HPA Axis in the Pathomechanism of Depression and Schizophrenia: New Therapeutic Strategies Based on Its Participation

Greater perceived stress and lower cortisol concentration increase the odds of depressive symptoms among adolescents

BACKGROUND

Adolescent depression is a major public health concern. Although stress has been linked to more severe depression, its association with mild depression among adolescents is not understood. This study assesses the relationship between perceived stress and cortisol (a physiologic measure of stress) and examines the relationships between these stress measures and depressive symptoms among adolescents 13-19 years of age.

METHODS

Stress was measured with the Perceived Stress Scale-10 and through salivary sampling for cortisol four times throughout the day. The Patient Health Questionnaire-9 was used to measure depressive symptoms (range 0-27), where ≥5 indicated the threshold for experiencing at least mild depressive symptoms. Spearman coefficients and multiple logistic regression models were used to examine the relationships between our variables of interest.

RESULTS

The mean age of the 73 participants in our study was 15.82 years. 49 % of the participants reported depressive symptoms (PHQ-9 score ≥ 5). Both higher perceived stress (odds ratio [OR] = 1.11, p = 0.022) and lower cortisol (area-under-the curve; AUCG) (OR = 0.99, p = 0.009) were associated with increased odds of having depressive symptoms.

LIMITATIONS

Few participants had moderate to severe PHQ-9 depression, therefore our study reported findings on mild depression or greater.

CONCLUSIONS

Perceived stress and cortisol appear to reflect distinct, independent components of the stress experience. However, both greater perceived stress and less circulating cortisol may indicate difficulties in regulating stress as potential factors underlying depressive symptoms. Future research should focus on the different types of adolescent stressors and the importance of routine screening of stress and depression, including mild depression.

The chronic unpredictable mild stress (CUMS) Paradigm: Bridging the gap in depression research from bench to bedside

Depression is a complicated neuropsychiatric condition with an incompletely understoodetiology, making the discovery of effective therapies challenging. Animal models have been crucial in improving our understanding of depression and enabling antidepressant medication development. The CUMS model has significant face validity since it induces fundamental depression symptoms in humans, such as anhedonia, behavioral despair, anxiety, cognitive impairments, and changes in sleep, food, and social behavior. Its construct validity is demonstrated by the dysregulation of neurobiological systems involved in depression, including monoaminergic neurotransmission, the hypothalamic-pituitary-adrenal axis, neuroinflammatory processes, and structural brain alterations. Critically, the model's predictive validity is demonstrated by the reversal of CUMS-induced deficits following treatment with clinically effective antidepressants such as selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, tricyclic antidepressants, and monoamine oxidase inhibitors. This review comprehensivelyassesses the multifarious depressive-like phenotypes in the CUMS model using behavioral paradigms like sucrose preference, forced swim, tail suspension, elevated plus maze, and novel object recognition tests. It investigates the neurobiological mechanisms that underlie CUMS-induced behaviors, including signaling pathways involving tumor necrosis factor-alpha, brain-derived neurotrophic factor and its receptor TrkB, cyclooxygenase-2, glycogen synthase kinase-3 beta, and the kynurenine pathway. This review emphasizes the CUMS model's importance as a translationally relevant tool for unraveling the complex mechanisms underlying depression and facilitating the development of improved and targeted interventions for this debilitating neuropsychiatric disorder by providing a comprehensive overview of its validity, behavioral assessments, and neurobiological underpinnings.

Flibanserin conquers murine depressive pseudodementia by amending HPA axis, maladaptive inflammation and AKT/GSK/STAT/BDNF trajectory: Center-staging of the serotonergic/adrenergic circuitry

Depressive pseudodementia (DPD) is a debilitating cognitive dysfunction that accompanies major and/or frequent depressive attacks. DPD has gained significant research attention owing to its negative effects on the patients' quality of life and productivity. This study tested the procognitive potential of Flibanserin (FBN), the serotonin (5HT) receptor modulator, against propranolol (PRP), as β/5HT1A receptors blocker. Serving this purpose, female Wistar Albino rats were subjected to chronic unpredictable stress (CUS) and subsequently treated with FBN only (3 mg/kg/day, p.o), PRP only (10 mg/kg/day, p.o), or PRP followed by FBN, using the same doses. FBN ameliorated the behavioral/cognitive alterations and calmed the hypothalamic-pituitary-adrenal (HPA) axis storm by reducing the levels of stress-related hormones, viz, corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH), corticosterone (CORT) parallel to epinephrine (EPI) hyperstimulation. The maladaptive inflammatory response, comprising of interleukin (IL)-1β/6, and tumor necrosis factor (TNF)-α, was consequently blunted. This was contemporaneous to the partial restoration of the protein kinase-B (AKT)/glycogen synthase kinase (GSK)3β/signal transducer and activator of transcription (STAT)-3 survival trajectory and the reinstatement of the levels of brain derived neurotrophic factor (BDNF). Microscopically, FBN repaired the hippocampal architecture and lessened CD68/GFAP immunoreactivity. Pre-administration of PRP partially abolished FBN effect along the estimated parameters, except for 5HT2A receptor expression and epinephrine level, to prove 5HT1A receptor as a fulcrum initiator of the investigated pathway, while its sole administration worsened the underlying condition. Ultimately, these findings highlight the immense procognitive potential of FBN, offering a new paradigm for halting DPD advancement via synchronizing adrenergic/serotonergic circuitry.

