The role of inflammation in depression: from evolutionary imperative to modern treatment target

[Interaction of somatic findings and psychiatric symptoms in COVID-19. A scoping review]

An infection with SARS-CoV‑2 can affect the central nervous system, leading to neurological as well as psychiatric symptoms. In this respect, mechanisms of inflammation seem to be of much greater importance than the virus itself. This paper deals with the possible contributions of organic changes to psychiatric symptomatology and deals especially with delirium, cognitive symptoms, depression, anxiety, posttraumatic stress disorder and psychosis. Processes of neuroinflammation with infection of capillary endothelial cells and activation of microglia and astrocytes releasing high amounts of cytokines seem to be of key importance in all kinds of disturbances. They can lead to damage in grey and white matter, impairment of cerebral metabolism and loss of connectivity. Such neuroimmunological processes have been described as a organic basis for many psychiatric disorders, as affective disorders, psychoses and dementia. As the activation of the glia cells can persist for a long time after the offending agent has been cleared, this can contribute to long term sequalae of the infection.

Neural, Anti-Inflammatory, and Clinical Effects of Transauricular Vagus Nerve Stimulation in Major Depressive Disorder: A Systematic Review

BACKGROUND

The discovery of effective treatments for major depressive disorder (MDD) may help target different brain pathways. Invasive vagus nerve stimulation (VNS) is an effective neuromodulation technique for the treatment of MDD; however, the effectiveness of the noninvasive technique, transauricular VNS (taVNS), remains unknown. Moreover, a mechanistic understanding of the neural effects behind its biological and therapeutic effects is lacking. This review aimed to evaluate the clinical evidence and the neural and anti-inflammatory effects of taVNS in MDD.

METHODS

Two searches were conducted using a systematic search strategy reviewed the clinical efficacy and neural connectivity of taVNS in MDD in humans and evaluated the changes in inflammatory markers after taVNS in humans or animal models of depression. A risk of bias assessment was performed in all human studies.

RESULTS

Only 5 studies evaluated the effects of taVNS in patients with depression. Although the studies demonstrated the efficacy of taVNS in treating depression, they used heterogeneous methodologies and limited data, thus preventing the conduct of pooled quantitative analyses. Pooled analysis could not be performed for studies that investigated the modulation of connectivity between brain areas; of the 6 publications, 5 were based on the same experiment. The animal studies that analyzed the presence of inflammatory markers showed a reduction in the level of pro-inflammatory cytokines or receptor expression.

CONCLUSIONS

Data on the clinical efficacy of taVNS in the treatment of MDD are limited. Although these studies showed positive results, no conclusions can be drawn regarding this topic considering the heterogeneity of these studies, as in the case of functional connectivity studies. Based on animal studies, the application of taVNS causes a decrease in the level of inflammatory factors in different parts of the brain, which also regulate the immune system. Therefore, further studies are needed to understand the effects of taVNS in patients with MDD.

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.

Dysconnectivity of the brain functional network and abnormally expressed peripheral transcriptional profiles in patients with anxious depression

BACKGROUND

Major depressive disorder (MDD) is a heterogeneous mental disorder, and accompanying anxiety symptoms, known as anxious depression (AD), are the most common subtype. However, the pathophysiology of AD may be distinct in depressed patients without anxiety (NAD) and remains unknown. This study aimed to investigate the relationship between functional connectivity and peripheral transcriptional profiles in patients with AD and NAD.

METHODS

Functional imaging data were collected to identify differences in functional networks among patients with AD (n = 66), patients with NAD (n = 115), and healthy controls (HC, n = 200). The peripheral transcriptional data were clustered as co-expression modules, and their associations with AD, AND, and HC were analyzed. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analyses of the genes in the significant module were performed. Correlation analysis was performed to identify functional network-associated gene co-expression modules.

RESULTS

A network was identified which consisted of 23 nodes and 28 edges that were significantly different among three sample groups. The regions of the network were located in temporal and occipital lobe. Two gene co-expression modules were shown to be associated with NAD, and one of which was correlated with the disrupted network in the AD group. The biological function of this module was enriched in immune regulation pathways.

CONCLUSION

The results suggested that immune-related mechanisms were associated with functional networks in AD.

Major stress in early childhood strengthens the association between peripheral inflammatory activity and corticostriatal responsivity to reward

BACKGROUND

Severe, chronic stress during childhood accentuates vulnerability to mental and physical health problems across the lifespan. To explain this phenomenon, the neuroimmune network hypothesis proposes that childhood stressors amplify signaling between peripheral inflammatory cells and developing brain circuits that support processing of rewards and threats. Here, we conducted a preliminary test of the basic premises of this hypothesis.

METHODS

180 adolescents (mean age = 19.1 years; 68.9 % female) with diverse racial and ethnic identities (56.1 % White; 28.3 % Hispanic; 26.1 % Asian) participated. The Childhood Trauma Interview was administered to quantify early adversity. Five inflammatory biomarkers were assayed in antecubital blood - C-reactive protein, tumor necrosis factor-a, and interleukins-6, -8, and -10 - and were averaged to form a composite score. Participants also completed a functional MRI task to measure corticostriatal responsivity to the anticipation and acquisition of monetary rewards.

RESULTS

Stress exposure and corticostriatal responsivity interacted statistically to predict the inflammation composite. Among participants who experienced major stressors in the first decade of life, higher inflammatory activity covaried with lower corticostriatal responsivity during acquisition of monetary rewards. This relationship was specific to participants who experienced major stress in early childhood, implying a sensitive period for exposure, and were evident in both the orbitofrontal cortex and the ventral striatum, suggesting the broad involvement of corticostriatal regions. The findings were independent of participants' age, sex, racial and ethnic identity, family income, and depressive symptoms.

CONCLUSIONS

Collectively, the results are consistent with hypotheses suggesting that major stress in childhood alters brain-immune signaling.

Exploring Clinical Subgroups of Participants with Major Depressive Disorder that may Benefit from Adjunctive Minocycline Treatment

Objective

: To explore illness-related factors in patients with major depressive disorder (MDD) recipients of adjunctive minocycline (200 mg/day) treatment. The analysis included participants experiencing MDD from a 12-week, double blind, placebo-controlled, randomized clinical trial (RCT).

Methods

: This is a sub-analysis of a RCT of all 71 participants who took part in the trial. The impact of illness chronicity (illness duration and number of depressive episodes), systemic illness (endocrine, cardiovascular and obesity), adverse effects and minocycline were evaluated as change from baseline to endpoint (12-week) using ANCOVA.

Results

: There was a consistent but statistically non-significant trend on all outcomes in favour of the use of adjunctive minocycline for participants without systemic illness, less illness chronicity, and fewer adverse effects.

Conclusion

: Understanding the relationship between MDD and illness chronicity, comorbid systemic illness, and adverse effects, can potentially better characterise those individuals who are more likely to respond to adjunctive anti-inflammatory medications.

Role of Inflammatory Mechanisms in Major Depressive Disorder: From Etiology to Potential Pharmacological Targets

The involvement of central and peripheral inflammation in the pathogenesis and prognosis of major depressive disorder (MDD) has been demonstrated. The increase of pro-inflammatory cytokines (interleukin (IL)-1β, IL-6, IL-18, and TNF-α) in individuals with depression may elicit neuroinflammatory processes and peripheral inflammation, mechanisms that, in turn, can contribute to gut microbiota dysbiosis. Together, neuroinflammation and gut dysbiosis induce alterations in tryptophan metabolism, culminating in decreased serotonin synthesis, impairments in neuroplasticity-related mechanisms, and glutamate-mediated excitotoxicity. This review aims to highlight the inflammatory mechanisms (neuroinflammation, peripheral inflammation, and gut dysbiosis) involved in the pathophysiology of MDD and to explore novel anti-inflammatory therapeutic approaches for this psychiatric disturbance. Several lines of evidence have indicated that in addition to antidepressants, physical exercise, probiotics, and nutraceuticals (agmatine, ascorbic acid, and vitamin D) possess anti-inflammatory effects that may contribute to their antidepressant properties. Further studies are necessary to explore the therapeutic benefits of these alternative therapies for MDD.

Efficacy of empagliflozin as adjunctive therapy to citalopram in major depressive disorder: a randomized double-blind, placebo-controlled clinical trial

BACKGROUND

Major depressive disorder is one of the most common psychiatric disorders, which is associated with a high disease burden. Current treatments using antidepressants have limitations, so using medication with neuromodulating and anti-inflammatory properties alongside them could be helpful. In a clinical trial, we studied the effectiveness of empagliflozin, a blood sugar-lowering drug, as an adjunctive therapy to reduce the severity of depression symptoms.

