Peripheral cytokine levels and response to antidepressant treatment in depression: a systematic review and meta-analysis

Splenic nerve denervation attenuates depression-like behaviors in Chrna7 knock-out mice via the spleen-gut-brain axis

BACKGROUND

Growing evidence highlights the role of the spleen-brain axis in inflammation-associated depression. The α7-subtype of nicotinic acetylcholine receptor (α7 nAChR, encoded by the Chrna7 gene) is implicated in systemic inflammation, with Chrna7 knock-out (KO) mice displaying depression-like behaviors. Yet, the influence of spleen nerve on depression-like behaviors in these KO mice remains to be elucidated.

METHODS

We investigated the effects of the splenic nerve denervation (SND) on depression-like behaviors, the protein expression in the prefrontal cortex (PFC), and the gut microbiota composition in Chrna7 KO mice.

RESULTS

SND markedly alleviated depression-like behaviors and the reduced expression of GluA1 and postsynaptic density protein-95 (PSD-95) in the PFC of Chrna7 KO mice. No changes in α-diversity of gut microbiota were noted among the control, KO + sham, and KO + SND groups. However, significant differences in β-diversity of gut microbiota were noted among the groups. Notable alterations in various microbiota (e.g., Fluviimonas_pallidilutea, Maribacter_arcticus, Parvibacter_caecicola) and plasma metabolites (e.g., helicide, N-acetyl-L-aspartic acid, α-D-galactose 1-phosphate, choline, creatine) were observed between KO + sham and KO + SND groups. Interestingly, correlations were found between the relative abundance of specific microbiota and other outcomes, including synaptic proteins, metabolites and behavioral data.

LIMITATIONS

The underlying mechanisms remain to be fully understood.

CONCLUSIONS

Our findings indicate that the splenic nerve contributes to depression-like phenotypes in Chrna7 KO mice via the spleen-gut-brain axis.

Graph convolutional network with attention mechanism improve major depressive depression diagnosis based on plasma biomarkers and neuroimaging data

BACKGROUND

The absence of clinically-validated biomarkers or objective protocols hinders effective major depressive disorder (MDD) diagnosis. Compared to healthy control (HC), MDD exhibits anomalies in plasma protein levels and neuroimaging presentations. Despite extensive machine learning studies in psychiatric diagnosis, a reliable tool integrating multi-modality data is still lacking.

METHODS

In this study, blood samples from 100 MDD and 100 HC were analyzed, along with MRI images from 46 MDD and 49 HC. Here, we devised a novel algorithm, integrating graph neural networks and attention modules, for MDD diagnosis based on inflammatory cytokines, neurotrophic factors, and Orexin A levels in the blood samples. Model performance was assessed via accuracy and F1 value in 3-fold cross-validation, comparing with 9 traditional algorithms. We then applied our algorithm to a dataset containing both the aforementioned protein quantifications and neuroimages, evaluating if integrating neuroimages into the model improves performance.

RESULTS

Compared to HC, MDD showed significant alterations in plasma protein levels and gray matter volume revealed by MRI. Our new algorithm exhibited superior performance, achieving an F1 value and accuracy of 0.9436 and 94.08 %, respectively. Integration of neuroimaging data enhanced our novel algorithm's performance, resulting in an improved F1 value and accuracy, reaching 0.9543 and 95.06 %.

LIMITATIONS

This single-center study with a small sample size requires future evaluations on a larger test set for improved reliability.

CONCLUSIONS

In comparison to traditional machine learning models, our newly developed MDD diagnostic model exhibited superior performance and showed promising potential for inclusion in routine clinical diagnosis for MDD.

Advances in biosensors for major depressive disorder diagnostic biomarkers

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

Effect of minocycline on changes in affective behaviors, cognitive function, and inflammation in breast cancer survivors undergoing chemotherapy: a pilot randomized controlled trial

PURPOSE

Minocycline suppresses chemotherapy-induced neuroinflammation in preclinical models, but its effects in cancer survivors are unknown. This study evaluated the longitudinal effects of minocycline on affective behaviors, cognitive functions, and inflammation in women with breast cancer (BC) undergoing chemotherapy.

METHODS

This is a pilot, double-blind, randomized controlled trial of oral minocycline (100 mg BID) versus placebo for chemotherapy-induced affective disorders in women initiating chemotherapy for stage I-III BC. Participants received minocycline or placebo up to one week before chemotherapy, continuing through cycle 4 (C4). Epidemiologic Studies Depression Scale (CES-D) and State-Trait Anxiety Inventory (STAI) were assessed at baseline, each cycle of chemotherapy (C1-C4), 2-3-week post-chemotherapy (end of chemotherapy), and 6-month post-chemotherapy (6 M) as the primary outcomes. Sub-group analysis of CES-D and STAI based on the severity of symptoms was also performed. Changes in self-reported cognition and serum inflammatory markers were also evaluated.

RESULTS

Fifty-seven women enrolled and 55 completed the study. Except for Interleukin-8 (p ≤ 0.03), changes in inflammatory markers, cognitive function, CES-D, and STAI were not significantly different between groups from baseline to any cycle or post-chemotherapy time point (all p > 0.05), adjusting for baseline scores. Increases in serum Interleukin-8 from baseline to C4 and 6 M were ameliorated by minocycline (p < 0.05). The sub-group symptomatic for depression (CES-D > = 16 at baseline) treated with minocycline had a greater reduction in CES-D score compared to placebo from baseline to 6 M (p = 0.01).

CONCLUSION

Despite attenuation of IL-8, minocycline did not alter self-reported affective symptoms or cognition in this cohort of BC survivors undergoing chemotherapy. The effect of minocycline on BC survivors symptomatic for depression before chemotherapy warrants further investigation.

Efficacy of Pentoxifylline for the Treatment of Bipolar I/II Patients with Treatment-Resistant Depression: A Proof-of-Concept, Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND

Immune dysregulation can play a role in depression pathophysiology, and immunological antagonists can improve depressive symptoms in treatment-resistant bipolar depression (TRD) patients according to studies.

OBJECTIVE

To evaluate the anti-depressant effects of the anti-inflammatory drug, pentoxifylline (PTX) in TRD bipolar I/II adult subjects.

METHODS

This 12-week, randomized, double-blind, placebo-controlled, parallel-group trial of 60 participants was conducted at Hawler Psychiatric Hospital and Private Clinic in Erbil, Iraq. Participants were confirmed as being qualified for bipolar I/II depression based on DSM-5 criteria. Data were analyzed using modified intent-to-treat analysis.

RESULTS

There were no significant differences between the two groups in Hamilton Rating Scale for Depression-17 (HAM-D-17) scores (χ2=1.9, P =.48) or a significant time × treatment interaction (χ2=7.1, P=.54). Nevertheless, a significant effect of time was observed with both groups' reduction in HAM-D-17 scores from the start to the endpoint (χ2= 2.11, P=.002). Besides, a significant time × treatment × CRP interaction was found (χ2=3.1, P=0.016), where there was more reduction in HAM-D-17 score in PTX-treated subjects with CRP> 7.1mg/L. The response rate difference between PTX and the placebo group did not reach a significance level (χ2=0.84, p=0.43). Furthermore, serum concentrations of TNF-α, CRP, and IL-6 significantly reduced at week 12 in the PTX group (P=.007,.04, and <.001, respectively).

CONCLUSION

The current proof of concept study found that in terms of overall anti-depressant effectiveness in bipolar patients with TRD, PTX is not superior to placebo. However, it may improve depressive mood in a subpopulation of subjects with a higher pretreatment inflammatory profile.

CLINICAL TRIAL REGISTRATION NUMBER

NCT05324735.

Integrated Single-Cell RNA-seq and ATAC-seq Reveals Heterogeneous Differentiation of CD4+ Naive T Cell Subsets is Associated with Response to Antidepressant Treatment in Major Depressive Disorder

The mechanism involved in major depressive disorder (MDD) is well-studied but the mechanistic origin of the heterogeneous antidepressant effect remains largely unknown. Single-cell RNA-sequencing (scRNA-seq) and assay for transposase-accessible chromatin using sequencing (ATAC-seq) on peripheral blood mononuclear cells from 8 healthy individuals and 8 MDD patients before or after 12 weeks of antidepressant treatment is performed. scRNA-seq analysis reveals a lower proportion of naive T cells, particularly CD4+ naive T cells, in MDD patients compared to controls, and in nonresponders versus responders at the baseline. Flow cytometry data analysis of an independent cohort of 35 patients and 40 healthy individuals confirms the findings. Enrichment analysis of differentially expressed genes indicated obvious immune activation in responders. A specific activated CD4+ naive T population in responders characterized by enhanced mitogen-activated protein kinases (MAPK) pathway is identified. E-twenty six (ETS) is proposed as an upstream regulator of the MAPK pathway and heterogeneous differentiation in activated CD4+ naive T population is associated with the response to antidepressant treatment in MDD patients. A distinct immune feature manifested by CD4+ naive T cells during antidepressant treatment in MDD is identified. Collectively, this proposes the molecular mechanism that underlies the heterogeneous antidepressant outcomes for MDD.

