The role of pro-inflammatory cytokines in neuroinflammation, neurogenesis and the neuroendocrine system in major depression

Gut dysbiosis-induced vitamin B6 metabolic disorder contributes to chronic stress-related abnormal behaviors in a cortisol-independent manner

Chronic stress can result in various conditions, including psychological disorders, neurodegenerative diseases, and accelerated brain aging. Gut dysbiosis potentially contributes to stress-related brain disorders in individuals with chronic stress. However, the causal relationship and key factors between gut dysbiosis and brain disorders in chronic stress remain elusive, particularly under non-sterile conditions. Here, using a repeated restraint stress (RRS) rat model, we show that sequential transplantation of the cecal contents of different RRS stages to normal rats reproduced RRS-induced core phenotypes, including abnormal behaviors, increased peripheral blood corticosterone and inflammatory cytokines, and a unique gut microbial phenotype. This core phenotypic development was effectively inhibited with probiotic supplement. The RRS-induced unique gut microbial phenotypes at the genus level were positively or negatively associated with the levels of 20 plasma metabolites, including vitamin B6 metabolites 4-pyridoxic acid and 4-pyridoxate. Vitamin B6 supplement during RRS alleviated weight loss, abnormal behaviors, peripheral inflammation, and neuroinflammation, but did not affect the peripheral corticosterone levels in chronic stressed rats. Dampening inflammatory signaling via knocking out caspase 11 or caspase 1 inhibitor abolished RRS-induced abnormal behaviors and peripheral and neuroinflammation but did not decrease peripheral corticosterone in mice. These findings show that gut dysbiosis-induced vitamin B6 metabolism disorder is a new non-hypothalamic-pituitary-adrenal axis mechanism of chronic stress-related brain disorders. Both probiotics and vitamin B6 supplement have potential to be developed as therapeutic strategies for preventing and/or treating chronic stress-related illness.

Glucocorticoid receptor signaling in the brain and its involvement in cognitive function

The hypothalamic-pituitary-adrenal axis regulates the secretion of glucocorticoids in response to environmental challenges. In the brain, a nuclear receptor transcription factor, the glucocorticoid receptor, is an important component of the hypothalamic-pituitary-adrenal axis's negative feedback loop and plays a key role in regulating cognitive equilibrium and neuroplasticity. The glucocorticoid receptor influences cognitive processes, including glutamate neurotransmission, calcium signaling, and the activation of brain-derived neurotrophic factor-mediated pathways, through a combination of genomic and non-genomic mechanisms. Protein interactions within the central nervous system can alter the expression and activity of the glucocorticoid receptor, thereby affecting the hypothalamic-pituitary-adrenal axis and stress-related cognitive functions. An appropriate level of glucocorticoid receptor expression can improve cognitive function, while excessive glucocorticoid receptors or long-term exposure to glucocorticoids may lead to cognitive impairment. Patients with cognitive impairment-associated diseases, such as Alzheimer's disease, aging, depression, Parkinson's disease, Huntington's disease, stroke, and addiction, often present with dysregulation of the hypothalamic-pituitary-adrenal axis and glucocorticoid receptor expression. This review provides a comprehensive overview of the functions of the glucocorticoid receptor in the hypothalamic-pituitary-adrenal axis and cognitive activities. It emphasizes that appropriate glucocorticoid receptor signaling facilitates learning and memory, while its dysregulation can lead to cognitive impairment. This provides clues about how glucocorticoid receptor signaling can be targeted to overcome cognitive disability-related disorders.

Unravelling the role of Interleukin-12 in Neuroinflammatory mechanisms: Pathogenic pathways linking Neuroinflammation to neuropsychiatric disorders

Neuropsychiatric disorders are clinically characterized conditions involving both neurology and psychiatry, arising from dysfunctioning of cerebral function, or indirect effects of extra cerebral disease. Neuropsychiatric disorders tend to influence emotions, mood, and brain functioning. Growing evidence indicates that the etiology of these disorders is not confined to neuronal abnormalities but extends to include inflammation. While the underlying mechanism of these disorders is still in its infancy, recent data highlights the significant role of neuroinflammation in their pathophysiology. Neuroinflammation concerns the inflammation within the neural tissue characterized by alteration in astrocytes, cytokines, microglia, and chemokines within the central nervous system. The cytokines include IFN-γ, IL-1β, IL-2, IL4, IL-6, IL-8, IL-10, and IL-12. This review focuses on interleukin-12 (IL-12), a key mediator of neuroinflammation, and its potential involvement in neuropsychiatric disorders. IL-12 promotes neuroinflammation and influences neurotransmitter systems. Additionally, it also affects the HPA axis, impairs neuroplasticity, and activates microglia by interacting with TLR, JAK-STAT, PI3K/Akt, GSK-3, NMDA, MAPK, PKC, VEGFR, ROCK, and Wnt signaling pathways and elicit its role in ND. In this review, we dwell on the current evidence supporting IL-12's pathogenic role and explore the possible mechanisms by which it contributes to the development and progression of these conditions. This review aims to provide insights that may aid in future therapeutic strategies by illuminating the interplay between neuroinflammation and neuropsychiatric disorders.

Zhi-Zi-Chi decoction ameliorates depression-like behavior in chronic unpredictable mild stress-induced mice via the PI3K/AKT/mTOR signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Zhi-Zi-Chi decoction (ZZCD), a famous classical prescription of traditional Chinese medicine (TCM), has long been used for depression treatment, but its detailed molecular anti-depression mechanisms remain to be further elucidated.

AIM OF THE STUDY

To explore the antidepressant properties and potential mechanisms of ZZCD in ameliorating depression-like behavior through network pharmacology and in vivo experimental validation.

MATERIALS AND METHODS

A chronic unpredictable mild stress (CUMS)-induced mouse depressive model was established in this present study. The sucrose preference test (SPT) and tail suspension test (TST) were performed to assess the antidepressant effects of ZZCD. In addition, the underlying molecular mechanisms of ZZCD against depression were dissected using an integrated network pharmacology approach, and these predicted results were verified in a mouse depressive model. Subsequently, the levels of inflammatory cytokines, neurotransmitters, genes or proteins associated with potential targets as well as the related proteins of the PI3K/AKT/mTOR signaling pathways were measured using ELISA kits, RT-qPCR, and western blot.

RESULTS

ZZCD effectively ameliorated CUMS-induced depressive behavior of mice. Treatments with ZZCD at doses of 3 and 6 g/kg obviously improved the sucrose preference rate in the SPT and attenuated the accumulated immobility time in the TST of CUMS mice. This was accompanied by a decrease in inflammatory factor levels and restoration of the 5-hydroxytryptamine (5-HT) levels in the hippocampi. The network informatics results revealed that the PI3K/AKT/mTOR signaling pathway, AKT1, TNF-α, and IL-6 might be the potential targets of ZZCD against depression. Correspondingly, an in vivo experiment verified that treatment with ZZCD up-regulated the protein expression levels of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR related to the PI3K/AKT/mTOR pathway and reversed the mRNA expression levels of IL-6, TNF-α, and AKT1 in the hippocampi.

CONCLUSION

Our research suggested that ZZCD had antidepressant effects in CUMS-induced depressive mice. The mechanisms underlying the effects of ZZCD against depression were associated with the modulation of inflammatory factor levels as well as related genes or protein expression of the PI3K/AKT/mTOR pathway. Accordingly, ZZCD might serve as a clinically promising TCM prescription for depression treatment.

Particulate matter 2.5 (PM2.5) - associated cognitive impairment and morbidity in humans and animal models: a systematic review

Particulate matter with an aerodynamic diameter of less than 2.5 µm (PM2.5) is one of the criteria air pollutants that (1) serve as an essential carrier of airborne toxicants arising from combustion-related events including emissions from industries, automobiles, and wildfires and (2) play an important role in transient to long-lasting cognitive dysfunction as well as several other neurological disorders. A systematic review was conducted to address differences in study design and various biochemical and molecular markers employed to elucidate neurological disorders in PM2.5 -exposed humans and animal models. Out of 340,068 scientific publications screened from 7 databases, 312 studies were identified that targeted the relationship between exposure to PM2.5 and cognitive dysfunction. Equivocal evidence was identified from pre-clinical (animal model) and human studies that PM2.5 exposure contributes to dementia, Parkinson disease, multiple sclerosis, stroke, depression, autism spectrum disorder, attention deficit hyperactivity disorder, and neurodevelopment. In addition, there was substantial evidence from human studies that PM2.5 also was associated with Alzheimer's disease, anxiety, neuropathy, and brain tumors. The role of exposome in characterizing neurobehavioral anomalies and opportunities available to leverage the neuroexposome initiative for conducting longitudinal studies is discussed. Our review also provided some areas that warrant consideration, one of which is unraveling the role of microbiome, and the other role of climate change in PM2.5 exposure-induced neurological disorders.