METHODS

A number of outpatients with moderate to severe depression (Hamilton Depression Rating Scale (HDRS) > = 17) who were not under related medication or had not taken medication for at least the last two months, had an age range of 18-60 years and had written informed consent to enter the study (N = 90) were randomly divided into two groups receiving placebo or empagliflozin (10 mg daily) combined with citalopram (40 mg daily) based on permuted block randomization method in an 8-week randomized, double-blind, placebo-controlled clinical trial. They were evaluated using the HDRS in weeks 0, 4, and 8.

RESULTS

HDRS scores were equal to 28.42(± 3.83), 20.20(± 3.82), and 13.42(± 3.42) in the placebo group during weeks 0,4, and 8, respectively. These scores were 27.36(± 3.77), 13.76(± 1.40), and 7.00(± 1.13), respectively, for the group treated with empagliflozin. Compared to the control group, patients treated with empagliflozin using repeated-measures ANOVA showed greater improvement in reducing the severity of depression symptoms over time (p value = 0.0001).

CONCLUSIONS

Considering the promising findings in this clinical trial, further study of empagliflozin as adjunctive therapy in MDD with larger sample sizes and longer follow-ups is recommended.

Exploring Novel Antidepressants Targeting G Protein-Coupled Receptors and Key Membrane Receptors Based on Molecular Structures

Major Depressive Disorder (MDD) is a complex mental disorder that involves alterations in signal transmission across multiple scales and structural abnormalities. The development of effective antidepressants (ADs) has been hindered by the dominance of monoamine hypothesis, resulting in slow progress. Traditional ADs have undesirable traits like delayed onset of action, limited efficacy, and severe side effects. Recently, two categories of fast-acting antidepressant compounds have surfaced, dissociative anesthetics S-ketamine and its metabolites, as well as psychedelics such as lysergic acid diethylamide (LSD). This has led to structural research and drug development of the receptors that they target. This review provides breakthroughs and achievements in the structure of depression-related receptors and novel ADs based on these. Cryo-electron microscopy (cryo-EM) has enabled researchers to identify the structures of membrane receptors, including the N-methyl-D-aspartate receptor (NMDAR) and the 5-hydroxytryptamine 2A (5-HT2A) receptor. These high-resolution structures can be used for the development of novel ADs using virtual drug screening (VDS). Moreover, the unique antidepressant effects of 5-HT1A receptors in various brain regions, and the pivotal roles of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) and tyrosine kinase receptor 2 (TrkB) in regulating synaptic plasticity, emphasize their potential as therapeutic targets. Using structural information, a series of highly selective ADs were designed based on the different role of receptors in MDD. These molecules have the favorable characteristics of rapid onset and low adverse drug reactions. This review offers researchers guidance and a methodological framework for the structure-based design of ADs.

Gender difference on the mediation effects of filial piety on the association between chronic obstructive pulmonary disease and depressive symptoms in older adults: A community-based study

Filial piety is viewed as strong family support for older Chinese people, and strongly associated with depressive symptoms. It is unknown if there exists gender difference in the mediation effects of filial piety on the relationship between chronic obstructive pulmonary disease (manifested as lung function) and depression. We investigated whether filial piety mediates the association between lung function and depression in community-dwelling older men and women using the Healthy Aging Longitudinal Study in Taiwan (HALST). Community dwelling adults aged 65 and above were analyzed. Pulmonary function, depressive symptoms, and filial piety expectation (FPE) and receipt of filial piety (RFP) were collected. The interaction and mediation of filial piety between lung function and depression was analyzed. We found that in older men, forced expiratory volume in the first second (FEV1) was inversely correlated with depression (β = -0.1281, p = 0.004) with no mediation effect of FPE. In older women, FEV1 was negatively associated with FPE, but FPE did not increase the risk of depression (β = 0.0605, p = 0.12). In both older men and women, FEV1 was negatively associated with RFP, while RFP reduced the risk of depression (p< 0.001). In older women, the correlation between FEV1 was complete mediation of RFP. Results indicate that feelings of insufficient filial piety may increase the likelihood of depression, especially in elderly women with worse lung function. Although modest, the main mediation effect of filial piety was improvement of lung function in older subjects, which might decrease depression.

Clinically approved immunomodulators ameliorate behavioral changes in a mouse model of hereditary spastic paraplegia type 11

We have previously demonstrated that neuroinflammation by the adaptive immune system acts as a robust and targetable disease amplifier in a mouse model of Spastic Paraplegia, type 11 (SPG11), a complicated form of Hereditary Spastic Paraplegia (HSP). While we identified an impact of neuroinflammation on distinct neuropathological changes and gait performance, neuropsychological features, typical and clinically highly relevant symptoms of complicated HSPs, were not addressed. Here we show that the corresponding SPG11 mouse model shows distinct behavioral abnormalities, particularly related to social behavior thus partially reflecting the neuropsychological changes in patients. We provide evidence that some behavioral abnormalities can be mitigated by genetic inactivation of the adaptive immune system. Translating this into a clinically applicable approach, we show that treatment with the established immunomodulators fingolimod or teriflunomide significantly attenuates distinct behavioral abnormalities, with the most striking effect on social behavior. This study links neuroinflammation to behavioral abnormalities in a mouse model of SPG11 and may thus pave the way for using immunomodulators as a treatment approach for SPG11 and possibly other complicated forms of HSP with neuropsychological involvement.

Chronic non-discriminatory social defeat stress during the perinatal period induces depressive-like outcomes in female mice

Depression is more prevalent in women than in men. Perinatal stress is one of the main risk factors for depression in women. However, there is no suitable female model for perinatal depression that uses the social defeat stress (SDS) paradigm. The standard chronic SDS protocol, which is the most useful method for developing a depression-like model, is effective only in male mice. Thus, this study aimed to characterize a novel SDS method for producing a perinatal depression-like model mouse. We induced chronic SDS in perinatal female mice, wherein chronic non-discriminatory SDS (ND-SDS) was used to induce substantial stress in female mice. The female mice were placed in aggressive ICR mouse cages with sentinel male mice under ND-SDS conditions. Stressed female mice subjected to ND-SDS during the perinatal period efficiently exhibited stress-susceptible phenotypes, such as a social avoidance phenotype and anhedonic behavior, whereas stressed female mice subjected to SDS did not show depressive-like behaviors. These results indicate that chronic ND-SDS in perinatal females could be used to develop a female perinatal depression-like model that can be used to study women's health.

Prenatal mood and anxiety disorders and associated cytokine changes

BACKGROUND

We examined whether women with prenatal mood and anxiety disorders would exhibit differential pro- and anti-inflammatory marker trajectories during the prenatal and postpartum periods compared to women without these disorders.

METHODS

Approximately 179 pregnant women participated in a longitudinal study conducted in two urban areas. Blood samples for inflammatory markers were collected at six study visits. The Structured Clinical Interview for the DSM-IV (SCID) was administered to participants scoring above cutoffs on anxiety and depression. Pregnant women with SCID Axis I diagnoses of mood and/or anxiety disorders were compared to other participants on inflammatory markers. Multilevel modeling tested associations between SCID diagnoses and within-person interleukin (IL)6 and IL10 trajectories.

RESULTS

Prenatal SCID diagnoses were associated with linear, quadratic and cubic change in IL6 from prenatal to postpartum timepoints. Women with a prenatal SCID diagnosis had steeper decreases and increases in IL6 during prenatal and postpartum periods. SCID diagnoses were associated with lower IL10 in mid-pregnancy to postpartum (b = -0.078, SE = 0.019; p = .015).

LIMITATIONS

Future studies would benefit from a larger sample size and a larger number of participants with SCID diagnoses. Future research should also examine whether different prenatal Axis 1 diagnoses are associated with different patterns of immune response in pregnancy.

CONCLUSIONS

Pregnant women with prenatal mood and anxiety disorders had greater fluctuations in IL6 across prenatal and postpartum periods and lower IL10 through pregnancy and postpartum. They may have different proinflammatory states that remain after birth without a reciprocal anti-inflammatory response.

Acylcarnitines metabolism in depression: association with diagnostic status, depression severity and symptom profile in the NESDA cohort

Background

Acylcarnitines (ACs) are involved in bioenergetics processes that may play a role in the pathophysiology of depression. Studies linking AC levels to depression are few and provide mixed findings. We examined the association of circulating ACs levels with Major Depressive Disorder (MDD) diagnosis, overall depression severity and specific symptom profiles.

Methods

The sample from the Netherlands Study of Depression and Anxiety included participants with current (n=1035) or remitted (n=739) MDD and healthy controls (n=800). Plasma levels of four ACs (short-chain: acetylcarnitine C2 and propionylcarnitine C3; medium-chain: octanoylcarnitine C8 and decanoylcarnitine C10) were measured. Overall depression severity as well as atypical/energy-related (AES), anhedonic and melancholic symptom profiles were derived from the Inventory of Depressive Symptomatology.