Peripheral CD4+ T helper lymphocytes alterations in major depressive disorder: A systematic review and meta-analysis

Previous research has shown that patients with major depressive disorder (MDD) develop immune dysfunction. However, the exact alterations of cluster of differentiation (CD)4+ T helper (Th) lymphocytes in MDD remains unclear. This meta-analysis aimed to examine the specific changes in CD4+ Th cells. A comprehensive search of PubMed, EMBASE, Web of Science, and PsycINFO databases was conducted to identify studies investigating CD4+ Th, Th1, Th2, Th17, and T regulatory (Treg) cell counts in the peripheral blood of MDD patients and healthy controls (HCs), covering the period up to June 22, 2024. Our findings revealed that patients with MDD might exhibit higher CD4+ Th cells (SMD=0.26, 95 %CI, 0.02 to 0.50), CD4+/CD8+ cell ratios (SMD=0.51, 95 %CI, 0.14 to 0.89), Th1/Th2 cell ratios (SMD=0.15, 95 %CI, 0.01 to 0.30) and lower Th1 (SMD=-0.17, 95 %CI, -0.30 to -0.03), Th2 (SMD=-0.25, 95 %CI, -0.40 to -0.11), and Treg cells (SMD=-0.69, 95 %CI, -1.27 to -0.11). However, no significant difference was observed in terms of Th17 cells and Th17/Treg cell ratios between MDD patients and the HCs. Heterogeneity was large (I2:18.1-95.2 %), and possible sources of heterogeneity were explored (e.g., age, depression scale, country, and antidepressant use). Our findings indicate that peripheral CD4+ T cells in depressed patients exhibit features of adaptive immune dysfunction, as evidenced by increased CD4+ Th cells and CD4+/CD8+ and decreased Treg cells. These findings offer insights into the underlying mechanism of MDD.

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

RATIONALE

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

Seasonal characteristics of nosocomial infection in a psychiatric hospital in China with different nosocomial prevention and control backgrounds: a retrospective study

This study aimed to investigate the relationship between various prevention and control measures for nosocomial infections (NIs) in psychiatric hospitals and patients with mental disorders. This study aimed to determine the characteristics of NIs in psychiatric hospitals and provide a reference for infection prevention and control in this setting. Data from the NI monitoring system of a psychiatric hospital in southeastern China were analysed. Patients who were hospitalized for mental disorders from January 1, 2016, to November 30, 2019, were classified into the non-COVID-19 containment group (NC19C group, n = 898), while those who were hospitalized from January 25, 2020, to November 30, 2022, were classified into the COVID-19 containment group (C19C group, n = 840). The data were analysed using SPSS version 22.0, and independent sample t tests, chi-square tests, correlation analyses, and multivariate logistic regression analyses were performed. A significance level of P < 0.0024 was applied. The incidence rate of NIs was higher in autumn in the NC19C group, while no seasonal difference was detected in the C19C group (P < 0.0024). Further analysis revealed that in the C19C group, the risk of hospitalized patients with mental disorders developing hospital-acquired pneumonia in spring was 0.362 times that in winter (OR = 0.362, 95% CI = 0.200 ~ 0.656, P = 0.001), and in summer, the risk was 0.342 times that in winter (OR = 0.342, 95% CI = 0.185 ~ 0.633 P = 0.001). Patients aged 18-44 years had a 4.260 times higher risk of developing hospital-acquired upper respiratory tract infections than did those aged 60 years and older (OR = 4.260, 95% CI = 2.143 ~ 8.470; P = 0.000). The risk of acquiring urinary tract infections in the hospital was 0.324 times greater among patients aged 18-44 years than for patients aged 60 years and older (OR = 0.324, 95% CI = 0.171-0.613; P = 0.001). The NC19C group did not exhibit the aforementioned differences. During the NC19C period, differences were observed in the diagnosis of hospital-acquired infections and sex (all P = 0.000). Psychiatric hospitals exhibit distinct nosocomial infection characteristics under the context of various infection control measures. Against the backdrop of strengthened infection control, the nosocomial infection characteristics of psychiatric hospitals may be associated with the features of mental disorders.

Biosensors for psychiatric biomarkers in mental health monitoring

Psychiatric disorders are associated with serve disturbances in cognition, emotional control, and/or behavior regulation, yet few routine clinical tools are available for the real-time evaluation and early-stage diagnosis of mental health. Abnormal levels of relevant biomarkers may imply biological, neurological, and developmental dysfunctions of psychiatric patients. Exploring biosensors that can provide rapid, in-situ, and real-time monitoring of psychiatric biomarkers is therefore vital for prevention, diagnosis, treatment, and prognosis of mental disorders. Recently, psychiatric biosensors with high sensitivity, selectivity, and reproducibility have been widely developed, which are mainly based on electrochemical and optical sensing technologies. This review presented psychiatric disorders with high morbidity, disability, and mortality, followed by describing pathophysiology in a biomarker-implying manner. The latest biosensors developed for the detection of representative psychiatric biomarkers (e.g., cortisol, dopamine, and serotonin) were comprehensively summarized and compared in their sensitivities, sensing technologies, applicable biological platforms, and integrative readouts. These well-developed biosensors are promising for facilitating the clinical utility and commercialization of point-of-care diagnostics. It is anticipated that mental healthcare could be gradually improved in multiple perspectives, ranging from innovations in psychiatric biosensors in terms of biometric elements, transducing principles, and flexible readouts, to the construction of 'Big-Data' networks utilized for sharing intractable psychiatric indicators and cases.

Unmasking the mental health scars of COVID-19: A longitudinal investigation of children and adolescents in post-lockdown China

The long-term mental health consequences of COVID-19 in children and adolescents remain unclear. We investigated the impact of COVID-19 infection on mental health after China's zero-COVID policy relaxation, focusing on symptom-specific and social-family risk factors for mental health issues in children and adolescents. In a longitudinal study, 8348 youths (aged 10-18) were assessed twice (T1: September to October 2022 and T2: April to May 2023). Mental health changes (Δ=T1-T2) were compared between COVID-19-infected (COVID+, n = 4108) and non-infected (COVID-, n = 4240). After balancing social-family confounding factors at T1 with propensity score-based inverse probability weights, multivariable logistic regression was employed to assess associations between COVID-19 infection and the onset/worsening of mental health symptoms. Multivariable logistic regression was conducted to explore specific acute COVID-19 symptoms and social-family risk factors associated with the onset/worsening of mental health symptoms in COVID + group. Compared to COVID- group, COVID + group exhibited lower overall mental health improvement (Δ). COVID + group was associated with increased risks of depression worsening (OR 1.20, 95 % CI 1.04-1.39), anxiety worsening (OR 1.30, 95 % CI 1.15-1.47), stress worsening (OR 1.23, 95 % CI 1.03-1.46), insomnia worsening (OR 1.21, 95 % CI 1.05-1.39), and emotional symptoms worsening (OR 1.72, 95 % CI 1.27-2.33). Moderate-to-severe difficulty thinking, breathlessness, and gastrointestinal symptoms were specific COVID-19 symptoms associated with worsening of various mental health outcomes. Furthermore, academic difficulties, economic disadvantages, family conflicts, food addiction, and alcohol consumption were identified as social-family risk factors for worsening mental health symptoms in COVID + youths. COVID-19 infection leaves lasting mental health scars in youths, extending beyond the acute phase. Specific symptoms, particularly cognitive dysfunction and respiratory/gastrointestinal distress play a significant role in this vulnerability. Social-family factors further modulate these effects, highlighting the need for comprehensive interventions that address both biological and psychosocial aspects. This study provides valuable insights for tailoring mental health support to youths navigating the consequences of the COVID-19 pandemic.

Cyclooxygenase-2 inhibitors alleviated depressive and anxious-like behaviors in mice exposed to lipopolysaccharide: Involvement of oxidative stress and neuroinflammation

Depression and anxiety disorders have their pathophysiologies linked to inflammation and oxidative stress. In this context, celecoxib (CLX) and etoricoxib (ETR) inhibit cyclooxygenase 2 (COX-2), an enzyme expressed by cells involved in the inflammatory process and found in the brain. Studies have been using CLX as a possible drug in the treatment of depression, although its mechanisms at the central nervous system level are not fully elucidated. In this study, the effects of CLX and ETR on behavioral, oxidative, and inflammatory changes induced by systemic exposure to Escherichia coli lipopolysaccharide (LPS) were evaluated in adult male swiss mice. For ten days, the animals received intraperitoneal injections of LPS at 0.5 mg/kg. From the sixth to the tenth day, one hour after LPS exposure, they were treated orally with CLX (15 mg/kg), ETR (10 mg/kg), or fluoxetine (FLU) (20 mg/kg). Twenty-four hours after the last oral administration, the animals underwent evaluation of locomotor activity (open field test), predictive tests for depressive-like behavior (forced swim and tail suspension tests), and anxiolytic-like effect (elevated plus maze and hole board tests). Subsequently, the hippocampus, prefrontal cortex and striatum were dissected for the measurement of oxidative and nitrosative parameters (malondialdehyde, nitrite, and glutathione) and quantification of pro-inflammatory cytokines (IL-1β and IL-6). LPS induced depressive and anxious-like behavior, and treatment with CLX or ETR was able to reverse most of the behavioral changes. It was evidenced that nitrosative stress and the degree of lipid peroxidation induced by LPS were reduced in different brain areas after treatment with the drugs, as well as the endogenous defense system against free radicals was strengthened. CLX and ETR also significantly reduced LPS-induced cytokine levels. These data are expected to expand information on the role of inflammation in depression and anxiety and provide insights into possible mechanisms of COX-2 inhibitors in psychiatric disorders with a neurobiological basis in inflammation and oxidative stress.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Pharmacological mechanism of natural antidepressants: The role of mitochondrial quality control

BACKGROUND

Depression is a mental illness characterized by persistent sadness and a reduced capacity for pleasure. In clinical practice, SSRIs and other medications are commonly used for therapy, despite their various side effects. Natural products present distinct advantages, including synergistic interactions among multiple components and targeting multiple pathways, suggesting their tremendous potential in depression treatment. Imbalance in mitochondrial quality control (MQC) plays a significant role in the pathology of depression, emphasizing the importance of regulating MQC as a potential intervention strategy in addressing the onset and progression of depression. However, the role and mechanism through which natural products regulate MQC in depression treatments still need to be comprehensively elucidated, particularly in clinical and preclinical settings.