Sirtuin 1 underlies depression-related behaviors by modulating the serotonin system in the dorsal raphe nucleus in female mice

Major depressive disorder (MDD) is a primary driver of disability and greatly escalates the worldwide disease burden. Sirtuin 1 (Sirt1), a key regulator of cellular metabolism, is associated with genetic variations in MDD. We investigated how Sirt1 in serotonin (5-HT) neurons within the dorsal raphe nucleus (DRN) in mice affected behaviors associated with depression and susceptibility to stress. Our findings revealed that Sirt1 expression in the DRN was decreased when chronic unpredictable stress was induced in depressed female mice. Additionally, Sirt1 was co-localized with 5-HT neurons within the DRN, and its selective ablation in these neurons have induced depressive phenotypes in female mice but not in males. Adeno-associated virus-mediated knockdown of Sirt1 in adult female mice induced depressive behaviors, whereas Sirt1 overexpression eliminated these behaviors. Moreover, fiber-optic recordings showed a decrease in the neural excitability of 5-HT neurons and 5-HT levels in the DRN after Sirt1 knockdown. Furthermore, we observed that Sirt1 knockdown reduced the expression of tryptophan hydroxylase-2 (Tph2) and phosphorylation levels of extracellular signal-regulated kinase (ERK) and CAMP response element binding protein (CREB). Finally, variable molecular targets regarding immune responses and cytokine productions after Sirt1 knockdown were analyzed via high-throughput RNA-seq analysis of specimens from the DRN. The findings of this study emphasize the importance of Sirt1 for regulating depression-related behaviors in female mice by influencing the activity of 5-HT neurons in the DRN.

Correlations between major depressive disorder, splenic morphology, and immune function

To analyze the symptoms, courses, and severities of depressive disorder, as well as the morphological changes in the spleens and related immune mechanisms, we recruited patients with first-episode or recurrent major depressive disorder (MDD) (patient group) and healthy controls (normal group) matched in age and gender. We measured their plasma MICB (pg/ml), ULBP1 (ng/ml), and splenic volume (cm3) at baseline. The patient group was randomly assigned to receive (S)-ketamine (study group) or saline (control group), and the above indices were collected again on the 4th weekend after administration. At baseline, both MICB and splenic volume were significantly higher in the patient group than in the normal group. A positive correlation was observed between MICB and splenic volume in the patient group. After (S)-ketamine administration, the elevated splenic volume and MICB levels decreased. These results suggest that the pathogenesis of MDD may involve abnormal MICB expression and splenic morphology. (S)-ketamine may ameliorate inflammation and enhance splenic function, thereby relieving MDD symptoms.

Acupoint massage: a comprehensive descriptive review of its forms, applications, and underlying mechanisms

Acupoint massage is a non-invasive traditional therapy that has demonstrated reliable clinical outcomes in pain management, mental health relief, sleep disorder regulation, gastrointestinal treatment, and as an adjunct therapy for cancer. Its convenience and cost-effectiveness further enhance its appeal. However, the existing English literature lacks a systematic review that encompasses the various forms of acupoint massage. The acupoint massage forms adaptability is particularly notable when considering the diverse conditions, it addresses, as well as its applicability across different age groups and gender differences. Providing a comprehensive understanding, it is crucial to outline common practices and explore specific applications in key areas. The comprehensive understanding can create opportunities for effective collaboration between preclinical and clinical studies. Defining and categorizing different forms of acupoint massage is essential, alongside investigating the neural circuits involved in touch sensation. Future efforts should enhance collaboration with modern biology, facilitating the transition from empirical to evidence-based practice. This review summarizes forms, applications, and mechanisms of mainstream acupoint massage and provides insights for future research and applications, promoting deeper integration into healthcare.

Design and discovery of novel heteroaryl substituted pregnenolone derivatives as potent anti-neuroinflammatory agents targeting LPS-stimulated BV-2 microglial cells

A new family of steroidal compounds based on a heteroaryl-4,5-dihydropyrazole thiazolinone core structure was designed and synthesized through structural modifications. The anti-neuroinflammatory activity of these compounds was evaluated in lipopolysaccharide (LPS)-stimulated murine microglial BV-2 cells in vitro. Among the synthesized compounds, 10b and 10d effectively inhibited nitric oxide (NO) production, with compound 10b emerging as the most potent anti-neuroinflammatory agent (IC50 = 2.05 μM). Compound 10b demonstrated significantly greater inhibitory effects than progesterone (prog) (IC50 = 3.23 μM) and reduced NO production in a concentration-dependent manner. Furthermore, compound 10b attenuated the release of pro-inflammatory mediators, including tumour necrosis factor (TNF)-α, interleukin-1β (IL-1β), interleukin-6 (IL-6), and prostaglandin E2 (PGE2). It also inhibited the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Mechanistic studies revealed that compound 10b significantly suppressed the transcriptional activity of nuclear factor kappa B (NF-κB) in activated microglial cells and prevented NF-κB p65 activation and IκBα degradation. These effects were likely mediated by the inhibition of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) signaling pathways. Additionally, molecular docking studies suggested that the anti-neuroinflammatory effects of compound 10b may result from its hydrophobic and hydrophilic interactions with iNOS and COX-2, supporting its proposed mechanism of action. In summary, these findings suggest that compound 10b exerts anti-neuroinflammatory effects in LPS-stimulated BV-2 microglial cells by modulating key inflammatory pathways, including NF-κB and MAPK signaling.

Neuroinflammation-A Crucial Factor in the Pathophysiology of Depression-A Comprehensive Review

Depression is a multifactorial psychiatric condition with complex pathophysiology, increasingly linked to neuroinflammatory processes. The present review explores the role of neuroinflammation in depression, focusing on glial cell activation, cytokine signaling, blood-brain barrier dysfunction, and disruptions in neurotransmitter systems. The article highlights how inflammatory mediators influence brain regions implicated in mood regulation, such as the hippocampus, amygdala, and prefrontal cortex. The review further discusses the involvement of the hypothalamic-pituitary-adrenal (HPA) axis, oxidative stress, and the kynurenine pathway, providing mechanistic insights into how chronic inflammation may underlie emotional and cognitive symptoms of depression. The bidirectional relationship between inflammation and depressive symptoms is emphasized, along with the role of peripheral immune responses and systemic stress. By integrating molecular, cellular, and neuroendocrine perspectives, this review supports the growing field of immunopsychiatry and lays the foundation for novel diagnostic biomarkers and anti-inflammatory treatment approaches in depression. Further research in this field holds promise for developing more effective and personalized interventions for individuals suffering from depression.

Brain injury, endocrine disruption, and immune dysregulation in HIV-positive men who have sex with men with late HIV diagnosis

Background

In the realm of public health, late human immunodeficiency virus (HIV) diagnosis remains prevalent and is associated with neuropsychiatric adverse events. However, there is limited documentation regarding the impact of late HIV diagnosis (LD) on brain integrity, neurotrophic factors, endocrine function, and immunity in HIV-positive men who have sex with men (MSM).

Methods

Participants (38 LD and 34 non-LD of MSM) underwent comprehensive infectious disease and psychiatric assessments, multimodal magnetic resonance imaging (MRI) scans, neurotrophic factors, endocrine, and immunological evaluations. Immune cell levels, along with peripheral plasma concentrations of neurotrophic factors and hormones, were measured using enzyme-linked immunosorbent assays and flow cytometry, respectively. T1-weighted images along with resting-state functional MRI were applied to assess brain function and structure while also examining correlations between imaging alterations and clinical as well as peripheral blood variables. The data for this study originated from a subset of the cohort in HIV-associated neuropsychiatric disorders research.

Results

Compared to participants in the non-LD group, those in the LD group showed a lower total gray matter volume (GMV), with reduced GMV primarily observed in the left supramarginal gyrus. Participants in the LD group exhibited differences in brain function with certain regions and decreased functional connectivity between these altered regions and connected structures. A two-way factorial analysis of variance examining the main effects and interactions between groups and neuropsychiatric disorders revealed significant main effects of LD on specific brain regions. Furthermore, we found that individuals in the LD group had higher levels of cortisol, a lower frequency of central memory T cells, and elevated expression levels of perforin in double-negative T cells. These imaging findings were significantly correlated with endocrine, immune, and clinical variables.

Conclusion

This study suggests that LD may contribute to brain injury, endocrine disruption, and immune dysregulation in HIV-positive MSM. Consequently, there is an urgent need to develop public health strategies targeting late diagnosis, with a focus on strengthening screening and early detection for high-risk populations, as well as monitoring brain injury, endocrine, and immune functions in individuals with LD, and formulating precise, individualized intervention strategies to reduce the long-term impact of LD on the health of HIV-positive MSM.