Therapeutic potential of fucoidan in central nervous system disorders: A systematic review

Central nervous system (CNS) disorders have a complicated pathogenesis, and to date, no single mechanism can fully explain them. Most drugs used for CNS disorders primarily aim to manage symptoms and delay disease progression, and none have demonstrated any pathological reversal. Fucoidan is a safe, sulfated polysaccharide from seaweed that exhibits multiple pharmacological effects, and it is anticipated to be a novel treatment for CNS disorders. To assess the possible clinical uses of fucoidan, this review aims to provide an overview of its neuroprotective mechanism in both in vivo and in vitro CNS disease models, as well as its pharmacokinetics and safety. We included 39 articles on the pharmacology of fucoidan in CNS disorders. In vitro and in vivo experiments demonstrate that fucoidan has important roles in regulating lipid metabolism, enhancing the cholinergic system, maintaining the functional integrity of the blood-brain barrier and mitochondria, inhibiting inflammation, and attenuating oxidative stress and apoptosis, highlighting its potential for CNS disease treatment. Fucoidan has a protective effect against CNS disorders. With ongoing research on fucoidan, it is expected that a natural, highly effective, less toxic, and highly potent fucoidan-based drug or nutritional supplement targeting CNS diseases will be developed.

Daytime Dysfunction: Symptoms Associated with Nervous System Disorders Mediated by SIRT1

Daytime dysfunction, including symptoms like sleepiness, poor memory, and reduced responsiveness, is not well researched. It is crucial to develop animal models and study the biological mechanisms involved. We simulated sleep disorders through sleep deprivation, and stressful stimuli were used to establish daytime functional animal models. We used tests like the sodium pentobarbital sleep synergy test and the DSI telemetry system to measure sleep duration and structure. We also used tests like the Morris water maze, open field test, grip test, and baton twirling test to assess mental and physical fatigue. To assess the intrinsic biological mechanisms, we measured sleep-wake-related neurotransmitters and related receptor proteins, circadian rhythm-related proteins and cognition-related proteins in hypothalamus tissue, and oxidative stress, inflammatory factors, S100β, and HPA axis-related indexes in serum. Multi-factor sleep deprivation resulted in the disruption of sleep-wakefulness structure, memory-cognitive function degradation, decreased grip coordination, and other manifestations of decreased energetic and physical strength. The intrinsic biological mechanisms were related to the disturbed expression of sleep-wake, circadian rhythm, memory-cognition-related proteins, as well as the significant elevation of inflammatory factors, oxidative stress, the HPA axis, and other related indicators. Intrinsically related biological mechanisms and reduced sirt1 expression can lead to disruption of circadian rhythms; resulting in disruption of their sleep-wake-related neurotransmitter content and receptor expression. Meanwhile, the reduced expression of sirt1 also resulted in reduced expression of synapse-associated proteins. This study prepared an animal model of daytime dysfunction by means of multi-factor sleep deprivation. With sirt1 as a core target, the relevant biological mechanisms of neurological disorders were modulated.

Synergistic Antidepressant-like Effects of Biotics and n-3 Polyunsaturated Fatty Acids on Dopaminergic Pathway through the Brain-Gut Axis in Rats Exposed to Chronic Mild Stress