PURPOSE

This review was aimed to summarize the findings of recent studies and outline the pharmacological mechanisms by which natural products modulate MQC to exert antidepressant effects. Additionally, it evaluated current research limitations and proposed new strategies for future preclinical and clinical applications in the depression domain.

METHODS

To study the main pharmacological mechanisms underlying the regulation of MQC by natural products in the treatment of depression, we conducted a thorough search across databases such as PubMed, Web of Science, and ScienceDirect databases to classify and summarize the relationship between MQC and depression, as well as the regulatory mechanisms of natural products.

RESULTS

Numerous studies have shown that irregularities in the MQC system play an important role in the pathology of depression, and the regulation of the MQC system is involved in antidepressant treatments. Natural products mainly regulate the MQC system to induce antidepressant effects by alleviating oxidative stress, balancing ATP levels, promoting mitophagy, maintaining calcium homeostasis, optimizing mitochondrial dynamics, regulating mitochondrial membrane potential, and enhancing mitochondrial biogenesis.

CONCLUSIONS

We comprehensively summarized the regulation of natural products on the MQC system in antidepressants, providing a unique perspective for the application of natural products within antidepressant therapy. However, extensive efforts are imperative in clinical and preclinical investigations to delve deeper into the mechanisms underlying how antidepressant medications impact MQC, which is crucial for the development of effective antidepressant treatments.

MDDOmics: multi-omics resource of major depressive disorder

Major depressive disorder (MDD) is a pressing global health issue. Its pathogenesis remains elusive, but numerous studies have revealed its intricate associations with various biological factors. Consequently, there is an urgent need for a comprehensive multi-omics resource to help researchers in conducting multi-omics data analysis for MDD. To address this issue, we constructed the MDDOmics database (Major Depressive Disorder Omics, (https://www.csuligroup.com/MDDOmics/), which integrates an extensive collection of published multi-omics data related to MDD. The database contains 41 222 entries of MDD research results and several original datasets, including Single Nucleotide Polymorphisms, genes, non-coding RNAs, DNA methylations, metabolites and proteins, and offers various interfaces for searching and visualization. We also provide extensive downstream analyses of the collected MDD data, including differential analysis, enrichment analysis and disease-gene prediction. Moreover, the database also incorporates multi-omics data for bipolar disorder, schizophrenia and anxiety disorder, due to the challenge in differentiating MDD from similar psychiatric disorders. In conclusion, by leveraging the rich content and online interfaces from MDDOmics, researchers can conduct more comprehensive analyses of MDD and its similar disorders from various perspectives, thereby gaining a deeper understanding of potential MDD biomarkers and intricate disease pathogenesis. Database URL: https://www.csuligroup.com/MDDOmics/.

Bovine colostrum supplementation as a new perspective in depression and substance use disorder treatment: a randomized placebo-controlled study

Introduction

This randomized, placebo-controlled, double-blind, parallel study aimed to evaluate the effect of 3-month supplementation of bovine colostrum (BOV-COL; 8x400 mg per day) on the outcomes of depression treatment in hospitalized patients with substance use disorder (SUD). The hypothesis is that BOV-COL supplementation as an add-on treatment results in favorable alternations in selected blood inflammatory markers or neurotransmitters, leading to better depression treatment outcomes compared with placebo (PLA).

Methods

Patients with a Minnesota Multiphasic Personality Inventory-2 score ≥60 points were enrolled. Twenty-nine participants (n=18 in the BOV-COL group and n=11 in the PLA group) completed the protocol.

Results

The mean Beck Depression Inventory-II score was significantly reduced after supplementation in both groups. However, the mean 17-point Hamilton Depression Rating Scale score was decreased in the BOV-COL group, but not in the PLA group. In the BOV-COL group, there was a reduction in interleukin (IL)-1, IL-6, IL-10, the IL-6:IL-10 ratio, IL-17, and tumor necrosis factor alpha (TNF-α), while in the PLA group only IL-6 decreased. Favorable alternations in the total count and differentials of white blood cell subsets were more pronounced in the BOV-COL. There were no changes in neurotransmitter concentrations.

Conclusions

BOV-COL supplementation is a promising add-on therapy in patients with depression and SUD.

Bidirectional relationship between C-reactive protein and depressive symptoms considering cumulative effect among Chinese middle-aged and older adults

Introduction

Research examining the bidirectional relationship between C-reactive protein (CRP) and depressive symptoms, while accounting for cumulative effect of repeated episodes of CRP or depressive symptoms, is currently deficient in non-Western populations.

Methods

A nationally representative population-based cohort data from the Chinese Health and Retirement Longitudinal Study (CHARLS) was utilized. In bi-directional analysis, we considered both single determinations and two successive determinations of CRP or depressive symptoms. Multivariate logistic regression assessed the association between elevated CRP levels at baseline or repeated episodes of CRP elevations over two successive determinations and subsequent elevated depressive symptoms, and vice versa.

Results

Although single determinations of CRP or depressive symptoms yielded non-significant results in both directions, full multivariate models, adjusting for baseline depressive symptoms, socio-demographic characteristics, health-related behaviors, metabolic measures, and health status, revealed a significantly positive association based on two successive determinations of CRP or depressive symptoms. This significant association was observed between cumulative effects of sustained CRP elevations over two successive determinations (2 vs. 0) and subsequent elevated depressive symptoms (OR=1.58; 95% CI: 1.15 to 2.17) and between cumulative effect of repeated episodes of depression (2 vs. 0) and later elevated CRP (OR=1.26; 95% CI: 1.02 to 1.56). Furthermore, sex-stratified analyses confirmed the robustness of these relationships.

Conclusion

There are bidirectional associations between depressive symptoms and CRP, driven by the cumulative effect of repeated episodes of CRP or depressive symptoms among middle-aged and older Chinese adults. These findings hold significant clinical implications, highlighting the potential of both anti-inflammatory and anti-depression approaches.

Effects of selective serotonin reuptake inhibitors (SSRIs) on suicide: A network meta-analysis of double-blind randomized trials

The relationship between the use of selective serotonin reuptake inhibitors (SSRIs) and suicide risk in patients with mental disorders remains controversial. We conducted a network meta-analysis to examine the effects of SSRIs on suicide risk in patients with mental disorders. A comprehensive search was conducted across PubMed, Web of Science, PsycINFO, CENTRAL, Wanfang Database, and China National Knowledge Infrastructure for articles published until December 19, 2023. The main outcomes were suicidal ideation and instances of suicidal behavior. We included 29 double-blind randomized trials in our analysis. The findings suggest that SSRIs primarily offer short-term protection against suicidal ideation. By week 2, paroxetine, fluoxetine, escitalopram, and non-SSRI treatments were linked to a decreased suicide risk compared with a placebo, with the exception of sertraline. This protective effect was diminished by week 8. In contrast, studies on instances of suicidal behavior from weeks 1 to 10 found no significant difference in efficacy between SSRIs, non-SSRIs, and placebo. These results indicate that SSRIs may offer short-term protection against suicidal ideation. However, their long-term effectiveness in mitigating suicidal ideation and preventing suicidal behaviors is limited.

Evidence of the Immunomodulatory Effects of Selective Serotonin Reuptake Inhibitors in Patients With Depression Through a Systematic Review

Depression is a common illness, affecting >264 million people worldwide. According to the literature, depression patients have baseline subclinical inflammation. The immunomodulatory effects of antidepressants, such as selective serotonin reuptake inhibitors (SSRIs), are largely unclear and poorly understood. Using evidence-based medicine, this study aimed to determine the immunomodulatory effects of SSRIs by assessing changes in immunomodulatory markers following SSRI treatment. Using the PubMed website, a literature search was conducted with various terminologies related to the treatment of depression and various markers of inflammation. Out of 387 retrieved articles, after critical appraisal and screening based on inclusion and exclusion criteria, 17 were selected. Qualitative synthesis and quantitative analysis were carried out. RevMan 5 software was used to synthesize and evaluate the data. Microsoft Word and Excel (Microsoft Corporation, Redmond, Washington, United States) were used for generating tables and figures. We extracted data from a total of 839 patients in 17 studies. A highly significant reduction in interleukins-6 (IL-6) (standardised mean difference (SMD) = 1.32 (95% confidence interval (CI): 0.58, 2.06), Z = 3.48, P = 0.0005), a significant reduction in tumor necrosis factor-alpha (TNF-α) (SMD = 1.29 (95% CI: 0.19, 2.39), Z = 2.30, P = 0.02) but no change in overall C-reactive protein (CRP) (SMD = 0.40 (95% CI: -0.26, 1.07), Z = 1.19, P = 0.23) levels were observed by using the random-effects model. There was substantial heterogeneity found between the studies. SSRIs have an immunomodulatory effect in patients with depression by significantly reducing the peripheral pro-inflammatory cytokine markers of IL-6 and TNF-α, which may contribute to ameliorating the response to antidepressant drug treatment. In contrast, no effects of SSRIs on acute-phase protein CRP were found.

