting data on C-reactive protein (CRP, n = 12,935), interleukin-6 (IL-6, n = 4108), tumour necrosis factor-α (TNF-α, n = 2256) and composite measures of inflammation (n = 1674) were included. Unadjusted models revealed that CRP (β = 0.003, 95 % LBCI 0.0002 to 0.0068), IL-6 (β = 0.003, 95 % LBCI 0.001 to 0.006), and composite inflammation (β = 0.009, 95 % LBCI 0.004 to 0.018) significantly mediated the association between ACEs and adult depression. The mediation effects no longer survived after adjusting for BMI; however, a serial mediation model revealed that BMI and IL-6 sequentially mediated the association between ACEs and depression (β = 0.002, 95 % LBCI 0.0005 to 0.0046), accounting for 14.59 % and 9.94 % of the variance of IL-6 and depressive symptoms, respectively. Due to the cross-sectional nature of assessment of inflammation and depression findings should be approached with caution; however, results suggest that complex interactions of psychoneuroimmunological and metabolic factors underlie the association between ACEs and adulthood depression.

Dissecting the association between gut microbiota, body mass index and specific depressive symptoms: a mediation Mendelian randomisation study

Background

Observational studies highlight the association between gut microbiota (GM) composition and depression; however, evidence for the causal relationship between GM and specific depressive symptoms remains lacking.

Aims

We aimed to evaluate the causal relationship between GM and specific depressive symptoms as well as the mediating role of body mass index (BMI).

Methods

We performed a two-sample Mendelian randomisation (MR) analysis using genetic variants associated with GM and specific depressive symptoms from genome-wide association studies. The mediating role of BMI was subsequently explored using mediation analysis via two-step MR.

Results

MR evidence suggested the Bifidobacterium genus (β=-0.03; 95% CI -0.05 to -0.02; p<0.001 and β=-0.03; 95% CI -0.05 to -0.02; p<0.001) and Actinobacteria phylum (β=-0.04; 95% CI -0.06 to -0.02; p<0.001 and β=-0.03; 95% CI -0.05 to -0.03; p=0.001) had protective effects on both anhedonia and depressed mood. The Actinobacteria phylum also had protective effects on appetite changes (β=-0.04; 95% CI -0.06 to -0.01; p=0.005), while the Family XI had an antiprotective effect (β=0.03; 95% CI 0.01 to 0.04; p<0.001). The Bifidobacteriaceae family (β=-0.01; 95% CI -0.02 to -0.01; p=0.001) and Actinobacteria phylum (β=-0.02; 95% CI -0.03 to -0.01; p=0.001) showed protective effects against suicidality. The two-step MR analysis revealed that BMI also acted as a mediating moderator between the Actinobacteria phylum and appetite changes (mediated proportion, 34.42%) and that BMI partially mediated the effect of the Bifidobacterium genus (14.14% and 8.05%) and Actinobacteria phylum (13.10% and 8.31%) on both anhedonia and depressed mood.

Conclusions

These findings suggest a potential therapeutic effect of Actinobacteria and Bifidobacterium on both depression and obesity. Further studies are required to translate these findings into clinical practice.

Association between peripheral plasma cytokine levels and suicidal ideation in first-episode, drug-naïve major depressive disorder

BACKGROUND

Inflammatory processes could potentially impact both mood and suicide risk, however, the relationship between cytokines and suicidal ideation remains unclear. This study aimed to investigate the association between plasma levels of cytokines and suicidal ideation in population with major depressive disorders (MDD).

METHODS

A cross-sectional study was performed to assess the peripheral plasma levels of interleukin-1β (IL-1β), IL-2, IL-6, IL-8, IL-10 and tumor necrosis factor-α (TNF-α) in 88 Chinese Han first-episode drug-naïve MDD patients. Suicidal ideation in the past week were identified using the Beck Scale for Suicide Ideation-Chinese Version (BSI-CV). The Hamilton Depression Rating Scale-17 (HAMD-17), the Hamilton Anxiety Rating Scale-14 (HAMA-14) and the Childhood Trauma Questionnaire (CTQ) was used to assess depression, anxiety and childhood trauma. Multivariable logistic regression models were used to estimate the association between cytokines and suicidal ideation. Interaction and stratified analyses were conducted according to age, sex, marital status, education, smoking status, BMI and physical activity.