Probiotics, postbiotics, and n-3 polyunsaturated fatty acids (PUFA) have antidepressant-like effects. However, the underlying mechanisms of the dopaminergic pathway are unclear. The present study investigated the hypothesis that probiotics and postbiotics combined with n-3 PUFA synergistically improve depression by modulating the dopaminergic pathway through the brain-gut axis. Rats were randomly divided into seven groups: non-chronic mild stress (CMS) with n-6 PUFA, and CMS with n-6 PUFA, n-3 PUFA, probiotics, postbiotics, probiotics combined with n-3 PUFA, and postbiotics combined with n-3 PUFA. Probiotics, postbiotics, and n-3 PUFA improved depressive behaviors, decreased blood concentrations of interferon-γ, and interleukin-1β, and increased the brain and gut concentrations of short chain fatty acids and dopamine. Moreover, probiotics, postbiotics, and n-3 PUFA increased the brain and gut expression of glucocorticoid receptor and tyrosine hydroxylase; brain expression of l-type amino acid transporter 1 and dopamine receptor (DR) D1; and gut expression of DRD2. The expression of phosphorylated protein kinase A/protein kinase A and phosphorylated cAMP response element-binding protein/cAMP response element-binding protein increased in the brain, however, decreased in the gut by the supplementation of probiotics, postbiotics, and n-3 PUFA. There was synergistic effect of probiotics and postbiotics combined with n-3 PUFA on the depressive behaviors and dopaminergic pathway in blood, brain, and gut. Moreover, no significant difference in the dopaminergic pathways between the probiotics and postbiotics was observed. In conclusion, probiotics and postbiotics, combined with n-3 PUFA have synergistic antidepressant-like effects on the dopaminergic pathway through the brain-gut axis in rats exposed to CMS.

Early Life Stress and Major Depressive Disorder-An Update on Molecular Mechanisms and Synaptic Impairments

Early life stress (ELS), characterized as abuse, neglect, and abandonment, can cause several adverse consequences in the lives of affected individuals. ELS experiences can affect an individual's development in variable ways, persisting in the long term and promoting lasting impacts, considering that early exposure to stressors can be biologically incorporated, as prolonged stimulation of stress response systems affects the development of the brain structure and other body systems, increasing the risk of diseases associated with stress and cognitive impairment. This type of stress increases the risk of developing major depressive disorder (MDD) in a severe form that does not respond adequately to traditional antidepressant treatments. Several alterations are studied as mechanisms that relate ELS with MDD, such as epigenetic alterations, neurotransmitters, and neuronal signaling. This review discusses research that brings evidence about the ELS mechanisms involved in synaptic impairments and MDD. The processes involved in epigenetic changes and the HPA axis are highlighted, as well as changes in neurotransmitters and neuronal signaling mechanisms.

Profiling the combination of bupropion and dextromethorphan as a treatment option for major depressive disorder

INTRODUCTION

Major Depressive Disorder (MDD) is a common mental health disorder marked by sadness, hopelessness, and anhedonia. Various therapies exist, but their effectiveness is limited. Dextromethorphan hydrobromide combined with bupropion hydrochloride (Auvelity®) is a recently approved alternative for treating this condition in adults.

AREAS COVERED

This review summarizes the neurobiology of major depression and delves into the pharmacology, efficacy, safety, and tolerability of dextromethorphan plus bupropion in adult patients. It is based on observational studies, clinical trials, and other secondary studies obtained through systematic literature searches.

EXPERT OPINION

The combination of bupropion and dextromethorphan as a new pharmacotherapy for mental health is an interesting addition to the treatment options that can be used for MDD. The combination can be used in a range of scenarios, including as a first line therapy, as a second option when a patient has failed to achieve remission with a serotonin targeting agent, and for treatment resistant depression. Further research for other indications, including addiction disorders, may provide exciting results. Although a new combination, clinicians will be very familiar with both agents, increasing their acceptability. This pharmacotherapy also may bring increased impetus for discovering other combinations that may have beneficial synergistic effects.

Relationships among tumor necrosis factor-alpha levels, beta-amyloid accumulation, and hippocampal atrophy in patients with late-life major depressive disorder

BACKGROUND

Major depressive disorder (MDD) is characterized by hippocampal volume reduction, impacting cognitive function. Inflammation, particularly elevated tumor necrosis factor-alpha (TNF-α) levels, is consistently implicated in MDD pathophysiology. This study investigates the relationships between TNF-α levels, hippocampal volume, beta-amyloid (Aβ) burden, and cognitive abilities in MDD patients, aiming to illuminate the complex interplay among inflammatory markers, pathology indicators, structural brain alterations, and cognitive performance in non-demented MDD individuals.

METHOD

Fifty-two non-demented MDD patients, comprising 25 with mild cognitive impairment (MCI), were recruited along with 10 control subjects. Each participant underwent a thorough assessment encompassing TNF-α blood testing, 18F-florbetapir positron emission tomography, magnetic resonance imaging scans, and neuropsychological testing. Statistical analyses, adjusted for age and education, were performed to investigate the associations between TNF-α levels, adjusted hippocampal volume (HVa), global Aβ burden, and cognitive performance.