Changes in neuroactive steroids, neurotrophins and immunological biomarkers after monotherapy 8-week rTMS treatment and their relationship with neurocognitive functions in depression

Repetitive transcranial magnetic stimulation (rTMS) has proven effective in the treatment of major depression. The underlying mechanisms of action are still poorly understood. We aimed to evaluate the changes in the levels of neuroactive steroids, neurotrophins and immunological biomarkers before and after rTMS treatment and assess the relationship of this change between clinical response and cognitive functions after monotherapy rTMS treatment. Twenty-three patients with major depressive disorder (MDD) and 25 matched healthy controls were included in the study. The Hamilton Depression Rating Scale (HDRS), Trail Making Test A and B forms and Digit Span Test were administered. Biomarkers (BDNF, TNF-α, IL-1ß, NAS) were run in the peripheral blood at the end of the first month that rTMS was administered daily and at the end of the 2nd month when that rTMS was administered once a week. Appropriate conditions were provided so that the relevant biomarkers were not affected by the biorhythm. After rTMS monotherapy, an increase in BDNF and allopregnanolone, a decrease in TNF-α, IL-1ß, DHEA, and DHEA-S levels was found to be statistically significant. The scores on cognitive tests increased with the treatment. Positive significant correlations was found between BDNF levels and cognitive tests at the end of the first and second months. Our findings suggest that the effects of rTMS treatment may be related to the neuroendocrine, neurotrophin, and immunological mechanisms. rTMS treatment is found to have positive effects on cognitive functions in the short term.

T cell activation and deficits in T regulatory cells are associated with major depressive disorder and severity of depression

Major depressive disorder (MDD) is associated with T cell activation, but no studies have examined the combined effects of T cell activation and deficits in T regulatory (Treg) cells on the severity of acute phase MDD. Using flow cytometry, we determined the percentage and median fluorescence intensity of CD69, CD71, CD40L, and HLADR-bearing CD3+, CD4+, and CD8+ cells, and cannabinoid type 1 receptor (CB1), CD152 and GARP (glycoprotein A repetitions predominant)-bearing CD25+ FoxP3 T regulatory (Treg) cells in 30 MDD patients and 20 healthy controls in unstimulated and stimulated (anti-CD3/CD28) conditions. Based on cytokine levels, we assessed M1 macrophage, T helper (Th)-1 cell, immune-inflammatory response system (IRS), T cell growth, and neurotoxicity immune profiles. We found that the immune profiles (including IRS and neurotoxicity) were significantly predicted by decreased numbers of CD152 or GARP-bearing CD25+ FoxP3 cells or CD152 and GARP expression in combination with increases in activated T cells (especially CD8+ CD40L+ percentage and expression). MDD patients showed significantly increased numbers of CD3+ CD71+, CD3+ CD40L+, CD4+ CD71+, CD4+ CD40L+, CD4+ HLADR+, and CD8+ HLADR+ T cells, increased CD3+ CD71+, CD4+ CD71+ and CD4+ HLADR+ expression, and lowered CD25+ FoxP3 expression and CD25+ FoxP+ CB1+ numbers as compared with controls. The Hamilton Depression Rating Scale score was strongly predicted (between 30 and 40% of its variance) by a lower number of CB1 or GARP-bearing Treg cells and one or more activated T cell subtypes (especially CD8+ CD40L+). In conclusion, increased T helper and cytotoxic cell activation along with decreased Treg homeostatic defenses are important parts of MDD that lead to enhanced immune responses and, as a result, neuroimmunotoxicity.

Effects of esketamine and fluoxetine on depression-like behaviors in chronic variable stress: a role of plasma inflammatory factors

Mounting evidence has identified the rapid and sustained antidepressive and anxiolytic-like effects of esketamine. However, the underlying mechanism of this no-monoamine target rapid-onset antidepressant is still underexplored. Immune-inflammatory pathways and cell-mediated immune activation, mainly including inflammatory cytokines in plasma, play a pivotal role in the pathogenesis of major depressive disorder and are also a potential therapeutic target for MDD. The current study was designed to clarify the role of esketamine on the expression of plasma cytokines in a depressive-like model introduced by chronic variable stress (CVS). In this study, a 21-day consecutive CVS protocol was applied to produce depressive- and anxiety-like behaviors. After the single dose or 7-day repeated administration of esketamine or fluoxetine, the depressive- and anxiety-like behaviors and the expression of inflammatory cytokines in plasma were examined. Both a single dose of esketamine and 7-days repeated fluoxetine administration elicited anti-depressive and anxiolytic effects in mice exposed to CVS. Additionally, CVS produced significant changes in the plasma inflammatory factors, notably increasing the expression of IL-1β, IL-6, IL-8, IL-17A, TNFα, IL-4, IL-9, IL-24, IL-37, IFN-β, and CXCL12, while reducing IL-10 and IL-33. With the administration of esketamine and fluoxetine, CVS-produced inflammatory disturbances were partially normalized. Together, our findings provide a novel insight that acute esketamine treatment could rescue CVS-produced depressive-like and anxiety-like behaviors in mice by normalizing the expression of inflammatory cytokines; this effect was similar to the repeated administration of fluoxetine. These results contributed to the understating of rapid anti-depressant effects elicited by esketamine.

IL-8 (CXCL8) Correlations with Psychoneuroimmunological Processes and Neuropsychiatric Conditions

Interleukin-8 (IL-8/CXCL8), an essential CXC chemokine, significantly influences psychoneuroimmunological processes and affects neurological and psychiatric health. It exerts a profound effect on immune cell activation and brain function, suggesting potential roles in both neuroprotection and neuroinflammation. IL-8 production is stimulated by several factors, including reactive oxygen species (ROS) known to promote inflammation and disease progression. Additionally, CXCL8 gene polymorphisms can alter IL-8 production, leading to potential differences in disease susceptibility, progression, and severity across populations. IL-8 levels vary among neuropsychiatric conditions, demonstrating sensitivity to psychosocial stressors and disease severity. IL-8 can be detected in blood circulation, cerebrospinal fluid (CSF), and urine, making it a promising candidate for a broad-spectrum biomarker. This review highlights the need for further research on the diverse effects of IL-8 and the associated implications for personalized medicine. A thorough understanding of its complex role could lead to the development of more effective and personalized treatment strategies for neuropsychiatric conditions.

Effects on peripheral and central nervous system of key inflammatory intercellular signalling peptides and proteins in psoriasis

Psoriasis is a chronic systemic inflammatory cutaneous disease. Where the immune system plays an important role in its pathogenesis, with key inflammatory intercellular signalling peptides and proteins including IL-17 and IL-23. The psychoneurological system also figures prominently in development of psoriasis. There is a high prevalence of comorbidity between psoriasis and mental health disorders such as depression, anxiety and mania. Patients with psoriasis often suffer from pathological pain in the lesions, and their neurological accidents could improve the lesions in innervated areas. The immune system and the psychoneurological system interact closely in the pathogenesis of psoriasis. Patients with psoriasis exhibit abnormal levels of neuropeptides both in circulating and localized lesion, acting as immunomodulators involved in the inflammatory response. Moreover, receptors for inflammatory factors are expressed in both peripheral and central nervous systems (CNSs), suggesting that nervous system can receive and be influenced by signals from immune system. Key inflammatory intercellular signalling peptides and proteins in psoriasis, such as IL-17 and IL-23, can be involved in sensory signalling and may affect synaptic plasticity and the blood-brain barrier of CNS through the circulation. This review provides an overview of the multiple effects on the peripheral and CNS under conditions of systemic inflammation in psoriasis, providing a framework and inspiration for in-depth studies of neuroimmunomodulation in psoriasis.

Duloxetine protected indomethacin-induced gastric mucosal injury by increasing serotonin-dependent RANTES expression and activating PI3K-AKT-VEGF pathway

Antidepressant duloxetine has been shown protective effect on indomethacin-induced gastric ulcer, which was escorted by inflammation in the gastric mucosa. Cytokines are the principal mediators of inflammation. Thus, by screening the differential expression of cytokines in the gastric mucosa using cytokine array at 3 h after indomethacin exposure, when the gastric ulcer began to format, we found that indomethacin increased cytokines which promoted inflammation responses, whereas duloxetine decreased pro-inflammatory cytokines increased by indomethacin and increased RANTES expression. RANTES was consistently increased by pretreated with both 5 mg/kg and 20 mg/kg duloxetine at 3 h and 6 h after indomethacin exposure in male rats. Selective blockade of RANTES-CCR5 axis by a functional antagonist Met-RANTES or a CCR5 antagonist maraviroc suppressed the protection of duloxetine. Considering the pharmacologic action of duloxetine on reuptake of monoamine neurotransmitters, we examined the serotonin (5-HT), norepinephrine and dopamine contents in the blood and discovered 20 mg/kg duloxetine increased 5-HT levels in platelet-poor plasma, while treatment with 5-HT promoted expression of RANTES in the gastric mucosa and alleviated the indomethacin-induced gastric injury. Furthermore, duloxetine activated PI3K-AKT-VEGF signaling pathway, which was regulated by RANTES-CCR5, and selective inhibitor of VEGF receptor axitinib blocked the prophylactic effect of duloxetine. Furthermore, duloxetine also protected gastric mucosa from indomethacin in female rats, and RANTES was increased by duloxetine after 6 h after indomethacin exposure too. Together, our results identified the role of cytokines, particularly RANTES, and the underlying mechanisms in gastroprotective effect of duloxetine against indomethacin, which advanced our understanding in inflammatory modulation by monoamine-based antidepressants.

