CRP, IL-6 and depression: a systematic review and meta-analysis of longitudinal studies

Insomnia and Inflammation Conspire to Heighten Depression Risk: Implications for Treatment and Prevention of Mood Disorders

Insomnia is ubiquitous, co-morbid with all major mental disorders, increases the risk of depression, and contributes to inflammatory morbidity and all-cause mortality. This review examines the relationships between insomnia and inflammation in the pathophysiology of depression. The unique role of insomnia on depression risk is examined with interrogation of what aspects of sleep disturbance contribute to depressed mood. Further, the influence of insomnia, as well as specific its specific aspects (i.e., short sleep duration, disturbance of sleep maintenance) on affective mechanisms are considered, with a focus on reward activation and emotion processing. Given that inflammation contributes to some types of depression, the bidirectional interactions between sleep and inflammation are examined with consideration of how sleep deprivation induces activation of systemic, cellular, and genomic inflammatory outcomes, and the causal role of inflammation in precipitating depressed mood and depressive symptoms. Key gaps in the literature linking insomnia and inflammation to depression risk are identified, and maps for future research are proposed. Specifically, this review considers how the components of insomnia and inflammation conspire together to exaggerate deficits in reward activation and recognition of emotion, which underlie depression risk and adverse depression outcomes. Finally, informed by this two-hit model of insomnia and inflammation on depression risk, this review examines the efficacy of behavioral interventions that target insomnia and reverse related inflammation, and discusses their potential to refine therapeutic approaches for depression treatment and prevention in persons with insomnia.

Effects of neutrophils on the relationship between physical activity and depression: Evidence from cross-sectional study and mendelian randomization analysis

OBJECTIVE

Physical activity (PA) is suggested to reduce the risk of depression, and inflammation is believed to play an important role in this antidepressant effect. The current study aims to investigate the effect of neutrophils, one of the most important markers of inflammation, on the relationship between PA and depression.

METHODS

We cross-sectionally analyzed 34,317 adults who participated in the National Health and Nutrition Examination Survey. The moderation and mediation effects of neutrophils on the relationship between PA and depression were assessed using a four-way decomposition approach. Additional Mendelian Randomization (MR) analysis was conducted to validate the potential causal mediation effect.

RESULTS

PA was associated with lower odds of depression [Odds Ratio (OR): 0.67; 95 % Confidence Interval (CI): 0.56-0.79] and a lower level of neutrophils (OR: 0.83; 95 % CI: 0.77-0.90). Neutrophils were associated with higher odds of depression in a non-linear manner. While neutrophils did not modify the association between PA and depression, a significant mediating effect was observed. The influence of PA and neutrophils on depression was attributed to the controlled direct effect (96 % proportion) and the pure indirect effect (2 % proportion). MR analysis did not confirm a potential causal effect.

CONCLUSION

There is a close relationship between PA, neutrophils, and depression. The effect of PA on depression did not differ among participants with different levels of neutrophils. Although neutrophils mediated the association between PA and depression, this mediating effect was not causal. Other unknown factors closely related to neutrophils may be involved in this mediating process.

Efficacy of probiotic adjuvant therapy in women with major depressive disorder: insights from a case series study

BACKGROUND

The therapeutic targeting of the intestinal microbiota has gained increasing attention as a promising avenue for addressing mood disorders. This study aimed to assess the potential effect of supplementing standard pharmacological treatment with the probiotic kefir in patients with Major Depressive Disorder (MDD).

METHODS

Thirty-eight female participants diagnosed with moderate MDD by the Hamilton Rating Scale for Depression (HAM-D) were selected to receive the probiotic kefir in conjunction with antidepressant therapy for 12 weeks. The participants were evaluated at baseline (T0) and 90 days after probiotic kefir supplementation (T90). HAM-D scores and blood samples were collected at both time points.

RESULTS

Probiotic supplementation significantly reduced MDD severity, as evidenced by lower HAM-D scores compared to baseline. Probiotic consumption for 90 days also significantly decreased interleukin-6 (IL-6), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) levels compared to baseline. However, probiotic kefir supplementation did not significantly affect serum serotonin levels. Additionally, after 90 days of probiotic consumption, insulin and morning cortisol levels were significantly reduced. In contrast, no significant changes were observed in serum levels of prolactin, vitamin D, and afternoon cortisol.

CONCLUSION

This study provides valuable insights into the potential benefits of probiotics, specifically kefir, as adjunctive therapy for female patients with MDD. The findings highlight promising results in ameliorating depressive symptoms and modulating inflammatory and hormonal markers.

The change of inflammatory cytokines after antidepressant treatment and correlation with depressive symptoms

BACKGROUND

The objective of this study was to explore the serum levels of IL-1, IL-6, IL-10, TNF-a, and high-sensitivity C-reactive protein (hs-CRP) in patients with depression before and after treatment and their correlation with the clinical symptoms of depression.

METHODS

Fifty depression patients newly diagnosed and untreated in the Fourth People's Hospital of Wuhu were chosen as the depression group, while 50 healthy individuals from the same period served as the control group. We contrasted the serum levels of these markers of inflammation in both groups. After 8 weeks of SSRI antidepressant therapy, changes in inflammatory cytokines, hs-CRP, and HAMD-17 scores were evaluated in the depression group.

RESULTS

The levels of serum inflammatory cytokines and hs-CRP in patients with depression were higher than the healthy control group significantly (P < 0.05). After treatment, the levels of serum inflammatory cytokines and hs-CRP in patients with depression decreased significantly (P < 0.05). The total score of HAMD-17 and the scores of sleep, cognitive impairment, inhibition, and anxiety somatization factors in the depression group were decreased than those before treatment (P < 0.01). The serum IL-1 concentration in the depression group inversely related to the decrease in the HAMD-17 inhibition factor (R = -0.359,P = 0.011); The serum IL-6 concentration change rate positively correlated with the reduction rate of the cognitive impairment factor of HAMD-17 (R = 0.426,P = 0.017); the change rate of hs-CRP concentration was positively correlated with the reduction rate of the anxiety somatization factor of HAMD-17 (R = 0.343,P = 0.015).

CONCLUSION

Antidepressant treatment affects the levels of serum inflammatory cytokines and hs-CRP significantly, and is correlated with changes in clinical symptoms.

Association of RDoC dimensions with post mortem brain transcriptional profiles in Alzheimer's disease

INTRODUCTION

Neuropsychiatric symptoms are common in people with Alzheimer's disease (AD) across all severity stages. Their heterogeneous presentation and variable temporal association with cognitive decline suggest shared and distinct biological mechanisms. We hypothesized that specific patterns of gene expression associate with distinct National Institute of Mental Health Research Domain Criteria (RDoC) domains in AD.

METHODS

Post-mortem bulk RNA sequencing of the insula and anterior cingulate cortex from 60 brain donors, representing the spectrum of canonical Alzheimer's disease neuropathology, was combined with natural language processing approaches based on the RDoC Clinical Domains to uncover transcriptomic patterns linked to disease progression.

RESULTS

Distinct sets of >100 genes (P false discovery rate < 0.05) were specifically associated with at least one clinical domain (cognitive, social, negative, positive, arousal). In addition, dysregulation of immune response pathways was shared across domains and brain regions.

DISCUSSION

Our findings provide evidence for distinct transcriptional profiles associated with RDoC domains suggesting that each dimension is characterized by sets of genes providing insight into the underlying mechanisms.

Highlights

Post mortem brain tissue investigations are critically important for Alzheimer's disease (AD) research.Neuropsychiatric symptoms in AD are common and an important aspect of AD.Categorical phenotypes are commonly used, but insufficiently describe the heterogenous presentation of AD.Using natural language processing (NLP) of post mortem brain donor health records provides insight into dimensional phenotypes of AD.We provide evidence for distinct RNA expression profiles associated with NLP-derived Research Domain Criteria clinical domain scores.

Revealing the Causal Relationship Between Differential White Blood Cell Counts and Depression: A Bidirectional Two-Sample Mendelian Randomization Study

Background: The link between white blood cells (WBC) and depression has been studied, but the causal relationship remains unclear. This study aimed to elucidate the potential bidirectional causal links between six specific WBC count features and depression using a two-sample Mendelian randomization (MR) analysis, leveraging summary statistics from genome-wide association studies (GWAS). Method: The dataset on depression (N = 406,986) was sourced from the FinnGen database, while the dataset on WBC (N = 563,085) was obtained from a combined dataset of Blood Cell Consortium (BCX) and UK Biobank. The MR analyses employed include inverse variance weighted (IVW), MR-Egger, weighted median, contamination mixture method (conmix), and constrained maximum likelihood-based Mendelian randomization (cML-MA). A threshold p < 0.05 after false discovery rate (FDR) correction was set as the criterion for causality based on IVW. Results: Reverse MR analysis indicated a causal relationship where depression leads to an increase in overall WBC count (IVW beta = 0.031, p = 0.015, p FDR = 0.044) and specifically in basophil count (IVW beta = 0.038, p = 0.006, p FDR = 0.038), with a marginally significant impact on lymphocyte count (beta = 0.029, p = 0.036, p FDR = 0.071). Furthermore, forward MR analysis suggested a potential role of monocyte count in decreasing depression risk (p = 0.028), though this association did not retain statistical significance after FDR correction. Conclusion: These findings suggest that depression may causally influence the immune system by elevating overall WBC and basophil counts, with a marginally significant increase in lymphocyte levels. Conversely, higher monocyte count might confer some protection against depression, albeit with less statistial certainty. This study provides novel insights into the complex interplay between depression and immune function.

Differential associations of somatic and cognitive-affective symptoms of depression with inflammation and insulin resistance: cross-sectional and longitudinal results from the Emotional Distress Sub-Study of the GRADE study

AIMS/HYPOTHESIS

Insulin resistance and inflammation are components of a biological framework that is hypothesised to be shared by type 2 diabetes and depression. However, depressive symptoms include a large heterogeneity of somatic and cognitive-affective symptoms, and this may obscure the associations within this biological framework. Cross-sectional and longitudinal data were used to disentangle the contributions of insulin resistance and inflammation to somatic and cognitive-affective symptoms of depression.