RESULTS

Among the 88 participants, 42 individuals (47.7%) reported suicidal ideation within the past week. In the fully adjusted model, a statistically significant trend was observed in the association between IL-2 level and suicidal ideation (OR: 1.40, 95% CI: 1.00-1.97). The stratified analysis showed a statistically significant association between IL-6 level and suicidal ideation among younger people (OR: 1.17, 95% CI: 1.01-1.36) and a significant positive association between IL-8 (OR: 1.59, 95% CI: 1.03-2.44) and IL-10 (OR: 2.51, 95% CI: 1.27-4.96) levels and suicide ideation among higher educated populations.

LIMITATIONS

The cross-sectional design, residual confounding effects and small sample size CONCLUSION: Our findings indicate a significant positive association between plasma IL-2 level and suicidal ideation in MDD patients. IL-2 has the potential to be a biomarker of suicidal ideation in patients with depression.

Distinct biological signature and modifiable risk factors underlie the comorbidity between major depressive disorder and cardiovascular disease

Major depressive disorder (MDD) and cardiovascular disease (CVD) are often comorbid, resulting in excess morbidity and mortality. Here we show that CVDs share most of their genetic risk factors with MDD. Multivariate genome-wide association analysis of shared genetic liability between MDD and atherosclerotic CVD revealed seven loci and distinct patterns of tissue and brain cell-type enrichments, suggesting the involvement of the thalamus. Part of the genetic overlap was explained by shared inflammatory, metabolic and psychosocial or lifestyle risk factors. Our data indicated causal effects of genetic liability to MDD on CVD risk, but not from most CVDs to MDD, and showed that the causal effects were partly explained by metabolic and psychosocial or lifestyle factors. The distinct signature of MDD-atherosclerotic CVD comorbidity suggests an immunometabolic subtype of MDD that is more strongly associated with CVD than overall MDD. In summary, we identified biological mechanisms underlying MDD-CVD comorbidity and modifiable risk factors for prevention of CVD in individuals with MDD.

Irritable Bowel Syndrome Is Associated With Brain Health by Neuroimaging, Behavioral, Biochemical, and Genetic Analyses

BACKGROUND

Irritable bowel syndrome (IBS) interacts with psychopathology in a complex way; however, little is known about the underlying brain, biochemical, and genetic mechanisms.

METHODS

To clarify the phenotypic and genetic associations between IBS and brain health, we performed a comprehensive retrospective cohort study on a large population. Our study included 171,104 participants from the UK Biobank who underwent a thorough assessment of IBS, with the majority also providing neuroimaging, behavioral, biochemical, and genetic information. Multistage linked analyses were conducted, including phenome-wide association analysis, polygenic risk score calculation, and 2-sample Mendelian randomization analysis.

RESULTS

The phenome-wide association analysis showed that IBS was linked to brain health problems, including anxiety and depression, and poor cognitive performance. Significantly lower brain volumes associated with more severe IBS were found in key areas related to emotional regulation and higher-order cognition, including the medial orbitofrontal cortex/ventromedial prefrontal cortex, anterior insula, anterior and mid-cingulate cortices, dorsolateral prefrontal cortex, and hippocampus. Higher triglycerides, lower high-intensity lipoprotein, and lower platelets were also related (p < 1 × 10-10) to more severe IBS. Finally, Mendelian randomization analyses demonstrated potential causal relationships between IBS and brain health and indicated possible mediating effects of dyslipidemia and inflammation.

CONCLUSIONS

For the first time, this study provides a comprehensive understanding of the relationship between IBS and brain health phenotypes, integrating perspectives from neuroimaging, behavioral performance, biochemical factors, and genetics, which is of great significance for clinical applications to potentially address brain health impairments in patients with IBS.