RESULTS

MCI MDD patients displayed elevated TNF-α levels and reduced HVa relative to controls. Correlation analyses demonstrated inverse relationships between TNF-α level and HVa in MCI MDD, all MDD, and all subjects groups. Both TNF-α level and HVa exhibited significant correlations with processing speed across all MDD and all subjects. Notably, global 18F-florbetapir standardized uptake value ratio did not exhibit significant correlations with TNF-α level, HVa, and cognitive measures.

CONCLUSION

This study highlights elevated TNF-α levels and reduced hippocampal volume in MCI MDD patients, indicating a potential association between peripheral inflammation and structural brain alterations in depression. Furthermore, our results suggest that certain cases of MDD may be affected by non-amyloid-mediated process, which impacts their TNF-α and hippocampal volume. These findings emphasize the importance of further investigating the complex interplay among inflammation, neurodegeneration, and cognitive function in MDD.

Pathophysiological Mechanisms of Psychosis-Induced Atrial Fibrillation: The Links between Mental Disorder and Arrhythmia

Atrial fibrillation (AF) is a common phenomenon of sustained arrhythmia leading to heart failure or stroke. Patients with mental disorders (MD), particularly schizophrenia and bipolar disorder, are at a high risk of AF triggered by the dysregulation of the autonomic nervous system, atrial stretch, oxidative stress, inflammation, and electrical or structural remodeling. Moreover, pathophysiological mechanisms underlying MD may also contribute to the genesis of AF. An overactivated hypothalamic-pituitary-adrenal axis, aberrant renin-angiotensin-aldosterone system, abnormal serotonin signaling, disturbed sleep, and genetic/epigenetic factors can adversely alter atrial electrophysiology and structural substrates, leading to the development of AF. In this review, we provide an update of our collective knowledge of the pathophysiological and molecular mechanisms that link MD and AF. Targeting the pathogenic mechanisms of MD-specific AF may facilitate the development of therapeutics that mitigate AF and cardiovascular mortality in this patient population.

Depression and type 2 diabetes risk: a Mendelian randomization study

Background

Extensive observational evidence has suggested an association between depression and type 2 diabetes (T2D). However, the causal relationships between these two diseases require further investigation. This study aimed to evaluate the bidirectional causal effect between two types of depression and T2D using two-sample Mendelian randomization (MR).

Methods

We applied two-step MR techniques, using single-nucleotide polymorphisms (SNPs) as the genetic instruments for analysis. We utilized summary data from genome-wide association studies (GWASs) for major depression (MD), depressive status (frequency of depressed mood in the last two weeks), T2D, and other known T2D risk factors such as obesity, sedentary behavior (time spent watching television), and blood pressure. The analysis utilized inverse variance weighted (IVW), MR-Egger regression, weighted median, weighted mode, MR pleiotropy residual sum, and outlier methods to determine potential causal relationships.

Results

The study found that MD was positively associated with T2D, with an odds ratio (OR) of 1.26 (95% CI: 1.10-1.43, p = 5.6×10-4) using the IVW method and an OR of 1.21 (95% CI: 1.04-1.41, p = 0.01) using the weighted median method. Depressive status was also positively associated with T2D, with an OR of 2.26 (95% CI: 1.03-4.94, p = 0.04) and an OR of 3.62 (95% CI: 1.33-9.90, p = 0.01) using the IVW and weighted median methods, respectively. No causal effects of MD and depressive status on T2D risk factors were observed, and T2D did not influence these factors.

Conclusion

Our study demonstrates a causal relationship between depression and an increased risk of developing T2D, with both major depression and depressive status being positively associated with T2D.

Nutritional Strategies in Major Depression Disorder: From Ketogenic Diet to Modulation of the Microbiota-Gut-Brain Axis

Major depressive disorder (MDD) is a leading cause of disability worldwide. While traditional pharmacological treatments are effective for many cases, a significant proportion of patients do not achieve full remission or experience side effects. Nutritional interventions hold promise as an alternative or adjunctive approach, especially for treatment-resistant depression. This review examines the potential role of nutrition in managing MDD through addressing biological deficits and modulating pathways relevant to its pathophysiology. Specifically, it explores the ketogenic diet and gut microbiome modulation through various methods, including probiotics, prebiotics, synbiotics, postbiotics, and fecal microbiota transplantation. Numerous studies link dietary inadequacies to increased MDD risk and deficiencies in nutrients like omega-3 s, vitamins D and B, magnesium, and zinc. These deficiencies impact neurotransmitters, inflammation, and other biological factors in MDD. The gut-brain axis also regulates mood, stress response, and immunity, and disruptions are implicated in MDD. While medications aid acute symptoms, nutritional strategies may improve long-term outcomes by preventing relapse and promoting sustained remission. This comprehensive review aims to provide insights into nutrition's multifaceted relationship with MDD and its potential for developing more effective integrated treatment approaches.