A microfluidic-based gut-on-a-chip model containing the gut microbiota of patients with depression reveals physiological characteristics similar to depression

The diverse commensal microbiome of the human intestine has been considered to play a central role in depression. However, no host-microbiota co-culture system has been developed for depression, which hinders the controlled study of the interaction between depression and gut microbiota. We designed and manufactured a microfluidic-based gut-on-a-chip model containing the gut microbiota of patients with depression (depression-on-gut-chip, DoGC), which enables the extended co-culture of viable aerobic human intestinal epithelial cells and anaerobic gut microbiota, and allows the direct study of interactions between human gut microbiota and depression. We introduced representative gut microbiota from individuals with depression into our constructed DoGC model, successfully recapitulating the gut microbiota structure of depressed patients. This further led to the manifestation of physiological characteristics resembling depression, such as reduced gut barrier function, chronic low-grade inflammatory responses and decreased neurotransmitter 5-HT levels. Metabolome analysis of substances in the DoGC revealed a significant increase in lipopolysaccharides and tyrosine, while hyodeoxycholic acid, L-proline and L-threonine were significantly reduced, indicating the occurrence of depression. The proposed DoGC can serve as an effective platform for studying the gut microbiota of patients with depression, providing important cues for their roles in the pathology of this condition and acting as a powerful tool for personalized medicine.

Long-Term Immunomodulatory Impact of VNS on Peripheral Cytokine Profiles and Its Relationship with Clinical Response in Difficult-to-Treat Depression (DTD)

Vagus nerve stimulation (VNS) represents a long-term adjunctive treatment option in patients with difficult-to-treat depression (DTD). Anti-inflammatory effects have been discussed as a key mechanism of action of VNS. However, long-term investigations in real-world patients are sparse. In this naturalistic observational study, we collected data on cytokines in peripheral blood in n = 6 patients (mean age 47.8) with DTD and VNS treatment at baseline and at 6 months follow-up. We have identified clusters of peripheral cytokines with a similar dynamic over the course of these 6 months using hierarchical clustering. We have investigated cytokine changes from baseline to 6 months as well as the relationship between the cytokine profile at 6 months and long-term response at 12 months. After 6 months of VNS, we observed significant correlations between cytokines (p < 0.05) within the identified three cytokine-pairs which were not present at baseline: IL(interleukin)-6 and IL-8; IL-1β and TNF-α; IFN-α2 and IL-33. At 6 months, the levels of all the cytokines of interest had decreased (increased in non-responders) and were lower (5-534 fold) in responders to VNS than in non-responders: however, these results were not statistically significant. VNS-associated immunomodulation might play a role in long-term clinical response to VNS.

A Novel Anti-Inflammatory Formulation Comprising Celecoxib and Cannabidiol Exerts Antidepressant and Anxiolytic Effects

Background: Ample research shows that anti-inflammatory drugs, particularly celecoxib, exert antidepressant effects, especially in patients with microglia activation. However, substantial cardiovascular adverse effects limit celecoxib's usefulness. Given that cannabidiol (CBD) exerts anti-inflammatory, microglia-suppressive, and antidepressant effects, we hypothesized that it may potentiate the therapeutic effects of celecoxib. Methods: The effects of celecoxib, CBD, and their combination were examined in murine models of antidepressant- and anxiolytic-like behavioral responsiveness, including the forced swim test (FST), elevated plus maze (EPM), lipopolysaccharide (LPS)-induced neuroinflammation, and chronic social defeat stress (CSDS), as well as in microglia cell cultures. Results: Acute administration of a combination of celecoxib plus CBD, at doses that had no effects by themselves (10 and 5 mg/kg, respectively), produced significant antidepressant- and anxiolytic-like effects in the FST and EPM, in male and female mice. In the LPS model, combinations of celecoxib (10 or 20 mg/kg) plus CBD (30 mg/kg) reversed the anxiety-like behavior in the open-field test (OFT) and anhedonia in the sucrose preference test (SPT), with minimal effects of celecoxib or CBD by themselves. In the CSDS paradigm, a combination of celecoxib plus CBD (each at 30 mg/kg) reversed the deficits in the OFT, EPM, social exploration, and SPT, whereas celecoxib or CBD by themselves had partial effects. In BV2 microglia cultures stimulated with LPS or α-synuclein, CBD markedly potentiated the suppressive effects of celecoxib over TNFα (tumor necrosis factor-α) and IL (interleukin)-1β secretion. Conclusions: Combinations of celecoxib plus CBD produce efficacious antidepressant- and anxiolytic-like effects, which may depend on their synergistic microglia-suppressive effects.

Zhi Zi Chi decoction (Gardeniae fructus and semen Sojae Praeparatum) attenuates anxious depression via modulating microbiota-gut-brain axis in corticosterone combined with chronic restraint stress-induced mice

BACKGROUND

The microbiota-gut-brain axis plays a critical role in neuropsychiatric disorders, particularly anxious depression, and attracts more attention gradually. Zhi Zi Chi decoction (ZZCD) consisting of Gardenia jasminoides J. Ellis and Glycine max (L.) Merr, is a classic formula in clinic and widely applied in anxiety and depression treatment. However, the underlying mechanisms of regulating microbiota-gut-brain axis in the treatment of anxious depression by oral administration of ZZCD remain elusive.

MATERIALS AND METHODS

In this project, we clarified the origin and preparation methods of the Gardenia jasminoides J. Ellis and Glycine max (L.) Merr and examined the chemical ingredients of ZZCD by liquid chromatograph mass spectrometer. Then, corticosterone combined with chronic restraint stress was applied to establish an anxious depression model. After treated with ZZCD standard decoction, based on enzyme-linked immunosorbent assay (ELISA), 16S rRNA technology, high-throughput sequencing, quantitative RT-PCR and fecal microbiota transplantation (FMT), the multiple associations between nucleus accumbens and intestinal flora in anxious depression mice were determined to clarify the mechanism of ZZCD in the treatment of anxiety and depression disorder.

RESULTS

We found various substances with antidepressant and antianxiety properties in ZZCD such as rosiridin and oleanolic acid. ZZCD could alleviate depressive and anxiety behaviors in anxious depression mice via regulating the disturbance of gut microbiota. Meanwhile, the bioactive compounds of ZZCD might directly active on neurodevelopment and neuroimmune-related genes. Furthermore, the secretion of prolactin and estrogen, and interfering with mitogen-activated protein kinase (MAPK) and tumor necrosis factor (TNF) signaling pathways were mainly involved in the multi-target therapeutic effects of ZZCD against anxiety and depression.

CONCLUSIONS

These findings suggested that ZZCD exerts antidepressant effects pleiotropically through modulating the microbiota-gut-brain.

Plasma levels of hydrogen sulfide and homocysteine correlate with the efficacy of antidepressant agents and serve as potential diagnostic and therapeutic markers

OBJECTIVE

Hydrogen sulfide (H2S) is associated with depressive-like behavior in rodents. We undertook cross-sectional and longitudinal analyses of plasma levels of H2S and its substrate homocysteine (Hcy) in depression and assessed the association of both parameters with psychopathology and cognitive function.

METHODS

Forty-one patients suffering from depression (PSDs) and 48 healthy volunteers were recruited. PSDs were treated for 8 weeks. Analyzable data were collected from all participants for assessment of their psychopathology and cognitive function. Plasma was collected for determination of levels of H2S and Hcy, and data were correlated to determine their potential as plasma biomarkers.

RESULTS

Cross-sectional analyses revealed PSDs to have a low plasma H2S level and high Hcy level. Longitudinal analyses revealed that 8 weeks of treatment reversed the changes in plasma levels of H2S and Hcy in PSDs. Plasma levels of H2S and Hcy were associated with psychopathology and cognitive function in depression. The area under the receiver operating characteristic curve (AUC) for a combination of plasma levels of H2S and Hcy and expression of the TNF gene (i.e., H2S-Hcy-TNF) was 0.848 for diagnosing depression and 0.977 for predicting the efficacy of antidepressant agents.

CONCLUSION

Plasma levels of H2S and Hcy reflect changes in psychopathology and cognitive function in depression and H2S-Hcy-TNF has the potential to diagnose depression and predict the efficacy of antidepressant medications.

Association between hs-CRP and depressive symptoms: a cross-sectional study

Background and aim

High-sensitivity C-reactive protein (hs-CRP) is a sensitive measure of low-grade inflammation and appears superior to conventional blood tests in assessing cardiovascular disease. The purpose of this investigation was to explore the link between high-sensitivity CRP and depressive symptoms among adults.