Investigating the causal relationship between thyroid dysfunction diseases and osteoporosis: a two-sample Mendelian randomization analysis

The prevalence of thyroid dysfunction diseases (TDFDs) and osteoporosis (OP) is high. Previous studies have indicated a potential association between TDFDs and OP, yet the causal direction remains unclear. This study aimed to investigate the potential causal relationship between TDFDs and the risk of developing OP and related fractures. We obtained pooled data from genome-wide association studies (GWASs) conducted on TDFDs and OP in European populations and identified single-nucleotide polymorphisms (SNPs) with genome-wide significance levels associated with exposure to TDFDs as instrumental variables. Inverse variance weighted (IVW) was employed as the primary method for Mendelian randomization (MR) analysis, supplemented by MR‒Egger, weighted median, simple mode and weighted mode methods. Sensitivity analyses were conducted to evaluate the robustness of the findings. The IVW method demonstrated an increased risk of OP in patients with TDFDs, including hyperthyroidism and hypothyroidism (TDFDs: OR = 1.11; 95% CI 1.09, 1.13; hypothyroidism: OR = 1.14; 95% CI 1.10, 1.17; hyperthyroidism: OR = 1.09; 95% CI 1.06, 1.12). These findings were supported by supplementary analysis, which revealed a positive correlation between TDFDs and the risk of OP. Multiple sensitivity analyses confirmed the absence of horizontal pleiotropy in the study, thus indicating the robustness of our results. The causal relationship between TDFDs and increased risk of OP implies the need for early bone mineral density (BMD) screening and proactive prevention and treatment strategies for individuals with TDFDs.

A novel biomarker of interleukin 6 activity and clinical and cognitive outcomes in depression

BACKGROUND

Inflammatory cytokines like interleukin-6 (IL-6) are implicated in depression, but most studies have hitherto focused on circulating levels of IL-6 rather than its activity. IL-6 trans-signalling is thought to be responsible for most of the pathogenic effects of IL-6 and is implicated in autoimmune diseases like rheumatoid arthritis. We tested the association between a multi-protein-derived measure of IL-6 trans-signalling and clinical and cognitive outcomes in patients with depression. We hypothesised that this novel measure of IL-6 activity/bioavailability would be associated with clinical and cognitive measures previously reported to be associated with inflammation in depression.

METHODS

Using data from 86 patients with International Classification of Diseases-10 diagnosis of depression, we calculated a ratio score representing IL-6 activity/bioavailability using serum IL-6, soluble IL-6 receptor (sIL-6R), and soluble glycoprotein 130 levels. We tested the relationship of this novel biomarker with 12 cytokines using correlation analyses and with cognitive and clinical measures using multivariable linear regression, following z-transformation of all immune exposures.

RESULTS

The novel measure of IL-6 activity/bioavailability was correlated with IL-6 (r=0.42, P=0.03), C-reactive protein (CRP) (r=0.42, P=0.03), sIL-6R (r=0.91, P<0.01), and tumour necrosis factor alpha (r=0.43, P=0.03). The IL-6 activity/bioavailability measure was associated with higher somatic symptoms of depression (β=1.09; 95% CI 0.30, 1.88; PFDR=0.01), fatigue (β=4.34; 95% CI 1.26, 7.42; PFDR=0.03), depression severity (β=3.06; 95% CI 0.71, 5.40; P=0.02), poorer quality of life (β=-0.07; 95% CI -0.13, -0.01; PFDR=0.045), and decreased psychomotor speed (β=-5.46; 95% CI -9.09, -1.84; PFDR=0.01),. There was little evidence of associations with reaction time, anhedonia, anxiety, emotional perception and recall, executive function, and sustained attention (Ps>0.05). The effect estimates for the associations of the novel measure with depression outcomes were comparable to those for individual immune proteins (i.e., IL-6, CRP, sIL-6R).

CONCLUSION

A novel multi-protein-derived measure of IL-6 activity/bioavailability shows robust associations with various inflammation-related clinical and cognitive outcomes in depression and performs well in comparison to single inflammatory proteins. We need replication of these findings in other samples, experiments for mechanistic validity of this novel biomarker, and clinical studies to assess its usefulness as a marker of illness risk and prognosis.