The gain-of-function variant in the NLRP3 gene predicts the effectiveness of brief psychotherapy but not the risk of major depression

Major depressive disorder (MDD) is a highly prevalent psychiatric condition whose pathophysiology has been linked to neuroinflammatory processes involving the NLRP3 inflammasome. To address this point, the study investigated the association of the NLRP3 rs10754558 polymorphism with MDD diagnosis in a young adults population based study and the effectiveness of brief psychotherapies in a randomized clinical trial. A cross-sectional, population-based study was conducted with 1100 individuals aged 18-35 years, including 615 controls and 485 patients with MDD. Diagnosis was determined using the Mini International Neuropsychiatric Interview (M.I.N.I.) based on DSM-IV criteria. Our clinical trial included 227 participants with MDD aged 18-60 years from a randomized clinical trial evaluating the effectiveness of two brief psychotherapies for MDD. Depressive and anxiety symptoms were assessed at baseline, post-treatment (16-18 weeks), and 6-month follow-up using the Beck Depression Inventory-II (BDI-II) and the Beck Anxiety Inventory (BAI). Statistical analyses included logistic regression and generalized estimating equation (GEE) model adjusted for demographic and clinical variables. The results showed no significant association between rs10754558 genotypes and MDD diagnosis. However, when evaluating the efficacy of brief psychotherapies, the GG genotype was associated with poorer treatment outcomes for both depressive and anxiety symptoms compared to the GC/CC genotypes (p < 0.05). Longitudinal analysis revealed significant differences over time, with GG individuals demonstrating less symptom improvement (BDI-II: baseline 36.61 to follow-up 21.75; BAI: baseline 26.32 to follow-up 19.55) compared to GC/CC genotypes (BDI-II: baseline 32.05 to follow-up 20.29; BAI: baseline 22.05 to follow-up 17.96). These findings suggest that the GG genotype, previously characterized as a gain-of-function variant, may contribute to genetic heterogeneity influencing psychotherapy outcomes. This highlights the potential for genetic markers, such as rs10754558, to inform personalized psychiatric treatments and improve therapeutic strategies.

Mechanisms underlying stress effects on the brain: Basic concepts and clinical implications

Chronic stress impacts the brain through complex physiological, neurological, and immunological responses. The stress response involves the activation of the sympathetic-adrenal-medullary (SAM) system and the hypothalamic-pituitary-adrenal (HPA) axis, releasing stress hormones like norepinephrine and cortisol. While these responses are adaptive short-term, chronic stress disrupts homeostasis, increasing the risk of cardiovascular diseases, neurodegenerative disorders, and psychiatric conditions such as depression. This dysregulation is linked to persistent neuroinflammation, oxidative stress, and neurotransmitter imbalances involving dopamine and serotonin, impairing neuroplasticity and leading to structural changes in critical brain areas, such as the hippocampus and prefrontal cortex. Moreover, stress affects gene expression, particularly neuroinflammatory pathways, contributing to long-term cognitive function and emotional regulation alterations. Advancements in neuroimaging and molecular techniques, including MRI, PET, and SPECT, hold promise for identifying biomarkers and better understanding stress-induced brain changes. These insights are critical for developing targeted interventions to mitigate the adverse effects of chronic stress on brain health.

Dissecting biological heterogeneity in major depressive disorder based on neuroimaging subtypes with multi-omics data

The heterogeneity of Major Depressive Disorder (MDD) has been increasingly recognized, challenging traditional symptom-based diagnostics and the development of mechanism-targeted therapies. This study aims to identify neuroimaging-based MDD subtypes and dissect their predominant biological characteristics using multi-omics data. A total of 807 participants were included in this study, comprising 327 individuals with MDD and 480 healthy controls (HC). The amplitude of low-frequency fluctuations (ALFF), a functional neuroimaging feature, was extracted for each participant and used to identify MDD subtypes through machine learning clustering. Multi-omics data, including profiles of genetic, epigenetics, metabolomics, and pro-inflammatory cytokines, were obtained. Comparative analyses of multi-omics data were conducted between each MDD subtype and HC to explore the molecular underpinnings involved in each subtype. We identified three neuroimaging-based MDD subtypes, each characterized by unique ALFF pattern alterations compared to HC. Multi-omics analysis showed a strong genetic predisposition for Subtype 1, primarily enriched in neuronal development and synaptic regulation pathways. This subtype also exhibited the most severe depressive symptoms and cognitive decline compared to the other subtypes. Subtype 2 is characterized by immuno-inflammation dysregulation, supported by elevated IL-1 beta levels, altered epigenetic inflammatory measures, and differential metabolites correlated with IL-1 beta levels. No significant biological markers were identified for Subtype 3. Our results identify neuroimaging-based MDD subtypes and delineate the distinct biological features of each subtype. This provides a proof of concept for mechanism-targeted therapy in MDD, highlighting the importance of personalized treatment approaches based on neurobiological and molecular profiles.

Disturbing sleep in female adolescent mice does not increase vulnerability to depression triggers later in life

Poor sleep quality is a major issue for many adolescents and is associated with fatigue, poor academic performance, and depression. Adolescence is a crucial neurodevelopmental stage where multiple neuropsychiatric illnesses often emerge, suggesting increased central nervous system vulnerability, specifically at this age, which could be exacerbated by poor sleep. Studies on adolescent mice show that sleep deprivation or sleep disturbance (SD) induces structural and functional brain changes, indicating that SD affects the adolescent brain. The long-term consequences of such changes are poorly understood. We hypothesize that SD during adolescence increases vulnerability to future depression triggers in adulthood, such as social isolation or inflammation. To test this, female adolescent mice (post-natal day (P)36) were subjected to SD for seven days, 4 h per day during the light phase (zeitgeber time 2-6). We demonstrate that this SD protocol acutely leads to changes in the expression of Cx3Cr1, and Dnmt3b in the hippocampus and of Htr1a in the prefrontal cortex. To examine the long-term consequences of the SD protocol during adulthood (P77-84), the mice were then either exposed to single housing or received a single injection of lipopolysaccharide (LPS) to mimic known triggers of depression. Behavioral changes were examined using digital ventilated cages to track home-cage activity and the open field and tail suspension tests to assess anxiety- and despair-like behavior, respectively. In contrast to our hypothesis, we did not observe any changes in home-cage activity, anxiety- or despair-like behavior as a result of combining SD in adolescent female mice with a depression trigger in adulthood. We conclude that the adolescent brain is sensitive to SD, but SD during adolescence in mice does not lead to an exacerbated depression-like response to social isolation or inflammation during adulthood.

Current Strategies and Future Directions of Wearable Biosensors for Measuring Stress Biochemical Markers for Neuropsychiatric Applications

Most wearable biosensors aimed at capturing psychological state target stress biomarkers in the form of physical symptoms that can correlate with dysfunction in the central nervous system (CNS). However, such markers lack the specificity needed for diagnostic or preventative applications. Wearable biochemical sensors (WBSs) have the potential to fill this gap, however, the technology is still in its infancy. Most WBSs proposed thus far target cortisol. Although cortisol detection is demonstrated as a viable method for approximating the extent and severity of psychological stress, the hormone also lacks specificity. Multiplex WBSs that simultaneously target cortisol alongside other viable stress-related biochemical markers (SBMs) can prove to be indispensable for understanding how psychological stress contributes to the pathophysiology of neuropsychiatric illnesses (NPIs) and, thus, lead to the discovery of new biomarkers and more objective clinical tools. However, none target more than one SBM implicated in NPIs. Till this review, cortisol's connection to dysfunctions in the CNS, to other SBMs, and their implication in various NPIs has not been discussed in the context of developing WBS technology. As such, this review is meant to inform the biosensing and neuropsychiatric communities of viable future directions and possible challenges for WBS technology for neuropsychiatric applications.

New insights into anti-depression effects of bioactive phytochemicals

Depression is one of the most common psychological disorders, and due to its high prevalence and mortality rates, it imposes a significant disease burden. Contemporary treatments for depression involve various synthetic drugs, which have limitations such as side effects, single targets, and slow onset of action. Unlike synthetic medications, phytochemicals offer the benefits of a multi-target and multi-pathway mode of treatment for depression. In this literature review, we describe the pharmacological actions, experimental models, and clinical trials of the antidepressant effects of various phytochemicals. Additionally, we summarize the potential mechanisms by which these phytochemicals prevent depression, including regulating neurotransmitters and their receptors, the HPA axis, inflammatory responses, managing oxidative stress, neuroplasticity, and the gut microbiome. Phytochemicals exert therapeutic effects through multiple pathways and targets, making traditional Chinese medicine (TCM) a promising adjunctive antidepressant for the prevention, alleviation, and treatment of depression. Therefore, this review aims to provide robust evidence for subsequent research into developing phytochemical resources as effective antidepressant agents.

Inflammatory signalling during the perinatal period: Implications for short- and long-term disease risk

During pregnancy and the postpartum, there are dynamic fluctuations in steroid and peptide hormone levels as well as inflammatory signalling. These changes are required for a healthy pregnancy and can persist well beyond the postpartum. Many of the same hormone and inflammatory signalling changes observed during the perinatal period also play a role in symptoms related to autoimmune disorders, psychiatric disorders, and perhaps neurodegenerative disease later in life. In this review, we outline hormonal and immunological shifts linked to pregnancy and the postpartum and discuss the possible role of these shifts in increasing psychiatric, neurodegenerative disease risk and autoimmune symptoms during and following pregnancy. Furthermore, we discuss how key variables such as the number of births (parity) and sex of the fetus can influence inflammatory signalling, and possibly future disease risk, but are not often studied. We conclude by discussing the importance of studying female experiences such as pregnancy and parenting on physiology and disease.