Results

As compared to healthy controls, subjects with current or remitted MDD presented similarly lower mean C2 levels (Cohen's d=0.2, p≤1e-4). Higher overall depression severity was significantly associated with higher C3 levels (ß=0.06, SE=0.02, p=1.21e-3). No associations were found for C8 and C10. Focusing on symptom profiles, only higher AES scores were linked to lower C2 (ß=-0.05, SE=0.02, p=1.85e-2) and higher C3 (ß=0.08, SE=0.02, p=3.41e-5) levels. Results were confirmed in analyses pooling data with an additional internal replication sample from the same subjects measured at 6-year follow-up (totaling 4195 observations).

Conclusions

Small alterations in levels of short-chain acylcarnitine levels were related to the presence and severity of depression, especially for symptoms reflecting altered energy homeostasis. Cellular metabolic dysfunctions may represent a key pathway in depression pathophysiology potentially accessible through AC metabolism.

Elevated body temperature is associated with depressive symptoms: results from the TemPredict Study

Correlations between altered body temperature and depression have been reported in small samples; greater confidence in these associations would provide a rationale for further examining potential mechanisms of depression related to body temperature regulation. We sought to test the hypotheses that greater depression symptom severity is associated with (1) higher body temperature, (2) smaller differences between body temperature when awake versus asleep, and (3) lower diurnal body temperature amplitude. Data collected included both self-reported body temperature (using standard thermometers), wearable sensor-assessed distal body temperature (using an off-the-shelf wearable sensor that collected minute-level physiological data), and self-reported depressive symptoms from > 20,000 participants over the course of ~ 7 months as part of the TemPredict Study. Higher self-reported and wearable sensor-assessed body temperatures when awake were associated with greater depression symptom severity. Lower diurnal body temperature amplitude, computed using wearable sensor-assessed distal body temperature data, tended to be associated with greater depression symptom severity, though this association did not achieve statistical significance. These findings, drawn from a large sample, replicate and expand upon prior data pointing to body temperature alterations as potentially relevant factors in depression etiology and may hold implications for development of novel approaches to the treatment of major depressive disorder.

Di (2-ethylhexyl) phthalate alters neurobehavioral responses and oxidative status, architecture, and GFAP and BDNF signaling in juvenile rat's brain: Protective role of Coenzyme10

Di-(2-ethylhexyl) phthalate (DEHP), a phthalate plasticizer, is widely spread in the environment, presenting hazards to human health and food safety. Hence, this study examined the probable preventive role of coenzyme10 (CQ10) (10 mg/kg.b.wt) against DEHP (500 mg/kg.wt) - induced neurotoxic and neurobehavioral impacts in juvenile (34 ± 1.01g and 3 weeks old) male Sprague Dawley rats in 35-days oral dosing trial. The results indicated that CQ10 significantly protected against DEHP-induced memory impairment, anxiety, depression, spatial learning disorders, and repetitive/stereotypic-like behavior. Besides, the DEHP-induced depletion in dopamine and gamma amino butyric acid levels was significantly restored by CQ10. Moreover, CQ10 significantly protected against the exhaustion of CAT, GPx, SOD, GSH, and GSH/GSSG ratio, as well as the increase in malondialdehyde, Caspas-3, interleukin-6, and tumor necrosis factor-alpha brain content accompanying with DEHP exposure. Furthermore, CQ10 significantly protected the brain from the DEHP-induced neurodegenerative alterations. Also, the increased immunoexpression of brain-derived neurotrophic factor, not glial fibrillary acidic protein, in the cerebral, hippocampal, and cerebellar brain tissues due to DEHP exposure was alleviated with CQ10. This study's findings provide conclusive evidence that CQ10 has the potential to be used as an efficient natural protective agent against the neurobehavioral and neurotoxic consequences of DEHP.

Peripheral inflammation associated with depression and reduced weight loss: a longitudinal study of bariatric patients

BACKGROUND

Research implicates inflammation in the vicious cycle between depression and obesity, yet few longitudinal studies exist. The rapid weight loss induced by bariatric surgery is known to improve depressive symptoms dramatically, but preoperative depression diagnosis may also increase the risk for poor weight loss. Therefore, we investigated longitudinal associations between depression and inflammatory markers and their effect on weight loss and clinical outcomes in bariatric patients.

METHODS

This longitudinal observational study of 85 patients with obesity undergoing bariatric surgery included 41 cases with depression and 44 controls. Before and 6 months after surgery, we assessed depression by clinical interview and measured serum high-sensitivity C-reactive protein (hsCRP) and inflammatory cytokines, including interleukin (IL)-6 and IL-10.

RESULTS

Before surgery, depression diagnosis was associated with significantly higher serum hsCRP, IL-6, and IL-6/10 ratio levels after controlling for confounders. Six months after surgery, patients with pre-existing depression still had significantly higher inflammation despite demonstrating similar weight loss to controls. Hierarchical regression showed higher baseline hsCRP levels predicted poorer weight loss (β = -0.28, p = 0.01) but had no effect on depression severity at follow-up (β = -0.02, p = 0.9). Instead, more severe baseline depressive symptoms and childhood emotional abuse predicted greater depression severity after surgery (β = 0.81, p < 0.001; and β = 0.31, p = 0.001, respectively).

CONCLUSIONS

Depression was significantly associated with higher inflammation beyond the effect of obesity and other confounders. Higher inflammation at baseline predicted poorer weight loss 6 months after surgery, regardless of depression diagnosis. Increased inflammation, rather than depression, may drive poor weight loss outcomes among bariatric patients.

Regulatory T-cell phenotypes in prenatal psychological distress

BACKGROUND

Experiencing symptoms of psychological distress during pregnancy is common and has been linked to dysregulated immune functioning. In this context, immunoregulatory function is especially relevant because of its crucial role in establishment and maintenance of healthy pregnancy. However, little research has examined associations between women's prenatal psychological distress and immunoregulatory biomarkers. We investigated how symptoms of depression, anxiety, and stress relate to circulating levels of regulatory T-cells (Tregs).

MATERIALS AND METHODS

Pregnant Latina women were assessed at around 12 weeks of pregnancy (N = 82). These assessments included blood draws and self-report questionnaires assessing symptoms of depression, state anxiety, pregnancy-related anxiety, and perceived stress. Flow cytometry on PBMCs was used to quantify circulating Tregs, defined as CD3+CD4+CD25hiCD127loFoxP3+, and subpopulations positive for one of the following intra- or extracellular markers, CD45RA, CTLA-4, Helios, PD-1, TIM-3, and TIGIT. We collected 82 samples at 12 weeks. Multivariable linear regressions tested for associations between symptoms of psychological distress and Treg concentrations, adjusted for gestational age.

RESULTS

State anxiety symptoms at 12 weeks were negatively associated with parent Treg cell levels (b = -4.02, p = 0.023) and subpopulations Helios+ (b = -3.29, p = 0.019) and TIM3+ (b = -3.17, p = 0.008). Perceived stress was negatively associated with the PD-1+ subpopulation at 12 weeks (b = -4.02, p = 0.023). Depression was not related to Tregs or the subpopulations.

CONCLUSION

Our observation that symptoms of anxiety and stress are related to tolerogenic immunology suggests a possible biomechanism explaining correlations of maternal mood disorders with adverse outcomes for mothers and offspring.

Did the prevalence of depressive symptoms change during the COVID-19 pandemic? A multilevel analysis on longitudinal data from healthcare workers

BACKGROUND

Healthcare workers (HCW) are at high risk to develop mental health problems during the COVID-19 pandemic because of additional work load, perceived stress, and exposure to patients with COVID-19. Currently, there are few studies on change over time in the prevalence of depressive symptoms during pandemic start among HCW. Thus, the aims of the current study were to examine whether depressive symptoms increased during the pandemic and were associated with perceived stress and own COVID-19 infection and workplace exposure to virus-infected patients.

METHODS

The cohort study used longitudinal data from HCW collected monthly (July 2020 till December 2020) during the first year of the pandemic before vaccination became available. The sample of n = 166 was drawn from a German hospital and included medical (e.g. nurses, therapists, and physicians) and administrative staff. Using multilevel models, we analyzed the change in depressive symptoms [assessed with General Depression Scale (GDS), a validated German version of the Center for Epidemiological Studies Depression Scale (CES-D)] and its association with perceived stress across the study period. Laboratory-confirmed own infection was tested as a potential moderator in this context. Subscales of the GDS were used to examine change over time of depressive symptom modalities (e.g. emotional, somatic, and social interactions (β, 95% confidence interval).

RESULTS

Depression scores increased significantly during the study period (β = .03, 95% CI [0.02, 0.05]). Perceived stress was associated with depressive symptoms (β = .12, 95% CI [0.10, 0.14]) but did not change over time. Exposure to COVID-19 infection was associated with a higher increase of depressive symptoms (β = .12, 95% CI [0.10, .14]). Somatic symptoms of depression increased among medical HCW with workplace exposure to COVID-19 (β = .25, 95% CI [0.13, 0.38]), but not in administrators (β = .03, 95% CI [-0.04, 0.11]).