METHODS

This secondary analysis used data from the Emotional Distress Sub-Study of the GRADE trial. Insulin resistance and inflammation were assessed using the HOMA-IR estimation and high-sensitivity C-reactive protein (hsCRP) levels, respectively, at baseline and at the study visits at year 1 and year 3 (HOMA-IR) and every 6 months (hsCRP) for up to 3 years of follow-up. Depressive symptoms were assessed at baseline using the Patient Health Questionnaire (PHQ-8), and a total score as well as symptom cluster scores for cognitive-affective and somatic symptoms were calculated. For the cross-sectional analyses, linear regression analyses were performed, with inflammation and insulin resistance at baseline as dependent variables. For the longitudinal analyses, linear mixed-effect regression analyses were performed, with inflammation and insulin resistance at the various time points as dependent variables. In all analyses, depressive symptoms (total score and symptom cluster scores) were the independent variables, controlled for important demographic, anthropometric and metabolic confounders. For the analysis of insulin resistance (HOMA-IR), data from 1321 participants were analysed. For the analysis of inflammation (hsCRP), data from 1739 participants were analysed.

RESULTS

In cross-sectional analysis and after adjustment for potential confounders, a one-unit increase in PHQ-8 total score was significantly associated with a 0.8% increase in HOMA-IR (p=0.007), but not with hsCRP (0.6% increase, p=0.283). The somatic symptom score was associated with a 5.8% increase in HOMA-IR (p=0.004). Single-item analyses of depressive symptoms showed that fatigue (3.6% increase, p=0.002) and increased/decreased appetite (3.5% increase, p=0.009) were significantly associated with HOMA-IR cross-sectionally. The cognitive-affective symptom score was not significantly associated with HOMA-IR at baseline. In longitudinal analyses, a one-unit increase in PHQ-8 total score was significantly associated with a 0.8% increase in hsCRP over time (p=0.014), but not with HOMA-IR over time (0.1% decrease, p=0.564). Again, only the somatic symptom cluster was significantly associated with hsCRP over time (5.2% increase, p=0.017), while the cognitive-affective symptom score was not.

CONCLUSION/INTERPRETATION

The results highlight the associations of depressive symptoms with markers of inflammation and insulin resistance, both cross-sectionally and longitudinally, in individuals with type 2 diabetes. In particular, somatic symptoms of depression appear to be the driver of these associations, even after controlling for concomitant conditions, with a potential role for fatigue and issues with appetite.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01794143.

Resting-state functional connectivity is correlated with peripheral inflammatory markers in patients with major depressive disorder and healthy controls

BACKGROUND

Recent studies have highlighted the significant role of inflammation in the development and progression of major depressive disorder (MDD). Elevated levels of proinflammatory cytokines have consistently been observed in MDD, and these markers are shown to be linked to disruptions in brain networks. Therefore, we aimed to explore the relationship between inflammatory markers and resting-state functional connectivity (RSFC) in patients with MDD.

METHODS

This study included 76 patients with MDD and 92 healthy controls (HCs). Seed-to-voxel RSFC analysis was performed using brain regions that have been identified in previous studies on the neural networks implicated in MDD. These regions served as key hubs in the default mode, salience, cognitive control, and frontostriatal networks and were used as seed regions.

RESULTS

Compared with HCs, patients with MDD exhibited elevated levels of interleukin (IL)-6 and IL-8. The MDD group showed significant alterations of the RSFC between the prefrontal cortex (PFC), anterior cingulate cortex, visual cortex, postcentral gyrus, and striatal regions compared to the HC group. Additionally, within the MDD group, a positive correlation was observed between tumor necrosis factor (TNF)-α levels and the RSFC of the right dorsolateral prefrontal cortex (dlPFC) and visual cortex. Conversely, in the HC group, TNF-α levels were negatively correlated with the RSFC between the right dlPFC and bilateral dorsomedial prefrontal cortex, while positive correlations were noted between the RSFC of the right dlPFC with occipital regions and the levels of both IL-8 and TNF-α.

CONCLUSIONS

The present study confirmed that cytokine levels are linked to alterations in the RSFC, particularly in the prefrontal regions. Our findings suggest that systemic inflammation may contribute to functional disruptions in the brain networks involved in emotion regulation and cognitive control in MDD.

Ketamine and Esketamine in Clinical Trials: FDA-Approved and Emerging Indications, Trial Trends With Putative Mechanistic Explanations

Ketamine has a long and very eventful pharmacological history. Its enantiomer, esketamine ((S)-ketamine), was approved by the US Food and Drug Administration (FDA) and EMA for patients with treatment-resistant depression (TRD) in 2019. The number of approved indications for ketamine and esketamine continues to increase, as well as the number of clinical trials. This analysis provides a quantitative overview of the use of ketamine and its enantiomers in clinical trials during 2014-2024. A total of 363 trials were manually assessed from clinicaltrial.gov with the search term "Ketamine." The highest number of trials were found for the FDA-approved indications: anesthesia (~22%) and pain management (~28%) for ketamine and TRD for esketamine (~29%). Clinical trials on TRD for both ketamine and esketamine also comprised a large proportion of these trials, and interestingly, have reached phase III and phase IV status. Combinatorial treatment of psychiatric disorders and non-psychiatric conditions with pharmacological and non-pharmacological combinations (electroconvulsive therapy, psychotherapeutic techniques, virtual reality, and transcranial magnetic stimulation) is prevalent. Sub-anesthetic doses of ketamine may represent novel therapeutic avenues in neuropsychiatric conditions, that is, major depression, schizophrenia, and bipolar disorder, where glutamate excitotoxicity and oxidative stress are likely to be involved. The study suggests that the number of ketamine studies will continue to grow and possible ketamine variants can be approved for treatment of additional indications.

Nonlinear association between depressive symptoms and homeostasis model assessment of insulin resistance: a cross-sectional analysis in the American population

Background

Depressive symptom, a pervasive mental health disorder, has garnered increasing attention due to its intricate interconnections with various physiological processes. One emerging avenue of investigation delves into the potential association between depressive symptom and Homeostasis Model Assessment of Insulin Resistance (HOMA-IR), a parameter reflecting insulin resistance. The intricate interplay between these two domains holds promising implications for understanding the multifaceted nature of depressive symptom and its impact on metabolic health.

Methods

We used weighted multivariable logistic regression models with subgroup analysis to explore the relationship between depressive symptom and homeostasis model assessment of insulin resistance. Non-linear correlations were explored using fitted smoothing curves. Then, we constructed a two-piece linear regression model and performed a recursive algorithm to calculate the inflection point.

Results

The study included 20,282 participants in the United States. In the regression model adjusted for all confounding variables, the odds ratio (OR) for the correlation between depressive symptom and the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) was 1.01 (95% CI: 1.00, 1.01). However, a significant discrepancy between trend tests and regression analyses suggests a potential non-linear relationship between depressive symptom and the assessment of insulin resistance using the Homeostasis Model. Constrained cubic spline analysis confirmed this non-linear relationship, identifying an inflection point at 10.47. Before the inflection point, depressive symptom exhibited a significantly positive correlation with the assessment of insulin resistance using the Homeostasis Model. However, after the inflection point, a negative correlation was observed, though it did not reach statistical significance.

Conclusion

We found a curve-like relationship between depressive symptom and homeostasis model assessment of insulin resistance.

The relationship between plasma interleukin-6 and cognition based on curve correlation in drug-naïve patients with major depressive disorder

BACKGROUND

The effect of interleukin-6 (IL-6) on cognition in patients with major depressive disorder (MDD) remains unclear. The aim of the present study was to investigate for the first time the non-linear relationship between plasma IL-6 and cognition and its sex-specific associations in patients with drug-naïve MDD.

METHODS

A total of 326 participants, including 237 drug-naïve MDD patients and 89 healthy controls (HCs), were included in this study. All participants completed the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and fasting venous blood was collected for IL-6 measurement. Patients with MDD completed the Hamilton Depression Scale-17 (HAMD-17) and the Hamilton Anxiety Scale-14 (HAMA-14) assessments. Two-way analysis of variance and curve estimation analyses were used to explore the effects of IL-6 on cognition and its sex differences.

RESULTS

We found that IL-6 and cognition were associated in different patterns in HCs and MDD patients. The best model for curve estimation between IL-6 and attention (F = 2.736, p = 0.045) and HAMA (F = 6.416, p < 0.001) in females with MDD was the cubic model. In male MDD patients, the best model for curve estimation between IL-6 and immediate memory was the cubic model (F = 3.077, p = 0.034). However, in HCs, the best model for curve estimation analysis between IL-6 and language was the quadratic model (F = 3.803, p = 0.026).

LIMITATIONS

The main limitations were cross-sectional design.

CONCLUSION

There was a non-linear and sex-specific relationship between IL-6 levels and cognition in patients with MDD.

Early adversity and inflammation at midlife: the moderating role of internalizing psychopathology

BACKGROUND

Childhood adversity has been associated with increased peripheral inflammation in adulthood. However, not all individuals who experience early adversity develop these inflammatory outcomes. Separately, there is also a link between various internalizing emotional distress conditions (e.g. depression, anxiety, and fear) and inflammation in adulthood. It is possible the combination of adult emotional distress and past childhood adversity may be uniquely important for explaining psychopathology-related immune dysfunction at midlife.

METHODS

Using data from the Midlife in the United States (MIDUS) study (n = 1255), we examined whether internalizing, defined as past 12-month emotional distress symptomatology and trait neuroticism, moderated associations between childhood adversity and heightened inflammation in adulthood. Using latent variable modeling, we examined whether transdiagnostic or disorder-specific features of emotional distress better predicted inflammation.

RESULTS

We observed that childhood adversity only predicted adult inflammation when participants also reported adult internalizing emotional distress. Furthermore, this moderation effect was specific to the transdiagnostic factor of emotional distress rather than the disorder-specific features.