Identification and Functional Investigation of Hub Genes Associated with Follicular Lymphoma

Follicular lymphoma (FL), the most common type of indolent lymphoma, originates from germinal center B cells within the lymphoid follicle. However, the underlying mechanisms of this disease remain unclear. This study aimed to identify the potential hub genes for FL and evaluate their functional roles in clinical applications. Microarray data and clinical characteristics of patients with FL were obtained from the Gene Expression Omnibus database. Differential expression analysis and weighted gene co-expression network analysis (WGCNA) were employed to explore hub genes for FL. Functional enrichment analysis was performed to investigate the potential roles of these hub genes in FL. Mendelian randomization (MR) analysis was performed to verify the causal effect of the top genes on FL risk. In addition, gene set enrichment analysis (GSEA) and immune cell analysis were performed to elucidate the involved mechanisms of the crucial genes in FL. A total of 1363 differentially expressed genes and 157 central genes were identified by differential expression analysis and WGCNA, respectively, resulting in 117 overlapping genes considered as hub genes for FL. Functional enrichment analysis revealed significant correlations between immune-related pathways and FL. MR analysis revealed a significant association only between zeta chain of T-cell receptor-associated protein kinase 70 (ZAP70) and FL risk, with no significance observed for the other top genes. GSEA and immune cell analysis suggested that ZAP70 may be involved in the development and progression of FL through immune-related pathways. By integrating bioinformatics and MR analyses, ZAP70 was successfully identified and validated as a promising FL biomarker. Functional investigations indicated a significant correlation between immune-related pathways and FL. These findings have important implications for the identification of targets for the diagnosis and treatment of FL and provide valuable insights into the molecular mechanisms underlying FL.

Depressive symptoms and all-cause mortality among middle-aged and older people in China and associations with chronic diseases

Introduction

It remains unclear whether depressive symptoms are associated with increased all-cause mortality and to what extent depressive symptoms are associated with chronic disease and all-cause mortality. The study aims to explore the relationship between depressive symptoms and all-cause mortality, and how depressive symptoms may, in turn, affect all-cause mortality among Chinese middle-aged and older people through chronic diseases.

Methods

Data were collected from the China Health and Retirement Longitudinal Study (CHARLS). This cohort study involved 13,855 individuals from Wave 1 (2011) to Wave 6 (2020) of the CHARLS, which is a nationally representative survey that collects information from Chinese residents ages 45 and older to explore intrinsic mechanisms between depressive symptoms and all-cause mortality. The Center for Epidemiological Studies Depression Scale (CES-D-10) was validated through the CHARLS. Covariates included socioeconomic variables, living habits, and self-reported history of chronic diseases. Kaplan-Meier curves depicted mortality rates by depressive symptom levels, with Cox proportional hazards regression models estimating the hazard ratios (HRs) of all-cause mortality.

Results

Out of the total 13,855 participants included, the median (Q1, Q3) age was 58.00 (51.00, 63.00) years. Adjusted for all covariates, middle-aged and older adults with depressive symptoms had a higher all-cause mortality rate (HR = 1.20 [95% CI, 1.09-1.33]). An increased rate was observed for 55-64 years old (HR = 1.23 [95% CI, 1.03-1.47]) and more than 65 years old (HR = 1.32 [95% CI, 1.18-1.49]), agricultural Hukou (HR = 1.44, [95% CI, 1.30-1.59]), and nonagricultural workload (HR = 1.81 [95% CI, 1.61-2.03]). Depressive symptoms increased the risks of all-cause mortality among patients with hypertension (HR = 1.19 [95% CI, 1.00-1.40]), diabetes (HR = 1.41[95% CI, 1.02-1.95]), and arthritis (HR = 1.29 [95% CI, 1.09-1.51]).

Conclusion

Depressive symptoms raise all-cause mortality risk, particularly in those aged 55 and above, rural household registration (agricultural Hukou), nonagricultural workers, and middle-aged and older people with hypertension, diabetes, and arthritis. Our findings through the longitudinal data collected in this study offer valuable insights for interventions targeting depression, such as early detection, integrated chronic disease care management, and healthy lifestyles; and community support for depressive symptoms may help to reduce mortality in middle-aged and older people.

Clinical effects of nonconvulsive electrotherapy combined with mindfulness-based stress reduction and changes of serum inflammatory factors in depression

BACKGROUND

Depression is a common and serious psychological condition, which seriously affects individual well-being and functional ability. Traditional treatment methods include drug therapy and psychological counseling; however, these methods have different degrees of side effects and limitations. In recent years, nonconvulsive electrotherapy (NET) has attracted increasing attention as a noninvasive treatment method. However, the clinical efficacy and potential mechanism of NET on depression are still unclear. We hypothesized that NET has a positive clinical effect in the treatment of depression, and may have a regulatory effect on serum inflammatory factors during treatment.