CONCLUSION

Research is needed to identify factors that promote the reduction of depressive symptoms in medical HCW with exposition to COVID-19 patients. Awareness of infection protection measures should be increased.

The molecular mechanism of polysaccharides in combating major depressive disorder: A comprehensive review

Major depressive disorder (MDD) is a complex psychiatric condition with diverse etiological factors. Typical pathological features include decreased cerebral cortex, subcortical structures, and grey matter volumes, as well as monoamine transmitter dysregulation. Although medications exist to treat MDD, unmet needs persist due to limited efficacy, induced side effects, and relapse upon drug withdrawal. Polysaccharides offer promising new therapies for MDD, demonstrating antidepressant effects with minimal side effects and multiple targets. These include neurotransmitter, neurotrophin, neuroinflammation, hypothalamic-pituitary-adrenal axis, mitochondrial function, oxidative stress, and intestinal flora regulation. This review explores the latest advancements in understanding the pharmacological actions and mechanisms of polysaccharides in treating major depression. We discuss the impact of polysaccharides' diverse structures and properties on their pharmacological actions, aiming to inspire new research directions and facilitate the discovery of novel anti-depressive drugs.

Protocol for teen inflammation glutamate emotion research (TIGER): Toward predictors of treatment response and clinical course in depressed adolescents

Adolescent-onset depression is a prevalent and debilitating condition commonly associated with treatment refractory depression and non-response to first-line antidepressants. There are, however, no objective tests to determine who may or may not respond to antidepressants. As depressed adolescents are especially vulnerable to the lifelong consequences of ineffectively-treated depression, it is critical to identify neurobiological predictors of treatment non-response in this population. Here, we describe the scientific rationale and protocol for the Teen Inflammation Glutamate Emotion Research (TIGER) study, a prospective 18-month investigation of 160 depressed adolescents who will be assessed before and after treatment with selective serotonin reuptake inhibitors. TIGER will be using ultra-high field imaging to test the effects of acute stress and antidepressant treatment on inflammatory and glutamatergic processes hypothesized to underlie depression maintenance. Results from this work will motivate future studies testing alternative therapeutics for depressed adolescents at risk for treatment resistant depression. ClinicalTrials.gov Identifier: NCT05329441.

Mitochondrial morphology in the mouse adrenal cortex: Influence of chronic psychosocial stress

Mitochondria within the adrenal cortex play a key role in synthesizing steroid hormones. The adrenal cortex is organized in three functionally specialized zones (glomerulosa, fasciculata, and reticularis) that produce different classes of steroid hormones in response to various stimuli, including psychosocial stress. Given that the functions and morphology of mitochondria are dynamically related and respond to stress, we applied transmission electron microscopy (TEM) to examine potential differences in mitochondrial morphology under basal and chronic psychosocial stress conditions. We used the chronic subordinate colony housing (CSC) paradigm, a murine model of chronic psychosocial stress. Our findings quantitatively define how mitochondrial morphology differs among each of the three adrenal cortex zones under basal conditions, and show that chronic psychosocial stress mainly affected mitochondria in the zona glomerulosa, shifting their morphology towards the more typical glucocorticoid-producing zona fasciculata mitochondrial phenotype. Analysis of adrenocortical lipid droplets that provide cholesterol for steroidogenesis showed that chronic psychosocial stress altered lipid droplet diameter, without affecting droplet number or inter-organellar mitochondria-lipid droplet interactions. Together, our findings support the hypothesis that each adrenal cortex layer is characterized by morphologically distinct mitochondria and that this adrenal zone-specific mitochondrial morphology is sensitive to environmental stimuli, including chronic psychosocial stressors. Further research is needed to define the role of these stress-induced changes in mitochondrial morphology, particularly in the zona glomerulosa, on stress resilience and related behaviors.

Mediating pathways that link adverse childhood experiences with cardiovascular disease

OBJECTIVES

There is uncertainty about which factors mediate the association between adverse childhood experiences (ACEs) and cardiovascular disease (CVD). This could inform secondary prevention targets.

STUDY DESIGN

Mediation analysis of a prospective cohort study.

METHODS

English Longitudinal Study of Ageing (ELSA) wave 3 data (2006/7) were used to measure retrospective exposure to 12 individual ACEs and waves 2 to 4 (2004/5 to 2008/9) data to measure current exposure to potential mediators [smoking, physical activity, alcohol consumption, body mass index, depression, and C-reactive protein (CRP)]. Waves 4 to 9 ELSA data (2008/9 to 2018/19) were used to measure incident CVD. Cumulative ACE exposure was categorised into experiencing 0, 1 to 3, or ≥4 individual ACEs. Associations were tested between ACE categories, potential mediators, and incident CVD, to inform which variables were analysed in causal mediation models.

RESULTS

The analytical cohort consisted of 4547 participants (56% women), with a mean age of 64 years (standard deviation = 9 years). At least one ACE had been experienced by 45% of the cohort, and 24% developed incident CVD over a median follow-up period of 9.7 years (interquartile range: 5.3-11.4 years). After adjusting for potential confounders, experiencing ≥4 ACEs compared with none was associated with incident CVD [odds ratio (OR): 1.55; 95% confidence interval (CI): 1.10, 2.17], and the association of one to three ACEs compared with none was non-significant (OR: 1.08; 95% CI: 0.93, 1.24). There were two statistically significant mediators of the association between ≥4 ACEs and incident CVD: CRP and depression, which accounted for 10.7% and 10.8% of the association, respectively.

CONCLUSIONS

Inflammation and depression partially mediated the association between ACEs and CVD. Targeting these factors may reduce the future incidence of CVD.

The biology of hope: Inflammatory and neuroendocrine profiles in ovarian cancer patients

INTRODUCTION

Although the concept of hope is highly relevant for cancer patients, little is known about its association with cancer-relevant biomarkers. Here we examined how hope was related to diurnal cortisol and interleukin-6 (IL-6), a pro-inflammatory cytokine previously associated with tumor biology and survival in ovarian cancer. Secondly, we examined whether hope and hopelessness are distinctly associated with these biomarkers.

METHOD

Participants were 292 high-grade ovarian cancer patients who completed surveys and provided saliva samples 4x/daily for 3 days pre-surgery to assess diurnal cortisol. Blood (pre-surgery) and ascites were assessed for IL-6. Hope and hopelessness were assessed using standardized survey items from established scales (Center for Epidemiological Studies Depression Scale; Profile of Mood States, Functional Assessment of Cancer Therapy). Two hopeless items were z-scored and combined into a composite for analysis. Regression models related these variables to nocturnal cortisol, cortisol slope, plasma and ascites IL-6, adjusting for cancer stage, BMI, age, and depression.

RESULTS

Greater hope was significantly related to a steeper cortisol slope, β = -0.193, p = 0.046, and lower night cortisol, β = -0.227, p = 0.018, plasma IL-6, β = -0.142, p = 0.033, and ascites IL-6, β = -0.290, p = 0.002. Secondary analyses including both hope and hopelessness showed similar patterns, with distinct relationships of hope with significantly lower nocturnal cortisol β = -0.233,p = 0.017 and ascites IL-6, β = -0.282,p = 0.003, and between hopelessness and a flatter cortisol slope, β = 0.211, p = 0.031.

CONCLUSIONS

These data suggest a biological signature of hope associated with less inflammation and more normalized diurnal cortisol in ovarian cancer. These findings have potential clinical utility but need replication with more diverse samples and validated assessments of hope.

Cognitive Impairment and Depression in Mastocytosis: A Synthesis of the Literature

PURPOSE OF REVIEW

Symptoms of depression and cognitive dysfunction are commonly reported in mastocytosis. The aims of this review paper are to summarize the current literature on cognitive dysfunction and depressive symptoms, elucidate some of the mechanistic pathways underlying depressive symptoms in mastocytosis, identify gaps in the literature, and offer guidance for future research in this area.

RECENT FINDINGS

The study of cognition and depression in mastocytosis is in its infancy and the methodological flaws of the current literature limit interpretability. There is preliminary evidence that some individuals with mastocytosis might experience mild deficits in memory. On average, depression symptom scores fell within the mild to moderate or sub-syndromal range. Regrettably, only one study utilized a standardized diagnostic instrument to assess major depressive disorder. The authors' tendency to inaccurately equate depressive symptoms with a diagnosis of major depressive disorder presents a notable issue. The prevalence of cognitive deficits and depression appears to be similar to other chronic illnesses. Future work needs to better characterize cognition and characterize "depression" in this population.