CONCLUSIONS

We discuss the possibility that adult internalizing symptoms and trait neuroticism together may signal the presence of temporally stable vulnerabilities that amplify the impact of childhood adversity on midlife immune alterations. The study highlights the importance of identifying emotional distress in individuals who have experienced childhood adversity to address long-term immune outcomes and enhance overall health.

The impact of inflammatory response on psychological status of medical staff during COVID-19 pandemic

BACKGROUND

Limited research has been conducted on the relationship between inflammatory markers and psychological status in medical staff fighting COVID-19.

OBJECTIVE

This article examines the psychological and inflammatory conditions of medical personnel working on the front lines of the battle against COVID-19.

METHODS

A total of 102 clinical staff members were included in this study. All subjects received the Symptom Checklist-90 questionnaire (SCL-90) and Posttraumatic Stress Disorder Checklist-Civilian questionnaires for assessing different mental symptoms. The levels of various inflammatory markers, including IL-1β, IL-2, IL-6, IL-8, TNF-a, and IFN-γ, along with GDNF, were evaluated.

RESULTS

Spearman correlation analysis showed that the levels of IL-6 were positively associated with the anxiety score (Spearman's rho = .230, p = .021), obsessive-compulsive symptoms (Spearman's rho = .201, p = .042). The levels of IL-8 were negatively associated with the anxiety score (Spearman's rho = -.223, p = .028), obsessive-compulsive symptoms (Spearman's rho = -.252, p = .012), hyperarousal (Spearman's rho = -.221, p = .028). The levels of TNF-α were positively associated with the anxiety score (Spearman's rho = .201, p = .045), obsessive-compulsive symptoms (Spearman's rho = .222, p = .035).

CONCLUSION

Generally, our results suggested that IL-6, IL-8 and TNF-α might play a role in the development of psychological symptoms among medical staff.

Relationship between systemic immune-inflammation index and depression among individuals with and without cardiovascular disease

OBJECTIVE

Depression is a common comorbidity in cardiovascular disease (CVD), and both conditions are associated with chronic inflammation. The systemic immune-inflammation index (SII) has emerged as a promising marker of systemic inflammation, but its role in association with depressive symptoms, particularly in the context of CVD, remains unclear. This study aims to investigate the association of SII with depressive symptoms in individuals with and without CVD using cross-sectional data from NHANES (2005-2016).

METHODS

A total of 29,479 participants from the National Health and Nutrition Examination Survey (NHANES) 2005-2016 waves were included. Depressive symptoms were assessed through Patient's Health Questionnaire (PHQ-9). SII was calculated as the platelet count × neutrophil count/lymphocyte count. In order to determine the relationships between SII and depressive symptoms in participants with and without CVD, binary logistic regression model and smooth curve fitting were used. We also performed sensitivity analyses and subgroup analysis.

RESULTS

The total prevalence of depressive symptoms was 8.73% among the 29,479 participants analyzed. After adjusting for confounding factors, a higher SII was significantly associated with increased depressive symptoms in the total population (OR per SD increase: 1.101, 95% CI: 1.060-1.144, P < 0.0001). This association was stronger in participants without CVD (OR: 1.121, 95% CI: 1.073-1.172, P < 0.0001) compared to those with CVD (OR: 1.055, 95% CI: 0.973-1.144, P = 0.19571). Participants in the highest SII tertile had a significantly higher risk of depressive symptoms compared to those in the lowest tertile, particularly in the non-CVD group (OR: 1.161, 95% CI: 1.026-1.313, P = 0.01765).

CONCLUSION

The SII is independently associated with an increased risk of depressive symptoms, particularly in individuals without CVD. These findings suggest that the SII may serve as a valuable predictor of depressive symptoms in the general population, with potential implications for early screening and intervention strategies. Further research is needed to elucidate the mechanisms underlying this association and to explore the clinical utility of SII in depressive symptoms assessment, especially in the context of cardiovascular health.

Psychoneuroimmunology of Mood Disorders

Recent research has shed light on the intricate relationship between mood disorders, such as major depressive disorder (MDD) and bipolar disorder (BD), and inflammation. This chapter explores the complex interplay involving immune and metabolic dysfunction in the pathophysiology of these disorders, emphasizing their association with autoimmunity/inflammatory conditions, chronic low-grade systemic inflammation, T cell overactivation, and immunosenescence. This perspective underscores the notion that MDD and BD are not solely brain disorders, highlighting their nature as multi-system conditions.

The risk for psychiatric disorders in offspring from thrombosis-prone pedigrees in Sweden: a nationwide family study

Background

Psychiatric disorders have been associated with venous thromboembolism (VTE). However, to our knowledge, no nationwide study has examined the familial association between VTE and psychiatric disorders.

Objectives

We took a pedigree-based approach and examined the risk of psychiatric disorders in offspring from extended pedigrees according to the densities of VTE in pedigrees.

Methods

This was a Swedish national family study. We identified a total of 482,184 Swedish pedigrees from the Swedish Multigeneration Register containing a mean of 14.2 parents, aunts/uncles, grandparents, and cousins of a core full-sibship that we termed the pedigree offspring (n = 751,060). We then derived 8 empirical classes of these pedigrees based on the density of cases of VTE. The risk was determined in offspring for psychiatric disorders as a function of VTE density in their pedigrees. Diagnoses of VTE and psychiatric disorders (F00-F69) were determined according to the International Classification of Diseases codes in Swedish registers. All results were Bonferroni corrected.

Results

Higher VTE density, especially for females in pedigrees, was significantly but weakly associated in the offspring with a higher risk of psychiatric disorders. Moreover, VTE density in pedigrees was significantly associated in the offspring with substance abuse disorders, mood (affective) disorders, neurotic, stress-related, and somatoform disorders, behavioral syndromes associated with psychological disturbances and physical factors, personality disorders of adult personality and behavior, depression, and anxiety disorders.

Conclusion

Offspring of pedigrees with a high density of VTE, especially for females, are slightly disadvantaged regarding several psychiatric disorders. VTE shares familial susceptibility, albeit weak, with several psychiatric disorders.

Metabolomics in Depression: What We Learn from Preclinical and Clinical Evidences

Depression is one of the predominant common mental illnesses that affects millions of people of all ages worldwide. Random mood changes, loss of interest in routine activities, and prevalent unpleasant senses often characterize this common depreciated mental illness. Subjects with depressive disorders have a likelihood of developing cardiovascular complications, diabesity, and stroke. The exact genesis and pathogenesis of this disease are still questionable. A significant proportion of subjects with clinical depression display inadequate response to antidepressant therapies. Hence, clinicians often face challenges in predicting the treatment response. Emerging reports have indicated the association of depression with metabolic alterations. Metabolomics is one of the promising approaches that can offer fresh perspectives into the diagnosis, treatment, and prognosis of depression at the metabolic level. Despite numerous studies exploring metabolite profiles post-pharmacological interventions, a quantitative understanding of consistently altered metabolites is not yet established. The article gives a brief discussion on different biomarkers in depression and the degree to which biomarkers can improve treatment outcomes. In this review article, we have systemically reviewed the role of metabolomics in depression along with current challenges and future perspectives.

Long-term characterisation of the relationship between change in depression severity and change in inflammatory markers following inflammation-stratified treatment with vortioxetine augmented with celecoxib or placebo

BACKGROUND

Major depressive disorder (MDD) is a highly prevalent condition with a substantial incidence of relapse or treatment resistance. A subset of patients show evidence of low-grade inflammation, with these patients having a higher likelihood of more severe or difficult to treat courses of illness. Anti-inflammatory treatment of MDD has been investigated with mixed results, and no known studies have included assessments beyond cessation of the anti-inflammatory agent, meaning it remains unknown if any benefit from treatment persists. The objective of the present study was to investigate treatment outcomes up to 29 weeks post-cessation of celecoxib or placebo augmentation of an antidepressant, and how concentrations of selected inflammatory markers change over the same period.

METHODS

The PREDDICT parallel-group, randomised, double-blind, placebo-controlled trial (University of Adelaide, Australia) ran from December 2017 to April 2020. Participants with MDD were stratified into normal range or elevated inflammation strata according to screening concentrations of high sensitivity C-reactive protein (hsCRP). Participants were randomised to treatment with vortioxetine and celecoxib or vortioxetine and placebo for six weeks, and vortioxetine alone for an additional 29 weeks (35 total weeks). Following a previous publication of results from the six-week RCT phase, exploratory analyses were performed on Montgomery-Åsberg Depression Rating Scale (MADRS) scores, response and remission outcomes, and selected peripheral inflammatory markers across the entire study duration up to week 35.

RESULTS

Participants retained at each observation were baseline N=119, week 2 N=115, week 4 N=103, week 6 N=104, week 8 N=98, week 22 N=81, and week 35 N=60. Those in the elevated hsCRP celecoxib-augmented group had a statistically significantly greater reduction in MADRS score from baseline to week 35 compared to all other groups, demonstrating the greatest clinical improvement long-term, despite no group or strata differences at preceding time points. Response and remission outcomes did not differ by treatment group or hsCRP strata at any time point. Changes in hsCRP between baseline and week 35 and Tumour Necrosis Factor-α (TNF-α) concentrations between baseline and week 6 and baseline and week 35 were statistically significantly associated with MADRS scores observed at week 6 and week 35 respectively, with reducing TNF-α concentrations associated with reducing MADRS scores and vice versa in each case. A post-hoc stratification of the participant cohort by baseline TNF-α concentrations led to significant prediction by the derived strata on clinical response at weeks 6, 8 and 35, with participants with elevated baseline TNF-α less likely to achieve clinical response.

INTERPRETATION

The present analysis suggests for the first time a possible longer-term clinical benefit of celecoxib augmentation of vortioxetine in inflammation-associated MDD treatment. However, further research is needed to confirm the finding and to ascertain the reason for such a delayed effect. Furthermore, the trial suggests that TNF-α may have a stronger relationship with anti-inflammatory MDD treatment outcomes than hsCRP, and should be investigated further for potential predictive utility.

CLINICAL TRIALS REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR), ACTRN12617000527369p. Registered on 11 April 2017, http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12617000527369p.