Methods and results

Multiple logistic regression and smoothed curve fitting were used to investigate the association between hs-CRP and depressive symptoms based on data from the, 2017-2020 National Health and Nutrition Examination Survey (NHANES). Subgroup analyses and interaction tests were used to assess the stability of this relationship across populations. The study comprised 6,293 non-clinical participants, which included 549 individuals with depressive symptoms. The prevalence of depressive symptoms was found to increase with increasing levels of hs-CRP. This trend persisted even after quartetting hs-CRP levels. In the fully adjusted model, each unit increase in hs-CRP was associated with a 10% increase in the odds of depressive symptoms (OR=1.10,95%CI:1.01-1.21). Participants in the highest quartile of hs-CRP had a 39% higher prevalence of depressive symptoms compared to those in the lowest quartile (OR=1.39,95%CI:1.01-1.92). Additionally, this positive correlation was more pronounced in men.

Conclusions

In adult Americans, there exists a positive association between elevated hs-CRP levels and depressive symptoms, with a more prominent manifestation of this association observed in males.

Relationship between inflammatory markers in human olfactory neural progenitor cells and antidepressant response

Response to antidepressants is related to hippocampal neurogenesis integrity, a process mediated by neurotrophins, such as Brain Derived Neurotrophic Factor (BDNF). In turn, pro-inflammatory state appears to reduce neurogenesis, and has been associated with refractory depressive states. We propose to analyze the human neural progenitor cells derived from the olfactory epithelium (HNPCs-OE) as an indicator of neurogenesis in humans. Therefore, we compared the number and content of HNPCs-OE in depressed patients taking antidepressants, according to response to treatment. Twenty depressed patients were followed during eight weeks after antidepressant treatment was prescribed. At the end evaluation they were divided in two groups according to Hamilton depression rating scale (HDRS) scores: responders and non-responders. We compared the number and components of HNPCs-OE between groups and observed an elevation of interleukine-8 in those patients who do not achieve response to treatment, BDNF levels were no related to antidepressant response.

Features of immunometabolic depression as predictors of antidepressant treatment outcomes: pooled analysis of four clinical trials

BACKGROUND

Profiling patients on a proposed 'immunometabolic depression' (IMD) dimension, described as a cluster of atypical depressive symptoms related to energy regulation and immunometabolic dysregulations, may optimise personalised treatment.

AIMS

To test the hypothesis that baseline IMD features predict poorer treatment outcomes with antidepressants.

METHOD

Data on 2551 individuals with depression across the iSPOT-D (n = 967), CO-MED (n = 665), GENDEP (n = 773) and EMBARC (n = 146) clinical trials were used. Predictors included baseline severity of atypical energy-related symptoms (AES), body mass index (BMI) and C-reactive protein levels (CRP, three trials only) separately and aggregated into an IMD index. Mixed models on the primary outcome (change in depressive symptom severity) and logistic regressions on secondary outcomes (response and remission) were conducted for the individual trial data-sets and pooled using random-effects meta-analyses.

RESULTS

Although AES severity and BMI did not predict changes in depressive symptom severity, higher baseline CRP predicted smaller reductions in depressive symptoms (n = 376, βpooled = 0.06, P = 0.049, 95% CI 0.0001-0.12, I2 = 3.61%); this was also found for an IMD index combining these features (n = 372, βpooled = 0.12, s.e. = 0.12, P = 0.031, 95% CI 0.01-0.22, I2= 23.91%), with a higher - but still small - effect size compared with CRP. Confining analyses to selective serotonin reuptake inhibitor users indicated larger effects of CRP (βpooled = 0.16) and the IMD index (βpooled = 0.20). Baseline IMD features, both separately and combined, did not predict response or remission.

CONCLUSIONS

Depressive symptoms of people with more IMD features improved less when treated with antidepressants. However, clinical relevance is limited owing to small effect sizes in inconsistent associations. Whether these patients would benefit more from treatments targeting immunometabolic pathways remains to be investigated.

Interplay of inflammatory biomarkers in heart disease patients with depressive symptoms: An update

The pathophysiological mechanisms that connect heart disease and depressive disorders have been identified as abnormal endothelial function, dysregulation of the Hypothalamic Pituitary Adrenal (HPA) axis and abnormal platelet activities. Among these mechanisms, both endothelial dysfunction and HPA axis dysregulation are influenced by low grade inflammation and play significant roles in both conditions. Consequently, it is hypothesized that inflammation is an integral part of the formation of atherosclerotic plaques, linking the occurrence of heart diseases to the activation and shedding of intercellular adhesion molecules (ICAMs), especially soluble ICAM-1. This process is accompanied by the local and systemic secretion of various inflammatory markers like interleukin-6, Tumour Necrosis Factor, and C-reactive protein. Therefore, this review primarily focuses on defining the potential role of different inflammatory biomarkers in depression and heart disease and assessing whether mediators could serve as predictive biomarkers for detecting depressive symptoms in patients with heart disease.

Autism spectrum disorder: pathogenesis, biomarker, and intervention therapy

Autism spectrum disorder (ASD) has become a common neurodevelopmental disorder. The heterogeneity of ASD poses great challenges for its research and clinical translation. On the basis of reviewing the heterogeneity of ASD, this review systematically summarized the current status and progress of pathogenesis, diagnostic markers, and interventions for ASD. We provided an overview of the ASD molecular mechanisms identified by multi-omics studies and convergent mechanism in different genetic backgrounds. The comorbidities, mechanisms associated with important physiological and metabolic abnormalities (i.e., inflammation, immunity, oxidative stress, and mitochondrial dysfunction), and gut microbial disorder in ASD were reviewed. The non-targeted omics and targeting studies of diagnostic markers for ASD were also reviewed. Moreover, we summarized the progress and methods of behavioral and educational interventions, intervention methods related to technological devices, and research on medical interventions and potential drug targets. This review highlighted the application of high-throughput omics methods in ASD research and emphasized the importance of seeking homogeneity from heterogeneity and exploring the convergence of disease mechanisms, biomarkers, and intervention approaches, and proposes that taking into account individuality and commonality may be the key to achieve accurate diagnosis and treatment of ASD.

Use of Serum Biomarkers to Aid Antidepressant Selection in Depressive Patients

Objective

: This study aimed to identify serum biomarkers prospectively associated with remission at 12 weeks in out-patients with depressive disorders receiving stepwise psychopharmacotherapy, according to the main antidepressant used during the treatment period.

Methods

: This study included 1,024 depressive outpatients initially treated using antidepressant monotherapy, followed by alternating pharmacological strategies during the acute phase (3-12 weeks; 3-week interval). Fourteen serum biomarkers, sociodemographics, and clinical characteristics were evaluated at baseline. Based on the use frequency and mechanism of action, four main antidepressant types were distinguished: escitalopram, other selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. A Hamilton Depression Rating Scale score ≤ 7 was take to indicate remission.

Results

: Lower high-sensitivity C-reactive protein levels were correlated with remission at 12 weeks for all antidepressant types. Lower interleukin (IL)-6 levels and tumor necrosis factor-alpha levels were associated with remission using escitalopram and other SSRIs respectively. Lower IL-1β and leptin levels, predicted remission in association with SSRIs including escitalopram. For SNRIs, remission at 12 weeks was predicted by lower IL-4 and IL-10 levels. For mirtazapine, remission at 12 weeks was associated with lower leptin levels, and higher serotonin and folate levels.

Conclusion

: Baseline serum status, as estimated by nine serum markers, may help clinicians determine the most appropriate antidepressant to achieve remission in the acute phase of depression.

Efficacy and mechanism of acupuncture in animal models of depressive-like behaviors: a systematic review and meta-analysis

Background

Many studies have investigated the efficacy of acupuncture in treating depression, but the mechanism of acupuncture for depression is still controversial and there is a lack of meta-analysis of mechanisms. Consequently, we investigated acupuncture's efficacy and mechanism of depression.

Methods

We searched the Cochrane Library, PubMed, EMBASE, Web of Science. The SYRCLE Risk of Bias Tool was used to assess bias risk. Meta-analysis was performed using Stata 15.0 for indicators of depression mechanisms, body weight and behavioral tests.

Results

A total of 22 studies with 497 animals with depressive-like behaviors were included. Meta-analysis showed that acupuncture significantly increased BDNF [SMD = 2.40, 95% CI (1.33, 3.46); I2 = 86.6%], 5-HT [SMD = 2.28, 95% CI (1.08, 3.47); I2 = 87.7%] compared to the control group (p < 0.05), and significantly reduced IL-1β [SMD = -2.33, 95% CI (-3.43, -1.23); I2 = 69.6%], CORT [SMD = -2.81, 95% CI (-4.74, -0.87); I2 = 86.8%] (p < 0.05). Acupuncture improved body weight [SMD = 1.35, 95% CI (0.58, 2.11); I2 = 84.5%], forced swimming test [SMD = -1.89, 95% CI (-2.55, -1.24); I2 = 76.3%], open field test (crossing number [SMD = 3.08, 95% CI (1.98, 4.17); I2 = 86.7%], rearing number [SMD = 2.53, 95% CI (1.49, 3.57); I2 = 87.0%]) (p < 0.05) compared to the control group.

Conclusion

Acupuncture may treat animals of depressive-like behaviors by regulating neurotrophic factors, neurotransmitters, inflammatory cytokines, neuroendocrine system.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023403318, identifier (CRD42023403318).