Differences in bacterial taxa between treatment-naive patients with major depressive disorder and non-affected controls may be related to a proinflammatory profile

BACKGROUND

Major depressive disorder (MDD) is characterized by sadness and anhedonia, but also physical symptoms such as changes in appetite and weight. Gut microbiota has been hypothesized to be involved in MDD through gut-brain axis signaling. Moreover, antidepressants display antibacterial properties in the gastrointestinal tract. The aim of this study was to compare the gut microbiota and systemic inflammatory profile of young patients with MDD before and after initiation of antidepressant treatment and/or psychotherapy in comparison with a non-depressed control group (nonMDD).

METHODS

Fecal and blood samples were collected at baseline and at follow-up after four and twelve weeks, respectively. Patients started treatment immediately after collection of the baseline samples. The gut microbiota was characterized by 16 S rRNA gene sequencing targeting the hypervariable V4 region. Plasma levels of 49 unique immune markers were assessed using Mesoscale.

RESULTS

In total, 27 MDD patients and 32 nonMDD controls were included in the study. The gut microbiota in the baseline samples of MDD versus nonMDD participants did not differ regarding α- or β-diversity. However, there was a higher relative abundance of the genera Ruminococcus gnavus group, and a lower relative abundance of the genera Desulfovibrio, Tyzzerella, Megamonas, Olsenella, Gordonibacter, Allisonella and Rothia in the MDD group compared to the nonMDD group. In the MDD group, there was an increase in the genera Rothia, Desulfovibrio, Gordinobacteer and Lactobacillus, while genera belonging to the Firmicutes phylum were found depleted at twelve weeks follow-up compared to baseline. In the MDD group, IL-7, IL-8 and IL-17b levels were elevated compared to the nonMDD group at baseline. Furthermore, MDI score in the MDD group was found to correlate with Bray-Curtis dissimilarity at baseline, and several inflammatory markers at both baseline and after initiation of antidepressant treatment.

CONCLUSION

Several bacterial taxa differed between the MDD group and the nonMDD group at baseline and changed in relative abundance during antidepressant treatment and/or psychotherapy. The MDD group was furthermore found to have a pro-inflammatory profile compared to the nonMDD group at baseline. Further studies are required to investigate the gut microbiota and pro-inflammatory profile of patients with MDD.

Distinct genomic signatures and modifiable risk factors underly the comorbidity between major depressive disorder and cardiovascular disease

Major depressive disorder (MDD) and cardiovascular disease (CVD) are often comorbid, resulting in excess morbidity and mortality. Using genomic data, this study elucidates biological mechanisms, key risk factors, and causal pathways underlying their comorbidity. We show that CVDs share a large proportion of their genetic risk factors with MDD. Multivariate genome-wide association analysis of the shared genetic liability between MDD and atherosclerotic CVD (ASCVD) revealed seven novel loci and distinct patterns of tissue and brain cell-type enrichments, suggesting a role for the thalamus. Part of the genetic overlap was explained by shared inflammatory, metabolic, and psychosocial/lifestyle risk factors. Finally, we found support for causal effects of genetic liability to MDD on CVD risk, but not from most CVDs to MDD, and demonstrated that the causal effects were partly explained by metabolic and psychosocial/lifestyle factors. The distinct signature of MDD-ASCVD comorbidity aligns with the idea of an immunometabolic sub-type of MDD more strongly associated with CVD than overall MDD. In summary, we identify plausible biological mechanisms underlying MDD-CVD comorbidity, as well as key modifiable risk factors for prevention of CVD in individuals with MDD.

The quest for a biological phenotype of adolescent non-suicidal self-injury: a machine-learning approach

Non-suicidal self-injury (NSSI) is a transdiagnostic psychiatric symptom with high prevalence and relevance in child and adolescent psychiatry. Therefore, it is of great interest to identify a biological phenotype associated with NSSI. The aim of the present study was to cross-sectionally investigate patterns of biological markers underlying NSSI and associated psychopathology in a sample of female patients and healthy controls. Comprehensive clinical data, saliva and blood samples, heart rate variability and pain sensitivity, were collected in n = 149 patients with NSSI and n = 40 healthy participants. Using machine-based learning, we tested the extent to which oxytocin, dehydroepiandrosterone (DHEA), beta-endorphin, free triiodothyronine (fT3), leukocytes, heart rate variability and pain sensitivity were able to classify participants regarding their clinical outcomes in NSSI, depression and borderline personality disorder symptomatology. We evaluated the predictive performance of several models (linear and logistic regression, elastic net regression, random forests, gradient boosted trees) using repeated cross-validation. With NSSI as an outcome variable, both logistic regression and machine learning models showed moderate predictive performance (Area under the Receiver Operating Characteristic Curve between 0.67 and 0.69). Predictors with the highest predictive power were low oxytocin (OR = 0.55; p = 0.002), low pain sensitivity (OR = 1.15; p = 0.021), and high leukocytes (OR = 1.67; p = 0.015). For the psychopathological outcome variables, i.e., depression and borderline personality disorder symptomatology, models including the biological variables performed not better than the null model. A combination of hormonal and inflammatory markers, as well as pain sensitivity, were able to discriminate between participants with and without NSSI disorder. Based on this dataset, however, complex machine learning models were not able to detect non-linear patterns of associations between the biological markers. These findings need replication and future research will reveal the extent to which the respective biomarkers are useful for longitudinal prediction of clinical outcomes or treatment response.

Depression in Women: Potential Biological and Sociocultural Factors Driving the Sex Effect

Important sex-related differences have been observed in the onset, prevalence, and clinical phenotype of depression, based on several epidemiological studies. Social, behavioural, and educational factors have a great role in underlying this bias; however, also several biological factors are extensively involved. Indeed, sexually dimorphic biological systems might represent the underlying ground for these disparities, including cerebral structures and neural correlates, reproductive hormones, stress response pathways, the immune system and inflammatory reaction, metabolism, and fat distribution. Furthermore, in this perspective, it is also important to consider and focus the attention on specific ages and life stages of individuals: indeed, women experience during their life specific periods of reproductive transitional phases, which are not found in men, that represent windows of particular psychological vulnerability. In addition to these, other biologically related risk factors, including the occurrence of sleep disturbances and the exposure to childhood trauma, which are found to differentially affect men and women, are also putative underlying mechanisms of the clinical bias of depression. Overall, by taking into account major differences which characterize men and women it might be possible to improve the diagnostic process, as well as treat more efficiently depressed individuals, based on a more personalized medicine and research.

Saikosaponin-d alleviates depression by promoting NLRP3 ubiquitination and inhibiting inflammasome activation

Saikosaponin-d (SSd) is a triterpene saponin from the roots of Bupleurum chinese. Recent studies have revealed its antidepressant activity, but its mechanism involved is unclear. This study's objective was to ascertain how SSd may reduce depression in depressed mice subjected to chronic unpredictable animal stress (CUMS) and to investigate the mechanisms underlying these effects. Models of CUMS depression were established and different groups were treated with SSd and escitalopram. After the last day of administration of the treatment, behavioral tests were performed. ELISA was used to measure the expression of IL-1β, TNF-α, and IL-18, and western blot was used to measure the presence of proteins associated with NLRP3. Hippocampal neuronal damage was observed using Nissl staining, and NLRP3 ubiquitination assay was performed by immunoprecipitation and gene silencing. An inflammatory cell model was constructed by treating BV2 cells with lipopolysaccharides (LPS) and adenosine triphosphate (ATP) to verify the ubiquitination modification of NLRP3 by SSd. Behavioral tests demonstrated that SSd effectively alleviated depression-like symptoms. SSd should substantially limit the degrees of proteins associated with NLRP3, as properly as limit the harm to hippocampal neurons. Gene silencing results showed that SSd regulates NLRP3 through the E3 ubiquitin ligase MARCHF7. In vitro, SSd remarkably increased the protein expression of K48-linked ubiquitin in inflammatory BV2 cells, while decreasing the protein levels of NLRP3. Our findings suggest that SSd has antidepressant effects in CUMS mice by promoting ubiquitination of NLRP3 to inhibit inflammasome activation and improve the inflammatory state.

Research progress on antidepressant effects and mechanisms of berberine

Depression, a global health problem with growing prevalence, brings serious impacts on the daily life of patients. However, the antidepressants currently used in clinical are not perfectly effective, which greatly reduces the compliance of patients. Berberine is a natural quaternary alkaloid which has been shown to have a variety of pharmacological effects, such as hypoglycemic, lipid-regulation, anti-cancer, antibacterial, anti-oxidation, anti-inflammatory, and antidepressant. This review summarizes the evidence of pharmacological applications of berberine in treating depression and elucidates the mechanisms of berberine regulating neurotransmitter levels, promoting the regeneration of hippocampal neurons, improving hypothalamic-pituitary-adrenal axis dysfunction, anti-oxidative stress, and suppressing inflammatory status in order to provide a reference for further research and clinical application of berberine.