Trajectory of peripheral inflammation during index ECT in association with clinical outcomes in treatment-resistant depression

Background

Electroconvulsive therapy (ECT) is a highly efficacious intervention for severe and intractable depression. Evidence suggests ECT provokes an initial acute inflammatory response that subsequently decreases with repeated administration. However, relationships between inflammatory changes and clinical effects are unclear. Improved understanding of these processes may provide critical insight into effective intervention for treatment-resistant depression (TRD).

Methods

Plasma inflammatory markers were assessed at pre-treatment (T1), after the second ECT session (T2), and after ECT index series completion (post-treatment/T3) in TRD (n = 40). Changes were examined over time and in association with post-treatment Responder/Non-responder status (≥50% reduction in global depression severity) and percent change in affective, cognitive and neurovegetative depressive symptom domains.

Results

C-reactive protein (CRP) and interleukin-6 (IL-6) increased from pre-treatment to T2, and decreased from T2 to post-treatment. Neither early (%T2-T1) nor total (%T1-T3) change in inflammation predicted clinical outcomes, however, the interaction between early/acute inflammatory response and post-treatment inflammation (relative to baseline) was associated with clinical outcomes. Larger initial increases in IL-6 predicted greater reductions in both affective and cognitive symptoms in subjects with higher post-treatment IL-6; those with lower post-treatment IL-6 trended toward the opposite. The same was found between changes in CRP and neurovegetative symptoms.

Conclusions

Though preliminary, these results demonstrate how processes involved in the acute inflammatory response to ECT may differentially influence clinical outcomes depending on overall trajectory of inflammation following ECT. Findings also highlight the importance of examining symptom-specific changes in depression when studying treatment mechanisms, rather than relying solely on global measures of severity.

Do specific myelin autoantibodies and increased cerebral dopamine neurotrophic factor in the context of inflammation predict the diagnosis of attention deficit hyperactivity disorder in medication-free children?

BACKGROUND

The aim of this study was to investigate the serum levels of anti-myelin basic protein (anti-MBP), anti-myelin oligodentrocyte glycoprotein (anti-MOG), myelin-associated glycoprotein (MAG), high-sensitivity C-reactive protein (hs-CRP), cerebral dopamine neurotrophic factor (CDNF), cerebellin-1, and reelin and their relationships with clinical severity and irritability behaviours in children with attention deficit (AD) hyperactivity disorder (ADHD) and typically developing (TD) healthy controls.

METHODS

In this study, 141 children with ADHD between the ages of 8 and 14 years who were medication-free and 135 TD healthy controls were included. The serum levels of anti-MBP, anti-MOG, MAG, CDNF, hs-CRP, cerebellin, and reelin were measured using enzyme-linked immunosorbent assay kits. The Turgay Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV)-based Screening and Evaluation Scale for Attention Deficit and Disruptive Behavior Disorders-Parent Form (TDSM-IV-O) and the affective reactivity index (ARI) scale were used to assess clinical severity and irritability behaviours in the children.

RESULTS

The MAG, CDNF, hs-CRP, reelin, and cerebellin levels were significantly higher in the ADHD group than in the control group, but no significant differences in anti-MBP and anti-MOG levels were found between the groups. Compared with the controls, the patients with ADHD showed significantly higher scores on the ARI self- and parent-report scales. The reelin, hs-CRP, and MAG levels were significantly associated with the TDSM-IV-O AD scores, AD and oppositional defiant (OD) disorder scores and hyperactivity, and OD and conduct disorder scores, respectively. Hs-CRP was significantly associated with anti-MBP and cerebellin levels. In an analysis of covariance, the results were unchanged even after controlling for potential confounders such as age, body mass index, and sex.

CONCLUSION

This study demonstrates that MAG, CDNF, hs-CRP, reelin, and cerebellin levels may play a potential role in the pathogenesis of ADHD.

Is Nasal Dysbiosis a Required Component for Neuroinflammation in Major Depressive Disorder?

Human microbiota is known to influence immune and cerebral responses by direct and/or indirect mechanisms, including hypothalamic-pituitary-adrenal axis signaling, activation of neural afferent circuits to the brain, and by altering the peripheral immune responses (cellular and humoral immune function, circulatory inflammatory cells, and the production of several inflammatory mediators, such as cytokines, chemokines, and reactive oxygen species). The inflammatory responses in the nasal mucosa (rhinitis) or paranasal sinuses (chronic rhinosinusitis) are dual conditions related with a greater risk for developing depression. In the nasal cavity, anatomic components of the olfactive function are in direct contact with the CNS through the olfactory receptors, neurons, and axons that end in the olfactory bulb and the entorhinal cortex. Local microbiome alterations (dysbiosis) are linked to transepithelial translocation of microorganisms and their metabolites, which disrupts the epithelial barrier and favors vascular permeability, increasing the levels of several inflammatory molecules (both cytokines and non-cytokine mediators: extracellular vesicles (exosomes) and neuropeptides), triggering local inflammation (rhinitis) and the spread of these components into the central nervous system (neuroinflammation). In this review, we discuss the role of microbiota-related immunity in conditions affecting the nasal mucosa (chronic rhinosinusitis and allergic rhinitis) and their relevance in major depressive disorders, focusing on the few mechanisms known to be involved and providing some hypothetical proposals on the pathophysiology of depression.

Single Exposure to Low-Intensity Focused Ultrasound Causes Biphasic Opening of the Blood-Brain Barrier Through Secondary Mechanisms

Background/Objective: The blood-brain barrier (BBB) is selectively permeable, but it also poses significant challenges for treating CNS diseases. Low-intensity focused ultrasound (LiFUS), paired with microbubbles is a promising, non-invasive technique for transiently opening the BBB, allowing enhanced drug delivery to the central nervous system (CNS). However, the downstream physiological effects following BBB opening, particularly secondary responses, are not well understood. This study aimed to characterize the time-dependent changes in BBB permeability, transporter function, and inflammatory responses in both sonicated and non-sonicated brain tissues following LiFUS treatment. Methods: We employed in situ brain perfusion to assess alterations in BBB integrity and transporter function, as well as multiplex cytokine analysis to quantify the inflammatory response. Results: Our findings show that LiFUS significantly increased vascular volume and glucose uptake, with reduced P-gp function in brain tissues six hours post treatment, indicating biphasic BBB disruption. Additionally, elevated levels of pro-inflammatory cytokines, including TNF-α and IL-6, were observed in both sonicated and non-sonicated regions. A comparative analysis between wild-type and immunodeficient mice revealed distinct patterns of cytokine release, with immunodeficient mice showing lower serum concentrations of IFN-γ and TNF-α, highlighting the potential impact of immune status on the inflammatory response to LiFUS. Conclusions: This study provides new insights into the biphasic nature of LiFUS-induced BBB disruption, emphasizing the importance of understanding the timing and extent of secondary physiological changes.

Chronic unpredictable stress induces anxiety-like behavior and oxidative stress, leading to diminished ovarian reserve

Chronic stress can adversely affect the female reproductive endocrine system, potentially leading to disorders and impairments in ovarian function. However, current research lacks comprehensive understanding regarding the biochemical characteristics and underlying mechanisms of ovarian damage induced by chronic stress. We established a stable chronic unpredictable stress (CUS)-induced diminished ovarian reserve (DOR) animal model. Our findings demonstrated that prolonged CUS treatment over eight weeks resulted in increased atresia follicles in female mice. This atresia was accompanied by decreased AMH and increased FSH levels. Furthermore, we observed elevated levels of corticosterone both in the peripheral blood and within the ovary. Additionally, we detected abnormalities in ATP metabolism within the ovarian tissue. CUS exposure led to oxidative stress in the ovaries, fostering a microenvironment characterized by oxidative damage to mouse ovarian granulosa cells (mGCs) and heightened levels of reactive oxygen species. Furthermore, CUS prompted mGCs to undergo apoptosis via the mitochondrial pathway. These findings indicate a direct association between the fundamental physiological alterations leading to DOR and the oxidative phosphorylation processes within mGCs. The diminished ATP production by mGCs, triggered by CUS, emerges as a pivotal indicator of CUS-induced DOR. Our study establishes an animal model to investigate the impact of chronic stress on ovarian reserve function and sheds light on potential mechanisms underlying this phenomenon.

Carvacrol is potential molecule for diabetes treatment

Diabetes is an important chronic disease that can lead to various negative consequences and complications. In recent years, several new alternative treatments have been developed to improve diabetes. Carvacrol found in essential oils of numerous plant species and has crucial potential effects on diabetes. The anti-diabetic effects of carvacrol have also been comprehensively studied in diabetic animal and cell models. In addition, carvacrol could improve diabetes through affecting diabetes-related enzymes, insulin resistance, insulin sensitivity, glucose uptake, anti-oxidant, and anti-inflammatory mechanisms. The use of carvacrol alone or in combination with anti-diabetic therapies could show a significant potential effect in the treatment of diabetes. This review contributes an overview of the effect of carvacrol in diabetes and anti-diabetic mechanisms.

