Selected Biomarkers of Depression: What Are the Effects of Cytokines and Inflammation?

Association between methylmalonic acid and prevalence of depression in US adults: evidence from NHANES 2011-2014

Background: Depression is a prevalent mental disorder with high morbidity and mortality globally. Methylmalonic acid (MMA) is involved in the pathogenesis of numerous diseases. However, it is unclear whether there is an association between MMA and the prevalence of depression.Methods: This study enrolled 7866 US adults from the 2011-2014 survey of the National Health and Nutrition Examination Survey (NHANES). Individuals were categorized into depression group and non-depression group based on Patient's Health Questionnaire-9 (PHQ-9) score. The association between MMA concentrations and prevalence of depression was analysed by multivariate logistic and linear regression, restricted cubic spline regression, and subgroup analysis. Mediation analysis was used to explore the role of inflammation in the relationship between MMA and depression.Results: MMA concentrations were higher in participants with depression than those without depression. There was a positive and linear relationship of MMA concentrations with PHQ-9 score and depression risk, respectively. Moreover, the association was stable in most subgroups. Furthermore, inflammatory factors were positively correlated to MMA concentrations and prevalence of depression. In addition, white blood cell, neutrophil and alkaline phosphatase (ALP) mediated the relationship between MMA and depression.Conclusion: Our findings revealed that there was a linear and positive correlation between MMA and the prevalence of depression in US adults, which might be mediated by inflammation.

Neuroprotective role of geniposide-loaded UMSC nanovesicles in depression via P2ry12 downregulation

BACKGROUND

Depression is a prevalent mental disorder characterized by persistent low mood, loss of interest, and cognitive impairment. Oxidative stress and inflammation play crucial roles in its pathogenesis. Novel therapeutic strategies targeting these mechanisms are needed to improve treatment outcomes.

PURPOSE

The purpose of this study is to gauge the therapeutic effectiveness of geniposide (GEN)-loaded umbilical cord-derived mesenchymal stem cell membrane biomimetic nanovesicles (CSPG@UMSC NPs) targeting the P2ry12 factor for depression management, considering its association with oxidative stress and inflammatory pathways.

STUDY DESIGN

A combination of in vitro neuronal cell culture experiments and an in vivo chronic unpredictable mild stress (CUMS) mouse model was used to assess the effects of CSPG@UMSC NPs.

METHODS

In vitro investigations involved culture and characterization of CSPG@UMSC NPs and transcriptome sequencing analysis to identify DEGs in neurons. In vivo experiments utilized a depression mouse model treated with CSPG@UMSC NPs, followed by behavioral tests, biomarker analysis, and histological assessments.

RESULTS

CSPG@UMSC NPs successfully downregulated P2ry12 expression, leading to improved neuronal activity, decreased inflammation, reduced cell apoptosis, and lowered reactive oxygen species levels in both in vitro and in vivo settings.

CONCLUSION

CSPG@UMSC NPs loaded with GEN inhibit oxidative stress and inflammation by downregulating P2ry12. This research unveils, for the initial instance, the vital role of P2ry12 in depression and proposes a novel nano-therapy strategy based on MSCs and GEN, offering new insights and potential clinical applications for the treatment of depression.

Ketogenic diet attenuates neuroinflammation and restores hippocampal neurogenesis to improve CUMS induced depression-like behavior in mice

The ketogenic diet (KD) has been proposed as a potential treatment for depression. However, the underlying mechanisms remain poorly understood. This study aimed to evaluate further the effects of KD on chronic unpredictable mild stress (CUMS)-induced depression in mice and investigate the underlying mechanisms. The results demonstrated that KD intervention significantly alleviated CUMS-induced depression-like behaviors, as evidenced by a decrease in immobility time in the forced swimming test and tail suspension test, an increase in distance traveled in the open field test, and a greater preference for sucrose in the sucrose preference test. KD alleviated neuroinflammation by reducing the levels of glial cell activation markers Iba-1 and GFAP, inhibiting the expression of inflammatory factors IL-1β, TNF-α, and COX-2, and suppressing the overactivation of the TLR4/MyD88/NF-κB signaling pathway. Furthermore, KD increased the number of DCX-, BrdU-, and PSD95-positive cells in the hippocampus and enhanced the BDNF/TrkB/CREB and Wnt/β-catenin signaling pathways, thereby promoting hippocampal neurogenesis. These findings suggested that KD alleviated CUMS-induced depression-like behaviors in mice by reducing neuroinflammation, enhancing neurotrophic signaling, and promoting hippocampal neurogenesis, thereby providing a mechanistic basis for its potential as a novel dietary antidepressant therapy.

Transcriptomic Profile of the Male Rat Hypothalamus and Nucleus Accumbens After Paroxetine Treatment and Withdrawal: Possible Causes of Sexual Dysfunction

Paroxetine, a selective serotonin reuptake inhibitor (SSRI), may induce sexual dysfunction during treatment and upon discontinuation. The mechanisms involved have been poorly explored so far. We have analyzed, by RNA sequencing, the whole transcriptomic profile in the hypothalamus and nucleus accumbens (NAc) (two brain regions involved in sexual behavior) of male rats daily treated for 2 weeks with paroxetine (T0) and at 1 month of withdrawal (T1). Data here reported show seven differentially expressed genes (DEGs) at T0 and 1 at T1 in the hypothalamus and 245 at T0 and 6 at T1 in the NAc. In addition, Gene-Set Enrichment, Gene Ontology, and Reactome analyses confirm that inflammatory signature and immune system activation were present at T0 in both brain areas. Considering that inflammation is generally associated with depression and that no paradigms inducing the pathology were here applied, these SSRI pro-depressive effects should be considered in patients without a clear indication of depression. Moreover, DEGs related to neurotransmitters with a role in sexual behavior and the reward system, such as dopamine (e.g., sialyltransferase 8B-ST8SIA3), glutamate (e.g., glutamate receptor ionotropic delta-2-GRID2) and GABA (e.g., glutamate decarboxylase type 2-GAD2) or associated with neurexin and neuroligin pathways and brain-derived neurotrophic factor (BDNF) signaling, were reported to be dysregulated in the NAc, further confirming dysfunction in this brain area. Interestingly, the analysis of DEGs altered at T1 in the NAc confirms the persistence of some of these side effects providing further information for post-SSRI sexual dysfunction (PSSD) etiopathogenesis.

A positive association between high dietary medium-chain fatty acids intake and depression: Mediation of inflammation

AIMS

Our aims were to investigate the association between dietary MCFAs and depression, with a focus on potential mediating factors.

METHODS

A total of 11,085 participants from NHANES were included in this study. The total intake of MCFAs, including octanoic acid (C8:0), decanoic acid (C10:0), and lauric acid (C12:0), was derived, and their respective ratios to total fatty acids were calculated as exposure. Depression was defined as a score of ≥10 on the Patient Health Questionnaire-9 (PHQ-9). Weighted logistic regression was used to analyze the relationship between MCFAs and depression. The contribution of MCFAs was assessed using weighted quartile sum (WQS). C-reactive protein (CRP) was included as a potential mediator in the analysis of underlying mechanisms.

RESULTS

The highest quartile (Q4) of dietary MCFAs was associated with a significantly greater likelihood of depression compared to the lowest quartile (Q1) (ORtotal MCFAs: 1.36, 95 % CI: 1.07-1.65; ORC8:0: 1.46, 95 % CI: 1.15-1.77; ORC10:0: 1.38, 95 % CI: 1.06-1.60; and ORC12:0: 1.31, 95 % CI: 1.03-1.68), but no significant associations were observed for Q2 and Q3. The WQS results indicated that C12:0 contributed the most to the association between total MCFAs and depression (weight percentage: 49.1 %). CRP partially mediated the association between the Q4 of MCFAs and depression, with a mediation proportion of 7.6 % to 9.1 %.

CONCLUSIONS

Excessive intake of MCFAs is associated with a higher risk of depression, particularly for C12:0, with CRP partially mediating this association.

Systemic inflammation correlates with depression and lower quality of life in patients with hidradenitis suppurativa independent of disease severity

Hidradenitis suppurativa (HS) is associated with a cumulative life course impairment and patients commonly present with signs of depression and anxiety. This study aimed to investigate the association between systemic inflammation, measured by laboratory markers, and psychological burden, evaluated using specific psychometric scores, in patients with HS. The study also evaluated the impact of treatment initiation on inflammatory biomarkers and psychometric scores. A prospective, observational, monocentric study was conducted on adult patients with HS of Hurley stage I, II and III, who were eligible for treatment initiation. Disease severity was assessed using the Hurley stage, and disease activity through the IHS4 scoring system. Laboratory evaluation of systemic inflammation included measurement of White Blood Cell count, Erythrocyte Sedimentation Rate (ESR) and C-reactive protein levels, at the study onset, right before treatment initiation, at 12 weeks and at 24 weeks following treatment onset. The impact of the disease on psychological status and overall quality of life was evaluated through psychometric scores. Our results indicate that systemic inflammation, reflected by laboratory inflammatory markers such as ESR, is associated with a higher probability of depression, loneliness and reduced quality of life independently of Hurley stage, severity score, and clinical characteristics such as gender and smoking status. Psychometric evaluation, including the presence of depression and loneliness in HS patients, independent of Hurley stage is advisable, especially in cases where serum inflammatory markers, such as ESR, are high.