Evaluation of serum interleukin-12 and interleukin-4 as potential biomarkers for the diagnosis of major depressive disorder

Recently, scientists have focused on pro-inflammatory cytokines and immunological dysregulation in major depressive disorder (MDD). Some research suggests pro-inflammatory cytokines' role in MDD development, whereas anti-inflammatory studies are sparse. There is no systematic investigation of Bangladeshi MDD patients' pro- and anti-inflammatory cytokines. This study examines the blood levels of IL-12 and IL-4 in Bangladeshi patients and healthy controls (HCs) to determine the diagnostic accuracy of these cytokines to identify MDD patients from those without MDD. A total of 110 people with MDD from the department of psychiatry of a teaching hospital in Dhaka and 107 HCs from Dhaka participated in this case-control study. Depression and illness severity were gauged using DSM-5 criteria and Ham-D scores. Commercially marketed ELISA kits were used in accordance with manufacturer guidelines to measure the levels of IL-12 and IL-4 in peripheral blood, allowing a comparison of the patient and control groups. In comparison to HCs, MDD patients (5333.00 ± 307.40 pg/ml) showed noticeably higher levels of IL-12 than in HCs (2331.00 ± 207.40 pg/ml). The increased levels were positively correlated with Ham-D scores (male: r = 0.351, p < 0.050; female: r = 0.389, p < 0.050), suggesting a possible relationship to disease progression. Additionally, compared to HCs (272.81 ± 23.94 pg/ml), MDD patients had significantly higher peripheral blood levels of IL-4 (876.35 ± 66.73 pg/ml) (p < 0.001). Also, there was a positive correlation between IL-4 serum levels and Ham-D scores (male: r = 0.361, p < 0.050; female: r = 0.398, p < 0.050). Therefore, we observed increased levels of these serum cytokines and their association with the severity of depression. The results of this study demonstrate the possibility of IL-12 and IL-4 blood levels as distinct markers capable of differentiating between MDD patients and HCs, possibly acting as markers of MDD susceptibility. To ascertain the diagnostic effectiveness of these two cytokines, more research is necessary.

Sex difference in the non-linear relationship between ethylene oxide exposure and depressive symptoms: A cross-sectional study

BACKGROUND

Ethylene oxide (EO) has been recognized as an animal carcinogen and environmental EO exposure was linked to several diseases. However, the association of EO exposure with depression prevalence is still not clear.

METHODS

We included 6016 participants with complete data on HbEO concentrations, depression diagnosis, and necessary covariates using the 2013-2020 National Health and Nutrition Examination Survey. Weighted multivariable logistic model was applied to examine the association of HbEO concentrations with depression risk. Weighted restricted cubic spline model was applied to draw the dose-response curve.

RESULTS

In the total population, individuals in the second, third, and fourth quartile of HbEO respectively had an adjusted OR of 0.99 (95%CI: 0.60, 1.63), 1.13 (95%CI: 0.73, 1.75), and 2.87 (95%CI: 1.86, 4.45) (Ptrend < 0.001) for depression with a significant "J" shaped non-linear dose-response relationship (Pnon-linear < 0.001). Females, drinkers, and smokers were susceptible to the depressive effect of EO. Doubling the HbEO concentrations was respectively associated with a 1.50-fold (95%CI: 1.25, 1.79), 1.29-fold (1.15, 1.44), and 1.17-fold (1.04, 1.33) increased risk of depression for females, drinkers, and smokers.

LIMITATIONS

Cross-sectional study design and self-reported depressive symptoms.

CONCLUSIONS

Environmental EO exposure was associated with increased depression risk, especially among females, drinkers, and smokers. Further prospective studies are required to affirm these findings.

Probiotic Lactobacillus rhamnosus alleviates the neurotoxicity of microcystin-LR in zebrafish (Danio rerio) through the gut-brain axis

Microcystin-LR (MCLR) is one of the most toxic cyanobacterial toxins and is harmful to the central nervous system of fish. Probiotic additives can improve neuroendocrine function in fish. Although both MCLR and probiotics aim at the nervous system, whether they interact with each other and the mechanisms remain unexplored. In the present study, 4-month-old zebrafish were exposed to 0, 2.2, and 22 μg/L of MCLR for 28 days with or without the probiotic L. rhamnosus. We found that MCLR exposure could inhibit the swimming speed of zebrafish, while the presence of L. rhamnosus mitigated this abnormality. To elucidate the mechanism of how L. rhamnosus alleviates MCLR-induced neurotoxicity, we examined the bioaccumulation of MCLR, changes in neurotransmitters, immune biochemical indicators, and hormone content of the hypothalamic-pituitary-interrenal (HPI) axis in zebrafish along the gut-brain axis. Our results showed L. rhamnosus could reverse the abnormal swimming behavior and eventually alleviate neurotoxicity in zebrafish by modulating intestinal and brain neural signaling, neuroinflammation, and HPI axis responses. This study provides implications for the application of probiotics in the aquaculture industry.

Increased expression of ER stress, inflammasome activation, and mitochondrial biogenesis-related genes in peripheral blood mononuclear cells in major depressive disorder

A subset of major depressive disorder (MDD) is characterized by immune system dysfunction, but the intracellular origin of these immune changes remains unclear. Here we tested the hypothesis that abnormalities in the endoplasmic reticulum (ER) stress, inflammasome activity and mitochondrial biogenesis contribute to the development of systemic inflammation in MDD. RT-qPCR was used to measure mRNA expression of key organellar genes from peripheral blood mononuclear cells (PBMCs) isolated from 186 MDD and 67 healthy control (HC) subjects. The comparative CT (2-ΔΔCT) method was applied to quantify mRNA expression using GAPDH as the reference gene. After controlling for age, sex, BMI, and medication status using linear regression models, expression of the inflammasome (NLRC4 and NLRP3) and the ER stress (XBP1u, XBP1s, and ATF4) genes was found to be significantly increased in the MDD versus the HC group. After excluding outliers, expression of the inflammasome genes was no longer statistically significant but expression of the ER stress genes (XBP1u, XBP1s, and ATF4) and the mitochondrial biogenesis gene, MFN2, was significantly increased in the MDD group. ASC and MFN2 were positively correlated with serum C-reactive protein concentrations. The altered expression of inflammasome activation, ER stress, and mitochondrial biogenesis pathway components suggest that dysfunction of these organelles may play a role in the pathogenesis of MDD.

Niuhuang Qingxin Wan ameliorates depressive-like behaviors and improves hippocampal neurogenesis through modulating TrkB/ERK/CREB signaling pathway in chronic restraint stress or corticosterone challenge mice

Introduction: Chronic stress-associated hormonal imbalance impairs hippocampal neurogenesis, contributing to depressive and anxiety behaviors. Targeting neurogenesis is thus a promising antidepressant therapeutic strategy. Niuhuang Qingxin Wan (NHQXW) is an herbal formula for mental disorders in Traditional Chinese Medicine (TCM) practice, but its anti-depressant efficacies and mechanisms remain unverified. Methods: In the present study, we tested the hypothesis that NHQXW could ameliorate depressive-like behaviors and improve hippocampal neurogenesis by modulating the TrkB/ERK/CREB signaling pathway by utilizing two depression mouse models including a chronic restraint stress (CRS) mouse model and a chronic corticosterone (CORT) stress (CCS) induced mouse model. The depression-like mouse models were orally treated with NHQXW whereas fluoxetine was used as the positive control group. We evaluated the effects of NHQXW on depressive- and anxiety-like behaviors and determined the effects of NHQXW on inducing hippocampal neurogenesis. Results: NHQXW treatment significantly ameliorated depressive-like behaviors in those chronic stress mouse models. NHQXW significantly improved hippocampal neurogenesis in the CRS mice and CCS mice. The potential neurogenic mechanism of NHQXW was identified by regulating the expression levels of BDNF, TrkB, p-ERK (T202/T204), p-MEK1/2 (S217/221), and p-CREB (S133) in the hippocampus area of the CCS mice. NHQXW revealed its antidepressant and neurogenic effects that were similar to fluoxetine. Moreover, NHQXW treatment revealed long-term effects on preventing withdrawal-associated rebound symptoms in the CCS mice. Furthermore, in a bioactivity-guided quality control study, liquiritin was identified as one of the bioactive compounds of NHQXW with the bioactivities of neurogenesis-promoting effects. Discussion: Taken together, NHQXW could be a promising TCM formula to attenuate depressive- and anxiety-like behaviors against chronic stress and depression. The underlying anti-depressant mechanisms could be correlated with its neurogenic activities by stimulating the TrkB/ERK/CREB signaling pathway.