Effects of Antipsychotics on the Hypothalamus-Pituitary-Adrenal Axis in a Phencyclidine Animal Model of Schizophrenia

Schizophrenia (SCH) is a mental disorder that requires long-term antipsychotic treatment. SCH patients are thought to have an increased sensitivity to stress. The dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, observed in SCH, could include altered levels of glucocorticoids, glucocorticoid receptors (GRs), and associated proteins. The perinatal administration of phencyclidine (PCP) to rodents represents an animal model of SCH. This study investigated the effects of perinatal PCP exposure and subsequent haloperidol/clozapine treatment on corticosterone levels measured by ELISA and the expression of GR-related proteins (GR, pGR, HSP70, HSP90, FKBP51, and 11β-Hydroxysteroid dehydrogenase-11β-HSD) determined by Western blot, in different brain regions of adult rats. Six groups of male rats were treated on the 2nd, 6th, 9th, and 12th postnatal days (PN), with either PCP or saline. Subsequently, one saline and one PCP group received haloperidol/clozapine from PN day 35 to PN day 100. The results showed altered GR sensitivity in the rat brain after PCP exposure, which decreased after haloperidol/clozapine treatment. These findings highlight disturbances in the HPA axis in a PCP-induced model of SCH and the potential protective effects of antipsychotics. To the best of our knowledge, this is the first study to investigate the effects of antipsychotic drugs on the HPA axis in a PCP animal model of SCH.

Peganum harmala L. seed extract attenuates anxiety and depression in rats by reducing neuroinflammation and restoring the BDNF/TrkB signaling pathway and monoamines after exposure to chronic unpredictable mild stress

Depression is a mental disorder characterised by persistent low mood, anhedonia and cognitive impairment that affects an estimated 3.8% of the world's population, including 5% of adults. Peganum harmala L. (P. harmala) is a medicinal plant and has been reported to be effective against Alzheimer's disease, Parkinson's disease and depression. The present study was aimed to evaluate the behavioral and pharmacological effects of P. harmala seed extract in rats exposed to chronic unpredictable mild stress (CUMS) in vivo and to investigate the mechanism of action. CUMS-exposed rats were treated with P. harmala extract (75 and 150 mg/kg, i.p.) for 2 weeks. HPLC analysis was used to determine the concentration of harmaline and harmine alkaloids in the extract. Heavy metal analysis in seeds was performed by ICP-MS. Our results showed that P. harmala at the dose of 150 mg/kg significantly reduced the depressive-like behaviors in CUMS-exposed rats, as evidenced by increased sucrose consumption in the sucrose preference test (SPT), decreased immobility time in the forced swim test (FST) and plasma corticosterone levels, increased the time spent in open arms in the elevated plus maze (EPM), and improved memory and learning in the passive avoidance test (PAT). In addition, P. harmala decreased monoamine oxidase-A (MAO-A) levels, and increased serotonin (5-HT), dopamine (DA), and noradrenaline (NA) levels in the brains of rats exposed to CUMS. P. harmala decreased the expression of the pro-inflammatory transcription factor nuclear factor-κB (NF-κB), and increased the antioxidant nuclear factor erythroid 2-related factor 2 (Nrf2) in rat brain. Furthermore, P. harmala improved brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB) protein expression in rat brain. In conclusion, P. harmala at a dose of 150 mg/kg is more effective in preventing depressive-like behavior in CUMS-exposed rats by improving neurotransmitter levels, reducing oxidative stress, suppressing neuroinflammation and activating the BDNF/TrkB pathway, all of which are important in the pathogenesis of depression.

Steroidomics in Men with Schizophrenia

Schizophrenia is associated with numerous abnormalities, including imbalances in all hormonal axes, among which steroids play a major role. Steroidomic studies therefore represent a promising tool for early diagnosis and appropriate treatment of schizophrenia. A total of 51 adult male schizophrenics aged 27 (22, 34) years (shown as median with quartiles) and 16 healthy controls (HCs) aged 28 (25, 32) years were enrolled into this study. Our results showed the effective differentiation of men with schizophrenia from controls based on steroidomic profiles. We also found an altered metabolic pathway from pregnenolone and its sulfate (PREG/S) to cortisol in schizophrenics with several metabolic bottlenecks such as lower PREG levels due to increased PREG sulfation and/or suppressed PREGS desulfation and attenuated conversion of 17-hydroxy-PREG to 17-hydroxy-progesterone, as well as the results suggestive of suppressed CYP11B1 activity. In contrast, steroid molar ratios suggested two counterregulatory steps involving increased conversion of PREG/S to 17-hydroxy-PREG/S and decreased conversion of cortisol to cortisone, which may maintain unchanged basal cortisol levels but may not ensure a sufficient cortisol response to stress. Our data also indicated a trend to higher 7α-, 7β-, and 16α-hydroxylation that may counteract the autoimmune complications and proinflammatory processes accompanying schizophrenia. Finally, a possible suppression of HSD17B3 activity was suggested, resulting in decreased circulating testosterone levels with increased androstenedione levels.