URB597 modulates neuroplasticity, neuroinflammatory, and Nrf2/HO-1 signaling pathways in the hippocampus and prefrontal cortex of male and female rats in a stress-induced model of depression

Major depressive disorder is often associated with cognitive impairments, and neuroinflammation is considered a key contributor to the onset of depression. Pharmacological inhibition of fatty acid amide hydrolase (FAAH), which augments endocannabinoid signaling, has emerged as a promising approach to treating depression. The main purpose of this study is to asses the influence of FAAH inhibitor URB597 on inflammatory response and oxidative stress in chronic unpredictable stress (CUS)-induced depressive female and male rats and to explore the underlying molecular mechanisms. Chronically stressed animals showed long-term memory deficits, while URB597 improved memory only in stressed males. URB597 treatment enhanced levels of brain-derived neurotrophic factor (BDNF) in the hippocampus and mPFC of stressed female and male rats and increased phosphorylated calcium/calmodulin-dependent protein kinase II (pCaMKII) levels in the hippocampus and mPFC of CUS males. Additionally, increased phosphorylation of JAK2 and STAT3 in the hippocampus and mPFC of CUS male and female rats, was reduced following URB597 treatment. URB597 decreased the CUS-enhanced iNOS protein expression in the hippocampus and mPFC of both sexes. Furthermore, URB597 normalized CUS-induced reductions in Nrf2 and HO-1 levels in the mPFC of both sexes, with no changes in the hippocampus. Our findings suggest that URB597 may inhibit the CUS-induced neuroinflammatory response by suppressing the pro-inflammatory mediators and the activation of the JAK2/STAT3 signaling in the hippocampus and mPFC of both sexes. URB597 treatment contributed to synaptic plasticity in a sex-specific manner by upregulating brain CaMKII signaling in males. URB597 also exerts neuroprotective effects through region-specific antioxidant properties. These results have implications for sex-specific treatment strategies in stress-related neuropsychiatric disorders.

The characteristics of anhedonia in depression: a review from a clinically oriented perspective

Anhedonia, as one of the core symptoms of major depressive disorder (MDD), has been regarded as a potential endophenotype of the disease. Multiple studies have evaluated the potential mechanisms of anhedonia in MDD, and found that MDD patients with anhedonia showed different functions in clinical features. In this review, we focus on the clinical research to explore the differences between MDD patients with and without anhedonia in the clinical manifestations and biological alterations, and elaborate the treatments and prognosis of anhedonia. It is demonstrated that anhedonia is associated with adverse outcomes including more severe depressive episode and suicidality, and poor prognosis in patients with MDD. At the biological level, MDD patients with anhedonia seem to present higher levels of inflammatory factors, abnormal metabolic function and hypermetabolism of BDNF. In brain imaging studies, there are some structural and/ or functional changes in multiple brain regions of subcortical and cortical areas, as well as the limbic system in MDD patients with anhedonia. Meanwhile, preliminary research findings have also indicated that there are associations between intestinal flora imbalance and anhedonia. Moreover, evidence indicated the benefit of some selective serotonin reuptake inhibitors seemed limited on anhedonia, and other treatments including psychotherapy, physical therapy and probiotic interventions has remained to be explored but has interesting potential. Therefore, increased awareness of the anhedonic symptoms and the unique clinical features would benefit improved early diagnosis and therapeutic effects in MDD.

Identifying early screening factors for depression in middle-aged and older adults: A cohort study

Objective

This study aims to explore the current status of depression and related factors in middle-aged and elderly people in China using a cohort database with multi-year follow-up.

Methods

The study population for this project was derived from the China Health and Retirement Longitudinal Study. Participants were divided into control and depression groups based on scores from the Center for Epidemiological Research Depression Scale. Continuous variables were compared using t-tests or Mann-Whitney U tests, while categorical variables were compared using chi-square tests. A multivariate logistic regression model was employed to evaluate factors associated with depression.

Results

A total of 9,749 participants were included in the study. Correlation analyses revealed that age, body mass index, diastolic blood pressure, waist circumference, total cholesterol, uric acid, and length of sleep were significantly associated with depression (p < 0.05). Women exhibited a higher risk of depression in middle and old age compared to men (p < 0.05). An increase in waist circumference was associated with a decreased risk of depression (p < 0.05). Longer sleep duration and higher educational levels were also associated with a reduced risk of depression (p < 0.05). Unfavorable marital status and decreased frequency of alcohol consumption were found to increase the risk of depression (p < 0.05).

Conclusion

In middle-aged and elderly individuals, women, low education level, and experiencing dissatisfaction in marriage are connected with a high risk of depression. On the other hand, increased waist circumference, moderate alcohol consumption, and longer sleep duration are connected with a low risk of depression.

Circulating Blood-Based Proteins in Psychopathology and Cognition: A Mendelian Randomization Study

Importance

Peripheral (blood-based) biomarkers for psychiatric illness could benefit diagnosis and treatment, but research to date has typically been low throughput, and traditional case-control studies are subject to potential confounds of treatment and other exposures. Large-scale 2-sample mendelian randomization (MR) can examine the potentially causal impact of circulating proteins on neuropsychiatric phenotypes without these confounds.

Objective

To identify circulating proteins associated with risk for schizophrenia (SCZ), bipolar disorder (BD), and major depressive disorder (MDD) as well as cognitive task performance (CTP).

Design, Setting, and Participants

In a 2-sample MR design, significant proteomic quantitative trait loci were used as candidate instruments, obtained from 2 large-scale plasma proteomics datasets: the UK Biobank Pharma Proteomics Project (2923 proteins per 34 557 UK individuals) and deCODE Genetics (4719 proteins per 35 559 Icelandic individuals). Data analysis was performed from November 2023 to November 2024.

Exposure

Genetic influence on circulating levels of proteins in plasma.

Main Outcomes and Measures

Outcome measures were summary statistics drawn from recent large-scale genome-wide association studies for SCZ (67 323 cases and 93 456 controls), BD (40 463 cases and 313 436 controls), MDD (166 773 cases and 507 679 controls), and CTP (215 333 individuals). MR was carried out for each phenotype, and proteins that showed statistically significant (Bonferroni-corrected P < .05) associations from MR analysis were used for pathway, protein-protein interaction, drug target enrichment, and potential druggability analysis for each outcome phenotype separately.

Results

MR analysis revealed 113 Bonferroni-corrected associations (46 novel) involving 91 proteins across the 4 outcome phenotypes. Immune-related proteins, such as interleukins and complement factors, showed pleiotropic effects across multiple outcome phenotypes. Drug target enrichment analysis provided support for repurposing of anti-inflammatory agents for SCZ, amantadine for BD, retinoic acid for MDD, and duloxetine for CTP.

Conclusions and Relevance

Identifying potentially causal effects of circulating proteins on neuropsychiatric phenotypes suggests potential biomarkers and offers insights for the development of innovative therapeutic strategies. The study also reveals pleiotropic effects of many proteins across different phenotypes, indicating shared etiology among serious psychiatric conditions and cognition.

Lipidomics and genomics in mental health: insights into major depressive disorder, bipolar disorder, schizophrenia, and obsessive-compulsive disorder

INTRODUCTION

This systematic review explores the hypothesis that various lipid categories and lipid metabolism-related genomic variations link to mental disorders, seeking potential clinically useful markers.

METHODS

We searched PubMed, Scopus, and PsycInfo databases until October 12th, 2024, using terms related to lipidomics, lipid-related genomics, and different mental disorders, i.e., Major Depressive Disorder (MDD), Bipolar Disorder (BD), Schizophrenia (SCZ), and Obsessive-Compulsive Disorder (OCD). Eligible studies were assessed. Extracted data included author, year, methodology, outcomes, genes, and lipids linked to disorders. Bias and evidence certainty were evaluated. The systematic review adhered to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and a registered protocol (PROSPERO: CRD42023438862).

RESULTS

A total of 27 studies were included. SCZ showed alterations in 77 lipids, including triglycerides (TG), ceramides, and phosphatidylcholine, while MDD and BD exhibited 97 and 47 altered lipids, respectively, with overlap among disorders. Shared genes, such as ABCA13, DGKZ, and FADS, and pathways involving inflammation, lipid metabolism, and mitochondrial function were identified. OCD was associated with sphingolipid signaling and peroxisomal metabolism.

DISCUSSION

Lipid signatures in MDD, BD, and SCZ shed light on underlying processes. Further research is needed to validate biomarkers and refine their clinical applications in precision psychiatry.

The association between uric acid to high-density cholesterol ratio and depression: A population-based cross-sectional study

BACKGROUND

Depression is associated with inflammation, and the uric acid to HDL-C cholesterol ratio (UHR) has emerged as a potential marker of increased inflammation; however, the association between UHR and depression is unclear. Therefore, we aimed to explore this association in a sample from the general US population.

METHODS

We conducted a cross-sectional study of 11,444 participants ≥20 years of age from the 2009-2014 NHANES database. We conducted weighted multivariate logistic regression analyses and restricted cubic spline function (RCS) models exploring the association between UHR and risk of depression, as well as subgroup analyses and tests of interaction.

RESULTS

UHR was positively associated with depression, especially in participants who drank alcohol (interaction P < 0.05).The prevalence of depression increased by 4 % for each 1-unit increase in UHR (OR = 1.04, 95 % CI = 1.02, 1.07, P = 0.003). After dividing the UHR into quartiles compared with the lowest reference group for UHR, participants in the fourth quartile had a significantly increased risk of depression after full adjustment (OR = 1.36, 95 % CI = 1.03, 1.80, P = 0.033).There was a linear dose-response relationship between the UHR and the risk of depression (P for nonlinear = 0.744).

LIMITATIONS

As this was a cross-sectional study, we could not determine a causal relationship between UHR and depression.

CONCLUSION

The UHR is positively associated with an increased prevalence of depression among adults in the U.S.

Cognitive and metabolic signatures of early and late-onset depression: A comparative study

BACKGROUND

Early-onset depression (EOD) and late-onset depression (LOD) are prevalent subtypes of major depressive disorder (MDD), but the clinical distinction between EOD and LOD remains blurred due to nonspecific symptoms and lack of biomarkers. This study aims to elucidate the characteristics in cognitive function and biochemical metabolism of EOD and LOD, and to identify biological factors influencing age of onset (AOO).