An updated overview on the relationship between human gut microbiome dysbiosis and psychiatric and psychological disorders

There is a lot of evidence establishing that nervous system development is related to the composition and functions of the gut microbiome. In addition, the central nervous system (CNS) controls the imbalance of the intestinal microbiota, constituting a bidirectional communication system. At present, various gut-brain crosstalk routes have been described, including immune, endocrine and neural circuits via the vagal pathway. Several empirical data have associated gut microbiota alterations (dysbiosis) with neuropsychiatric diseases, such as Alzheimer's disease, autism and Parkinson's disease, and with other psychological disorders, like anxiety and depression. Fecal microbiota transplantation (FMT) therapy has shown that the gut microbiota can transfer behavioral features to recipient animals, which provides strong evidence to establish a causal-effect relationship. Interventions, based on prebiotics, probiotics or synbiotics, have demonstrated an important influence of microbiota on neurological disorders by the synthesis of neuroactive compounds that interact with the nervous system and by the regulation of inflammatory and endocrine processes. Further research is needed to demonstrate the influence of gut microbiota dysbiosis on psychiatric and psychological disorders, and how microbiota-based interventions may be used as potential therapeutic tools.

A meta-analysis of the efficacy and safety of the traditional Chinese medicine formula Kaixinsan decoction for depression

BACKGROUND

Kaixinsan (KXS) decoction is a traditional Chinese herbal formulation commonly used to treat depression. This study aimed to evaluate the efficacy and safety of KXS, which is widely used, alone and in combination with other therapies, for the treatment of depression. The main objective was to assess the efficacy and safety of KXS in the treatment of depression as a single agent or in combination with other methods.

METHODS

Randomized controlled trials of KXS in the treatment of depression were systematically searched from several Chinese and English databases with no language restriction. Patients in these studies met the relevant diagnostic criteria for depression. Data on HAMD, SDS, practical situations, and occurrence of side effects in the studies were extracted. Finally, the methodological quality and risk of bias of the included studies were assessed using the Jadad scale and Cochrane bias evaluation tool.

RESULTS

Twelve studies with 1034 patients were included after screening. The Jadad scale and Cochrane bias evaluation tool indicated that the quality of the studies ranged from fair to good, with 41.7% categorized as good and 58.3% as poor. Egger test and funnel plots showed that the publication bias remain low.

CONCLUSION

The results showed that the frequency of side effects in the control group was higher than that in the treatment group, and there was a statistically significant difference. KXS was comparable or superior to antidepressants in treating depression and has fewer side effects. The data analysis showed that effectiveness and other indicators differed significantly by geographic area and dosage form, which has implications for future clinical work.

Efficacy and safety of repeated transcranial magnetic stimulation combined with escitalopram in the treatment of major depressive disorder: a meta-analysis

Objective

This study was designed to systematically review the efficacy and safety of repeated transcranial magnetic stimulation (rTMS) combined with escitalopram in treating major depressive disorder (MDD).

Methods

Databases including PubMed, Embase, Cochrane, Web of Science, CNKI, Wanfang, VIP Journal, and China Biomedical Literature databases were electronically searched for randomized controlled trials of rTMS combined with escitalopram intervention for MDD treatment from the inception of these databases to 27 May 2023. Two reviewers independently screened the studies, extracted the data, and assessed the quality of the included studies. R 4.2.2 was then used for a meta-analysis.

Results

In total, 19 articles involving 1,032 patients were included. The results of the meta-analysis showed that Hamilton Depression Rating Scale (HAMD) scores were significantly lower in the group receiving rTMS combined with escitalopram (experimental group) than that in the control group [weighted mean difference (WMD) = -5.30, 95% confidence interval (95% CI): -6.44 to -4.17, p < 0.01]. The response rate of the experimental group was significantly higher than that of the control group [odds ratio (OR): 5.48; 95% CI: 3.72 to 8.07; p < 0.01]. No significant difference in the adverse reaction rate was observed between the two groups (OR: 1.04, 95% CI: 0.71 to 1.52, p = 0.82).

Conclusion

Our findings suggest that rTMS combined with escitalopram can benefit patients with MDD in a safe manner, which may help in guiding clinical practice.

Systematic review registration

DOI number: 10.37766/inplasy2023.11.0114, INPLASY2023110114.

Role of NLRP3 Inflammasome in Post-Spinal-Cord-Injury Anxiety and Depression: Molecular Mechanisms and Therapeutic Implications

The majority of research on the long-term effects of spinal cord injury (SCI) has primarily focused on neuropathic pain (NP), psychological issues, and sensorimotor impairments. Among SCI patients, mood disorders, such as anxiety and depression, have been extensively studied. It has been found that chronic stress and NP have negative consequences and reduce the quality of life for individuals living with SCI. Our review examined both human and experimental evidence to explore the connection between mood changes following SCI and inflammatory pathways, with a specific focus on NLRP3 inflammasome signaling. We observed increased proinflammatory factors in the blood, as well as in the brain and spinal cord tissues of SCI models. The NLRP3 inflammasome plays a crucial role in various diseases by controlling the release of proinflammatory molecules like interleukin 1β (IL-1β) and IL-18. Dysregulation of the NLRP3 inflammasome in key brain regions associated with pain processing, such as the prefrontal cortex and hippocampus, contributes to the development of mood disorders following SCI. In this review, we summarized recent research on the expression and regulation of components related to NLRP3 inflammasome signaling in mood disorders following SCI. Finally, we discussed potential therapeutic approaches that target the NLRP3 inflammasome and regulate proinflammatory cytokines as a way to treat mood disorders following SCI.

Dose-response associations of maternal prenatal noise exposure duration with antepartum depression status

BACKGROUND

Antepartum depression has been reported to be associated with the intensity of maternal prenatal noise exposure; however, the association between noise exposure duration and the development of antepartum depression has not been established. This study aimed to determine the total and trimester-specific association of prenatal noise exposure duration with the development of antepartum depression.

METHODS

From May 2018 to June 2021, we recruited 2,166 pregnant women from Shengjing Hospital, northeast China. We used a standardized questionnaire to assess women's prenatal noise exposure and used the Edinburgh Postnatal Depression Scale to assess pregnant women's antepartum depression during the 1st -, 2nd -, and 3rd - trimesters. We calculated a cumulative noise exposure score ranging from 0 to 3, with a higher score reflecting higher frequency and longer duration of noise exposure during pregnancy.

RESULTS

Women who were exposed to noise for ≥ 15 min per day had an increased risk of antepartum depression compared with women who were not exposed to noise during pregnancy [odds ratio (OR) = 1.83, 95%CI:1.18, 2.83]. Noise exposure in a specific trimester was associated with higher risk of depression in the same trimester and subsequent trimesters. We observed increases in antepartum depression risk with increasing cumulative noise exposure scores (P for trend < 0.05 for all). Pregnant women with the highest scores had the highest risk of antepartum depression during the first (OR = 1.30, 95%CI:1.02, 1.65), second (OR = 1.75, 95%CI:1.23, 2.50) trimesters. Women with a cumulative noise exposure score of 2 had the highest risk of antepartum depression during the third trimester (OR = 1.79, 95%CI:1.14, 2.80), as well as during the whole pregnancy (OR = 1.94, 95%CI:1.14, 3.30).

CONCLUSIONS

Maternal prenatal noise exposure duration was positively associated with antepartum depression risk in a dose-response manner. It is necessary to develop strategies by which pregnant women can avoid excessive exposure to noise to prevent antepartum depression.

Chronic Stress Exposure Alters the Gut Barrier: Sex-Specific Effects on Microbiota and Jejunum Tight Junctions

Background

Major depressive disorder (MDD) is the leading cause of disability worldwide. Of individuals with MDD, 30% to 50% are unresponsive to common antidepressants, highlighting untapped causal biological mechanisms. Dysfunction in the microbiota-gut-brain axis has been implicated in MDD pathogenesis. Exposure to chronic stress disrupts blood-brain barrier integrity; still, little is known about intestinal barrier function in these conditions, particularly for the small intestine, where absorption of most foods and drugs takes place.

Methods

We investigated how chronic social or variable stress, two mouse models of depression, impact the jejunum intestinal barrier in males and females. Mice were subjected to stress paradigms followed by analysis of gene expression profiles of intestinal barrier-related targets, fecal microbial composition, and blood-based markers.

Results

Altered microbial populations and changes in gene expression of jejunum tight junctions were observed depending on the type and duration of stress, with sex-specific effects. We used machine learning to characterize in detail morphological tight junction properties, identifying a cluster of ruffled junctions in stressed animals. Junctional ruffling is associated with inflammation, so we evaluated whether lipopolysaccharide injection recapitulates stress-induced changes in the jejunum and observed profound sex differences. Finally, lipopolysaccharide-binding protein, a marker of gut barrier leakiness, was associated with stress vulnerability in mice, and translational value was confirmed on blood samples from women with MDD.

Conclusions

Our results provide evidence that chronic stress disrupts intestinal barrier homeostasis in conjunction with the manifestation of depressive-like behaviors in a sex-specific manner in mice and, possibly, in human depression.