Psychiatric Disorders and Associated Factors in Left Ventricular Assist Device Implantation and Heart Transplant Candidates

INTRODUCTION

End-stage heart failure (ESHF) remains a significant challenge despite optimal treatment, with heart transplantation (HTx) being the gold standard of care. Mechanical circulatory support (MCS) devices such as left ventricular assist devices (LVADs) are increasingly used for temporary or permanent treatment. Psychiatric comorbidities are common in patients with ESHF and may affect treatment outcomes, but the relationship between sociodemographic, clinical, and psychiatric characteristics remains unclear.

METHODS

A medical record based, descriptive cross-sectional study was conducted on 94 ESHF patients scheduled for HTx or LVAD therapy. Sociodemographic, clinical, and psychiatric data, including psychiatric diagnoses and systemic inflammatory markers, were collected from medical records. Univariate analyses compared patients with (PD) and without psychiatric disorders (No-PD).

RESULTS

Of the participants, 37% had active psychopathology, with major depressive disorder (MDD) and generalized anxiety disorder (GAD) being prevalent. Approximately half of those diagnosed received their first psychiatric diagnosis at the time of assessment. Sociodemographic factors did not differ significantly between the PD and No-PD groups. While no significant difference was observed in ejection fraction (%) and inflammatory markers such as C-reactive protein (CRP), lymphocyte count was higher in the PD group.

CONCLUSIONS

Preoperative psychiatric assessment is crucial to identify psychiatric comorbidities in ESHF patients undergoing HTx or LVAD therapy. Despite limitations, this study sheds light on previously unexplored aspects, such as the relationship between ejection fraction and psychiatric comorbidities and the relationship between depressive symptoms and inflammatory markers obtained from complete blood count. Furthermore, the fact that almost half of the patients with psychiatric comorbidity were first diagnosed during the pre-treatment psychiatric assessment underlines the importance of pre-LVAD and pre-HTX psychiatric evaluation.

Phenome-wide investigation of bidirectional causal relationships between major depressive disorder and common human diseases

The high comorbidity of major depressive disorder (MDD) with other diseases has been well-documented. However, the pairwise causal connections for MDD comorbid networks are poorly characterized. We performed Phenome-wide Mendelian randomization (MR) analyses to explore bidirectional causal associations between MDD (N = 807,553) and 877 common diseases from FinnGen datasets (N = 377,277). The inverse variance weighting method was the primary technique, and other methods (weighted median and MR-Egger) were used for sensitivity analyses. Our MR analyses showed that the genetic liability to MDD is causally associated with the risks of 324 disease phenotypes (average b: 0.339), including 46 psychiatric and behavioral disorders (average b: 0.618), 18 neurological diseases (average b: 0.348), 44 respiratory diseases (average b: 0.345), 40 digestive diseases (average b: 0.281), 18 circulatory diseases (average b: 0.237), 37 genitourinary diseases (average b: 0.271), 66 musculoskeletal and connective diseases (average b: 0.326), 22 endocrine diseases (average b: 0.302), and others. In a reverse analysis, a total of 51 genetic components predisposing to various diseases were causally associated with MDD risk (average b: 0.086), including 5 infectious diseases (average b: 0.056), 11 neurological diseases (average b: 0.106), 14 oncological diseases (average b: 0.108), and 5 psychiatric and behavioral disorders (average b: 0.114). Bidirectional causal associations were identified between MDD and 15 diseases. For most MR analyses, little evidence of heterogeneity and pleiotropy was detected. Our findings confirmed the extensive and significant causal role of genetic predisposition to MDD in contributing to human disease phenotypes, which were more pronounced than those seen in the reverse analysis of the causal influences of other diseases on MDD.

Quality of life after idiopathic multicentric Castleman disease in China: a cross-sectional, multi-center survey of patient reported outcome and caregiver reported outcome

The majority of multicentric Castleman disease (MCD) patients in China are of the idiopathic subtype (iMCD) with systemic manifestations. However, the impact of iMCD on life quality, mental and psychological status, social function, and caregiving burden is poorly understood. To address this gap, a cross-sectional web-based survey was conducted with 178 iMCD patients and 82 caregivers, including 42 patient-caregiver dyads. Patient-reported outcome measurements were performed using four self-administered questionnaires (MCD-SS, SF-36, PHQ-9, and WPAI:GH). Caregiver-reported outcome measurements were performed using three questionnaires (SF-36, Zarit-22, CRA) to assess the caregiving burden. Correlation analysis was performed in patient-caregiver dyads. Patients reported a median of nine symptoms by MCD-SS, with a high mean score of 4.34 for the Fatigue domain. Their SF-36 scores indicated significant declines in physical and mental health compared to the Chinese general population (p < 0.001). Based on PHQ-9, around 65% of patients exhibited depressive symptoms, with 28.6% of them experiencing mild to severe major depression. Only 47.2% (84/178) of the patients were employed, and 28.5% experienced impaired work time. Caregivers also reported lower SF-36 scores than the general population (p < 0.05) and expressed feeling of self-criticism, lack of family support and financial problems. Correlations were observed between patients' symptom burden, mental health impairment and caregiving burden (correlation coefficient: 0.31 ~ 0.55). Our study concluded that fatigue and depressive symptoms significantly impact the life quality and social well-being of iMCD patients. The disease also affect the physical and mental health of caregivers, leading to feelings of guilt and a lack of family support.

Inflammation and depression: A study protocol to dissect pathogenetic mechanisms in the onset, comorbidity and treatment response

About one third of patients suffering from Major Depressive Disorder (MDD) do not respond to any antidepressant medications and 75% experience relapses and general health deterioration. Importantly, inflammation can contribute to such negative outcomes, as well as to cause depression in patients who have been exposed to adverse childhood experiences and/or to viral infections, including COVID-19. Depressed patients also have an increased risk for developing comorbidities, such as cardio-metabolic dysfunctions, where inflammatory alterations, again, play a role in connecting MDD and these comorbid conditions. Here, we present our study protocol funded by the Italian Ministry of Health in the context of the PNRR call (M6/C2_CALL 2022; Project code: PNRR-MAD-2022-12375859). The project aims to clarify the role of inflammation: i) in the onset of depression in association with environmental factors; ii) in the mechanisms associated with treatment response/resistance; iii) in depression and its comorbidity. To reach all these aims, we will perform biochemical, transcriptomic, genetic variants analyses on inflammatory/immune genes, pharmacokinetics and machine learning techniques, taking advantage of different human cohorts (adolescent depressed patients exposed to childhood trauma; adult depressed patients; treatment resistant depression patients; both prevalent and incident depression cases identified within a large population cohort). Moreover, we will use in vitro models (primary cultures of astrocytes, neurons and microglia) treated with pro-inflammatory or stressful challenges and preventive compounds to clarify the underlying mechanisms. This 2-years project will increase the knowledge on the role of inflammation in the prevention and treatment of MDD and in comorbid disorders, and it will also provide experimental evidence for the development of novel targets and tools for innovative personalized intervention strategies.

A comprehensive analysis of the differential expression in the hippocampus of depression induced by gut microbiota compared to traditional stress

Depression, which is a disease of heterogeneous etiology, is characterized by high disability and mortality rates. Gut microbiota are associated with the development of depression. To further explore any differences in the mechanisms of depression induced by gut microbiota and traditional stresses, as well as facilitate the development of microbiota-based interventions, a fecal microbiota transplantation (FMT) depression model was made. This was achieved by transplanting feces from major depressive disorder (MDD) patients into germ-free mice. Second, the mechanisms of the depression induced by gut microbiota were analyzed in comparison with those of the depression caused by different forms of stress. It turned out that mice exhibited depressive-like behavior after FMT. Then, PCR array analysis was performed on the hippocampus of the depressed mice to identify differentially expressed genes (DEGs). The KEGG analysis revealed that the pathways of depression induced by gut microbes are closely associated with immuno-inflammation. To determine the pathogenic pathways of physiological stress and psychological stress-induced depression, raw data was extracted from several databases and KEGG analysis was performed. The results from the analysis revealed that the mechanisms of depression induced by physiological and psychological stress are closely related to the regulation of neurotransmitters and energy metabolism. Interestingly, the immunoinflammatory response was distinct across different etiologies that induced depression. The findings showed that gut microbiota dysbiosis-induced depression was mainly associated with adaptive immunity, while physiological stress-induced depression was more linked to innate immunity. This study compared the pathogenesis of depression caused by gut microbiota dysbiosis, and physiological and psychological stress. We explored new intervention methods for depression and laid the foundation for precise treatment.

Peripheral Endothelial Dysfunction Is Associated With Incident Major Depressive Disorder

BACKGROUND

A subset of individuals with major depressive disorder (MDD) have a high burden of cardiovascular risk factors and cerebral small-vessel disease, implicating vascular disease in the development of depression. Cross-sectional studies demonstrate a link between endothelial dysfunction and MDD, but the prospective association between peripheral endothelial dysfunction (PED) and an incident diagnosis of MDD is unknown.

METHODS AND RESULTS

Patients undergoing a baseline assessment of cardiovascular risk were evaluated for PED using reactive hyperemia-peripheral arterial tonometry (≤1.8 consistent with PED). Patient medical records were reviewed to identify those who underwent a formal clinical evaluation of MDD after the index PED evaluation. The frequency of PED was compared in those with and without MDD. Logistic regression analyses were performed to assess the association between baseline PED and incident MDD. Between January 2006 and December 2020, 1614 patients underwent testing for PED. Four hundred eighty-four (30.1%) patients underwent a formal evaluation for MDD after (0-15 years) the index procedure (mean±SD age, 52.8±13.8 years; 65.2% women). Of these, 157 (32.4%) had PED and 108 (31.0%) were diagnosed with MDD. Individuals with MDD had a higher frequency of PED (40.2% versus 30.2%; P=0.034) compared with those without MDD. In multivariable analyses, PED was significantly associated with MDD (odds ratio, 2.3 [95% CI, 1.4-3.8]; P<0.001).