METHODS

Seventy patients with MDD (40 with EOD and 30 with LOD) and sixty-eight age-matched healthy controls (HC) were included in this study. Participants were evaluated for clinical features, cognitive function, and serum trace elements levels. Proton magnetic resonance spectroscopy (1H-MRS) was employed to quantify neurometabolites levels, including N-acetyl aspartate (NAA), choline (Cho), and creatine (Cr).

RESULTS

Patients with LOD experienced more episodes and severe depressive symptoms than those with EOD (p = 0.025, p < 0.001). EOD patients performed significantly worse than LOD patients on social cognition (p = 0.005), while LOD patients performed worse than EOD patients on reasoning and problem solving (p = 0.005). Additionally, LOD patients displayed higher ceruloplasmin (Cp) levels compared to EOD patients (p = 0.004), but no difference was found in neurometabolic levels between EOD and LOD. Multiple linear regression indicated a positive correlation between serum Cp levels and AOO of depression (p < 0.001), while bilateral thalamic NAA/Cr showed a negative correlation with AOO (p = 0.012, p = 0.016).

CONCLUSIONS

Patients with EOD were characterized by social cognition impairments, while patients with LOD were marked by reasoning and problem-solving deficits. Serum Cp levels demonstrated an AOO-related effect and served as a positive predictor for the AOO of depression. Furthermore, a negative correlation has been established between bilateral thalamic NAA/Cr and the AOO of MDD.

LIMITATIONS

The limited sample size and the challenge in distinguishing whether observed results are attributed to age or AOO effects.

Using inflammatory biomarkers in early pregnancy to predict subsequent antenatal depression

BACKGROUND

Antenatal depression (AD) is one of the most common pregnancy complications. Recent studies indicated that immune responses during pregnancy may contribute to development of AD.

OBJECTIVES

This study aimed to identify possible inflammatory biomarkers in early pregnancy to predict maternal depressive symptoms before delivery.

METHODS

This case-control study was conducted within the Maternal and Infant Health (MI-Health) birth cohort (Beijing, China) and depressive symptoms were assessed by Zung Self-rating Depression Scale (SDS) in both second and third trimesters. By using immune multi-factors kits, we tested 26 inflammatory factors in the serum of 38 cases with antenatal depression symptoms in both trimesters (SDS ≥ 53) and 38 controls. Logistic regression was used to identify candidate biomarkers, and the predictive capabilities were evaluated by using Receiver Operator Characteristics (ROC) analysis.

RESULTS

The concentrations of ln(CCL24) (p = 0.020), IL-7 (p = 0.006) and IL-10 (p = 0.014) were higher in early pregnancy among women with depressive symptoms comparing to healthy controls. The difference remained statistically significant after adjusting for maternal age, education level, gestational diabetes mellitus, pre-pregnancy BMI and gestational weeks of blood sampling (OR(ln(CCL24)) = 4.625, OR(IL-7) = 1.414, OR(IL-10) = 1.151). In ROC analysis, ln(CCL24), IL-7, and IL-10 achieved discrimination for depressive symptoms antepartum, with the values of AUC estimated at 0.75.

LIMITATIONS

The sample size is limited, and the infectious disease infection records were not collected for control.

CONCLUSION

Higher levels of CCL24, IL-7 and IL-10 may indicate the higher risk of antenatal depression and are potential biomarkers indicating pathogenesis of antenatal depression.

Mental Health Disorders Due to Gut Microbiome Alteration and NLRP3 Inflammasome Activation After Spinal Cord Injury: Molecular Mechanisms, Promising Treatments, and Aids from Artificial Intelligence

Aside from its immediate traumatic effects, spinal cord injury (SCI) presents multiple secondary complications that can be harmful to those who have been affected by SCI. Among these secondary effects, gut dysbiosis (GD) and the activation of the NOD (nucleotide-binding oligomerization domain) like receptor-family pyrin-domain-containing three (NLRP3) inflammasome are of special interest for their roles in impacting mental health. Studies have found that the state of the gut microbiome is thrown into disarray after SCI, providing a chance for GD to occur. Metabolites such as short-chain fatty acids (SCFAs) and a variety of neurotransmitters produced by the gut microbiome are hampered by GD. This disrupts healthy cognitive processes and opens the door for SCI patients to be impacted by mental health disorders. Additionally, some studies have found an increased presence and activation of the NLRP3 inflammasome and its respective parts in SCI patients. Preclinical and clinical studies have shown that NLRP3 inflammasome plays a key role in the maturation of pro-inflammatory cytokines that can initiate and eventually aggravate mental health disorders after SCI. In addition to the mechanisms of GD and the NLRP3 inflammasome in intensifying mental health disorders after SCI, this review article further focuses on three promising treatments: fecal microbiome transplants, phytochemicals, and melatonin. Studies have found these treatments to be effective in combating the pathogenic mechanisms of GD and NLRP3 inflammasome, as well as alleviating the symptoms these complications may have on mental health. Another area of focus of this review article is exploring how artificial intelligence (AI) can be used to support treatments. AI models have already been developed to track changes in the gut microbiome, simulate drug-gut interactions, and design novel anti-NLRP3 inflammasome peptides. While these are promising, further research into the applications of AI for the treatment of mental health disorders in SCI is needed.

Exploring stress and depressive symptoms in pregnancy and the IL-1β, IL-6, and C-reactive protein pathway: Looking for possible biomarker targets

Background

Individuals undergo significant stress throughout pregnancy and are at high risk for depressive symptoms. Elevated stress and depressive symptoms are associated with inflammatory processes and adverse maternal-infant outcomes. However, the biological processes associated with psychosocial outcomes and the maternal immune system remain unclear. As such, we aimed to examine associations among perceived stress, depressive symptoms, salivary IL-1β, IL-6, and CRP levels, and hair and salivary cortisol levels during the second and third trimesters of pregnancy.

Methods

We conducted an ancillary study consisting of 37 pregnant individuals. Participants collected salivary samples and measures of perceived stress and depression at 17-19 weeks, 25-27 weeks, and 32-34 weeks gestation. We collected a one-time hair sample between 36 and 40 weeks. Provided salivary samples were used to detect changes in cortisol, IL-1β, IL-6, and CRP levels. Hair was used to detect changes in cortisol levels throughout pregnancy.

Results

Elevated levels of perceived stress and depressive symptoms are associated with increased salivary CRP levels, respectively (p = 0.0142, p = 0.0008). Salivary and hair cortisol increased significantly throughout the second and third trimesters of pregnancy (p = 0.0004 and p < 0.0001). We also observed variations in IL-6 during pregnancy (p = 0.029) and significant increases between 25 and 27 weeks (p = 0.016).

Conclusion

Salivary samples may provide a non-invasive measurement of alterations in cytokine and cortisol levels in pregnant individuals reporting elevated stress and depressive symptoms. These may be candidate biomarkers for mechanistic study possibly aiding providers in early detection of deleterious immunological processes which could result in adverse maternal-infant outcomes.

What is the relationship between exposure to environmental pollutants and severe mental disorders? A systematic review on shared biological pathways

Severe mental disorders are multi-dimensional constructs, resulting from the interaction of genetic, biological, psychosocial, and environmental factors. Among the latter, pollution and climate change are frequently being considered in the etiopathogenesis of severe mental disorders. This systematic review aims to investigate the biological mechanisms behind the relationship between environmental pollutants, climate change, and mental disorders. An extensive literature search was performed on PubMed, Scopus, and APA PsycInfo databases according to the PRISMA guidelines. Articles were considered eligible if they involved humans or animals examining the association between exposure to environmental pollutants and if the resulting biological mechanisms that may have an impact on mental health and may support or even cause severe mental disorders (SMD) are assessed. For this reason, only studies dealing with biomarkers or biological pathways were taken into account. The 47 papers included in the review were divided into two groups: those conducted on human participants (15 studies) and those utilizing animal models (31 studies); one study included both humans and animals. Studies carried out with humans, which are mainly focused on measuring the impact of particulate matter (PM2.5 and PM10) exposure on mental health, showed an increased risk of depression or psychotic relapses through the inflammation and oxidative stress pathways, or through the alteration of the hypothalamic-pituitary-adrenal (HPA) axis. Animal models showed the potential impact of pollution on brain functioning through increased inflammatory responses, oxidative stress, HPA axis disruption, hippocampal damage, and neurotransmitters dysregulation. Our findings show that environmental pollutants have an impact on human mental health through different biological pathways. The biological mechanisms by which environmental pollution and climate change influence the onset and exacerbation of severe mental disorders are complex and include gene expression, inflammation, oxidative stress, and anatomical brain changes. A better understanding of those pathways is important for the progress of knowledge on the pathophysiology of severe mental disorders according to the one health model, that promotes a collaborative, multisectoral, and transdisciplinary approach across various levels to optimize health outcomes by recognizing the interconnectedness of humans, animals, plants, and their shared environment.

Ascorbic acid supplementation in adolescent rats ameliorates anxiety-like and depressive-like manifestations of nicotine-ethanol abstinence: Role of oxidative stress, inflammatory, and serotonergic mechanisms

BACKGROUND

The present study aims to assess the therapeutic potential of vitamin C (Vit C) on anxiety- and depressive-like behavior induced by abstinence from chronic nicotine-ethanol co-exposure in adolescent male rats.

MATERIALS AND METHODS

Adolescent male rats were divided into seven experimental groups with ten rats as follows: 1) vehicle, 2) Nicotine (Nic)-Ethanol (Eth): received Nic (2 mg/kg) and Eth (20%) in drinking water from 21 to 42 days of age, 3-5) Nic-Eth-Vit C 100/200/400: received Nic and Eth from 21 to 42 days of age and received Vit C 100/200/400 mg/kg from 43 to 63 days of age, 6) Nic-Eth-Bupropion (Bup)- Naloxone (Nal): received Nic and Eth from 21 to 42 days of age and received Bup and Nal from 43 to 63 days of age, and 7) Vit C 400 mg/kg: received Vit C 400 mg/kg from 43 to 63 days of age. Behavioral assessments were done by elevated plus maze (EPM), forced swimming test (FST), marble burring test (MBT), and open field tests (OFT). Furthermore, specific biochemical variables associated with oxidative, inflammatory, and serotonergic profiles were quantified.