The effects of childhood maltreatment on social support, inflammation, and depressive symptoms in adulthood

RATIONALE

Social Safety Theory (SST) suggests that social threats increase inflammation, exacerbating health risks, but that social support may decrease inflammatory signaling. One of the key health problems affected by both social forces and inflammation is major depression.

OBJECTIVE

The present study sought to test aspects of the SST, to understand how social support and inflammation may mediate the effects of childhood maltreatment on depressive symptoms in adulthood.

METHODS

This study utilized data from the national Midlife Development in the United States study (n = 1969; mean age 53; 77.2% White; 53.6% female) to model the effects of childhood maltreatment on depressive symptoms in adulthood and the potential serial mediating effects of social support and inflammation. Analyses were conducted via structural equation modeling, using the four subscales of the Center for Epidemiologic Studies Depression Scale to indicate depressive symptoms, the five subscales of the Childhood Trauma Questionnaire to indicate childhood maltreatment, and the Positive Relations Scale and a network level measure of support as indicators of social support. Inflammation was indexed using C-reactive protein (CRP). The model was estimated via maximum likelihood with robust standard errors and significance of indirect effects were assessed via a Sobel test.

RESULTS

Childhood maltreatment was associated with increased depressive symptoms and CRP but decreased social support. Social support was associated with decreased depressive symptoms while CRP was associated with increased depressive symptoms. Assessing indirect effects yielded no serial mediation effect; however, a significant indirect effect from childhood maltreatment to depressive symptoms through social support was identified.

CONCLUSIONS

Analyses indicate mixed support for the SST with respect to depressive symptoms. Results highlight the role of social support in mitigating the effects depressive symptoms in adulthood; although, alternative strategies may be needed to decrease the effects of childhood maltreatment on inflammation as indexed by CRP.

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.

Homo temporus: Seasonal Cycles as a Fundamental Source of Variation in Human Psychology

Many animal species exhibit seasonal changes in their physiology and behavior. Yet despite ample evidence that humans are also responsive to seasons, the impact of seasonal changes on human psychology is underappreciated relative to other sources of variation (e.g., personality, culture, development). This is unfortunate because seasonal variation has potentially profound conceptual, empirical, methodological, and practical implications. Here, we encourage a more systematic and comprehensive collective effort to document and understand the many ways in which seasons influence human psychology. We provide an illustrative summary of empirical evidence showing that seasons impact a wide range of affective, cognitive, and behavioral phenomena. We then articulate a conceptual framework that outlines a set of causal mechanisms through which seasons can influence human psychology-mechanisms that reflect seasonal changes not only in meteorological variables but also in ecological and sociocultural variables. This framework may be useful for integrating many different seasonal effects that have already been empirically documented and for generating new hypotheses about additional seasonal effects that have not yet received empirical attention. The article closes with a section that provides practical suggestions to facilitate greater appreciation for, and systematic study of, seasons as a fundamental source of variation in human psychology.

Schizophrenia in the genetic era: a review from development history, clinical features and genomic research approaches to insights of susceptibility genes

Schizophrenia is a devastating neuropsychiatric disorder affecting 1% of the world population and ranks as one of the disorders providing the most severe burden for society. Schizophrenia etiology remains obscure involving multi-risk factors, such as genetic, environmental, nutritional, and developmental factors. Complex interactions of genetic and environmental factors have been implicated in the etiology of schizophrenia. This review provides an overview of the historical origins, pathophysiological mechanisms, diagnosis, clinical symptoms and corresponding treatment of schizophrenia. In addition, as schizophrenia is a polygenic, genetic disorder caused by the combined action of multiple micro-effective genes, we further detail several approaches, such as candidate gene association study (CGAS) and genome-wide association study (GWAS), which are commonly used in schizophrenia genomics studies. A number of GWASs about schizophrenia have been performed with the hope to identify novel, consistent and influential risk genetic factors. Finally, some schizophrenia susceptibility genes have been identified and reported in recent years and their biological functions are also listed. This review may serve as a summary of past research on schizophrenia genomics and susceptibility genes (NRG1, DISC1, RELN, BDNF, MSI2), which may point the way to future schizophrenia genetics research. In addition, depending on the above discovery of susceptibility genes and their exact function, the development and application of antipsychotic drugs will be promoted in the future.

Higher Blood-brain barrier permeability in patients with major depressive disorder identified by DCE-MRI imaging

BACKGROUND

Studies from animal models and clinical trials of blood and cerebrospinal fluid have proposed that blood-brain barrier (BBB) dysfunction in depression (MDD). But there are no In vivo proves focused on BBB dysfunction in MDD patients. The present study aimed to identify whether there was abnormal BBB permeability, as well as the association with clinical status in MDD patients using dynamic contrast-enhanced magnetic resonance (DCE-MRI) imaging.

METHODS

Patients with MDD and healthy adults were recruited and underwent DCE-MRI and structural MRI scans. The mean volume transfer constant (Ktrans) values were calculated for a quantitative assessment of BBB leakage. For each subject, the mean Ktrans values were calculated for the whole gray matter, white matter, and 90 brain regions of the anatomical automatic labeling template (AAL). The differences in Ktrans values between patients and controls and between treated and untreated patients were compared.

RESULTS

23 MDD patients (12 males and 11 females, mean age 28.09 years) and 18 healthy controls (HC, 8 males and 10 females, mean age 30.67 years) were recruited in the study. We found that the Ktrans values in the olfactory, caudate, and thalamus were higher in MDD patients compared to healthy controls (p<0.05). The Ktrans values in the orbital lobe, anterior cingulate gyrus, putamen, and thalamus in treated patients were lower than the patients never treated. There were positive correlations between HAMD total score with Ktrans values in whole brain WM, hippocampus and thalamus. The total HAMA score was positively correlated with the Ktrans of hippocampus.

CONCLUSION

These findings supported a link between blood-brain barrier leakage and depression and symptom severity. The results also suggested a role for non-invasive DCE-MRI in detecting blood-brain barrier dysfunction in depression patients.

Fetal CCL2 signaling mediates offspring social behavior and recapitulates effects of prenatal stress

Maternal stress during pregnancy is prevalent and associated with increased risk of neurodevelopmental disorders in the offspring. Maternal and offspring immune dysfunction has been implicated as a potential mechanism by which prenatal stress shapes offspring neurodevelopment; however, the impact of prenatal stress on the developing immune system has yet to be elucidated. Furthermore, there is evidence that the chemokine C-C motif chemokine ligand 2 (CCL2) plays a key role in mediating the behavioral sequelae of prenatal stress. Here, we use an established model of prenatal restraint stress in mice to investigate alterations in the fetal immune system, with a focus on CCL2. In the placenta, stress led to a reduction in CCL2 and Ccr2 expression with a concomitant decrease in leukocyte number. However, the fetal liver exhibited an inflammatory phenotype, with upregulation of Ccl2, Il6, and Lbp expression, along with an increase in pro-inflammatory Ly6CHi monocytes. Prenatal stress also disrupted chemokine signaling and increased the number of monocytes and microglia in the fetal brain. Furthermore, stress increased Il1b expression by fetal brain CD11b+ microglia and monocytes. Finally, intra-amniotic injections of recombinant mouse CCL2 partially recapitulated the social behavioral deficits in the adult offspring previously observed in the prenatal restraint stress model. Altogether, these data suggest that prenatal stress led to fetal inflammation, and that fetal CCL2 plays a role in shaping offspring social behavior.

Hormonal contraceptive use is associated with differences in women's inflammatory and psychological reactivity to an acute social stressor

Women using hormonal contraceptives (HCs) exhibit numerous signs of chronic inflammation, including elevated C-reactive protein levels and greater risk of developing mood and autoimmune disorders. However, users and non-users of HCs often have similar circulating proinflammatory cytokine levels, making the mechanism of association unclear. One possible explanation for this paradox is that HC users exhibit differences in their inflammatory responses to psychosocial stress that, over time, could contribute to chronic inflammation and its pathologies. Here, we tested this possibility by examining women's glucocorticoid, inflammatory, and psychological responses to the Trier Social Stress Test (TSST) in 67 naturally cycling (NC) and 60 oral HC-using women (Mage = 19.31, SDage = 1.95). As hypothesized, HC users and NC women exhibited different glucocorticoid and proinflammatory cytokine responses to the TSST. For NC women, TSST-induced increases in glucocorticoids were uncommon, and increases in glucocorticoids were accompanied by elevations in IL-6. In contrast, for women using HCs, increases in glucocorticoids in response to the TSST were common, and increases in glucocorticoids were accompanied by increases in TNF-α. HC users and NC women also differed in their psychological responses to the TSST, with HC users reporting elevated stress levels compared to NC women. Together, these results suggest that HC use impacts women's glucocorticoid, inflammatory, and psychological responses to psychosocial stress, potentially contributing to observed differences in these women's mental and physical health.