AIM

To assess the effects of NET on depression and analyze changes in serum inflammatory factors.

METHODS

This retrospective study enrolled 140 patients undergoing treatment for depression between May 2017 and June 2022, the observation group that received a combination of mindfulness-based stress reduction (MBSR) and NET treatment (n = 70) and the control group that only received MBSR therapy (n = 70). The clinical effectiveness of the treatment was evaluated by assessing various factors, including the Hamilton Depression Scale (HAMD)-17, self-rating idea of suicide scale (SSIOS), Pittsburgh Sleep Quality Index (PSQI), and levels of serum inflammatory factors before and after 8 wk of treatment. The quality of life scores between the two groups were compared. Comparisons were made using t and χ2 tests.

RESULTS

After 8 wk of treatment, the observation group exhibited a 91.43% overall effectiveness rate which was higher than that of the control group which was 74.29% (64 vs 52, χ2 = 7.241; P < 0.05). The HAMD, SSIOS, and PSQI scores showed a significant decrease in both groups. Moreover, the observation group had lower scores than the control group (10.37 ± 2.04 vs 14.02 ± 2.16, t = 10.280; 1.67 ±0.28 vs 0.87 ± 0.12, t = 21.970; 5.29 ± 1.33 vs 7.94 ± 1.35, t = 11.700; P both < 0.001). Additionally, there was a notable decrease in the IL-2, IL-1β, and IL-6 in both groups after treatment. Furthermore, the observation group exhibited superior serum inflammatory factors compared to the control group (70.12 ± 10.32 vs 102.24 ± 20.21, t = 11.840; 19.35 ± 2.46 vs 22.27 ± 2.13, t = 7.508; 32.25 ± 4.6 vs 39.42 ± 4.23, t = 9.565; P both < 0.001). Moreover, the observation group exhibited significantly improved quality of life scores compared to the control group (Social function: 19.25 ± 2.76 vs 16.23 ± 2.34; Emotions: 18.54 ± 2.83 vs 12.28 ± 2.16; Environment: 18.49 ± 2.48 vs 16.56 ± 3.44; Physical health: 19.53 ± 2.39 vs 16.62 ± 3.46; P both < 0.001) after treatment.

CONCLUSION

MBSR combined with NET effectively alleviates depression, lowers inflammation (IL-2, IL-1β, and IL-6), reduces suicidal thoughts, enhances sleep, and improves the quality of life of individuals with depression.

Genetic evidence for the causal effects of C-reactive protein on self-reported habitual sleep duration

Inflammatory responses to acute stimuli are proposed to regulate sleep, but the relationship between chronic inflammation and habitual sleep duration is elusive. Here, we study this relation using genetically predicted level of chronic inflammation, indexed by CRP and IL6 signaling, and self-reported sleep duration. By Mendelian randomization analysis, we show that elevated CRP level within <10 mg/L has a homeostatic effect that facilitates maintaining 7-8 h sleep duration per day - making short-sleepers sleep longer (p = 2.42 × 10-2) and long-sleepers sleep shorter (1.87 × 10-7); but it is not associated with the overall sleep duration (p = 0.17). This homeostatic effect replicated in an independent CRP dataset. We observed causal effects of the soluble interleukin 6 receptor and gp130 on overall sleep duration (p = 1.62 × 10-8, p = 2.61 × 10-58, respectively), but these effects disappeared when CRP effects were accounted for in the model. Using polygenic score analysis, we found that the homeostatic effect of CRP on sleep duration stems primarily from the genetic variants within the CRP gene region: when genetic variants outside of this region were used to predict CRP levels, the opposite direction of effect was observed. In conclusion, we show that elevated CRP level may causally facilitate maintaining an optimal sleep duration that is beneficial to health, thus updating our current knowledge of immune regulation on sleep.