RESULTS

According to the obtained results, Nic and Eth induced anxiety and depression in treated rats. We showed that two higher doses of Vit C increases the active struggling time in FST and decreases both the time spent in the peripheral zone of OFT and the time spent in the closed arms of EPM. In addition, animals treated by Vit C buried less number of marbles in MBT compared to their control counterparts. Nic and Eth induced oxidative stress and inflammation in cortical tissues of treated rats. Biochemical parameters were improved in the Nic-Eth group receiving Vit C 200/400 mg/kg and Bup-Nal through establishing a balance between oxidant/anti-oxidant and inflammatory/anti-inflammatory mediators. In addition, serotonin level was increased, while Monoamine oxidase (MAO) activity was notably decreased.

CONCLUSION

The present findings support the beneficial effect of Vit C on anxiety- and depressive-like behavior induced by Nic-Eth withdrawal through various mechanisms such as the promotion of antioxidant defense, suppression of inflammatory mediators, and enhancement of serotoninergic function.

Progress in the application of novel inflammatory indicators in chronic kidney disease

Chronic kidney disease has become a public health problem endangering the health of all humans because of its high prevalence, high mortality and high medical burden. The chronic micro-inflammatory state is recognized as a significant component of CKD, playing a key role in disease progression. Intervening in chronic inflammation during the disease course can enhance prognosis. Recent studies have demonstrated that novel inflammatory indices, such as the neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and systemic immune-inflammatory index are closely associated with CKD, meanwhile may serve as prognostic monitors of all-cause death and poor renal prognosis for the disease. This article comprehensively reports on the mechanisms of micro-inflammation in CKD, the relationship between inflammatory indicators and CKD, and their impact on prognosis.

Nobiletin-rich kososan, a Kampo formula, prevents the onset of apathy-like behavior and neuroinflammation in sickness behavior mouse model induced by increasing doses of lipopolysaccharide

Infectious diseases are often concomitant with symptoms of lassitude and emotional disturbances, including depression, the so-called sickness behavior. Kososan, a Kampo (traditional Japanese herbal) formula, has been clinically used for depressive mood, with demonstrated efficacy in stress-induced depressive-like behavior mouse models. Additionally, our previous study has shown that nobiletin-rich kososan (NKS) prevents aging-related depressive-like behaviors and neuroinflammation in mice. Here, we examined whether NKS alleviates depressive-like behavior and neuroinflammation in a mouse model of sickness behavior induced by lipopolysaccharide (LPS). Repeated oral administration of NKS and the positive control antidepressant paroxetine (Paro) significantly prevented this behavior. NKS and Paro significantly increased the anti-inflammatory milieu in the hippocampus and prefrontal cortex (PFC), as well as brain microglia, of LPS-injected mice. The expression of the vascular tight junction protein claudin-5 was also significantly increased by the treatment with NKS, but not with Paro, in the hippocampus and PFC of LPS-injected mice. In vitro analysis using brain microvascular endothelial cells (BMVECs) showed that incubation with 5% serum derived from mice orally administered NKS resulted in a significant increase in the expression of anti-inflammatory heme oxygenase 1 as well as autophagic flux markers. Moreover, the claudin-5 levels in BMVECs were also increased under LPS-stimulated conditions. These results suggest that NKS exerts prophylactic effects against the LPS-induced apathy-like behavior, partly mediated by the increase in the anti-inflammatory milieu and in the levels of tight junction proteins in the brain. This study provides scientific evidence supporting the potential efficacy of NKS in preventing post-infection depression.

Application of functional near-infrared spectroscopy and machine learning to predict treatment response after six months in major depressive disorder

Depression treatment responses vary widely among individuals. Identifying objective biomarkers with predictive accuracy for therapeutic outcomes can enhance treatment efficiency and avoid ineffective therapies. This study investigates whether functional near-infrared spectroscopy (fNIRS) and clinical assessment information can predict treatment response in major depressive disorder (MDD) through machine-learning techniques. Seventy patients with MDD were included in this 6-month longitudinal study, with the primary treatment outcome measured by changes in the Hamilton Depression Rating Scale (HAM-D) scores. fNIRS and clinical information were strictly evaluated using nested cross-validation to predict responders and non-responders based on machine-learning models, including support vector machine, random forest, XGBoost, discriminant analysis, Naïve Bayes, and transformers. The task change of total haemoglobin (HbT), defined as the difference between pre-task and post-task average HbT concentrations, in the dorsolateral prefrontal cortex (dlPFC) is significantly correlated with treatment response (p < 0.005). Leveraging a Naïve Bayes model, inner cross-validation performance (bAcc = 70% [SD = 4], AUC = 0.77 [SD = 0.04]) and outer cross-validation results (bAcc = 73% [SD = 3], AUC = 0.77 [SD = 0.02]) were yielded for predicting response using solely fNIRS data. The bimodal model combining fNIRS and clinical data showed inferior performance in outer cross-validation (bAcc = 68%, AUC = 0.70) compared to the fNIRS-only model. Collectively, fNIRS holds potential as a scalable neuroimaging modality for predicting treatment response in MDD.

Relationships between clinical symptoms, cognitive functioning, and TMS-evoked potential features in patients with major depressive disorder

BACKGROUND

Cognitive impairment is a common clinical symptom of patients with major depressive disorder (MDD). Transcranial magnetic stimulation-evoked potentials (TEPs) detect cortical excitability and connectivity and provide potential biomarkers for MDD patients and their cognitive impairment. This study aimed to investigate the interrelationships between clinical symptoms, cognitive function, and electrophysiological marker TEPs in patients with MDD.

METHODS

A total of 117 participants were recruited, including 59 MDD patients and 58 healthy controls. Clinical symptoms were assessed by the Hamilton Depression Rating Scale and Hamilton Anxiety Rating Scale, and cognitive functioning was assessed by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). TEPs were recorded by transcranial magnetic stimulation combined with electroencephalography (TMS-EEG).

RESULTS

MDD patients exhibited lower RBANS total (P < 0.001), immediate memory (P = 0.001), language (P = 0.003), attention (P < 0.001), and delayed memory (P = 0.008) scores than HCs. Patients with MDD had larger amplitudes for N100 (P = 0.040) and N280 (P = 0.037), compared to HCs. Correlation analysis indicated significant correlations between the following RBANS scores and TEPs: language and N45 amplitude (r = 0.222, P = 0.024), language and P60 amplitude (r = 0.278, P = 0.004), attention and P180 amplitude (r = 0.213, P = 0.030), RBANS total score and P30 amplitude (r = 0.198, P = 0.044), visuospatial/constructional index and N100 amplitude (r = -0.272, P = 0.005).

CONCLUSION

The results of this study indicate that cortical dysfunction and cognitive impairment are present in patients with MDD and that there is a strong correlation between them, suggesting that TEPs detected by the TMS-EEG may be used as a biomarker for MDD patients and their cognitive impairment.

Neohesperidin Improves Depressive-Like Behavior Induced by Chronic Unpredictable Mild Stress in Mice

Depression is a common and complex neuropsychiatric disorder affecting people of all ages worldwide, associated with high rates of relapse and disability. Neohesperidin (NEO) is a dietary flavonoid with applications in therapeutics; however, its effects on depressive-like behavior remain unknown. Here, we evaluated the effects of NEO on depressive-like behavior induced by chronic and unpredictable mild stress (CUMS). NEO (25, 50, and 100 mg kg-1) treatment for two weeks dose-dependently improved CUMS-induced depressive-like behavior measured by the sucrose preference, open field, forced swimming, and tail suspension tests. Moreover, NEO effectively blocked the decrease of superoxide dismutase, catalase, and glutathione peroxidase activity and the increase of malondialdehyde levels, which are markers of oxidative stress. In addition, NEO inhibited microglial activation and the production of proinflammatory cytokines interleukin-1β (IL-1β), IL-6 and tumor necrosis factor α (TNF-α) in the hippocampus and prefrontal cortex. Molecular docking and dynamic simulations showed that NEO has good affinity for NOD-like receptor protein 3 (NLRP3), suggesting that NEO may play an antidepressant role by regulating the NLRP3 signaling pathway. Western blotting results further revealed that the increased expression level of NLRP3 inflammasome components (NLRP3, caspase-1, and ASC) in CUMS mice was significantly reversed by NEO treatment. These results suggest that NEO is a candidate for treating depression and should be considered for further clinical development.

Compassionate use of esketamine intranasal in patients with severe major depressive disorder resistant to the treatment

BACKGROUND

Treatment-resistant depression (TRD) is defined as the failure of at least two antidepressants in adequate doses and timing during a major depressive episode. Esketamine intranasal (ESK-IN) has been approved by the Food and Drug Administration and the European Medicines Agency for the treatment of TRD in combination with other antidepressants.

AIMS

To assess the effectiveness and tolerability of a sample of TRD patients who received treatment with ESK-IN as part of the compassionate use program.

METHODS

A retrospective, observational study was carried out on patients with a diagnosis of TRD enrolled in the early access program of ESK-IN in nine centers. Effectiveness was assessed with the Montgomery-Asberg depression rating scale (MADRS) at four time points: baseline, 28, 90, and 180 days of treatment.

RESULTS

The sample included 71 patients (70% women) with a mean baseline MADRS score of 38.27 ± 5.9 and total or partial work disability rates of 85%. ESK-IN treatment was associated with a statistically and clinically significant reduction in the severity of depressive symptoms at all time points assessed. The presence of side effects was common but the majority were mild in severity and resolved after the observation period. Those patients who received psychotherapy in combination with ESK-IN showed a significantly lower MADRS score at 90 and 180 days than those patients who did not undergo psychotherapy.