Exploring the anti-depressant effects and nitric oxide modulation of quercetin: A preclinical study in Socially Isolated mice

OBJECTIVES

This study investigates the effects of quercetin, an antioxidant and nitric oxide (NO) modulator, on depressive-like behaviours triggered by social isolation stress (SIS) in mice. SIS, known to harm psychosocial functioning and increase the risk of depression, involves oxidative stress and NO in its pathophysiology.

METHODS

72 male mice were divided into nine groups, including the social (SC) group as the control group (stress-free with normal saline intake). The isolation (IC) groups received normal saline, quercetin at doses of 10, 20, and 40 mg/kg, the nitric oxide synthetase inhibitor L-NAME at a dose of 5 mg/kg, the NO precursor L-arginine at a dose of 100 mg/kg, an ineffective dose of quercetin combined with L-NAME and an effective dose of quercetin combined with L-arginine. Behavioural tests (open-field, forced swimming, and splash tests) were conducted, followed by measuring hippocampal nitrite levels.

RESULTS

Quercetin significantly reduced immobility in the forced swimming test, increased activity in the open-field test, and enhanced grooming behaviour, particularly at 40 mg/kg. Co-administration of an ineffective dose of quercetin (10 mg/kg) with L-NAME increased immobility and grooming activity time. Interestingly, co-administration of the effective dose of quercetin (40 mg/kg) with L-arginine increased immobility time in the FST. Additionally, administration of quercetin at doses of 20 and 40 mg/kg significantly reduced the nitrite level in the hippocampus of SIS mice. Furthermore, co-administration of L-NAME and L-arginine with ineffective and effective doses of quercetin decreased and increased nitrite levels in the hippocampus and increased immobility time in the FST compared to their respective counterparts administered alone.

CONCLUSIONS

These results suggest quercetin's potential in alleviating depression by modulating NO levels, pointing to its promise in treating depression associated with chronic stressors like social isolation.

Air pollution mixture exposure during pregnancy and postpartum psychological functioning: racial/ethnic- and fetal sex-specific associations

BACKGROUND

Prenatal air pollution (AP) exposure has been linked to postpartum psychological functioning, impacting health outcomes in both women and children. Extant studies primarily focused on individual pollutants.

OBJECTIVE

To assess the association between prenatal exposure to a mixture of seven AP components and postpartum psychological functioning using daily exposure data and data-driven statistical methods.

METHODS

Analyses included 981 women recruited at 24.0 ± 9.9 weeks gestation and followed longitudinally. We estimated prenatal daily exposure levels for constituents of fine particles [elemental carbon (EC), organic carbon (OC), nitrate (NO3-), sulfate (SO42-), ammonium (NH4+)], nitrogen dioxide (NO2), and ozone (O3) using validated global 3-D chemical-transport models and satellite-based hybrid models based on residential addresses. Edinburgh Postnatal Depression Scale (EPDS) was administered to participants to derive a total EPDS score and the subconstruct scores for anhedonia and depressive symptoms. A distributed lag model (DLM) was employed within Bayesian Kernel Machine Regression (BKMR) to develop time-weighted exposure profile for each pollutant. These exposures were then input into a Weighted Quantile Sum (WQS) regression to estimate an overall mixture effect, adjusted for maternal age, education, race/ethnicity, season of delivery, and delivery year. Effect modification by race/ethnicity and fetal sex was also examined.

RESULTS

Women were primarily Hispanic (51%) and Black (32%) reporting ≤12 years of education (58%). Prenatal exposure to an AP mixture was significantly associated with increased anhedonia subscale z-scores, particularly in Hispanics (β = 0.07, 95%CI = 0.004-0.13, per unit increase in WQS index). It was also borderline associated with increased total EPDS (β = 0.11, 95%CI = 0.00-0.22) and depressive symptom subscale (β = 0.09, 95%CI = -0.02 to 0.19) z-scores, particularly among Hispanic women who gave birth to a male infant. Sulfate (SO42-), O3 and OC were major contributors to these associations.

IMPACT

This study utilizes an advanced data-driven approach to examine the temporally- and mixture-weighted effects of prenatal air pollution exposure on postpartum psychological functioning. We found that exposure to a prenatal air pollution mixture predicted poorer postpartum psychological functioning, particularly anhedonia symptoms in Hispanic women. Findings underscore the importance of considering both exposure mixtures as well as potential modifying factors to better help identify particular pollutants that drive effects and susceptible populations, which can inform more effective intervention strategies.

Seeing through "brain fog": neuroimaging assessment and imaging biomarkers for cancer-related cognitive impairments

Advances in cancer diagnosis and treatment have substantially improved patient outcomes and survival in recent years. However, up to 75% of cancer patients and survivors, including those with non-central nervous system (non-CNS) cancers, suffer from "brain fog" or impairments in cognitive functions such as attention, memory, learning, and decision-making. While we recognize the impact of cancer-related cognitive impairment (CRCI), we have not fully investigated and understood the causes, mechanisms and interplays of various involving factors. Consequently, there are unmet needs in clinical oncology in assessing the risk of CRCI and managing patients and survivors with this condition in order to make informed treatment decisions and ensure the quality of life for cancer survivors. The state-of-the-art neuroimaging technologies, particularly clinical imaging modalities like magnetic resonance imaging (MRI) and positron emission tomography (PET), have been widely used to study neuroscience questions, including CRCI. However, in-depth applications of these functional and molecular imaging methods in CRCI and their clinical implementation for CRCI management are largely limited. This scoping review provides the current understanding of contributing neurological factors to CRCI and applications of the state-of-the-art multi-modal neuroimaging methods in investigating the functional and structural alterations related to CRCI. Findings from these studies and potential imaging-biomarkers of CRCI that can be used to improve the assessment and characterization of CRCI as well as to predict the risk of CRCI are also highlighted. Emerging issues and perspectives on future development and applications of neuroimaging tools to better understand CRCI and incorporate neuroimaging-based approaches to treatment decisions and patient management are discussed.

Smart Response Biomaterials for Pain Management

The intricate nature of pain classification and mechanism constantly affects the recovery of diseases and the well-being of patients. Key medical challenges persist in devising effective pain management strategies. Therefore, a comprehensive review of relevant methods and research advancements in pain management is conducted. This overview covers the main categorization of pain and its developmental mechanism, followed by a review of pertinent research and techniques for managing pain. These techniques include commonly prescribed medications, invasive procedures, and noninvasive physical therapy methods used in rehabilitation medicine. Additionally, for the first time, a systematic summary of the utilization of responsive biomaterials in pain management is provided, encompassing their response to physical stimuli such as ultrasound, magnetic fields, electric fields, light, and temperature, as well as changes in the physiological environment like reactive oxygen species (ROS) and pH. Even though the application of responsive biomaterials in pain management remains limited and at a fundamental level, recent years have seen the examination and debate of relevant research findings. These profound discussions aim to provide trends and directions for future research in pain management.

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.

Prebiotics Mitigate the Detrimental Effects of High-Fat Diet on memory, anxiety and microglia functionality in Ageing Mice

Ageing is characterised by a progressive increase in systemic inflammation and especially neuroinflammation. Neuroinflammation is associated with altered brain states that affect behaviour, such as an increased level of anxiety with a concomitant decline in cognitive abilities. Although multiple factors play a role in the development of neuroinflammation, microglia have emerged as a crucial target. Microglia are the only macrophage population in the CNS parenchyma that plays a crucial role in maintaining homeostasis and in the immune response, which depends on the activation and subsequent deactivation of microglia. Therefore, microglial dysfunction has a major impact on neuroinflammation. The gut microbiota has been shown to significantly influence microglia from birth to adulthood in terms of development, proliferation, and function. Diet is a key modulating factor that influences the composition of the gut microbiota, along with prebiotics that support the growth of beneficial gut bacteria. Although the role of diet in neuroinflammation and behaviour has been well established, its relationship with microglia functionality is less explored. This article establishes a link between diet, animal behaviour and the functionality of microglia. The results of this research stem from experiments on mouse behaviour, i.e., memory, anxiety, and studies on microglia functionality, i.e., cytochemistry (phagocytosis, cellular senescence, and ROS assays), gene expression and protein quantification. In addition, shotgun sequencing was performed to identify specific bacterial families that may play a crucial role in the brain function. The results showed negative effects of long-term consumption of a high fat diet on ageing mice, epitomised by increased body weight, glucose intolerance, anxiety, cognitive impairment and microglia dysfunction compared to ageing mice on a control diet. These effects were a consequence of the changes in gut microbiota modulated by the diet. However, by adding the prebiotics fructo- and galacto-oligosaccharides, we were able to mitigate the deleterious effects of a long-term high-fat diet.