CONCLUSIONS

PED is significantly associated with incident MDD. Thus, PED may be a useful marker to identify individuals at increased risk of depression who may benefit from more frequent and earlier management strategies.

Associations between prenatal stress with offspring inflammation, depression and anxiety

PURPOSE

Few longitudinal studies have investigated the mediating role of inflammation during childhood in associations between prenatal maternal stress and adolescent mental health. The objective of this study was to examine the associations between prenatal maternal stress, concentrations of immune markers at age 9, and symptoms of generalized anxiety disorder (GAD) and depression during adolescence.

METHODS

This study included 3723 mother-child pairs from the Avon Longitudinal Study of Parents and Children (ALSPAC). Prenatal maternal stress was examined using 55 items measured during pregnancy. Inflammation was assessed using serum concentrations of interleukin-6 (IL-6) and C-reactive protein (CRP) when children were 9 years old. GAD and depression were assessed when children were 16 and 18 years of age, respectively. Analyses comprised of structural equation models.

RESULTS

Prenatal maternal stress was associated with higher concentrations of IL-6 in childhood, and with greater symptoms of depression and GAD in adolescence. However, we did not observe associations between prenatal maternal stress and CRP; also, CRP and IL-6 were not associated with depression and GAD. There was no evidence that CRP and IL-6 mediated the associations between prenatal maternal stress and either GAD or depression.

CONCLUSIONS

Prenatal maternal stress is associated with IL-6 levels in childhood, and with GAD and depression during adolescence. Future studies should examine immune activity at multiple points during development in relation to mental health into adulthood to determine whether inflammation at different points during development could increase risk for mental health problems among children whose mothers experienced significant stressors during pregnancy.

Associations between oral health and depression and anxiety: A cross-sectional and prospective cohort study from the UK Biobank

AIM

To investigate the associations between oral health and depression, anxiety and their comorbidity in the UK Biobank cohort.

MATERIALS AND METHODS

Oral health problems were self-reported at baseline. Symptoms of depression and anxiety were assessed using the Mental Health Questionnaire (PHQ-4) in a cross-sectional study. In the cohort study, diagnoses of depression and anxiety disorders were based on hospital records. Logistic regression and Cox regression models were used to analyse the association between oral health and depression/anxiety.

RESULTS

A total of 305,188 participants were included in the cross-sectional study, and multivariate analysis showed that periodontal disease was associated with depression and/or anxiety (odds ratio [OR]: 1.79, 95% confidence interval [CI]: 1.73-1.86). In the prospective cohort study involving 264,706 participants, periodontal disease was significantly associated with an increased risk of depression and/or anxiety (hazard ratio [HR]: 1.14, 95% CI: 1.10-1.19), depression (HR: 1.19, 95% CI: 1.13-1.25) and anxiety (HR: 1.13, 95% CI: 1.07-1.19). Periodontal disease was also significantly associated with comorbid depression and anxiety (HR: 1.27, 95% CI: 1.16-1.38). Multiple mediation analysis using baseline inflammatory factors showed that white blood cell count and C-reactive protein explained 3.07% and 3.15% of the association between periodontal disease and depression and anxiety, respectively. However, the results of longitudinal multiple mediation analysis of inflammatory factors at first follow-up (N = 10,673) were not significant.

CONCLUSIONS

Periodontal disease was found to be consistently associated with an increased risk of depression, anxiety and their comorbidity.

Luteal phase sertraline treatment of premenstrual dysphoric disorder (PMDD): Effects on markers of hypothalamic pituitary adrenal (HPA) axis activation and inflammation

RATIONALE

Premenstrual dysphoric disorder (PMDD) is characterized by severe affective symptoms during the luteal phase of the menstrual cycle. There is some evidence of altered interactions between the hypothalamic pituitary gonadal (HPG) and hypothalamic pituitary adrenal (HPA) axes in PMDD. There is also evidence that similar affective disorders such as major depression and perinatal depression are associated with dysregulation in immune factors, but this has not been characterized in PMDD.

AIMS

The goals of this exploratory study were to identify 1) whether HPA-HPG axis interactions and immune markers differ between PMDD patients and controls across the menstrual cycle; 2) how luteal phase sertraline treatment impacts stress and inflammatory markers.

METHODS

Participants were females age 18-50 with regular menstrual cycles, not using psychotropic or hormonal medications, and were assigned to a control group or PMDD group based on prospective daily symptom ratings and clinical interview. Blood was drawn in the follicular and luteal phases, during laboratory sessions involving a mildly stressful task. In a second luteal phase, PMDD participants received open-label sertraline (50 mg/d) from ovulation to menses. Serum cortisol and ACTH were measured via ELISA and operationalized as area under the curve with respect to ground (AUCg), and peak level following laboratory task. Serum TNF-α, IL-6, CXCL-8, and IL-1β were measured using multiplex kits. Serum allopregnanolone (ALLO) was measured by gas chromatography/mass spectroscopy. To characterize HPA-HPG axis interactions across the menstrual cycle in PMDD participants and controls, multilevel linear models predicted cortisol and ACTH from the interaction of cycle phase (controlling for sertraline treatment), ALLO, and group. To determine the effects of sertraline treatment on inflammatory markers and how groups might differ in cyclical change on each marker, multilevel linear models predicted inflammatory markers from cycle phase (controlling for sertraline treatment) and group. A final set of exploratory models tested whether inflammatory markers predict premenstrual symptom score severity.

RESULTS

The sample included n=77 participants (41 controls, 36 PMDD); 28 participants with PMDD completed sertraline treatment. Group x phase x ALLO interactions showed that higher ALLO levels predicted lower cortisol peak in the treated luteal phase (interaction between phase and ALLO, p=0.042), and there was a higher cortisol peak in the treated luteal phase than the untreated luteal phase (p=0.038). CXCL-8 was significantly associated with premenstrual symptom severity after controlling for group and cycle phase (p=0.011). There were no main effects of group, phase, or ALLO on cortisol AUCg, ACTH AUCg, IL-6, CXCL-8, IL-1β, nor TNF-α (p's>0.05).

CONCLUSION

Serum markers of HPA axis and immune function did not vary by menstrual cycle phase nor PMDD status. However, sertraline treatment in the luteal phase was associated with higher ALLO levels predicting lower cortisol peak in response to mild laboratory stress, suggesting that sertraline treatment may normalize HPG-HPA axis interactions among individuals with PMDD. Greater premenstrual symptomatology was associated with higher levels of the inflammatory marker CXCL-8, but further research is needed into the potential role of inflammation in PMDD.

Association between TNF-α & IL-6 level changes and remission from depression with duloxetine treatment

PURPOSE/AIM OF THE STUDY

The pathophysiology of major depressive disorder (MDD) involves multiple factors, including inflammatory processes. This study investigated the relationship between changes in the levels of cytokines and remission in patients with MDD following duloxetine treatment.

MATERIALS AND METHODS

MDD patients were administered duloxetine for 16 weeks. Clinical evaluation and immunological monitoring were performed every 4 weeks.

RESULTS

Our results indicated that changes in serum levels of TNF-α and IL-6 were associated with remission following duloxetine treatment in MDD patients. There was a slight increase in TNF-α levels in the first four weeks following duloxetine treatment, which correlated significantly with patients who were in remission. Furthermore, patients in remission exhibited an initial increase in IL-6 levels in the first four weeks, followed by a decrease at 16 weeks.

CONCLUSIONS

These results suggest an important relationship between changes in cytokine levels and remission in patients with major depression after duloxetine treatment.

An integration of neuroimaging and serum proteomics analysis suggests immune and inflammation are associated with white matter microstructure changes in cerebral small vessel disease with depressive symptoms

INTRODUCTION

Depressive symptoms are a common concomitant of cerebral small vessel disease (CSVD), of which pathogenesis requires more study. White matter microstructural abnormalities and proteomic alternation have been widely reported regarding depression in the elderly with CSVD. Exploring the relationship between cerebral white matter microstructural alterations and serum proteins may complete the explanation of molecular mechanisms for the findings from neuroimaging research of CSVD combined with depressive symptoms.

METHODS

An untargeted proteomics approach based on mass spectrometry was used to obtain serum proteomic profiles, which were clustered into co-expression protein modules. White matter microstructural integrity was measured using the FMRIB Software Library (FSL) and MATLAB to analyze diffusion tensor imaging (DTI) data and calculate the differences in fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) for 50 regions of interest (ROI). Integrating the proteome with the DTI results, weighted gene co-expression analysis (WGCNA) was used to identify protein modules related to white matter microstructural alterations, and the proteins of the corresponding modules were analyzed for functional enrichment through bioinformatics techniques.

RESULTS

DTI measurements were analCerebral small vessel disease (CSVD); Depression; Diffusion tensor imaging (DTI); Proteomics; Inflammationyzed between individuals with CSVD and depressive symptoms (CSVD+D) (n = 24) and those without depressive symptoms (CSVD-D) (n = 35). Results showed an overall increase in MD, AD, and RD within the left hemisphere of the CSVD+D group, suggesting widespread loss of white matter integrity and axonal demyelination, including left superior longitudinal fasciculus (SLF), left posterior corona radiata (PCR) and right external capsule (EC). We identified two protein modules associated with DTI diffusivity, and functional enrichment analyses revealed that complement and coagulation cascades and immune responses participate in the alternation of white matter microstructure in the CSVD+D group.

CONCLUSION

The results suggested immune- and inflammation-related mechanism was associated with white matter microstructure changes in CSVD with depressive symptoms.