CONCLUSION

ESK-IN has proven to be effective and safe in a clinical sample of patients with severe TRD. To optimize clinical outcomes, the pharmacological treatment for TRD should always be integrated into a comprehensive therapeutic plan that encompasses strategies such as psychotherapy, social support, and family interventions.

The effect of exercise on depression and gut microbiota: Possible mechanisms

Exercise can effectively prevent and treat depression and anxiety, with gut microbiota playing a crucial role in this process. Studies have shown that exercise can influence the diversity and composition of gut microbiota, which in turn affects depression through immune, endocrine, and neural pathways in the gut-brain axis. The effectiveness of exercise varies based on its type, intensity, and duration, largely due to the different changes in gut microbiota. This article summarizes the possible mechanisms by which exercise affects gut microbiota and how gut microbiota influences depression. Additionally, we reviewed literature on the effects of exercise on depression at different intensities, types, and durations to provide a reference for future exercise-based therapies for depression.

The differences in symptom networks of depression, anxiety, and sleep in college students with different stress levels

BACKGROUND

Stress is closely related to depression, anxiety, and sleep problems. However, few studies have explored the complex symptom-level relationships among these variables at different stress levels among college students.

METHODS

From March to April 2024, a survey was conducted using a convenience sampling method in three universities in Daqing City, Heilongjiang Province. A total of 7,845 participants (2,447 males and 5,398 females) were assessed using the Psychological Stress Tolerance Index (PSTR), the General Health Questionnaire-20 (GHQ-20), and the Self-Rating Scale of Sleep (SRSS). Based on the GHQ-20 scores, college students were categorized into low, medium, and high-stress levels. Non-parametric tests and Post-hoc tests were conducted to explore the impact of stress levels on depression, anxiety, and sleep. Network analysis methods were used to reveal the differences in the symptom networks of depression, anxiety, and sleep among college students at different stress levels.

RESULTS

Non-parametric test results indicate significant differences in depression, anxiety, and sleep scores among high, medium, and low-stress groups. Post-hoc tests reveal that the high-stress group scores significantly higher in depression, anxiety, and sleep than the medium and low-stress groups. The medium-stress group scored significantly higher than the low-stress group. Network analysis shows that the core symptoms in the low-stress group are "Difficulty falling asleep", "Anxious and restless", and "Taking sleeping pills", with bridging symptoms including "Hopeless future", "Feeling useless", "Life is a battlefield", and "Anxious and restless". For the medium-stress group, the core symptoms are "Difficulty falling asleep", "Easily awakened after sleeping", and "Life is hopeless", with bridging symptoms including "Feeling useless", "Life is a battlefield", "Anxious and restless", and "Taking sleeping pills". In the high-stress group, the core symptoms are "Difficulty falling asleep", "Feeling useless", and "Anxious and resless", with bridging symptoms including "Feeling useless", "Life is a battlefield", "Anxious and restless", and "Stress hinders tasks".

CONCLUSION

Stress exacerbates depression, anxiety, and sleep problems among college students, with differences in core symptoms and bridging symptoms of depression, anxiety, and sleep disturbances at varying levels of stress. Therefore, precise interventions can be implemented based on the core and bridge symptoms of the three networks, further improving university students' physical and mental health.

Bilateral oophorectomy amplifies depression risk following hysterectomy NHANES 2006-2017

This study aims to evaluate the association between hysterectomy with bilateral salpingo-oophorectomy (HBSO) and depressive symptoms, exploring the impact of different surgical approaches on the severity of depression. Data from the 2006-2017 National Health and Nutrition Examination Survey (NHANES) were used to analyze the relationship between surgical methods and depressive symptoms.This study analyzed data from 10,780 women aged 20-80 years, with a diverse racial composition: 44.2% non-Hispanic White, 20.4% non-Hispanic Black, 14.7% Mexican American, 11.0% Other Hispanic, and 9.7% Other Race.The Patient Health Questionnaire-9 (PHQ-9), a validated depression screening tool, was utilized to assess depressive symptoms. Multivariable linear regression and binary logistic regression analyses were conducted to evaluate the association between surgical approaches and depressive symptoms, with results presented as odds ratios (OR) and their 95% confidence intervals (CI). Subgroup analyses employed stratified regression models to investigate interactions between baseline characteristics and surgical methods. Demographic analysis showed differences in age, marital status, education, income, smoking, BMI, and chronic disease prevalence between the depressive and non-depressive groups. HBSO was significantly associated with higher PHQ-9 scores and a higher likelihood of significant depressive symptoms (PHQ-9 ≥ 10). Hysterectomy was also associated with depressive symptoms, but to a lesser extent. Further analysis revealed that hysterectomy was significantly associated with higher depressive scores, particularly in the PHQ-9 ≥ 20 group. Subgroup analysis indicated significant interaction effects between surgical types and factors such as BMI, Income-to-Poverty Ratio (IPR), smoking, and alcohol consumption. The findings suggest a significant association between hysterectomy, particularly HBSO, and the severity of depressive symptoms. Lifestyle and behavioral factors, such as BMI, smoking, and alcohol consumption, significantly influence the occurrence of postoperative depression. Thorough evaluation of patients' psychological health and related factors is essential when considering gynecological surgery.

Research on the correlation between inflammatory bowel disease and depression: A bibliometric analysis

BACKGROUND

The aim of this study was to conduct a bibliometric analysis of published studies on the relationship between inflammatory bowel disease (IBD) and depression. The study also aims to identify the major researchers, institutions, and countries and regions in this field to identify current research hotspots.

METHODS

The Web of Science Core Database in the Science Citation Index Expanded database was selected as the data source and was searched to obtain relevant literature on IBD and depression. Bibliometric analysis of relevant publications was performed by utilizing VOSviewer, CiteSpace, bibliometrix, and Microsoft Excel 2019.

RESULTS

A total of 393 papers were included from January 1, 2014, to December 25, 2023, showing a general upward trend in the number of publications. There were 48 countries and 743 institutions, of which the United States had the largest number of publications. There were 2250 authors involved in research in the field, with clear collaborations between authors. There were currently 163 journals that have published research on this topic, with IBDs being the most cited journal. IBD and depression-related studies are gradually gaining attention from researchers, and the research direction is gradually expanding to epidemiology, gut microbiota, and other related topics.

CONCLUSION

This study comprehensively summarizes the research trends and developments of IBD and depression through bibliometrics. This information points out the research frontiers and hot directions in recent years, which will serve as a reference for researchers in this field.

Assessment of IL-8, RANTES, MIG, MCP-1, IP-10, and IL-12p70 and Their Association with Anxiety and Quality of Life in Patients with Chronic Kidney Disease or After Kidney Transplantation

Anxiety is a subjective feeling of fear in response to stressful or threatening situations. Chronic diseases (such as chronic kidney disease) or the state after kidney transplantation are such situations and they may result in a decreased quality of life. The main aim of this research was to evaluate if the proteins IL-8, RANTES, MIG, MCP-1, IP-10, and IL-12p70 could be indicators of higher levels of anxiety or decreased quality of life in chronically ill women. The assessment was conducted using the STAI and SF-36 questionnaires and with the measurement of listed proteins from the patient's blood sample. The study group consisted of 107 women-101 patients from the Nephrological Clinic and 6 from the Dialysis Center. Both of the facilities are part of University Clinical Hospital No. 2 in Szczecin. Statistical analysis was performed using JASP software (JASP 0.18.3 version). Anxiety levels and quality of life correlations between STAI and SF-36 scores and individual variables were assessed. Logistic regression models were performed for both questionnaire outcomes: SF-36 and STAI. Lower quality of life was found in the group with a higher IL-8 concentration compared to the group of women with a lower IL-8 concentration. A positive weak correlation was found between a decreased quality of life and IL-8 and RANTES. A higher RANTES level increases the odds of a lower quality of life. This study shows that special care should be provided for chronically ill women (especially with CKD or after KTx) with a higher RANTES or IL-8 concentration. They would highly benefit from close monitoring of their mental health.

Retrospective evaluation of novel serum inflammatory biomarkers in first-episode psychiatric disorders: diagnostic potential and immune dysregulation

Background

This study assessed the diagnostic capabilities of eight inflammatory biomarkers in first-episode schizophrenia (SCZ), bipolar disorder (BD), and depression (D), examining their differential expression across these psychiatric disorders. The markers studied include neutrophils/lymphocyte ratio (NLR), aggregate index of systemic inflammation (AISI), systemic immune-inflammation index (SII), systemic inflammation response index (SIRI), lymphocytes/high-density lipoprotein (HDL) ratio (LHR), monocytes/HDL ratio (MHR), neutrophils/HDL ratio (NHR), and platelets/HDL ratio (PHR).

Methods

We conducted a retrospective observational study involving 335 individuals with SCZ, 68 with BD, 202 with D, and 282 healthy controls (C) to evaluate hematologic parameters from untreated patients and controls.

Results

Significant differences in biomarker levels were found between patient groups and controls. Logistic regression analysis indicated that NHR and MHR (p < 0.001), as well as LHR and NLR (p < 0.01), were predictive factors for SCZ. MHR was a predictive factor for BD (p < 0.05). NHR (p < 0.01) and MHR (p < 0.001) were predictive factors for distinguishing between D and C. The area under the curve (AUC) value of the NHR + MHR + NLR composite index model for the SCZ group was 0.846 (p < 0.001). In the BD group, the AUC value for the MHR was 0.816 (p < 0.001). The D group's combined AUC value of NHR + MHR was 0.824 (p < 0.001).

Conclusion

This study highlights the diagnostic value of inflammatory biomarkers in distinguishing SCZ, BD, and D based on their differential expression.