Maternal separation as early-life stress: Mechanisms of neuropsychiatric disorders and inspiration for neonatal care

The establishment of positive early parent-infant relationships provide essential nourishment and social stimulation for newborns. During the early stages of postnatal brain development, events such as synaptogenesis, neuronal maturation and glial differentiation occur in a highly coordinated manner. Maternal separation, as an early-life stress introducer, can disrupt the formation of parent-child bonds and exert long-term adverse effects throughout life. When offspring are exposed to maternal separation, the body regulates the stress of maternal separation through multiple mechanisms, including neuroinflammatory responses, neuroendocrinology, and neuronal electrical activity. In adulthood, early maternal separation has long-term effects, such as the induction of neuropsychiatric disorders such as anxiety, depression, and cognitive dysfunction. This review summarized the application of maternal separation models and the mechanisms of stress system response in neuropsychiatric disorders, serving as both a reminder and inspiration for approaches to improve neonatal care, "from bench to bedside".

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Therapeutic Efficacy of Adipose Tissue-Derived Components in Neuropathic Pain: A Systematic Review

BACKGROUND

Neuropathic pain results from a defect in the somatosensory nervous system caused by a diversity of etiologies. The effect of current treat-ment with analgesics and surgery is limited. Studies report the therapeutic use of adipose tissue-derived components to treat neuropathic pain as a new treatment modality.

OBJECTIVE

The aim of this systematic review was to investigate the therapeutic clinical efficacy of adipose tissue-derived components on neuro-pathic pain.

METHODS

PubMed, Medline, Cochrane and Embase databases were searched until August 2023. Clinical studies assessing neuropathic pain after autologous fat grafting or the therapeutic use of adipose tissue-derived com-ponents were included. The outcomes of interest were neuropathic pain and quality of life.

RESULTS

In total, 433 studies were identified, of which 109 dupli-cates were removed, 324 abstracts were screened and 314 articles were excluded. In total, ten studies were included for comparison. Fat grafting and cellular stromal vascular fraction were used as treatments. Fat grafting indications were post-mastectomy pain syndrome, neuromas, post-herpetic neuropathy, neuro-pathic scar pain and trigeminal neuropathic pain. In seven studies, neuropathic pain levels decreased, and overall, quality of life did not improve.

CONCLUSIONS

The therapeutic efficacy of adipose tissue-derived components in the treatment of neuropathic pain remains unclear due to the few performed clinical trials with small sample sizes for various indications. Larger and properly designed (randomized) controlled trials are required.

"Inflamed" depression: A review of the interactions between depression and inflammation and current anti-inflammatory strategies for depression

Depression is a common mental disorder, the effective treatment of which remains a challenging issue worldwide. The clinical pathogenesis of depression has been deeply explored, leading to the formulation of various pathogenic hypotheses. Among these, the monoamine neurotransmitter hypothesis holds a prominent position, yet it has significant limitations as more than one-third of patients do not respond to conventional treatments targeting monoamine transmission disturbances. Over the past few decades, a growing body of research has highlighted the link between inflammation and depression as a potential key factor in the pathophysiology of depression. In this review, we first summarize the relationship between inflammation and depression, with a focus on the pathophysiological changes mediated by inflammation in depression. The mechanisms linking inflammation to depression as well as multiple anti-inflammatory strategies are also discussed, and their efficacy and safety are assessed. This review broadens the perspective on specific aspects of using anti-inflammatory strategies for treating depression, laying the groundwork for advancing precision medicine for individuals suffering from "inflamed" depression.

Emerging Roles of Bile Acids and TGR5 in the Central Nervous System: Molecular Functions and Therapeutic Implications

Bile acids (BAs) are cholesterol derivatives synthesized in the liver and released into the digestive tract to facilitate lipid uptake during the digestion process. Most of these BAs are reabsorbed and recycled back to the liver. Some of these BAs progress to other tissues through the bloodstream. The presence of BAs in the central nervous system (CNS) has been related to their capacity to cross the blood-brain barrier (BBB) from the systemic circulation. However, the expression of enzymes and receptors involved in their synthesis and signaling, respectively, support the hypothesis that there is an endogenous source of BAs with a specific function in the CNS. Over the last decades, BAs have been tested as treatments for many CNS pathologies, with beneficial effects. Although they were initially reported as neuroprotective substances, they are also known to reduce inflammatory processes. Most of these effects have been related to the activation of the Takeda G protein-coupled receptor 5 (TGR5). This review addresses the new challenges that face BA research for neuroscience, focusing on their molecular functions. We discuss their endogenous and exogenous sources in the CNS, their signaling through the TGR5 receptor, and their mechanisms of action as potential therapeutics for neuropathologies.

Arctiin Mitigates Neuronal Injury by Modulating the P2X7R/NLPR3 Inflammasome Signaling Pathway

Depression, recognized globally as a primary cause of disability, has its pathogenesis closely related to neuroinflammation and neuronal damage. Arctiin (ARC), the major bioactive component of Fructus arctii, has various pharmacological activities, such as anti-inflammatory and neuroprotective effects. Building on previous findings that highlighted ARC's capability to mitigate depression by dampening microglial hyperactivation and thereby reducing neuroinflammatory responses and cortical neuronal damage in mice, the current study delves deeper into ARC's therapeutic potential by examining its impact on hippocampal neuronal damage in depression. Utilizing both chronic unpredictable mild stress (CUMS)-induced depression model in mice and corticosterone (CORT)-stimulated PC12 cell model of neuronal damage, the techniques including Nissl staining, immunohistochemistry, western blotting, ELISA, lactate dehydrogenase assays, colony formation assays, immunofluorescence staining and molecular docking were employed to unravel the mechanisms behind ARC's neuroprotective effects. The findings revealed that ARC not only mitigates hippocampal neuropathological damage and reduces serum CORT levels in CUMS-exposed mice but also enhances cell activity while reducing lactate dehydrogenase release in CORT-stimulated PC12 cells. ARC attenuated neuroinflammatory responses and neuronal apoptosis by inhibiting the overactivation of the P2X7 receptor (P2X7R)/NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome signaling pathway, similar to the effect of A438079 (P2X7R antagonist). Interestingly, pretreatment with A438079 blocked the neuroprotective effect of ARC. Computer modeling predicted that both ARC and A438079 have strong binding with P2X7R and they have the same binding site. These results suggested that ARC may exert a neuroprotective role by binding to P2X7R, thereby inhibiting the P2X7R/NLRP3 inflammasome signaling pathway.

Dysregulated zinc homeostasis and microadenomas in the anterior pituitary: pathological insights into suicide risk

Background

Suicide is a significant public health problem influenced by various risk factors, including dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis. Zinc (Zn), essential for pituitary function in hormone synthesis and release, has been linked to suicide, with studies noting reduced serum levels and altered brain transport mechanisms. Despite Zn's crucial role in pituitary function and its involvement in suicidal behavior, information on pituitary Zn in suicide is scarce. Tumor cells modify Zn dynamics in tissues, and a previous report suggests microadenomas in the anterior pituitary as a risk factor for suicide.

Methods

Histopathological analysis with hematoxylin-eosin stain and histochemical techniques to assess Zn homeostasis were carried out on anterior pituitary postmortem samples from 14 suicide completers and 9 non-suicidal cases.

Results

Pituitary microadenomas were identified in 35% of suicide cases and none in the non-suicidal cases. Furthermore, compartmentalized Zn (detected via dithizone reactivity), but not free Zn levels (detected via zinquin reactivity), was lower in the suicide cases compared to the non-suicidal group.

Conclusion

This is the first report of a potential association between disrupted Zn homeostasis and microadenomas in the anterior pituitary as a feature in suicide and provides critical insights for future neuroendocrine Zn-related research.

Histone 3 Trimethylation Patterns are Associated with Resilience or Stress Susceptibility in a Rat Model of Major Depression Disorder

Major Depressive Disorder (MDD) is a severe and multifactorial psychiatric condition. Evidence has shown that environmental factors, such as stress, significantly explain MDD pathophysiology. Studies have hypothesized that changes in histone methylation patterns are involved in impaired glutamatergic signaling. Based on this scenario, this study aims to investigate histone 3 involvement in depression susceptibility or resilience in MDD pathophysiology by investigating cellular and molecular parameters related to i) glutamatergic neurotransmission, ii) astrocytic functioning, and iii) neurogenesis. For this, we subjected male Wistar rats to the Chronic Unpredictable Mild Stress (CUMS) model of depression. We propose that by evaluating the sucrose consumption, open field, and object recognition test performance from animals submitted to CUMS, it is possible to predict with high specificity rats with susceptibility to depressive-like phenotype and resilient to the depressive-like phenotype. We also demonstrated, for the first time, that patterns of H3K4me3, H3K9me3, H3K27me3, and H3K36me3 trimethylation are strictly associated with the resilient or susceptible to depressive-like phenotype in a brain-region-specific manner. Additionally, susceptible animals have reduced DCx and GFAP and resilient animals present increase of AQP-4 immunoreactivity. Together, these results provide evidence that H3 trimethylations are related to the development of the resilient or susceptible to depressive-like phenotype, contributing to further advances in the pathophysiology of MDD and the discovery of mechanisms behind resilience.