Neurobiological and psychological factors to depression

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

Prevalence, demographic characteristics, and clinical features of suicide risk in first episode drug-naïve schizophrenia patients with comorbid severe anxiety

BACKGROUND

Both anxiety symptoms and suicide risk are common in schizophrenia. However, previous findings about the association between anxiety and suicide risk in schizophrenia were controversial. This study is the first to examine the prevalence of suicide risk and related demographic, clinical features in a large sample of first episode drug-naïve (FEDN) schizophrenia patients with comorbid severe anxiety.

METHODS

In total, 316 patients with FEDN schizophrenia were enrolled in this study. Patients' symptoms were assessed using the Hamilton Depression Scale (HAMD), Hamilton Anxiety Rating Scale (HAMA), and Positive and Negative Syndrome Scale (PANSS). Serum levels of glucose, insulin, uric acid, and lipids including total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C), were evaluated.

RESULTS

In the current study, 56.3% patients presented comorbid severe anxiety. The rate of suicide risk was higher in the severe anxiety group (55.6%) than in the mild-moderate anxiety group (33.3%). The interactions among severe anxiety, uric acid and HDL-C were associated with suicide risk. Compared with patients with normal uric acid, those with abnormal uric acid exhibited a stronger association between HAMA scores and HAMD-suicide item scores. This enhanced association was also observed for patients with abnormal HDL-C levels.

CONCLUSIONS

In FEDN schizophrenia patients with comorbid severe anxiety, our findings suggested a high incidence of suicide risk. Abnormal levels of uric acid and low levels of HDL-C, as well as high depression may be associated with an increased risk of suicide in FEDN schizophrenia patients with comorbid severe anxiety.

PI3K/AKT signaling pathway: Molecular mechanisms and therapeutic potential in depression

Depression is a serious global mental disorder. Numerous studies have found that depression may be closely related to decreased neurogenesis, neuroinflammation, neurotransmitter imbalance, and synaptic plasticity dysfunction. The pathogenesis of depression is complex and involves multiple signal transduction pathways and molecular changes. The PI3K/AKT pathway is an essential signaling pathways in neurons, which is widely expressed in emotion-related regions of the brain. Therefore, the PI3K/AKT pathway may play a moderating role in mood disorders. However, the role and mechanism of the PI3K/AKT signaling pathway in depression have not been fully described. This review systematically summarized the role of the PI3K/AKT signaling pathway in the pathogenesis of depression and discussed its potential in the treatment of depression. This will help in the treatment of depression and the development of antidepressants.

Deconstructing depression by machine learning: the POKAL-PSY study

Unipolar depression is a prevalent and disabling condition, often left untreated. In the outpatient setting, general practitioners fail to recognize depression in about 50% of cases mainly due to somatic comorbidities. Given the significant economic, social, and interpersonal impact of depression and its increasing prevalence, there is a need to improve its diagnosis and treatment in outpatient care. Various efforts have been made to isolate individual biological markers for depression to streamline diagnostic and therapeutic approaches. However, the intricate and dynamic interplay between neuroinflammation, metabolic abnormalities, and relevant neurobiological correlates of depression is not yet fully understood. To address this issue, we propose a naturalistic prospective study involving outpatients with unipolar depression, individuals without depression or comorbidities, and healthy controls. In addition to clinical assessments, cardiovascular parameters, metabolic factors, and inflammatory parameters are collected. For analysis we will use conventional statistics as well as machine learning algorithms. We aim to detect relevant participant subgroups by data-driven cluster algorithms and their impact on the subjects' long-term prognosis. The POKAL-PSY study is a subproject of the research network POKAL (Predictors and Clinical Outcomes in Depressive Disorders; GRK 2621).