Sex differences in the inflammation-depression link: A systematic review and meta-analysis

Major Depressive Disorder (MDD) is a heterogeneous disorder that affects twice as many women than men. Precluding advances in more tailored and efficacious treatments for depression is the lack of reliable biomarkers. While depression is linked to elevations in inflammatory immune system functioning, this relationship is not evident among all individuals with depression and may vary based on symptom subtypes and/or sex. This systematic review and meta-analysis examined whether inflammatory immune peripheral markers of depression are sex-specific. PRISMA guidelines were followed for the systematic review, and a comprehensive search strategy that identified studies from PubMed and PsycInfo was applied. Studies were included if they reported C-reactive protein (CRP), interleukin (IL)-6, tumor necrosis factor (TNF)-α and/or IL-1β for males and/or females among depressed and healthy adults. We identified 23 studies that satisfied these inclusion criteria. Random-effects meta-analysis models were fit, and measures of association were summarized between levels of circulating markers of inflammation in depressed and healthy males and females. Sex-based analyses revealed elevated levels of CRP among females with depression (Cohen's d = 0.19) relative to their healthy counterparts (p = 0.02), an effect not apparent among males (Cohen's d = -0.01). Similarly, levels of IL-6 were increased among females with depression compared to healthy controls (Cohen's d = 0.51; p = 0.04), but once again this was not found among males (Cohen's d = 0.16). While TNF-α levels were elevated among individuals with depression compared to controls (p = 0.01), no statistically significant sex differences were found. The meta-analysis for IL-1β resulted in only three articles, and thus, results are presented in the supplemental section. This meta-analysis advances our understanding of the unique involvement of inflammatory biomarkers in depression among men and women, which may help inform more tailored sex-specific treatment approaches in the future.

The Role of Inflammation in Depression and Beyond: A Primer for Clinicians

PURPOSE OF REVIEW

We evaluate available evidence for the role of inflammation in depression. We reappraise literature involving systemic inflammation, neuroinflammation and neurotransmission and their association with depression. We review the connection between depression, autoimmunity and infectious diseases. We revise anti-inflammatory treatments used in depression.

RECENT FINDINGS

Peripheral inflammatory markers are present in a subset of patients with depression and can alter common neurotransmitters in this population but there is no clear causality between depression and systemic inflammation. Infectious conditions and autoimmune illnesses do not have a clear correlation with depression. Certain medications have positive evidence as adjunctive treatments in depression but studies are heterogenic, hence they are sparsely used in clinical settings. The current evidence does not fully support inflammation, infections or autoimmunity as possible etiologies of depression. The available studies have numerous confounders that obscure the findings. Anti-inflammatory agents may have potential for treatment of depression, but further research is needed to clarify their usefulness in routine clinical practice.

Sex-specific association of peripheral blood cell indices and inflammatory markers with depressive symptoms in early adolescence

BACKGROUND

Previous studies have reported the correlation of dysregulated blood cell indices and peripheral inflammatory markers with depression in adults but limited studies have examined this correlation in early adolescents.

METHODS

This study used data from the Chinese Early Adolescents Cohort Study, which was conducted in Anhui, China. Students' depression symptoms were repeatedly measured using the Chinese version of the Center for Epidemiological Studies Depression Scale for Children. Students' blood samples were collected in September 2019 and September 2021. The peripheral blood cell counts and inflammatory marker levels were determined using routine blood tests. Multivariable regression models were used to explore the associations between blood cell indices and adolescent depressive symptoms in both the whole sample and the sex-stratified samples.

RESULTS

The white blood cell (WBC) count, neutrophil count (NC), platelet (PLT) count, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio, and systemic immune inflammation index (SII) were positively correlated with the severity of depressive symptoms during follow-up. The mean corpuscular volume (MCV), mean hemoglobin (HGB) volume (MCH), and mean corpuscular HGB concentration (MCHC) exhibited negative temporal correlations with depressive symptoms. Additionally, several sex-specific blood cell markers were correlated with depression. Male adolescents with increased red blood cell (RBC) and female adolescents with decreased HGB levels and upregulated WBC, NC, NLR, and SII levels exhibited severe depressive symptoms at follow-up.

CONCLUSIONS

These findings suggested the potential usefulness of peripheral blood cell indices in the assessment of depression in early adolescents.

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.

Possible roles of neuropeptide/transmitter and autoantibody modulation in emotional problems and aggression

The theoretical foundations of understanding psychiatric disorders are undergoing changes. Explaining behaviour and neuroendocrine cell communication leaning towards immunology represents a different approach compared to previous models for understanding complex central nervous system processes. One such approach is the study of immunoglobulins or autoantibodies, and their effect on peptide hormones in the neuro-endocrine system. In the present review, we provide an overview of the literature on neuropeptide/transmitter and autoantibody modulation in psychiatric disorders featuring emotional problems and aggression, including associated illness behaviour. Finally, we discuss the role of psycho-immunology as a growing field in the understanding of psychiatric disorders, and that modulation and regulation by IgG autoAbs represent a relatively new subcategory in psycho-immunology, where studies are currently being conducted.

Revealing genetic causality between blood-based biomarkers and major depression in east Asian ancestry

Introduction

Major Depression (MD) is a common mental disorder. In East Asian ancestry, the association, causality, and shared genetic basis between blood-based biomarkers and MD remain unclear.

Methods

We investigated the relationships between blood-based biomarkers and MD through a cross-sectional study and Mendelian randomization (MR) analysis. Cross-trait analysis and enrichment analyses were used to highlight the shared genetic determinants and biological pathways. We conducted summary data-based MR to identify shared genes, which were then validated using a transcriptome dataset from drug-naïve patients with MD.

Results

In the cross-sectional study, C-Reactive Protein showed the significantly positive correlation with depressive symptoms, while hematocrit, hemoglobin, and uric acid exhibited significantly negative correlations. In MR analysis, basophil count (BASO) and low-density lipoprotein cholesterol (LDLc) had a significant causal effect on MD. The enrichment analysis indicated a significant role of inflammatory cytokines and oxidative stress. The shared genes MFN2, FAM55C, GCC2, and SCAPER were validated, with MFN2 identified as a pleiotropic gene involved in MD, BASO, and LDLc.

Discussion

This study highlighted that BASO and LDLc have a causal effect on MD in East Asian ancestry. The pathological mechanisms of MD are related not only to inflammatory cytokines and oxidative stress but also to down regulation of MFN2 expression and mitochondrial dysfunction.

Associations Between Early-Pregnancy Vitamin D Status and Postpartum Depressive and Anxiety Symptoms

OBJECTIVE

Maternal postpartum depressive and anxiety symptoms are risk factors for subsequent maternal and child mental health problems. Little is known about the potential role of antepartum vitamin D and C-reactive protein (CRP) in the etiology of maternal postpartum affective symptoms. We investigated associations between antepartum vitamin D status and postpartum depressive and anxiety symptoms and whether antepartum CRP mediated these associations.

METHODS

In 2483 participants of the Amsterdam Born Children and their Development prospective cohort, maternal serum vitamin D and CRP were measured at a median of 13 weeks' gestation. Vitamin D status was defined as deficient (≤29.9 nM), insufficient (30-49.9 nM), sufficient (50-79.9 nM), or normal (≥80 nM). Maternal depressive symptoms (Center for Epidemiologic Studies-Depression) and anxiety (State-Trait Anxiety Inventory) were assessed 3 months postpartum.

RESULTS

After adjustments for confounders, vitamin D deficiency was only associated with increased postpartum anxiety symptoms ( B = 0.17, 95% confidence interval [CI] = 0.03-0.30, p = .017) compared to normal vitamin D levels (≥80 nM). In women not taking vitamin D supplementation ( n = 2303), vitamin D deficiency was associated with increased postpartum depressive and anxiety symptoms ( B = 0.14, 95% CI = 0.03-0.28, p = .045; and B = 0.17, 95% CI = 0.03-0.32, p = .015). Antepartum CRP did not mediate these links.

CONCLUSIONS

We found some evidence that antepartum vitamin D deficiency was associated with increased postpartum affective symptoms, especially in women not taking vitamin D supplementation. Clinical trials should determine whether vitamin D supplementation can reduce the risk for postpartum affective disorders.

Low-Grade Inflammation Associated with Major Depression Subtypes: A Cross-Sectional Study

Major depressive disorder (MDD) is associated with inflammation and a high level of comorbidities. Atypical depression (AD) is a MDD subtype based on DSM criteria, that could have specific underlying biological mechanisms. AD is associated with elevated cardiovascular (CVD) comorbidities, higher risk of suicide attempts, hypersomnia, and anxiety disorder. In this study, we aim to investigate if AD and polysomnographic parameters could be associated with low-grade inflammation (LGI). LGI is defined by a range from 3 to 10 mg/L of C-reactive protein levels. We carried out a retrospective cohort study in which 765 individuals with MDD were split into two groups: with and without LGI. Our results exhibit differences between the groups for the polysomnographic parameters, with the LGI group showing parameters already associated with inflammation such as reduced rapid eye movement sleep and elevated hypoxemia markers (identified as CVD risk factor). We found that AD is associated with LGI (OR 1.48; p = 0.047) after adjustment. Likewise, we found an LGI prevalence in AD higher (34.8%) than in MDD without atypical features (26.8%). Overall, these results confirm the low-grade inflammation feature of AD and highlight polysomnographic parameters associated with LGI that could also act as risk factors in this context.

Associations between soluble urokinase plasminogen activator receptor (suPAR) concentration and psychiatric disorders - A systematic review and meta-analysis

BACKGROUND

There is some evidence of an association between inflammation in the pathogenesis of mental disorders. Soluble urokinase plasminogen activator receptor (suPAR) is a biomarker of chronic inflammation, which provides a more stable index of systemic inflammation than more widely used biomarkers. This review aims to synthesise studies that measured suPAR concentrations in individuals with a psychiatric disorder, to determine if these concentrations are altered in comparison to healthy participants.

METHOD

Comprehensive literature searches from inception to October 2023 were conducted of five relevant databases (PubMed, Web of Science, Embase, Scopus, APA PsychInfo). Random-effects meta-analyses were performed to compare the standardised mean difference of blood suPAR levels (i.e. plasma or serum) for individuals with any psychiatric disorder relative to controls. Separate meta-analyses of suPAR levels were conducted for individuals with schizophrenia or other psychotic disorder and depressive disorder. Risk of bias was assessed using the Newcastle Ottawa Scale. Post-hoc sensitivity analyses included excluding studies at high risk of bias, and analyses of studies that measured suPAR concentrations either in serum or in plasma separately.