Macrophage-Centric Biomaterials for Bone Regeneration in Diabetes Mellitus: Contemporary Advancements, Challenges, and Future Trajectories

Increased susceptibility to bone fragility and the diminution of bone regenerative capacity are recognized as significant and frequent sequelae of diabetes mellitus. Research has elucidated the pivotal role of macrophages in the pathogenesis and repair of diabetic bone defects. Notwithstanding this, the therapeutic efficacy of traditional interventions remains predominantly inadequate. Concomitant with substantial advancements in tissue engineering in recent epochs, there has been an escalation in the development of biomaterials designed to modulate macrophage activity, thereby augmenting osseous tissue regeneration in the context of hyperglycemia. This review amalgamates insights from extant research and delineates recent progressions in the domain of biomaterials that target macrophages for the regeneration of diabetic bone, whilst also addressing the clinical challenges and envisaging future directions within this field.

Hippocampal subfield morphology from first episodes of bipolar disorder type II and major depressive disorder in a drug naïve Chinese cohort

INTRODUCTION

Symptoms during the onset of major depressive disorder [MDD] and bipolar disorder type II [BD-II] are similar. The difference of hippocampus subregion could be a biological marker to distinguish MDD from BD-II.

METHODS

We recruited 61 drug-naïve patients with a first-episode MDD and BD-II episode and 30 healthy controls (HC) to participate in a magnetic resonance imaging [MRI] study. We built a general linear model (one-way analysis of covariance) with 22 hippocampal subfields and two total hippocampal volumes as dependent variables, and the diagnosis of MDD, BD-II, and HC as independent variables. We performed pair-wise comparisons of hippocampal subfield volumes between MDD and HC, BD-II and MDD, BD-II and HC with post hoc for primary analysis.

RESULTS

We identified three regions that differed significantly in size between patients and controls. The left hippocampal fissure, the hippocampal-amygdaloid transition area (HATA), and the right subiculum body were all significantly larger in patients with MDD compared with the HC. In the onset of first-episode of MDD, the hippocampal volume increased significantly, especially on the left side comparing to HC. However, we found differences between MDD and BD-II were not statistically significant. The volume of the left HATA and right subiculum body in BD-II was larger.

CONCLUSIONS

The sample size of this study is relatively small, as it is a cross-sectional comparative study. In both MDD and BD-II groups, the volume of more left subregions appeared to increase. The left subregions were severely injured in the development of depressive disorder.

Altered blood parameters in "major depression" patients receiving repetitive transcranial magnetic stimulation (rTMS) therapy: a randomized case-control study

Major depressive disorder (MDD) is a debilitating illness that includes depressive mood. Repetitive Transcranial Magnetic Stimulation (rTMS) is a therapy method used in the treatment of MDD. The purpose of this study was to assess neurotrophic factors, and oxidative stress levels in MDD patients and evaluate the changes in these parameters as a result of rTMS therapy. Twenty-five patients with MDD and twenty-six healthy volunteers with the same demographic characteristics were included in the study. Brain-derived neurotrophic factors were measured photometrically with commercial kits. Oxidative stress parameters were measured by the photometric method. Oxidative stress index (OSI) and disulfide (DIS) levels were calculated with mathematical formulas. In this study, total antioxidant status (TAS), total thiol (TT), and native thiol (NT) antioxidant parameters and brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), and allopregnanolone (ALLO) levels were reduced in pre-rTMS with regard to the healthy control group; TOS, OSI, DIS, and S100 calcium-binding protein B (S100B) levels were increased statistically significantly (p < 0.01). Moreover, owing to TMS treatment; TAS, TT, NT, BDNF, GDNF, and ALLO levels were increased compared to pre-rTMS, while DIS, TOS, OSI, and S100B levels were decreased significantly (p < 0.01). The rTMS treatment reduces oxidative stress and restores thiol-disulfide balance in MDD patients. Additionally, rTMS modulates neurotrophic factors and neuroactive steroids, suggesting its potential as an antidepressant therapy. The changes in the biomarkers evaluated may help determine a more specific approach to treating MDD with rTMS therapy.

Omics approaches open new horizons in major depressive disorder: from biomarkers to precision medicine

Major depressive disorder (MDD) is a recurrent episodic mood disorder that represents the third leading cause of disability worldwide. In MDD, several factors can simultaneously contribute to its development, which complicates its diagnosis. According to practical guidelines, antidepressants are the first-line treatment for moderate to severe major depressive episodes. Traditional treatment strategies often follow a one-size-fits-all approach, resulting in suboptimal outcomes for many patients who fail to experience a response or recovery and develop the so-called "therapy-resistant depression". The high biological and clinical inter-variability within patients and the lack of robust biomarkers hinder the finding of specific therapeutic targets, contributing to the high treatment failure rates. In this frame, precision medicine, a paradigm that tailors medical interventions to individual characteristics, would help allocate the most adequate and effective treatment for each patient while minimizing its side effects. In particular, multi-omic studies may unveil the intricate interplays between genetic predispositions and exposure to environmental factors through the study of epigenomics, transcriptomics, proteomics, metabolomics, gut microbiomics, and immunomics. The integration of the flow of multi-omic information into molecular pathways may produce better outcomes than the current psychopharmacological approach, which targets singular molecular factors mainly related to the monoamine systems, disregarding the complex network of our organism. The concept of system biomedicine involves the integration and analysis of enormous datasets generated with different technologies, creating a "patient fingerprint", which defines the underlying biological mechanisms of every patient. This review, centered on precision medicine, explores the integration of multi-omic approaches as clinical tools for prediction in MDD at a single-patient level. It investigates how combining the existing technologies used for diagnostic, stratification, prognostic, and treatment-response biomarkers discovery with artificial intelligence can improve the assessment and treatment of MDD.

Blocking CCR5 activity by maraviroc augmentation in post-stroke depression: a proof-of-concept clinical trial

BACKGROUND

Post-stroke depression (PSD) is a significant impediment to successful rehabilitation and recovery after a stroke. Current therapeutic options are limited, leaving an unmet demand for specific and effective therapeutic options. Our objective was to investigate the safety of Maraviroc, a CCR5 antagonist, as a possible mechanism-based add-on therapeutic option for PSD in an open-label proof-of-concept clinical trial.

METHODS

We conducted a 10-week clinical trial in which ten patients with subcortical and cortical stroke, suffering from PSD. were administered a daily oral dose of 300 mg Maraviroc. Participants were then monitored for an additional eight weeks. The primary outcome measure was serious treatment-emergent adverse events (TEAEs) and TEAEs leading to discontinuation. The secondary outcome measure was a change in the Montgomery-Asberg Depression Rating Scale (MADRS).

RESULTS

Maraviroc was well tolerated, with no reports of serious adverse events or discontinuations due to intolerance. The MADRS scores substantially reduced from baseline to week 10 (mean change: -16.4 ± 9.3; p < 0.001). By the conclusion of the treatment phase, a favorable response was observed in five patients, with four achieving remission. The time to response was relatively short, approximately three weeks. After the cessation of treatment, MADRS scores increased at week 18 by 6.1 ± 9.6 points (p = 0.014).

CONCLUSIONS

Our proof-of-concept study suggests that a daily dosage of 300 mg of Maraviroc may represent a well-tolerated and potentially effective pharmacological approach to treating PSD. Further comprehensive placebo-controlled studies are needed to assess the impact of Maraviroc augmentation on PSD.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05932550, Retrospectively registered: 28/06/2023.

Immunization with a low dose of zymosan A confers resistance to depression-like behavior and neuroinflammatory responses in chronically stressed mice

Stimulation of the innate immune system prior to stress exposure is a possible strategy to prevent depression under stressful conditions. Based on the innate immune system stimulating activities of zymosan A, we hypothesize that zymosan A may prevent the development of chronic stress-induced depression-like behavior. Our results showed that a single injection of zymosan A 1 day before stress exposure at a dose of 2 or 4 mg/kg, but not at a dose of 1 mg/kg, prevented the development of depression-like behaviors in mice treated with chronic social defeat stress (CSDS). The prophylactic effect of a single zymosan A injection (2 mg/kg) on CSDS-induced depression-like behaviors disappeared when the time interval between zymosan A and stress exposure was extended from 1 day or 5 days to 10 days, which was rescued by a second zymosan A injection 10 days after the first zymosan A injection and 4 days (4×, once daily) of zymosan A injections 10 days before stress exposure. Further analysis showed that a single zymosan A injection (2 mg/kg) 1 day before stress exposure could prevent the CSDS-induced increase in pro-inflammatory cytokines in the hippocampus and prefrontal cortex. Inhibition of the innate immune system by pretreatment with minocycline (40 mg/kg) abolished the preventive effect of zymosan A on CSDS-induced depression-like behaviors and CSDS-induced increase in pro-inflammatory cytokines in the brain. These results suggest that activation of the innate immune system triggered by zymosan A prevents the depression-like behaviors and neuroinflammatory responses in the brain induced by chronic stress.