Depression clinical trials worldwide: a systematic analysis of the ICTRP and comparison with ClinicalTrials.gov

Major depressive disorder (MDD), commonly known as depression, affects over 300 million people worldwide as of 2018 and presents a wide range of clinical symptoms. The international clinical trials registry platform (ICTRP) introduced by WHO includes aggregated data from ClinicalTrials.gov and 17 other national registers, making it the largest clinical trial platform. Here we analysed data in ICTRP with the aim of providing comprehensive insights into clinical trials on depression. Applying a novel hidden duplicate identification method, 10,606 depression trials were identified in ICTRP, with ANZCTR being the largest non- ClinicalTrials.gov database at 1031 trials, followed by IRCT with 576 trials, ISRCTN with 501 trials, CHiCTR with 489 trials, and EUCTR with 351 trials. The top four most studied drugs, ketamine, sertraline, duloxetine, and fluoxetine, were consistent in both groups, but ClinicalTrials.gov had more trials for each drug compared to the non-ClinicalTrials.gov group. Out of 9229 interventional trials, 663 unique agents were identified, including approved drugs (74.5%), investigational drugs (23.2%), withdrawn drugs (1.8%), nutraceuticals (0.3%), and illicit substances (0.2%). Both ClinicalTrials.gov and non-ClinicalTrials.gov databases revealed that the largest categories were antidepressive agents (1172 in ClinicalTrials.gov and 659 in non-ClinicalTrials.gov) and nutrients, amino acids, and chemical elements (250 in ClinicalTrials.gov and 659 in non-ClinicalTrials.gov), indicating a focus on alternative treatments involving dietary supplements and nutrients. Additionally, 26 investigational antidepressive agents targeting 16 different drug targets were identified, with buprenorphine (opioid agonist), saredutant (NK2 antagonist), and seltorexant (OX2 antagonist) being the most frequently studied. This analysis addresses 40 approved drugs for depression treatment including new drug classes like GABA modulators and NMDA antagonists that are offering new prospects for treating MDD, including drug-resistant depression and postpartum depression subtypes.

The Relationship between Canine Behavioral Disorders and Gut Microbiome and Future Therapeutic Perspectives

Canine behavioral disorders have become one of the most common concerns and challenging issues among dog owners. Thus, there is a great demand for knowledge about various factors affecting dogs' emotions and well-being. Among them, the gut-brain axis seems to be particularly interesting, especially since in many instances the standard treatment or behavioral therapies insufficiently improve animal behavior. Therefore, to face this challenge, the search for novel therapeutic methods is highly required. Existing data show that mammals' gut microbiome, immune system, and nervous system are in continuous communication and influence animal physiology and behavior. This review aimed to summarize and discuss the most important scientific evidence on the relationship between mental disorders and gut microbiota in dogs, simultaneously presenting comparable outcomes in humans and rodent models. A comprehensive overview of crucial mechanisms of the gut-brain axis is included. This refers especially to the neurotransmitters crucial for animal behavior, which are regulated by the gut microbiome, and to the main microbial metabolites-short-chain fatty acids (SCFAs). This review presents summarized data on gut dysbiosis in relation to the inflammation process within the organism, as well as the activation of the hypothalamic-pituitary-adrenal (HPA) axis. All of the above mechanisms are presented in this review in strict correlation with brain and/or behavioral changes in the animal. Additionally, according to human and laboratory animal studies, the gut microbiome appears to be altered in individuals with mental disorders; thus, various strategies to manipulate the gut microbiota are implemented. This refers also to the fecal microbiome transplantation (FMT) method, based on transferring the fecal matter from a donor into the gastrointestinal tract of a recipient in order to modulate the gut microbiota. In this review, the possible effects of the FMT procedure on animal behavioral disorders are discussed.

Investigating the Impacts of Diet, Supplementation, Microbiota, Gut-Brain Axis on Schizophrenia: A Narrative Review

Schizophrenia is a disease with a complex etiology that significantly impairs the functioning of patients. In recent years, there has been increasing focus on the importance of the gut microbiota in the context of the gut-brain axis. In our study, we analyzed data on the gut-brain axis in relation to schizophrenia, as well as the impacts of eating habits, the use of various supplements, and diets on schizophrenia. Additionally, the study investigated the impact of antipsychotics on the development of metabolic disorders, such as diabetes, dyslipidemia, and obesity. There may be significant clinical benefits to be gained from therapies supported by supplements such as omega-3 fatty acids, B vitamins, and probiotics. The results suggest the need for a holistic approach to the treatment of schizophrenia, incorporating both drug therapy and dietary interventions.

Association of gut dysbiosis with first‑episode psychosis (Review)

The gut‑microbiota‑brain axis is a complex bidirectional communication system linking the gastrointestinal tract to the brain. Changes in the balance, composition and diversity of the gut‑microbiota (gut dysbiosis) have been found to be associated with the development of psychosis. Early‑life stress, along with various stressors encountered in different developmental phases, have been shown to be associated with the abnormal composition of the gut microbiota, leading to irregular immunological and neuroendocrine functions, which are potentially responsible for the occurrence of first‑episode psychosis (FEP). The aim of the present narrative review was to summarize the significant differences of the altered microbiome composition in patients suffering from FEP vs. healthy controls, and to discuss its effects on the occurrence and intensity of symptoms in FEP.