Understanding genetic variants in context

Over the last three decades, human genetics has gone from dissecting high-penetrance Mendelian diseases to discovering the vast and complex genetic etiology of common human diseases. In tackling this complexity, scientists have discovered the importance of numerous genetic processes - most notably functional regulatory elements - in the development and progression of these diseases. Simultaneously, scientists have increasingly used multiplex assays of variant effect to systematically phenotype the cellular consequences of millions of genetic variants. In this article, we argue that the context of genetic variants - at all scales, from other genetic variants and gene regulation to cell biology to organismal environment - are critical components of how we can employ genomics to interpret these variants, and ultimately treat these diseases. We describe approaches to extend existing experimental assays and computational approaches to examine and quantify the importance of this context, including through causal analytic approaches. Having a unified understanding of the molecular, physiological, and environmental processes governing the interpretation of genetic variants is sorely needed for the field, and this perspective argues for feasible approaches by which the combined interpretation of cellular, animal, and epidemiological data can yield that knowledge.

Genetic-epigenetic-neuropeptide associations in mood and anxiety disorders: Toward personalized medicine

Mood and anxiety disorders are complex psychiatric conditions shaped by the multifactorial interplay of genetic, epigenetic, and neuropeptide factors. This review aims to elucidate the intricate interactions among these factors and their potential in advancing personalized medicine. We examine the genetic underpinnings, emphasizing key heritability studies and specific gene associations. The role of epigenetics is discussed, focusing on how environmental factors can modify gene expression and contribute to these disorders. Neuropeptides, including substance P, CRF, AVP, NPY, galanin, and kisspeptin, are evaluated for their involvement in mood regulation and their potential as therapeutic targets. Additionally, we address the emerging role of the gut microbiome in modulating neuropeptide activity and its connection to mood disorders. This review integrates findings from genetic, epigenetic, and neuropeptide research, offering a comprehensive overview of their collective impact on mood and anxiety disorders. By highlighting novel insights and potential clinical applications, we underscore the importance of a multi-omics approach in developing personalized treatment strategies. Future research directions are proposed to address existing knowledge gaps and translate these findings into clinical practice. Our review provides a fresh perspective on the pathophysiology of mood and anxiety disorders, paving the way for more effective and individualized therapies.

Feasibility of Using Serum, Plasma, and Platelet 5-hydroxytryptamine as Peripheral Biomarker for the Depression Diagnosis and Response Evaluation to Antidepressants: Animal Experimental Study

Objective

Whether peripheral blood 5-hydroxytrptamine (5-HT) levels serve as biomarker for depression diagnosis/response evaluation has not been well determined. This work was explored to address this inconclusive issue.

Methods

Animals were randomized into normal control group (NC, n = 10) and chronic unpredictable mild stress model group (CUMS-model, n = 20), respectively. Animals in CUMS-model group were subjected to chronic stress, then they were randomly subdivided into CUMS subgroup and CUMS + fluoxetine subgroup (CUMS + FLX). After FLX treatment, blood and tissues were collected. 5-HT and relevant protein expression were measured.

Results

In mice model, there was a significant increase in serum and a significant reduction in plasma 5-HT levels in CUMS-model group versus NC group, while platelet 5-HT levels change little. After FLX treatment, serum and platelet 5-HT levels were significantly decreased in CUMS + FLX subgroup, while plasma 5-HT levels had not much change versus CUMS subgroup. Chronic stress enhanced colon and platelet serotonin transporter (SERT) expression and FLX treatment mitigated SERT expression. In rats' model, there was a significant increase in serum 5-HT levels while plasma and platelet 5-HT levels showed little change in CUMS group versus NC group. After FLX treatment, serum, plasma and platelet 5-HT levels were significantly decreased in CUMS + FLX subgroup versus CUMS subgroup. The profile of relevant proteins expression changed by FLX were like those in mice.

Conclusion

Serum 5-HT levels might serve as a potential biomarker for depression diagnosis, meanwhile serum and platelet 5-HT levels might respond to antidepressant treatment.

'The effect of neuropeptide Y1 receptor agonist on hypothalamic neurogenesis in rat experimental depression model'

Depression is responsible for neuropathies such as decreased neurogenesis and increased dendritic atrophy. There is information that antidepressant treatments have an effect by increasing hippocampal neurogenesis and neurotrophic factor expression. The neuropeptide Y1 (NPY1R) receptor agonist has been suggested to have anxiolytic effects. Based on this information, it was aimed to investigate the effect of NPY1R agonist on depression in rats with depression using the CMS model and to determine how depression affects cell proliferation in the hypothalamus and hypothalamic peptide levels. Forty-eight adult, male Wistar albino rats were divided into groups as Control, Depression (D), Depression + NPY1R and NPY1R. Various stressors were applied to D for 30 days. An open field test (OFT) and forced swim test (FST) were performed to check whether the animals were depressed. On the 16th day, an osmotic mini pump was placed under the skin and NPY1R (130 ul/kg/day) was applied for 15 days. Behavioral tests were performed, hypothalamic peptide gene expression levels were analyzed by quantitative RT-PCR and statistical evaluations were made using ANOVA. A decrease in the percentage of movement in the D and control groups were noted in the OFT, an increase in the immobility time in the D group in the FST, and an increase in swimming behavior in the DNPY1R group. The animals did not display any anxiety behavior based on the elevated plus maze test results. It caused a decrease in IGF1R, FGF2, POMC, NPY and GLUT2 gene expression in the hypothalamus of depression group animals, and an increase in NPY gene expression in NPY1R treatment. This study compellingly demonstrated that exposure to chronic mild stress simultaneously downregulates gene expression in the hypothalamus; we observed that NPY receptor NPY1R treatment increased the effect of NPY. Therefore, adjunctive treatments with appropriate molecules such as NPY, Y1 receptor agonists or pharmacological derivatives may have significant potential in the treatment of depression.

Toward molecular diagnosis of major depressive disorder by plasma peptides using a deep learning approach

Major depressive disorder (MDD) is a severe psychiatric disorder that currently lacks any objective diagnostic markers. Here, we develop a deep learning approach to discover the mass spectrometric features that can discriminate MDD patients from health controls. Using plasma peptides, the neural network, termed as CMS-Net, can perform diagnosis and prediction with an accuracy of 0.9441. The sensitivity and specificity reached 0.9352 and 0.9517 respectively, and the area under the curve was enhanced to 0.9634. Using the gradient-based feature importance method to interpret crucial features, we identify 28 differential peptide sequences from 14 precursor proteins (e.g. hemoglobin, immunoglobulin, albumin, etc.). This work highlights the possibility of molecular diagnosis of MDD with the aid of chemical and computer science.

A cross-section study of the comparison of plasma inflammatory cytokines and short-chain fatty acid in patients with depression and schizophrenia

BACKGROUND

Major depressive disorder (MDD) and schizophrenia (SCH) are common and severe mental disorders that are mainly diagnosed depending on the subjective identification by psychiatrists. Finding potential objective biomarkers that can distinguish these two diseases is still meaningful.

METHODS

In the present study, we investigate the differences in plasma inflammatory cytokines and short-chain fatty acids (SCFAs) among patients with MDD (n = 24) and SCH (n = 24), and gender- and age-matched healthy controls (HC, n = 27) and identify potential plasma biomarkers.

RESULTS

We found that the concentrations of pro-inflammatory cytokines were increased, whereas the anti-inflammatory cytokines were decreased in both MDD and SCH. Meanwhile, except for an increase in 4-Methylvaleric acid, other SCFAs with statistical differences were reduced in both MDD and SCH. Moreover, potential biomarker panels were developed that can effectively discriminate MDD from HC (AUC = 0.997), SCH from HC (AUC = 0.999), and from each other (MDD from SCH, AUC = 0.983).

CONCLUSIONS

These data suggest that alterations in plasma cytokines and SCFAs might be one of the potential features for distinguishing MDD and SCH.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR2100051243, registration date: 2021/09/16.

The links between neuroinflammation, brain structure and depressive disorder: A cross-sectional study protocol

INTRODUCTION

It is known that symptoms of major depressive disorder (MDD) are associated with neurodegeneration, that lipopolysaccharide (LPS) can induce symptoms of MDD, and that blood LPS levels are elevated in neurodegeneration. However, it is not known whether blood LPS and cytokine levels correlate with MDD, cognition and brain structure, and this is tested in this study.

METHODS AND ANALYSIS

This cross-sectional study includes individuals with MDD (n = 100) and a control group of individuals with no one-year history of a mental disorder (n = 50). A comprehensive evaluation is performed, including the collection of basic sociodemographic information, data on smoking status, body mass index, course of MDD, past treatment, comorbid diseases, and current use of medications. Diagnosis of MDD is performed according to the WHO's [2019] International Classification of Diseases and related health problems by psychiatrist and severity of MDD is evaluated using the Montgomery-Åsberg Depression Scale. The Cambridge Neuropsychological Test Automated Battery is used to evaluate cognitive functioning. Venous blood samples are taken to measure genetic and inflammatory markers, and multiparametric brain magnetic resonance imaging is performed to evaluate for blood-brain barrier permeability, structural and neurometabolic brain changes. Descriptive and inferential statistics, including linear and logistic regression, will be used to analyse relationships between blood plasma LPS and inflammatory cytokine concentrations in MDD patients and controls. The proposed sample sizes are suitable for identifying significant differences between the groups, according to a power analysis.

ADMINISTRATIVE INFORMATION

Trial registration: Clinicaltrials.gov NCT06203015.