Fluoxetine mitigates depressive-like behaviors in mice via anti-inflammation and enhancing neuroplasticity

Neuroplasticity and inflammation represent a common final pathway for effective antidepressant treatment. SSRIs are the most commonly prescribed medications for depression and have demonstrated efficacy in reducing depressive symptoms. However, the precise impact of SSRIs on neuroplasticity and inflammation remains unclear. In this study, we aimed to investigate the influence of long-term treatment with SSRIs on hippocampal neuron, inflammation, synaptic function and morphology. Our findings revealed that fluoxetine treatment significantly alleviated behavioral despair, anhedonia, and anxiety in reserpine-treated mice. Moreover, fluoxetine mitigated hippocampal neuron impairment, inhibited inflammatory release, and increased the expression of synaptic proteins markers (SYP and PSD95) in mice. Notably, fluoxetine also suppressed reserpine-induced synapse loss in the hippocampus. Based on these results, fluoxetine has been demonstrated effectively to ameliorate depressive mood and cognitive dysfunction, possibly through the enhancement of synaptic plasticity. Overall, our study contributes to a further understanding of the mechanisms underlying the therapeutic effects of fluoxetine and its potential role in improving depressive symptoms and cognitive impairments.

Potential Role of Bmal1 in Lipopolysaccharide-Induced Depression-Like Behavior and its Associated "Inflammatory Storm"

Inflammation plays an important role in the pathogenesis of depression; however, the underlying mechanisms remain unclear. Apart from the disordered circadian rhythm in animal models and patients with depression, dysfunction of clock genes has been reported to be involved with the progress of inflammation. This study aimed to investigate the role of circadian clock genes, especially brain and muscle ARNT-like 1 (Bmal1), in the linkage between inflammation and depression. Lipopolysaccharide (LPS)-challenged rats and BV2 cells were used in the present study. Four intraperitoneal LPS injections of 0.5 mg/kg were administered once every other day to the rats, and BV2 cells were challenged with LPS for 24 h at the working concentration of 1 mg/L, with or without the suppression of Bmal1 via small interfering RNA. The results showed that LPS could successfully induce depression-like behaviors and an "inflammatory storm" in rats, as indicated by the increased immobility time in the forced swimming test and the decreased saccharin preference index in the saccharin preference test, together with hyperactivity of the hypothalamic-pituitary-adrenal axis, hyperactivation of astrocyte and microglia, and increased peripheral and central abundance of tumor necrosis factor-α, interleukin 6, and C-reactive protein. Moreover, the protein expression levels of brain-derived neurotrophic factor, triggering receptor expressed on myeloid cells 1, Copine6, and Synaptotagmin1 (Syt-1) decreased in the hippocampus and hypothalamus, whereas the expression of triggering receptor expressed on myeloid cells 2 increased. Interestingly, the fluctuation of temperature and serum concentration of melatonin and corticosterone was significantly different between the groups. Furthermore, protein expression levels of the circadian locomotor output cycles kaput, cryptochrome 2, and period 2 was significantly reduced in the hippocampus of LPS-challenged rats, whereas Bmal1 expression was significantly increased in the hippocampus but decreased in the hypothalamus, where it was co-located with neurons, microglia, and astrocytes. Consistently, apart from the reduced cell viability and increased phagocytic ability, LPS-challenged BV2 cells presented a similar trend with the changed protein expression in the hippocampus of the LPS model rats. However, the pathological changes in BV2 cells induced by LPS were reversed after the suppression of Bmal1. These results indicated that LPS could induce depression-like pathological changes, and the underlying mechanism might be partly associated with the imbalanced expression of Bmal1 and its regulated dysfunction of the circadian rhythm.

Cytokine profile in first-episode drug-naïve major depressive disorder patients with or without anxiety

OBJECTIVE

It is known that cytokines play a role in both depression and anxiety. This study aimed to compare the levels of multiple cytokines in patients with first-episode drug-naive major depressive disorder (MDD) with or without anxiety and analyze the correlation between the level of depression or anxiety and the serum cytokine levels.

METHODS

The study involved 55 patients with first-episode drug-naive MDD. To assess anxiety symptoms, the 14-item HAMA was used. MDD patients were divided into two groups: 23 MDD patients without anxiety and 32 MDD patients with anxiety. The measurement of 37 cytokines was conducted. Serum cytokine levels between patients with MDD without anxiety and anxiety were compared. In multiple linear regression models, the relationship between the group and abnormal cytokines was explored. The receiver operating characteristic (ROC) curve analysis was performed to estimate diagnostic performance of serum cytokines in discriminating MDD patients with anxiety from MDD patients without anxiety. A correlation was evaluated between the scores of HAMD or HAMA and the serum cytokine levels.

RESULTS

In MDD patients with anxiety, IL-17 C and CCL17 levels were significantly lower than in MDD patients without anxiety (all P < 0.05). Multiple measurements were corrected with Benjamini-Hochberger corrections, but none of these differences persisted (all P > 0.05). The results of multiple linear regression models revealed that after controlling for other independent variables, group was not a significant independent predictor of serum IL-17 C or CCL17 (all P > 0.05). The AUC values of IL-17 C and CCL17 were 0.643 and 0.637, respectively, in discriminating MDD patients with anxiety from MDD patients without anxiety. The results of partial correlation analyses showed the scores of HAMD were negatively correlated with the IL-17 C (r = -0.314, P = 0.021) levels with sex as a covariate.

CONCLUSIONS

The findings suggest that there is a potential absence of disparity in the levels of circulating cytokines among individuals diagnosed with first-episode drug-naïve MDD, regardless of the presence or absence of comorbid anxiety.

Therapeutic potential and possible mechanisms of ginseng for depression associated with COVID-19

Recently, a global outbreak of COVID-19 has rapidly spread to various national regions. As the number of COVID-19 patients has increased, some of those infected with SARS-CoV-2 have developed a variety of psychiatric symptoms, including depression, cognitive impairment, and fatigue. A distinct storm of inflammatory factors that contribute to the initial disease but also a persistent post-acute phase syndrome has been reported in patients with COVID-19. Neuropsychological symptoms including depression, cognitive impairment, and fatigue are closely related to circulating and local (brain) inflammatory factors. Natural products are currently being examined for their ability to treat numerous complications caused by COVID-19. Among them, ginseng has anti-inflammatory, immune system stimulating, neuroendocrine modulating, and other effects, which may help improve psychiatric symptoms. This review summarizes the basic mechanisms of COVID-19 pneumonia, psychiatric symptoms following coronavirus infections, effects of ginseng on depression, restlessness, and other psychiatric symptoms associated with post-COVID syn-dromes, as well as possible mechanisms underlying these effects.

Genetic evidence for causal effects of immune dysfunction in psychiatric disorders: where are we?

The question of whether immune dysfunction contributes to risk of psychiatric disorders has long been a subject of interest. To assert this hypothesis a plethora of correlative evidence has been accumulated from the past decades; however, a variety of technical and practical obstacles impeded on a cause-effect interpretation of these data. With the advent of large-scale omics technology and advanced statistical models, particularly Mendelian randomization, new studies testing this old hypothesis are accruing. Here we synthesize these new findings from genomics and genetic causal inference studies on the role of immune dysfunction in major psychiatric disorders and reconcile these new data with pre-omics findings. By reconciling these evidences, we aim to identify key gaps and propose directions for future studies in the field.

Distinguishing features of depression in dementia from primary psychiatric disease

Depression is a common and devastating neuropsychiatric symptom in the elderly and in patients with dementia. In particular, nearly 80% of patients with Alzheimer's Disease dementia experience depression during disease development and progression. However, it is unknown whether the depression in patients with dementia shares the same molecular mechanisms as depression presenting as primary psychiatric disease or occurs and persists through alternative mechanisms. In this review, we discuss how the clinical presentation and treatment differ between depression in dementia and as a primary psychiatric disease, with a focus on major depressive disorder. Then, we hypothesize several molecular mechanisms that may be unique to depression in dementia such as neuropathological changes, inflammation, and vascular events. Finally, we discuss existing issues and future directions for investigation and treatment of depression in dementia.

NLRP3 inflammatory pathway. Can we unlock depression?

Depression holds the title of the largest contributor to worldwide disability, with the numbers expected to continue growing. Currently, there are neither reliable biomarkers for the diagnosis of the disease nor are the current medications sufficient for a lasting response in nearly half of patients. In this comprehensive review, we analyze the previously established pathophysiological models of the disease and how the interplay between NLRP3 inflammasome activation and depression might offer a unifying perspective. Adopting this inflammatory theory, we explain how NLRP3 inflammasome activation emerges as a pivotal contributor to depressive inflammation, substantiated by compelling evidence from both human studies and animal models. This inflammation is found in the central nervous system (CNS) neurons, astrocytes, and microglial cells. Remarkably, dysregulation of the NLRP3 inflammasome extends beyond the CNS boundaries and permeates into the enteric and peripheral immune systems, thereby altering the microbiota-gut-brain axis. The integrity of the brain blood barrier (BBB) and intestinal epithelial barrier (IEB) is also compromised by this inflammation. By emphasizing the central role of NLRP3 inflammasome activation in depression and its far-reaching implications, we go over each area with potential modulating mechanisms within the inflammasome pathway in hopes of finding new targets for more effective management of this debilitating condition.