Role of Inflammation in Depressive and Anxiety Disorders, Affect, and Cognition: Genetic and Non-Genetic Findings in the Lifelines Cohort Study

Background

Low-grade systemic inflammation is implicated in the pathogenesis of various neuropsychiatric conditions affecting mood and cognition. While much of the evidence concerns depression, large-scale population studies of anxiety, affect, and cognitive function are scarce. Importantly, causality remains unclear. We used complementary non-genetic, genetic risk score (GRS), and Mendelian randomization (MR) analyses to examine whether inflammatory markers are associated with affect, depressive and anxiety disorders, and cognitive performance in the Lifelines Cohort; and whether associations are likely to be causal.

Methods

Using data from up to 55,098 (59% female) individuals from the Dutch Lifelines cohort, we tested the cross-sectional and longitudinal associations of C-reactive protein (CRP) with (i) depressive and anxiety disorders; (ii) positive and negative affect scores, and (iii) five cognitive measures assessing attention, psychomotor speed, episodic memory, and executive functioning (figural fluency and working memory). Additionally, we examined the association between inflammatory marker GRSs (CRP, interleukin-6 [IL-6], IL-6 receptor [IL-6R and soluble IL-6R (sIL-6R)], glycoprotein acetyls [GlycA]) on these same outcomes (Nmax=57,946), followed by MR analysis examining evidence of causality of CRP on outcomes (Nmax=23,268). In genetic analyses, all GRSs and outcomes were z-transformed.

Results

In non-genetic analyses, higher CRP was associated with diagnosis of any depressive disorder, lower positive and higher negative affect scores, and worse performance on tests of figural fluency, attention, and psychomotor speed after adjusting for potential confounders, although the magnitude of these associations was small. In genetic analyses, CRPGRS was associated with any anxiety disorder (β=0.002, p=0.037, N=57,047) whereas GlycAGRS was associated with major depressive disorder (β=0.001, p=0.036; N=57,047). Both CRPGRS (β=0.006, p=0.035, N=57,946) and GlycAGRS (β=0.006, p=0.049; N=57,946) were associated with higher negative affect score. Inflammatory marker GRSs were not associated with cognitive performance, except sIL-6RGRS which was associated with poorer memory performance (β=-0.009, p=0.018, N=36,783). Further examination of the CRP-anxiety association using MR provided some weak evidence of causality (β=0.12; p=0.054).

Conclusions

Genetic and non-genetic analyses provide consistent evidence for an association between CRP and negative affect. Genetic analyses suggest that IL-6 signaling could be relevant for memory, and that the association between CRP and anxiety disorders could be causal. These results suggest that dysregulated immune physiology may impact a broad range of trans-diagnostic affective symptoms. However, given the small effect sizes and multiple tests conducted, future studies are required to investigate whether effects are moderated by sub-groups and whether these findings replicate in other cohorts.

Real-world evidence from a retrospective study on suicide during depression: clinical characteristics, treatment patterns and disease burden

BACKGROUND

Suicide stands as both a primary symptom and the direst outcome of major depressive disorder (MDD). The scarcity of effective treatment strategies makes managing MDD patients with suicide especially challenging. Hence, it is crucial to investigate disease characteristics and efficacious therapeutic strategies for these patients, drawing insights from disease databases and real-world data.

METHODS

In this retrospective study, MDD patients hospitalized between January 2013 and December 2020 were investigated using Electronic Health Records (EHR) data from Beijing Anding Hospital. The study enrolled 4138 MDD patients with suicidal ideation or behavior (MDS) and 3848 without (MDNS). Demographic data, clinical attributes, treatment approaches, disease burden, and re-hospitalization within one year of discharge were extracted and compared.

RESULTS

Patients in the MDS group were predominantly younger and female, exhibiting a higher prevalence of alcohol consumption, experiencing frequent life stress events, and having an earlier onset age. Re-hospitalizations within six months post-discharge in the MDS group were significantly higher than in the MDNS group (11.36% vs. 8.91%, p < 0.001). Moreover, a more considerable fraction of MDS patients underwent combined electroconvulsive therapy treatment (56.72% vs. 43.71%, p < 0.001). Approximately 38% of patients in both groups were prescribed two or more therapeutic regimes, and over 90% used antidepressants, either alone or combined. Selective serotonin reuptake inhibitors (SSRIs) were the predominant choice in both groups. Furthermore, antidepressants were often prescribed with antipsychotics or mood stabilizers. When medication alterations were necessary, the favoured options involved combination with antipsychotics or transitioning to alternative antidepressants. Yet, in the MDS group, following these initial modifications, the addition of mood stabilizers tended to be the more prioritized alternative.