Mechanistic insights regarding neuropsychiatric and neuropathologic impacts of air pollution

Air pollution is a significant environmental health risk for urban areas and developing countries. Air pollution may contribute to the incidence of cardiopulmonary and metabolic diseases. Evidence also points to the role of air pollution in worsening or developing neurological and neuropsychiatric conditions. Inhaled pollutants include compositionally differing mixtures of respirable gaseous and particulate components of varied sizes, solubilities, and chemistry. Inhalation of combustibles and volatile organic compounds (VOCs) or other irritant particulate matter (PM) may trigger lung sensory afferents which initiate a sympathetic stress response via activation of the hypothalamic-pituitary-adrenal (HPA) and sympathetic-adrenal-medullary (SAM) axes. Activation of SAM and HPA axes are associated with selective inhibition of hypothalamic-pituitary-gonadal (HPG) and hypothalamic-pituitary-thyroid (HPT) axes following exposure. Regarding chronic exposure in susceptible hosts, these changes may become pathological by causing neuroinflammation, neurotransmitter, and neuroendocrine imbalances. Soluble PM, such as metals and nano-size particles may translocate across the olfactory, trigeminal, or vagal nerves through retrograde axonal transport, or through systemic circulation which may disrupt the blood-brain barrier (BBB) and deposit in neural tissue. Neuronal deposition of metallic components can have a negative impact through multiple molecular mechanisms. In addition to systemic translocation, the release of pituitary and stress hormones, altered metabolic hormonal status and resultant circulating metabolic milieu, and sympathetically and HPA-mediated changes in immune markers, may secondarily impact the brain through a variety of regulatory adrenal hormone-dependent mechanisms. Several reviews covering air pollution as a risk factor for neuropsychiatric disorders have been published, but no reviews discuss the in-depth intersection between molecular and stress-related neuroendocrine mechanisms, thereby addressing adaptation and susceptibility variations and link to peripheral tissue effects. The purpose of this review is to discuss evidence regarding neurochemical, neuroendocrine, and molecular mechanisms which may contribute to neuropathology from air pollution exposure. This review also covers bi-directional neural and systemic interactions which may raise the risk for air pollution-related systemic illness.

Microbiota-gut-brain axis: Natural antidepressants molecular mechanism

BACKGROUND

Major depressive disorder (MDD) is a severe mental health condition characterized by persistent depression, impaired cognition, and reduced activity. Increasing evidence suggests that gut microbiota (GM) imbalance is closely linked to the emergence and advancement of MDD, highlighting the potential significance of regulating the "Microbiota-Gut-Brain" (MGB) axis to impact the development of MDD. Natural products (NPs), characterized by broad biological activities, low toxicity, and multi-target characteristics, offer unique advantages in antidepressant treatment by regulating MGB axis.

PURPOSE

This review was aimed to explore the intricate relationship between the GM and the brain, as well as host responses, and investigated the mechanisms underlying the MGB axis in MDD development. It also explored the pharmacological mechanisms by which NPs modulate MGB axis to exert antidepressant effects and addressed current research limitations. Additionally, it proposed new strategies for future preclinical and clinical applications in the MDD domain.

METHODS

To study the effects and mechanism by which NPs exert antidepressant effects through mediating the MGB axis, data were collected from Web of Science, PubMed, ScienceDirect from initial establishment to March 2024. NPs were classified and summarized by their mechanisms of action.

RESULTS

NPs, such as flavonoids,alkaloids,polysaccharides,saponins, terpenoids, can treat MDD by regulating the MGB axis. Its mechanism includes balancing GM, regulating metabolites and neurotransmitters such as SCAFs, 5-HT, BDNF, inhibiting neuroinflammation, improving neural plasticity, and increasing neurogenesis.

CONCLUSIONS

NPs display good antidepressant effects, and have potential value for clinical application in the prevention and treatment of MDD by regulating the MGB axis. However, in-depth study of the mechanisms by which antidepressant medications affect MGB axis will also require considerable effort in clinical and preclinical research, which is essential for the development of effective antidepressant treatments.

Predictive Value of Inflammatory Biomarkers in Assessing Major Depression in Adults

Background: There are studies that have investigated the association of pro-inflammatory cytokines with depressive disorders, but they often present certain limitations. In this study, two substantial groups of patients were analyzed: 92 patients with major depressive disorder and 76 without depressive disorders. The strict inclusion and exclusion criteria for the analyzed groups significantly increased the value of the obtained results. The research question of this study was whether levels of inflammation, measured by the inflammatory markers IL-6, IL-1α, and TNF-α, could predict the severity of depressive symptoms. This could provide additional evidence supporting the hypothesis that inflammation plays a notable role in the pathogenesis of depression. The data analysis supports the hypothesis that the biological mechanisms of inflammation contribute to the clinical manifestations of depression. Elevated levels of inflammatory markers, especially interleukins (IL-6, IL-1α) and tumor necrosis factor-alpha (TNF α), have been identified in patients with major depressive disorder compared to the findings in healthy controls. Materials and Methods: Inflammatory markers (IL-6, IL-1α, and TNF-α) were measured in a sample of 92 patients hospitalized at the Socola Institute of Psychiatry in Iasi, Romania, and compared to a control group with no depression or inflammatory conditions (n = 76). Severity of depressive symptoms was assessed using HAM-D scores. Results: The study results indicated that values of plasma inflammatory markers were significantly higher in patients with major depressive disorder (MDD) compared to the control group (IL-1α: 1.16 ± 0.44 pg/mL vs. 0.89 ± 0.25 pg/mL, p = 0.0004; IL-6: 9.21 ± 4.82 pg/mL vs. 7.16 ± 4.32 pg/mL, p = 0.0149; and TNF-α: 2.02 ± 0.96 pg/mL vs. 1.67 ± 0.8 pg/mL, p = 0.0286). The differences remained significant after applying logarithmic transformation, which was necessary to adjust for outlier values. An analysis of demographic characteristics showed that the frequency of women (67.4% vs. 36.84%, p < 0.001), cohabiting individuals (28.26% vs. 10.53%, p = 0.0001), and alcohol consumers (67.39% vs. 47.37%, p = 0.0087) was significantly higher in patients with MDD. The level of education was significantly lower in patients with MDD (median (IQR): 12 (2.5) years vs. 14 (8) years, p = 0.0016). The evaluation of confounding variables, including patients' gender, marital status, education level, and alcohol consumption, was performed using multiple linear regression models. The results indicated that these demographic variables did not significantly influence the correlation between the HAM-D score and the values of IL-6, IL-1α, and TNF-α. A significant correlation between the HAM-D score and the logarithmic values of inflammatory markers was observed for log IL-1α in men (r = 0.355, p = 0.0014), log IL-6 in women (r = 0.0313, p = 0.0027), and log TNF-α in women (r = 0.3922, p = 0.0001). The results of the multiple linear regression and predictive analysis indicated that IL-1α (AUC = 0.677, p = 0.0004), IL-6 (AUC = 0.724, p < 0.001), and TNF-α (AUC = 0.861, p < 0.001) demonstrate high accuracy in discriminating patients with MDD. Conclusions: The results highlighted that IL-6 (AUC = 0.724; 95% CI: 0.648-0.801) and TNF-α (AUC = 0.861; 95% CI: 0.797-0.925) are significant predictors for major depressive disorder. The study highlights the potential of cytokines (IL-1α, IL-6 and TNF-α) as diagnostic markers. These findings support the hypothesis that inflammation may play an important role in the development or exacerbation of depressive symptoms.

Serum L-selectin levels as predictive markers for chronic major depressive disorder progression

BACKGROUND

Major depressive disorder (MDD) exhibits a recurrence rate of up to 70%. Frequent recurrence can lead to chronic depression, which has considerable personal and societal consequences. This study aims to identify a serum protein biomarker to predict MDD recurrence and progression to chronicity.

METHODS

Serum samples from the MDD with single episode group (MDD-S), MDD with recurrence group (MDD-R), and a healthy control group were collected. Non-targeted analysis of the serum proteome was conducted using liquid chromatography-tandem mass spectrometry. Statistically significant common proteins when comparing the three groups were chosen. The selected marker candidates were subsequently validated through multiple response monitoring (MRM), incorporating a healthy control, MDD-S, MDD-R(2) (two episodes), and MDD-R(> 2) (more than two episodes) groups.

RESULTS

L-selectin levels showed an upward trend in the MDD-R group compared to the healthy control and MDD-S groups. MRM validation revealed a decreased tendency for L-selectin in the MDD-R(> 2) group, indicative of a chronic state, versus the healthy control and MDD-S groups. The receiver operating characteristic analysis highlighted L-selectin as the chosen biomarker due to its classification efficacy for the MDD-R(> 2) group.

CONCLUSION

L-selectin emerged as a predictive biomarker for MDD recurrence and its potential evolution into chronic depression. This marker offers insights into changes in leukocyte-mediated inflammatory responses characteristic of chronic depression. Consequently, it may forecast the transition from acute to chronic inflammation in depressive patients.

Serum TNFα and IL-17A levels may predict increased depressive symptoms: findings from the Shika Study cohort project in Japan

BACKGROUND

Low-grade systemic inflammation may be a key player in the immune activation that has been reported for mental health deterioration. We hypothesised that elevated serum levels of inflammatory cytokines increase neuroinflammation and exacerbate depressive symptoms.

METHODS

The participants were part of a cohort study for whom data was available for both 2015 and 2019. In 2015, blood samples were collected from 232 participants. Their depressive symptoms were assessed both 2015 and 2019 using the Centre for Epidemiologic Studies Depression Scale (CES-D) (n = 33). The multiplex immunoassay system (Luminex® 200) was used to measure the serum concentrations of IL-6, IL-10, IL-12, IL-17A and TNFα. Data were analysed using linear models with the level of significance considered to be p < 0.05.

RESULTS

After controlling for age, BMI, smoking and alcohol consumption, in 2015 the serum concentrations of IL-17A and TNFα in 2015 were significantly positively associated with the CES-D scores of women (standardised β (B) = .027, p < 0.01 and B = 0.26, p < 0.01, respectively). The serum concentrations of IL-17A and TNFα of men were significantly positively associated with the CES-D scores of 2019 (B = 0.62, p = 0.02 and B = 0.59, p = 0.02, respectively).