Plasma cytokine and growth factor response to acute psychosocial stress in major depressive disorder

BACKGROUND

Pro-inflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α are elevated in response to psychosocial stress; however, less is known about other inflammatory markers.

METHODS

We explored response to the Trier Social Stress Test (TSST) of 16 cytokines and growth factors in patients with major depressive disorder (MDD, n = 12) vs. healthy volunteers (HV, n = 16). Outcomes were baseline and post-stress levels estimated by area under the curve (AUCi) and peak change over 3 timepoints. We also explored correlations between biomarkers and clinical characteristics.

RESULTS

Baseline concentrations were higher in MDD for platelet-derived growth factor (PDGF)-AB/BB (p = 0.037, d = 0.70), granulocyte-macrophage colony-stimulating factor (GM-CSF, p = 0.033, d = 0.52), and IL-8 (p = 0.046, d = 0.74). After TSST, AUCi was higher in MDD for GM-CSF (p = 0.003, d = 1.21), IL-5 (p = 0.014, d = 1.62), and IL-27 (p = 0.041, d = 0.74). In MDD, depression severity correlated positively with soluble CD40L (sCD40L) for AUCi (Spearman's ρ = 0.76, p = 0.004) and with baseline vascular endothelial growth factor A (VEGFA, r = 0.85, p < 0.001), but negatively with baseline monokine induced by gamma interferon (MIG, aka CXCL9; r = -0.77, p = 0.003).

CONCLUSIONS

Effect sizes were robust in this exploratory study, although interpretation of the results must be cautious, given small sample size and multiple comparisons. Differential study of stress-induced biomarkers may have important ramifications for MDD treatment.

Constipation preceding depression: a population-based cohort study

Background

Constipation is generally considered a common physical symptom of depression or a side effect of antidepressant treatments. However, according to the gut-brain axis hypothesis, the association between depression and constipation might be bi-directional. This study investigated the association between premorbid constipation and depression.

Methods

We conducted a retrospective cohort study using data from UK Biobank. Individuals free of depression between 2006 and 2010 were included. Constipation status was determined using diagnostic codes from electronic health records or a baseline questionnaire. Data on covariates, including socio-demographic characteristics, lifestyle factors, health conditions, and regular medication use, were also collected through a baseline questionnaire. The primary outcome is incident depression, which was extracted from hospital inpatient admissions, primary care, self-report, and death data from baseline to 2022. The secondary outcome is depressive symptoms, which was assessed by Patient Health Questionnaire-9 (PHQ-9) from an online survey in 2016. Cox proportional hazard regression models were employed to assess the prospective association between constipation and incident depression. Logistic regression models were used to assess its association with depressive symptoms.

Findings

Among the 449,459 participants included in the study, 18,596 (4.1%) experienced constipation at baseline, and 18,576 (4.1%) developed depression over a median follow-up period of 12.3 years. Premorbid constipation is associated with a 2.28-fold higher risk of depression. After adjusting the covariates, we found those with constipation still had a 48% higher risk of developing depression (adjusted hazard ratio [aHR] 1.48; 95% CI, 1.41-1.56) than those without constipation. Self-reported and diagnosed constipation were both associated with a higher risk of depression, with the aHR being 1.42 (95% CI: 1.34-1.51) and 1.66 (95% CI: 1.51-1.82), respectively. Participants with constipation were more likely to report depressive symptoms than people without (adjusted odds ratio 2.18; 95% CI, 1.97-2.43). These findings remained consistent in sensitivity analyses.

Interpretation

Diagnosed and self-reported constipation are both prospectively associated with an elevated risk of depression. These explorative findings suggest that constipation may be an independent risk factor or a prodromal symptom of depression. Gastroenterologists and primary care physicians should pay more attention to the depressive symptoms of their constipation patients.

Funding

The Shenzhen Science and Technology Program and the Strategic Priority Research Program of Chinese Academy of Sciences.

Adult hippocampal neurogenesis: pharmacological mechanisms of antidepressant active ingredients in traditional Chinese medicine

Depression is characterized by prominent indicators and manifestations, such as anhedonia, which refers to the inability to experience pleasure, and persistent feelings of hopelessness. In clinical practice, the primary treatment approach involves the utilization of selective serotonin reuptake inhibitors (SSRIs) and related pharmacological interventions. Nevertheless, it is crucial to recognize that these agents are associated with significant adverse effects. Traditional Chinese medicine (TCM) adopts a multifaceted approach, targeting diverse components, multiple targets, and various channels of action. TCM has potential antidepressant effects. Anomalies in adult hippocampal neurogenesis (AHN) constitute a pivotal factor in the pathology of depression, with the regulation of AHN emerging as a potential key measure to intervene in the pathogenesis and progression of this condition. This comprehensive review presented an overview of the pharmacological mechanisms underlying the antidepressant effects of active ingredients found in TCM. Through examination of recent studies, we explored how these ingredients modulated AHN. Furthermore, we critically assessed the current limitations of research in this domain and proposed novel strategies for preclinical investigation and clinical applications in the treatment of depression in future.

Dose-dependent action of cordycepin on the microbiome-gut-brain-adipose axis in mice exposed to stress

The high risk for anxiety and depression among individuals with stress has become a growing concern globally. Stress-related mental disorders are often accompanied by symptoms of metabolic dysfunction. Cordycepin is a Chinese herbal medicine commonly used for its metabolism-enhancing effects. We aimed to investigate the dose-dependent effects of cordycepin on psycho-metabolic disorders induced by stress. Our behavioral tests revealed that 12.5 mg/kg cordycepin by oral gavage significantly attenuated the anxiety- and depression-like behaviors induced by stress in mice. At 25 mg/kg, cordycepin restored the reduced weight and cell size of adipose tissues caused by stress. Besides ameliorating the metabolic dysbiosis of gut microbiota due to stress, cordycepin significantly reduced the elevated contents of 5-hydroxyindoleacetic acid in the serum and prefrontal cortex at 12.5 mg/kg and reversed the decrease in adipose induced by stress at 25 mg/kg. Correlation analyses further revealed that 12.5 mg/kg cordycepin reversed stress-induced changes in the intestinal microbiome of NK4A214_group and decreased serum Myristic acid and PC(15:0/18:1(11Z)) and cytokines, such as IFN-γ and IL-1β. 25 mg/kg cordycepin reversed stress-induced changes in the abundances of Prevoteaceae_UCG-001 and Desulfovibrio, increased serum L-alanine level, and decreased serum Inosine-5'-monophosphate level. Cordycepin thereby ameliorated the anxiety- and depression-like behaviors as well as disturbances in the adipose metabolism of mice exposed to stress. Overall, these findings offer evidence indicating that the prominent effects of cordycepin in the brain and adipose tissues are dose dependent, thus highlight the importance of evaluating the precise therapeutic effects of different cordycepin doses on psycho-metabolic diseases.

Major depressive disorder as a neuro-immune disorder: Origin, mechanisms, and therapeutic opportunities

Notwithstanding advances in understanding the pathophysiology of major depressive disorder (MDD), no single mechanism can explain all facets of this disorder. An expanding body of evidence indicates a putative role for the inflammatory response. Several meta-analyses showed an increase in systemic peripheral inflammatory markers in individuals with MDD. Numerous conditions and circumstances in the modern world may promote chronic systemic inflammation through mechanisms, including alterations in the gut microbiota. Peripheral cytokines may reach the brain and contribute to neuroinflammation through cellular, humoral, and neural pathways. On the other hand, antidepressant drugs may decrease peripheral levels of inflammatory markers. Anti-inflammatory drugs and nutritional strategies that reduce inflammation also could improve depressive symptoms. The present study provides a critical review of recent advances in the role of inflammation in the pathophysiology of MDD. Furthermore, this review discusses the role of glial cells and the main drivers of changes associated with neuroinflammation. Finally, we highlight possible novel neurotherapeutic targets for MDD that could exert antidepressant effects by modulating inflammation.

Pro-inflammatory markers are associated with response to sequential pharmacotherapy in major depressive disorder: a CAN-BIND-1 report

OBJECTIVE

There is limited literature on associations between inflammatory tone and response to sequential pharmacotherapies in major depressive disorder (MDD).

METHODS

In a 16-week open-label clinical trial, 211 participants with MDD were treated with escitalopram 10-20 mg daily for 8 weeks. Responders continued escitalopram while non-responders received adjunctive aripiprazole 2-10 mg daily for 8 weeks. Plasma levels of pro-inflammatory markers-C-reactive protein, interleukin (IL)-1β, IL-6, IL-17, interferon-gamma (IFN)-Γ, tumor necrosis factor (TNF)-α, and Chemokine C-C motif ligand-2 (CCL-2)-measured at baseline, and after 2, 8 and 16 weeks were included in logistic regression analyzes to assess associations between inflammatory markers and treatment response.

RESULTS

Pre-treatment IFN-Γ and CCL-2 levels were significantly associated with a lower of odds of response to escitalopram at 8 weeks. Increases in CCL-2 levels from weeks 8 to 16 in escitalopram non-responders were significantly associated with higher odds of non-response to adjunctive aripiprazole at week 16.

CONCLUSION

Higher pre-treatment levels of IFN-Γ and CCL-2 were associated with non-response to escitalopram. Increasing levels of these pro-inflammatory markers may be associated with non-response to adjunctive aripiprazole. These findings require validation in independent clinical populations.