RESULTS

The literature search identified 149 records. Ten full-text studies were screened for eligibility and 9 studies were included for review. Primary analyses revealed no significant difference in suPAR levels between individuals with any psychiatric disorder compared to controls (k = 7, SMD = 0.42, 95 % CI [-0.20, 1.04]). However, those with depressive disorder had elevated suPAR levels relative to controls (k = 3, SMD = 0.61, 95 % CI [0.34, 0.87]). Similarly, secondary analyses showed no evidence of a significant difference in suPAR levels in individuals with any psychiatric disorder when studies at high risk of bias were excluded (k = 6, SMD = 0.54, 95 % CI [-0.14, 1.22]), but elevated suPAR concentrations for those with schizophrenia or other psychotic disorder were found (k = 3, SMD = 0.98, 95 % CI [0.39, 1.58]). Furthermore, studies that analysed plasma suPAR concentrations found elevated plasma suPAR levels in individuals with any psychiatric disorder relative to controls (k = 5, SMD = 0.84, 95 % CI [0.38, 1.29]), while studies measuring serum suPAR levels in any psychiatric disorder did not find a difference (k = 2, SMD = -0.61, 95 % CI [-1.27, 0.04]). For plasma, elevated suPAR concentrations were also identified for those with schizophrenia or other psychotic disorder (k = 3, SMD = 0.98, 95 % CI [0.39, 1.58]).

DISCUSSION

When studies measuring either only serum or only plasma suPAR were considered, no significant difference in suPAR levels were observed between psychiatric disorder groups, although significantly elevated suPAR levels were detected in those with moderate to severe depressive disorder. However, plasma suPAR levels were significantly elevated in those with any psychiatric disorder relative to controls, while no difference in serum samples was found. A similar finding was reported for schizophrenia or other psychotic disorder. The plasma findings suggest that chronic inflammatory dysregulation may contribute to the pathology of schizophrenia and depressive disorder. Future longitudinal studies are required to fully elucidate the role of this marker in the psychopathology of these disorders.

Whole-Genome Metagenomic Analysis of the Oral Microbiota in Patients with Obstructive Sleep Apnea Comorbid with Major Depressive Disorder

Background

Obstructive sleep apnea (OSA) patients commonly experience high rates of depression. This study aims to examine the oral microbiota characteristics of OSA and those with comorbid major depressive disorder (OSA+MDD) patients.

Methods

Participants were enrolled from Aug 2022 to Apr 2023. Polysomnography, psychiatrist interviews, and scales were used to diagnose OSA and MDD. Oral samples were collected from participants by rubbing swabs on buccal mucosa, palate, and gums. Oral microbiota was analyzed via whole-genome metagenomics and bioinformatic analysis followed sequencing. Venous blood was drawn to detect plasma inflammatory factor levels.

Results

The study enrolled 33 OSA patients, 28 OSA+MDD patients, and 28 healthy controls. Significant differences were found in 8 phyla, 229 genera, and 700 species of oral microbiota among the three groups. Prevotellaceae abundance in the OSA and OSA+MDD groups was significantly lower than that in healthy controls. Linear discriminant analysis effect size (LEfSe) analysis showed that Streptococcaceae and Actinobacteria were the characteristic oral microbiota of the OSA and OSA+MDD groups, respectively. KEGG analysis indicates 30 pathways were changed in the OSA and OSA+MDD groups compared with healthy controls, and 23 pathways were changed in the OSA group compared with the OSA+MDD group. Levels of IL-6 in the OSA+MDD group were significantly higher than in the healthy group, correlating positively with the abundance of Schaalia, Campylobacter, Fusobacterium, Alloprevotella, and Candidatus Nanosynbacter in the oral, as well as with Hamilton Anxiety Rating Scale and Hamilton Depression Rating Scale scores.

Conclusion

Significant differences in oral microbiota populations and gene function were observed among the three groups. OSA patients were characterized by a decreased abundance of Prevotellaceae and an increased abundance of Streptococcaceae. OSA+MDD patients had an increased abundance of Actinobacteria. IL-6 might regulate the relationship between depression and the oral microbiota in OSA+MDD patients.

The association between depressive symptoms and high-sensitivity C-reactive protein: Is body mass index a moderator?

Objective

Depression and obesity are highly comorbid conditions with shared biological mechanisms. It remains unclear how depressive symptoms and body mass index (BMI) interact in relation to inflammation. This cross-sectional study investigated the independent associations of depressive symptoms and BMI with high sensitivity C-reactive protein (hs-CRP), as well as the moderating role of BMI on the depressive symptoms-hs-CRP association.

Methods

Participants (n = 8827) from the 2015-2018 National Health and Nutrition Examination Surveys were aged ≥20 with a BMI ≥18.5 kg/m2, completed the Depression Screener, and had hs-CRP data. Multivariable linear regression was used to analyze hs-CRP in relation to depressive symptoms and BMI. An interaction term was included to examine whether the depressive symptoms-hs-CRP relationship differs depending on BMI.

Results

There was a slight, albeit non-significant, increase in hs-CRP levels with each one-point increase in depressive symptoms (aCoef.Estm. = 0.01, 95% CI = -0.05, 0.06, p = 0.754). Participants with overweight (aCoef.Estm. = 1.07, 95% CI = 0.61, 1.53, p < 0.001) or obese (aCoef.Estm. = 3.51, 95% CI = 3.04, 3.98, p < 0.001) BMIs had higher mean hs-CRP levels than those with a healthy BMI. There were no significant interactions between depressive symptoms and overweight (aCoef.Estm. = 0.04, 95% CI = -0.04, 0.13, p = 0.278) or obese (aCoef.Estm. = 0.11, 95% CI = -0.01, 0.22, p = 0.066) BMI indicating a lack of difference in the depressive symptoms-hs-CRP association across participants in the healthy versus overweight and obese ranges.

Conclusions

This study suggests that BMI might not act as a moderator in the association between depressive symptoms and hs-CRP. Results should be replicated in larger samples. Further research is warranted to understand underlying mechanisms.

Leptin's Inverse Association With Brain Morphology and Depressive Symptoms: A Discovery and Confirmatory Study Across 2 Independent Samples

BACKGROUND

Major depressive disorder has a complex, bidirectional relationship with metabolic dysfunction, but the neural correlates of this association are not well understood.

METHODS

In this cross-sectional investigation, we used a 2-step discovery and confirmatory strategy utilizing 2 independent samples (sample 1: 288 participants, sample 2: 196 participants) to examine the association between circulating indicators of metabolic health (leptin and adiponectin) and brain structures in individuals with major depressive disorder.

RESULTS

We found a replicable inverse correlation between leptin levels and cortical surface area within essential brain areas responsible for emotion regulation, such as the left posterior cingulate cortex, right pars orbitalis, right superior temporal gyrus, and right insula (standardized beta coefficient range: -0.27 to -0.49, puncorrected < .05). Notably, this relationship was independent of C-reactive protein levels. We also identified a significant interaction effect of leptin levels and diagnosis on the cortical surface area of the right superior temporal gyrus (standardized beta coefficient = 0.26 in sample 1, standardized beta coefficient = 0.30 in sample 2, puncorrected < .05). We also observed a positive correlation between leptin levels and atypical depressive symptoms in both major depressive disorder groups (r = 0.14 in sample 1, r = 0.29 in sample 2, puncorrected < .05).

CONCLUSIONS

The inverse association between leptin and cortical surface area in brain regions that are important for emotion processing and leptin's association with atypical depressive symptoms support the hypothesis that metabolic processes may be related to emotion regulation. However, the molecular mechanisms through which leptin may exert these effects should be explored further.

Pentoxifylline as a Novel Add-on Therapy for Major Depressive Disorder in Adult Patients: A Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND

Evidence indicates an association between immune dysregulation and major depressive disorder (MDD). Pentoxifylline (PTX), a phosphodiesterase inhibitor, has been shown to reduce pro-inflammatory activities. The aim of this study was to evaluate changes in depressive symptoms and pro-inflammatory markers after administration of PTX as an adjunctive agent to citalopram in patients with MDD.

METHODS

One hundred patients were randomly assigned to either citalopram (20 mg/day) plus placebo (twice daily) (n=50) or citalopram (20 mg/day) plus PTX (400 mg) (twice daily) (n=50). The Hamilton Depression Rating Scale-17 (HAM-D-17) scores at baseline, weeks 2, 4, 6, 8, 10, and 12 and serum levels of interleukin1-β (IL-1-β), tumor necrosis factor-α, C-reactive protein, IL-6, serotonin, IL-10, and brain-derived neurotrophic factor (BDNF) at baseline and week 12 were evaluated.

RESULTS

HAM-D-17 score in the PTX group significantly reduced in comparison to the control group after weeks 4, 6, 8,10, and 12 ((LSMD): - 2.193, p=0.021; - 2.597, p=0.036; - 2.916, p=0.019; - 4.336, p=0.005; and - 4.087, p=0.008, respectively). Patients who received PTX had a better response (83%) and remission rate (79%) compared to the placebo group (49% and 40%, p=0.006 and p=0.01, respectively). Moreover, the reduction in serum concentrations of pro-inflammatory factors and increase in serotonin and BDNF in the PTX group was significantly greater than in the placebo group (p<0.001).

CONCLUSION

These findings support the safety and efficacy of PTX as an adjunctive antidepressant agent with anti-inflammatory effects in patients with MDD.