CONCLUSIONS

In this cross-sectional study, we found a significant positive correlation between the depressive symptoms and serum TNFα and IL-17A levels of women. In addition, our longitudinal findings suggest the possibility that TNFα and IL-17A could elevate the depressive symptoms of men.

Inflammatory biomarkers in depression: scoping review

BACKGROUND

Inflammation is increasingly recognised as a fundamental component of the pathophysiology of major depressive disorder (MDD), with a variety of inflammatory biomarkers playing pivotal roles. These markers are closely linked to both the severity of symptoms and the responsiveness to treatments in MDD.

AIMS

This scoping review aims to explore the scientific literature investigating the complex relationships between inflammatory biomarkers and depression, by identifying new studies and critical issues in current research.

METHOD

Following the PRISMA Extension for Scoping Reviews guidelines, we systematically searched databases including PubMed, Scopus, PsycINFO, Open Grey and Cochrane Library. Our search focused on articles published from 1 January 2020 to 1 May 2024. We included studies evaluating inflammatory biomarkers in adult patients with MDD, utilising observational and randomised controlled trial designs, and review studies.

RESULTS

Our analysis examined 44 studies on the complex interplay between inflammation and its multiple effects on MDD. Significant associations between specific inflammatory biomarkers and depression severity were found, requiring cautious interpretation. We also highlight several methodological limitations in the current studies, which warrant caution in directly applying these findings to clinical practice. However, identified methodologies show potential for using these biomarkers as diagnostic tools or therapeutic targets, including anti-inflammatory interventions.

CONCLUSIONS

The findings emphasise the need for sophisticated, integrative research to understand inflammation's role in MDD. Future studies should identify specific biomarker panels for diagnosing depression and bridging peripheral biomarker measurements with central neuroinflammatory processes, leading to better diagnostic and treatment strategies.

Depression and inflammation in COVID-19 patients during and after hospitalisation – a systematic review and meta-analysis

Introduction: The severity of depression symptoms in COVID-19 patients differs among populations investigated and changes over time. Increasing evidence supports the hypothesis about the involvement of inflammation in the development of depression. Methods: A systematic review and a meta-analysis of the cross-sectional and cohort studies published between 2019 and 2023 were conducted according to the PRISMA criteria. The outcomes of interest were the proportions of mild, moderate, and severe depression symptoms during and after hospitalisation, and associations between depression and inflammation in COVID-19 patients. Results: Thirty articles were included in the systematic review. In the quantitative meta-analysis, the overall proportions of moderate-to-severe and mild-to-severe depression were estimated at 0.21 (95% CI: 0.13–0.31) and 0.35 (95% CI: 0.23–0.48), respectively. The fixed effects model of the meta-analysis of inflammatory markers showed a difference between COVID-19 patients with and without depression, with higher concentrations of both C-reactive protein and neutrophil-lymphocyte ratio detected among people suffering mood disturbances. However, in random effects models, findings for C-reactive protein lost significance, and for neutrophil-lymphocyte ratio were on the boundary of significance (p = 0.053). Conclusions: According to the study results, the proportion of depression decreases over time after a COVID-19 diagnosis. The relationship between depression and inflammation is still uncertain and requires further research.

Integrating network pharmacology and bioinformatics to explore the mechanism of Xiaojian Zhongtang in treating major depressive disorder: An observational study

Major depressive disorder (MDD) is a common mental illness. The traditional Chinese medicine compound Xiaojian Zhongtang (XJZT) has a good therapeutic effect on MDD, but the specific mechanism is not clear. The aim of this study is to explore the molecular mechanism of XJZT in the treatment of MDD through network pharmacology and bioinformatics. The traditional Chinese medicine system pharmacology database was used to screen the chemical components and targets of XJZT, while the online Mendelian inheritance in man, DisGeNET, Genecards, and therapeutic target database databases were used to collect MDD targets and identify the intersection targets of XJZT and MDD. A "drugs-components-targets" network was constructed using the Cytoscape platform, and the STRING was used for protein-protein interaction analysis of intersecting targets. Gene Ontology and Kyoto encyclopedia of genes and genomes analysis of intersecting targets was performed using the DAVID database. Obtain serum and brain transcriptome datasets of MDD from the gene expression omnibus database, and perform differentially expressed genes, weighted gene co-expression network analysis, gene set enrichment analysis, and receiver operating characteristic analysis. A total of 127 chemical components and 767 targets were obtained from XJZT, among which quercetin, kaempferol, and maltose are the core chemical components, and 1728 MDD targets were screened out, with 77 intersecting targets between XJZT and MDD. These targets mainly involve AGE-RAGE signaling pathway in diabetic complexes, epidermal growth factor receptor tyrosine kinase inhibitor resistance, and HIF-1 signaling pathway, and these core targets have strong binding activity with core components. In addition, 1166 differentially expressed genes were identified in the MDD serum transcriptome dataset, and weighted gene co-expression network analysis identified the most relevant gene modules (1269 genes), among which RAC-alpha serine/threonine-protein kinase (AKT1), D(4) dopamine receptor (DRD4), and kynurenine 3-monooxygenase (KMO) were target genes for the treatment of MDD with XJZT, these 3 genes are mainly related to the ubiquitin-mediated proteolysis, arachidonic acid (AA) metabolism, and Huntington disease pathways, and the expression of AKT1, DRD4, and KMO was also found in the MDD brain transcriptome dataset, which is significantly correlated with the occurrence of MDD. We have identified 3 key targets for XJZT treatment of MDD, including AKT1, KMO, and DRD4, and they can be regulated by the key components of XJZT, including quercetin, maltose, and kaempferol. This provides valuable insights for the early clinical diagnosis and development of therapeutic drugs for MDD.

Etanercept ameliorates chronic mild stress-induced depressive-like behavior in rats: Crosstalk between MAPK and STAT3 pathways and norepinephrine and serotonin transporters

Depression is a serious medical illness characterized by persistent feelings of sadness, hopelessness, and lack of interest in daily activities. It can interfere with daily functioning and quality of life. Despite decades of research, the pathophysiology of depression remains incompletely understood. The correlation between depression and inflammation has recently attracted considerable attention. This study investigated the potential antidepressant effect of etanercept, a tumor necrosis factor-alpha (TNF-α) inhibitor, utilizing a chronic mild stress (CMS) model in rats. Male Wistar rats were divided into two groups; one following a non-stressed protocol and the other a stressed protocol for 5 weeks. From the beginning of the third week, rats were treated either with saline daily or with etanercept twice a week (0.3 mg/kg, i.p.) or with fluoxetine daily (10 mg/kg, i.p) as a reference. Etanercept exhibited comparable effects to those of fluoxetine in counteracting CMS-induced behavioral manifestation in the forced swimming and splash tests. Etanercept also restored serotonin and norepinephrine levels to control values in the prefrontal cortex (PFC). Moreover, the current study verified the antioxidant and anti-inflammatory effects of etanercept. Interestingly, etanercept halted the expression of both norepinephrine and serotonin transporters in stressed rats. This could be attributed to abrogation of the p38 mitogen-activated protein kinase (p38 MAPK) and signal transducer and activator of transcription 3 (STAT-3) pathways in the PFC. The findings of the present study contribute to the understanding of the potential of etanercept as an antidepressant and provide insights into the neurobiological mechanisms underlying its therapeutic effects.

GPCR-mediated natural products and compounds: Potential therapeutic targets for the treatment of neurological diseases

G protein-coupled receptors (GPCRs), widely expressed in the human central nervous system (CNS), perform numerous physiological functions and play a significant role in the pathogenesis of diseases. Consequently, identifying key therapeutic GPCRs targets for CNS-related diseases is garnering immense interest in research labs and pharmaceutical companies. However, using GPCRs drugs for treating neurodegenerative diseases has limitations, including side effects and uncertain effective time frame. Recognizing the rich history of herbal treatments for neurological disorders like stroke, Alzheimer's disease (AD), and Parkinson's disease (PD), modern pharmacological research is now focusing on the understanding of the efficacy of traditional Chinese medicinal herbs and compounds in modulating GPCRs and treatment of neurodegenerative conditions. This paper will offer a comprehensive, critical review of how certain natural products and compounds target GPCRs to treat neurological diseases. Conducting an in-depth study of herbal remedies and their efficacies against CNS-related disorders through GPCRs targeting will augment our strategies for treating neurological disorders. This will not only broaden our understanding of effective therapeutic methodologies but also identify the root causes of altered GPCRs signaling in the context of pathophysiological mechanisms in neurological diseases. Moreover, it would be informative for the creation of safer and more effective GPCR-mediated drugs, thereby establishing a foundation for future treatment of various neurological diseases.

Factors Associated with the Development of Depression and the Influence of Obesity on Depressive Disorders: A Narrative Review

Depression affects several aspects of life, including socioeconomic status, relationships, behavior, emotions, and overall health. The etiology of depression is complex and influenced by various factors, with obesity emerging as a significant contributor. This narrative review aims to investigate the factors associated with the development of depression, with a particular focus on the role of obesity. The literature search was conducted on PubMed, Embase, and PsycINFO from May to July 2024. The review highlights the impact of environmental and socioeconomic conditions; lifestyle choices, including physical activity and dietary habits; stress; traumatic experiences; neurotransmitter imbalances; medical and psychological conditions; hormone fluctuations; and epigenetic factors on depression. A key emphasis is placed on the inflammatory processes linked to obesity, which may drive the bidirectional relationship between obesity and depression. The findings suggest that obesity is associated with an increased risk of depression, potentially due to chronic inflammation, neurochemical dysregulation, and the emotional and social challenges related to weight stigma and obesity management. Understanding these interconnected factors is important for developing targeted interventions to address both obesity and depression, leading to improved quality of life for those affected.