CONCLUSIONS

MDD patients with suicidal ideation or behaviour displayed distinctive demographic and clinical features. They exhibited intricate treatment patterns, a pronounced burden of illness, and an increased likelihood of relapse.

Genetic evidence suggests a genetic association between major depressive disorder and reduced cortical gray matter volume: A Mendelian randomization study and mediation analysis

BACKGROUND

Several studies have suggested an association between major depressive disorder (MDD) and abnormal brain structure. However, it is unclear whether MDD affects cortical gray matter volume, a common indicator of cognitive function. We aimed to determine whether MDD was associated with decreased cortical gray matter volume (GMV) through a Mendelian randomization (MR) study.

METHODS

We obtained summary genetic data from a study conducted by the Psychiatric Genomics Consortium, which recruited a total of 480,359 participants (135,458 cases and 344,901 controls). Genetic tools-single nucleotide polymorphisms (SNPs)-of MDD were extracted from the study and their effects on gray matter volumes of the cortex and total brain were evaluated in a large cohort from the UK Biobank (n = 8427). The effects of the SNPs were pooled using inverse variance weighted (IVW) analysis and further tested in several sensitivity analyses. We tested whether C-reactive protein (CRP) levels and interleukin-6 signaling were the mediators of the effects using a multivariate MR model.

RESULTS

Thirty-three SNPs were identified and adopted as genetic tools for predicting MDD. IVW analysis showed that MDD was associated with lower overall GMV (beta value -0.106, 95%CI -0.188 to -0.023, p = 0.011) in the frontal pole (left frontal pole, -0.152, 95%CI -0.177 to -0.127, p = 0.013; right frontal pole, -0.133, 95%CI -0.253 to -0.013, p = 0.028). Multivariate and mediation analysis showed that interleukin-6 was an important mediator of GMV reduction. Reverse causality analysis found no evidence that total GMV affected the risk of MDD, but showed that increased left precuneus cortex volume and left posterior cingulate cortex volume were associated with increased risk of MDD.

LIMITATIONS

Potential pleiotropic effects and overestimation of real-world effects. Key assumptions for MR analysis may not be satisfactorily met.

CONCLUSION

MDD was associated with a reduced GMV, and interleukin-6 might be a mediator of GMV reduction.

Interleukin-6 signaling pathway in Mendelian randomization: A 10-year bibliometric analysis

Interleukin 6 (IL-6), a pleiotropic cytokine, is crucial in a variety of inflammatory and immunological disorders. In recent years, mendelian randomization, which is a widely used and successful method of analyzing causality, has recently been investigated for the relationship between the IL-6 pathway and related diseases. However, no studies have been conducted to review the research hotspots and trends in the field of IL-6 signaling pathway in Mendelian randomization. In this study, the Web of Science Core Collection (WoSCC) served as our literature source database to gather articles about the IL-6 signaling pathway in Mendelian randomization from 2013 to 2023. VOSviewer (version 1.6.18), Microsoft Excel 2021, and Scimago Graphica were employed for bibliometric and visualization analysis. A total of 164 documents that were written by 981 authors coming from 407 institutions across 41 countries and published in 107 journals were located from January 2013 to August 2023. With 64 and 25, respectively, England and the University of Bristol had the highest number of publications. Frontiers in Immunology is the most prolific journal, and Golam M Khandaker has published the highest number of significant articles. The most co-cited article was an article entitled the interleukin-6 receptor as a target for prevention of coronary-heart-disease: a Mendelian randomization analysis, written by Daniel I Swerdlow. The most popular keywords were "mendelian randomization," "interleukin-6," "il-6," "c-reactive protein," "association," "coronary-heart-disease," "inflammation," "instruments," "risk," "rheumatoid arthritis," "depression." The full extent of the existing literature over the last 10 years is systematically revealed in this study, which can provide readers with a valuable reference for fully comprehending the research hotspots and trends in the field of IL-6 signaling pathway in Mendelian randomization.