Disturbed sex hormone milieu in males and females with major depressive disorder and low-grade inflammation

Sex hormones have biological effects on inflammation, and these might contribute to the sex-specific features of depression. C-reactive protein (CRP) is the most widely used inflammatory biomarker and consistent evidence shows a significant proportion (20-30 %) of patients with major depressive disorder (MDD) have CRP levels above 3 mg/L, a threshold indicating at least low-grade inflammation. Here, we investigate the interplay between sex hormones and CRP in the cross-sectional, observational Biomarkers in Depression Study. We measured serum high-sensitivity (hs-)CRP, in 64 healthy controls and 178 MDD patients, subdivided into those with hs-CRP below 3 mg/L (low-CRP; 53 males, 72 females) and with hs-CRP above 3 mg/L (high-CRP; 19 males, 34 females). We also measured interleukin-6, testosterone, 17-β-estradiol (E2), progesterone, sex-hormone binding globulin (SHBG), follicle-stimulating and luteinising hormones, and calculated testosterone-to-E2 ratio (T/E2), free androgen and estradiol indexes (FAI, FEI), and testosterone secretion index. In males, high-CRP patients had lower testosterone than controls (p = 0.001), and lower testosterone (p = 0.013), T/E2 (p < 0.001), and higher FEI (p = 0.015) than low-CRP patients. In females, high-CRP patients showed lower SHGB levels than controls (p = 0.033) and low-CRP patients (p = 0.034). The differences in testosterone, T/E2 ratio, and FEI levels in males survived the Benjamini-Hochberg FDR correction. In linear regression analyses, testosterone (β = -1.069 p = 0.033) predicted CRP concentrations (R2 = 0.252 p = 0.002) in male patients, and SHBG predicted CRP levels (β = -0.628 p = 0.009, R2 = 0.172 p = 0.003) in female patients. These findings may guide future research investigating interactions between gonadal and immune systems in depression, and the potential of hormonal therapies in MDD with inflammation.

Frailty and psychiatric disorders: A bidirectional Mendelian randomization study

BACKGROUND

The association between frailty and psychiatric disorders has been reported in observational studies. However, it is unclear whether frailty facilitates the appearance of psychiatric disorders or vice versa. Therefore, we conducted a bidirectional Mendelian randomization (MR) study to evaluate the causality.

METHODS

Independent genetic variants associated with frailty index (FI) and psychiatric disorders were obtained from large genome-wide association studies (GWAS). The inverse variance weighted method was utilized as the primary method to estimate causal effects, followed by various sensitivity analyses. Multivariable analyses were performed to further adjust for potential confounders.

RESULTS

The present MR study revealed that genetically predicted FI was significantly and positively associated with the risk of major depressive disorder (MDD) (odds ratio [OR] 1.79, 95 % confidence interval [CI] 1.48-2.15, P = 1.06 × 10-9), anxiety disorder (OR 1.61, 95 % CI 1.19-2.18, P = 0.002) and neuroticism (OR 1.38, 95 % CI 1.18-1.61, P = 3.73 × 10-5). In the reverse MR test, genetic liability to MDD (beta 0.232, 95 % CI 0.189-0.274, P = 1.00 × 10-26) and neuroticism (beta 0.128, 95 % CI 0.081-0.175, P = 8.61 × 10-8) were significantly associated with higher FI. Multivariable analyses results supported the causal association between FI and MDD and neuroticism.

LIMITATIONS

Restriction to European populations, and sample selection bias.

CONCLUSIONS

Our study suggested a bidirectional causal association between frailty and MDD neuroticism, and a positive correlation of genetically predicted frailty on the risk of anxiety disorder. Developing a deeper understanding of these associations is essential to effectively manage frailty and optimize mental health in older adults.

Exploring the causal relationship between interleukin-6 or C reactive protein and malignant melanoma using a two-sample Mendelian randomization approach

The goal was to explore the effect of interleukin-6 (IL6) and C reactive protein (CRP) on malignant melanoma (MM) using two-sample Mendelian randomization.

Methods

Data for this study were obtained from the IEU Open GWAS project website for genome-wide association study data (GWAS) on interleukin-6, C reactive protein levels and malignant melanoma. Inverse variance weighted (IVW) method was mainly used and supplemented with MR-Egger regression and weighted median. Finally, horizontal multivariate validity and heterogeneity tests were performed to assess the stability and reliability of the results.

Results

The results of univariate two-sample MR analyses showed no significant effect of CRP on MM: inverse variance weighting method (OR=0.999, 95% CI: 0.998-1.001, P=0.343), MR-Egger regression (OR= 1.000, 95% CI: 0.998-1.001, P= 0.180), and weighted median method (OR= 0.999, 95% CI: 0.997 to 1.000, P= 0.583), and weighted model (OR= 0.999, 95% CI: 0.998 to 1.001, P= 0.328). Also,IL-6 had no significant effect on MM: inverse variance weighting method (OR= 1.001, 95% CI: 0.999 to 1.002, P=0.461), MR-Egger regression (OR= 1.000, 95% CI: 0.997 to 1.004, P= 0.910), weighted median method (OR= 1.000, 95% CI: 0.998 to 1.002, P= 0.749), and weighted mode (OR= 1.000, 95% CI: 0.998 to 1.002, P= 0.820).

Conclusion

There was no causal relationship between C-reactive protein and IL-6 on the risk of malignant melanoma.

Neurobiological and psychological factors to depression

Major Depressive Disorder (MDD) is a common condition with complex psychological and biological background. While its aetiology is still unclear, chronic stress stands amongst major risk factors to MDD pathogenesis. When researching on MDD, it is necessary to be familiar with the neurobiological effects of several prominent contributors to the chronic stress factor experienced across hypothalamic-pituitary-adrenal (HPA) axis, neurotransmission, immune system reflexivity, and genetic alterations. Bi-directional flow of MDD pathogenesis suggests that psychological factors produce biological effects. Here, a summary of how the MDD expresses its mechanisms of action across an overactive HPA axis, the negative impacts of reduced neurotransmitter functions, the inflammatory responses and their gene x environment interactions. This paper builds on these conceptual factors and their input towards the MDD symptomatology with a purpose of synthesising the current findings and create an integrated view of the MDD pathogenesis. Finally, relevant treatment implications will be summarised, along with recommendations to a multimodal clinical practice.

Voluntary wheel running as a promising strategy to promote autonomic resilience to social stress in females: Vagal tone lies at the heart of the matter

Social stress is a major risk factor for comorbid conditions including cardiovascular disease and depression. While women exhibit 2-3× the risk for these stress-related disorders compared to men, the mechanisms underlying heightened stress susceptibility among females remain largely unknown. Due to a lack in understanding of the pathophysiology underlying stress-induced comorbidities among women, there has been a significant challenge in developing effective therapeutics. Recently, a causal role for inflammation has been established in the onset and progression of comorbid cardiovascular disease/depression, with women exhibiting increased sensitivity to stress-induced immune signaling. Importantly, reduced vagal tone is also implicated in stress susceptibility, through a reduction in the vagus nerve's well-recognized anti-inflammatory properties. Thus, examining therapeutic strategies that stabilize vagal tone during stress may shed light on novel targets for promoting stress resilience among women. Recently, accumulating evidence has demonstrated that physical activity exerts cardio- and neuro-protective effects by enhancing vagal tone. Based on this evidence, this mini review provides an overview of comorbid cardiovascular and behavioral dysfunction in females, the role of inflammation in these disorders, how stress may impart its negative effects on the vagus nerve, and how exercise may act as a preventative. Further, we highlight a critical gap in the literature with regard to the study of females in this field. This review also presents novel data that are the first to demonstrate a protective role for voluntary wheel running over vagal tone and biomarkers of cardiac dysfunction in the face of social stress exposure in female rats.

A Chemical Structure and Machine Learning Approach to Assess the Potential Bioactivity of Endogenous Metabolites and Their Association with Early Childhood Systemic Inflammation

Metabolomics has gained much attention due to its potential to reveal molecular disease mechanisms and present viable biomarkers. This work uses a panel of untargeted serum metabolomes from 602 children from the COPSAC2010 mother-child cohort. The annotated part of the metabolome consists of 517 chemical compounds curated using automated procedures. We created a filtering method for the quantified metabolites using predicted quantitative structure-bioactivity relationships for the Tox21 database on nuclear receptors and stress response in cell lines. The metabolites measured in the children's serums are predicted to affect specific targeted models, known for their significance in inflammation, immune function, and health outcomes. The targets from Tox21 have been used as targets with quantitative structure-activity relationships (QSARs). They were trained for ~7000 structures, saved as models, and then applied to the annotated metabolites to predict their potential bioactivities. The models were selected based on strict accuracy criteria surpassing random effects. After application, 52 metabolites showed potential bioactivity based on structural similarity with known active compounds from the Tox21 set. The filtered compounds were subsequently used and weighted by their bioactive potential to show an association with early childhood hs-CRP levels at six months in a linear model supporting a physiological adverse effect on systemic low-grade inflammation.

Serum Levels of Zinc, Albumin, Interleukin-6 and CRP in Patients with Unipolar and Bipolar Depression: Cross Sectional Study

Unipolar (UD) and bipolar depression (BDD) show a high degree of similarity in clinical presentations, which complicates the differential diagnosis of these disorders. The aim of this study was to investigate the serum levels of interleukin 6 (IL-6), C-reactive protein (CRP), albumin (Alb), and zinc (Zn) in patients with UD, BDD, and healthy controls (HC). A total of 211 samples were collected: 131 patient samples (65 UD and 68 BDD) and 80 HC. The Montgomery-Asberg Depression Rating Scale (MADRS), along with the Hamilton Depression Rating Scale (HAMD-17), were administered to patient groups to evaluate symptoms. A cross-sectional study was performed to analyse the serum levels of IL-6, CRP, albumin, and zinc. The concentration of CRP was determined using the immunoturbidimetry method, zinc using the colorimetric method, and albumin using the colorimetric method with bromocresol green on the Alinity c device. IL-6 cytokine concentration in serum samples was ascertained using a commercial enzyme immunoassay, ELISA. We found no significant differences in serum concentrations of zinc, albumin, CRP, and IL-6 between the groups of patients with unipolar and bipolar depression. There was a significant statistical difference (p < 0.001) between serum levels of all investigated parameters in both groups of depressed patients in comparison with HC. Furthermore, correlations with specific items on HAMD-17; (namely, hypochondrias, work and activities, somatic symptoms-general, and weight loss) and on MADRS (concentration difficulties, lassitude) were observed in both patient groups. These findings confirm the presence of low-grade inflammation in depression, thus adding better insight into the inflammation hypothesis directed to explain the aetiology of depressive disorders. Our results do not indicate potential biomarkers for distinguishing between unipolar and bipolar depression.