Association between Vitamin D Levels During Pregnancy and Postpartum Depression: A Narrative Reviews

Background

Postpartum Depression (PPD) is a serious depression that develops in the first year, with unknown explained reasons. Many studies evaluated the impact of Vitamin D (VD) levels on depression during pregnancy and postnatal. This narrative review aims to review any association between serum VD levels during pregnancy and the development of PPD.

Materials and Methods

PPD data from published trials and research articles (period from 2012 to 2022) were assessed through PubMed, Scopus, Science Direct, and Google Scholar using the following terms: Depression, pregnancy, 25-hydroxyvitamin D (25OH VD), vitamin D deficiency (VDD) and postpartum (PP). Articles were selected manually and with careful tracking to avoid duplication. Articles that investigated any association between VD levels during pregnancy and PPD in the time frame were included in the study, while articles investigating VD levels of PP without depression were excluded.

Results

In this narrative review, five out of seven studies showed an association between PPD and VDD during pregnancy. Danish National Birth Cohort (DNBC), Edinburgh Postnatal Depression Scale (EPDS) and Center for Epidemiologic Studies Depression Scale (CES-D) enrolled among different studies from 3 days to 1 year PP to assess PPD.

Conclusions

Pregnant women with VDD are significantly associated with PPD. Longitudinal follow-up studies are needed to evaluate the association between VDD with PPD. Screening VD levels among pre-postnatal mothers may be essential for awareness programs that can be implemented to promote remission of postnatal depression.

Pro-inflammatory cytokines in stress-induced depression: Novel insights into mechanisms and promising therapeutic strategies

Stress-mediated depression is one of the common psychiatric disorders with a high prevalence and suicide rate, there is a lack of effective treatment. Accordingly, effective treatments with few adverse effects are urgently needed. Pro-inflammatory cytokines (PICs) may play a key role in stress-mediated depression. Thereupon, both preclinical and clinical studies have found higher levels of IL-1β, TNF-α and IL-6 in peripheral blood and brain tissue of patients with depression. Recent studies have found PICs cause depression by affecting neuroinflammation, monoamine neurotransmitters, hypothalamic pituitary adrenal axis and neuroplasticity. Moreover, they play an important role in the symptom, development and progression of depression, maybe a potential diagnostic and therapeutic marker of depression. In addition, well-established antidepressant therapies have some relief on high levels of PICs. Importantly, anti-inflammatory drugs relieve depressive symptoms by reducing levels of PICs. Collectively, reducing PICs may represent a promising therapeutic strategy for depression.

Human olfactory neural progenitor cells reveal differences in IL-6, IL-8, thrombospondin-1, and MCP-1 in major depression disorder and borderline personality disorder

Background

Discovering biological markers is essential for understanding and treating mental disorders. Despite the limitations of current non-invasive methods, neural progenitor cells from the olfactory epithelium (hNPCs-OE) have been emphasized as potential biomarker sources. This study measured soluble factors in these cells in Major Depressive Disorder (MDD), Borderline Personality Disorder (BPD), and healthy controls (HC).

Methods

We assessed thirty-five participants divided into MDD (n=14), BPD (n=14), and HC (n=7). MDD was assessed using the Hamilton Depression Rating Scale. BPD was evaluated using the DSM-5 criteria and the Structured Clinical Interview for Personality Disorders. We isolated hNPCs-OE, collected intracellular proteins and conditioned medium, and quantified markers and soluble factors, including Interleukin-6, interleukin-8, and others. Analysis was conducted using one-way ANOVA or Kruskal-Wallis test and linear regression.

Results

We found that hNPCs-OE of MDD and BPD decreased Sox2 and laminin receptor-67 kDa levels. MASH-1 decreased in BPD, while tubulin beta-III decreased in MDD compared to controls and BPD. Also, we found significant differences in IL-6, IL-8, MCP-1, and thrombospondin-1 levels between controls and MDD, or BPD, but not between MDD and BPD.

Conclusions

Altered protein markers are evident in the nhNPCs-OE in MDD and BPD patients. These cells also secrete higher concentrations of inflammatory cytokines than HC cells. The results suggest the potential utility of hNPCs-OE as an in vitro model for researching biological protein markers in psychiatric disorders. However, more extensive validation studies are needed to confirm their effectiveness and specificity in neuropsychiatric disorders.

Altered serum cytokines in patients with symptomatic disk herniation and depressive symptoms

Purpose

An increasing number of studies have indicated the important role of cytokines in the development of depressive disturbances (DD). In medically ill patients, cytokines can provoked sickness behavior, the signs of which resemble DD. This results in alterations in behavior to limit energy expenditure and redirect it to cope with particular diseases. The aim of our study was to investigate the role of pro-inflammatory IL-6, TNF-α, and IL-1β and anti-inflammatory IL-10 and TGF-β in DD observed in patients suffering from pain caused by disk herniation (DH) qualified for surgery.

Patients and methods

The intensity of DD assessed by using Beck Depression Inventory, pain intensity, and functional impairment were evaluated in 70 patients with DH who were qualified for surgery. Pro-inflammatory serum levels of TNF-α, IL-1, IL-6, anti-inflammatory TGF-β, and IL-10 were measured.

Results

Elevated serum levels of TGF-β, IL-10, and IL-6 were found in the group with moderate and severe depressive symptoms (SD) compared with the groups with mild (MD) or no depressive symptoms (ND). TGF-β levels were negatively correlated with pain intensity, as assessed using the Present Pain Intensity scale in SD. Functional impairment measured using the Oswestry Disability Index was the most advanced in SD group.

Conclusion

Results of our study can suggest association between depressive disturbances and anti-inflammatory cytokines TGF-β and IL-10. Functional impairment of SD group is more severe but serum levels of TGF-β and IL-10, which are involved in the healing processes, are increased.

Autophagy in Neuroinflammation: A Focus on Epigenetic Regulation

Neuroinflammation, characterized by the secretion of abundant inflammatory mediators, pro-inflammatory polarization of microglia, and the recruitment of infiltrating myeloid cells to foci of inflammation, drives or exacerbates the pathological processes of central nervous system disorders, especially in neurodegenerative diseases. Autophagy plays an essential role in neuroinflammatory processes, and the underlaying physiological mechanisms are closely correlated with neuroinflammation-related signals. Inhibition of mTOR and activation of AMPK and FOXO1 enhance autophagy and thereby suppress NLRP3 inflammasome activity and apoptosis, leading to the relief of neuroinflammatory response. And autophagy mitigates neuroinflammation mainly manifested by promoting the polarization of microglia from a pro-inflammatory to an anti-inflammatory state, reducing the production of pro-inflammatory mediators, and up-regulating the levels of anti-inflammatory factors. Notably, epigenetic modifications are intimately associated with autophagy and the onset and progression of various brain diseases. Non-coding RNAs, including microRNAs, circular RNAs and long noncoding RNAs, and histone acetylation have been reported to adjust autophagy-related gene and protein expression to alleviate inflammation in neurological diseases. The present review primarily focuses on the role and mechanisms of autophagy in neuroinflammatory responses, as well as epigenetic modifications of autophagy in neuroinflammation to reveal potential therapeutic targets in central nervous system diseases.

Associations between insomnia symptoms and inflammatory cytokines in adolescents with first-episode and recurrent major depressive disorder

BACKGROUND

Insomnia symptoms are often associated with increased levels of inflammatory biomarkers. However, such associations have not been adequately explored in adolescents with major depressive disorder (MDD). This study aimed to examine the associations between insomnia symptoms with inflammatory cytokines in adolescents with first-episode and recurrent MDD.

METHODS

From January to December 2021, this study included 164 adolescents with MDD and 76 healthy controls (HCs). The Center for Epidemiological Studies Depression Scale (CES-D) and the Insomnia Severity Index Scale (ISI) were used to assess depressive and insomnia symptoms, respectively. Also, plasma levels of interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-17 A and tumor necrosis factor-α (TNF-α) were measured.

RESULTS

The prevalence of mild, moderate and severe insomnia in adolescents with MDD was 40.24 %, 36.59 % and 6.71 %, respectively. The patients had higher levels of IL-1β, IL-6 and TNF-α than HCs (all p < 0.05). ISI score was positively correlated with CES-D score and levels of IL-1β, IL-6 and TNF-α in first-episode patients but not in recurrent patients. A further multivariate stepwise linear regression analysis showed that ISI score was independently associated with CES-D score (beta = 0.523, t = 5.833, p < 0.001) and TNF-α levels (beta = 0.254, t = 2.832, p = 0.006).

LIMITATIONS

The cross-sectional design leads to failure to make causal inferences.

CONCLUSION

Insomnia symptoms are common in adolescents with MDD and associated with elevated levels of inflammatory cytokines in first-episode patients. The findings suggest that inflammatory cytokines may relate to the pathogenesis of insomnia symptoms in adolescents with MDD, but further longitudinal studies are needed to explore the causal association between insomnia symptoms and inflammatory cytokines in MDD.