Microbiota-brain axis: Exploring the role of gut microbiota in psychiatric disorders - A comprehensive review

Mental illness is a hidden epidemic in modern science that has gradually spread worldwide. According to estimates from the World Health Organization (WHO), approximately 10% of the world's population suffers from various mental diseases each year. Worldwide, financial and health burdens on society are increasing annually. Therefore, understanding the different factors that can influence mental illness is required to formulate novel and effective treatments and interventions to combat mental illness. Gut microbiota, consisting of diverse microbial communities residing in the gastrointestinal tract, exert profound effects on the central nervous system through the gut-brain axis. The gut-brain axis serves as a conduit for bidirectional communication between the two systems, enabling the gut microbiota to affect emotional and cognitive functions. Dysbiosis, or an imbalance in the gut microbiota, is associated with an increased susceptibility to mental health disorders and psychiatric illnesses. Gut microbiota is one of the most diverse and abundant groups of microbes that have been found to interact with the central nervous system and play important physiological functions in the human gut, thus greatly affecting the development of mental illnesses. The interaction between gut microbiota and mental health-related illnesses is a multifaceted and promising field of study. This review explores the mechanisms by which gut microbiota influences mental health, encompassing the modulation of neurotransmitter production, neuroinflammation, and integrity of the gut barrier. In addition, it emphasizes a thorough understanding of how the gut microbiome affects various psychiatric conditions.

Use of Extracellular Monomeric Ubiquitin as a Therapeutic Option for Major Depressive Disorder

Major depressive disorder (MDD) is a mood disorder that has become a global health emergency according to the World Health Organization (WHO). It affects 280 million people worldwide and is a leading cause of disability and financial loss. Patients with MDD present immunoendocrine alterations like cortisol resistance and inflammation, which are associated with alterations in neurotransmitter metabolism. There are currently numerous therapeutic options for patients with MDD; however, some studies suggest a high rate of therapeutic failure. There are multiple hypotheses explaining the pathophysiological mechanisms of MDD, in which several systems are involved, including the neuroendocrine and immune systems. In recent years, inflammation has become an important target for the development of new therapeutic options. Extracellular monomeric ubiquitin (emUb) is a molecule that has been shown to have immunomodulatory properties through several mechanisms including cholinergic modulation and the generation of regulatory T cells. In this perspective article, we highlight the influence of the inflammatory response in MDD. In addition, we review and discuss the evidence for the use of emUb contained in Transferon as a concomitant treatment with selective serotonin reuptake inhibitors (SSRIs).

Impacts of Unhealthy Behaviors on Mental Health among Public Health Residents: The PHRASI Study

Unhealthy behaviors (UBs) can affect mental health. The most impactful of these are alcohol abuse, sedentary behavior, and sleep disturbances. Since these UBs are not well explored in medical residents, this study aims to overcome this gap, focusing on outcomes such as depression and anxiety. The Public Health Residents' Anonymous Survey in Italy (PHRASI) is a nationwide cross-sectional study based on an 88-item questionnaire. UBs were explored through validated questionnaires: the Alcohol Use Disorders Identification Test-c (AUDIT-C), the International Physical Activity Questionnaire (IPAQ), and the Insomnia Severity Index (ISI). Depressive symptoms and anxiety were detected by Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7), respectively. Hierarchical cluster analysis described clusters using responses from the AUDIT-C, IPAQ, and ISI. A total of 375 participants were included in this study. Three distinct clusters (CL) were identified: CL1 was characterized by a moderate risk for alcohol abuse and high insomnia dissatisfaction, with a significantly higher frequency of depressive symptoms (46%, p < 0.001) and anxiety (53%, p < 0.001); CL2 had no risk for alcohol abuse, high sleep satisfaction, and better mental health profile, with the lowest prevalence of depressive symptoms (15%, p < 0.001); CL3 had the highest risk of alcohol abuse, the highest rate of physical activity (40%, p = 0.013), and the lowest prevalence of anxiety (27%, p < 0.001). Subjects belonging to CL1 required much more attention to prevent the worsening of mental outcomes. Interventions for promoting mental health should be addressed in all Public Health schools to create more sustainable working conditions.

Research progress on insomnia treated by traditional Chinese medicine and acupuncture based on microbial-gut-brain axis theory

Insomnia, as one of the emotional diseases, has been increasing in recent years, which has a great impact on people's life and work. Therefore, researchers are eager to find a more perfect treatment. The microbiome-gut-brain axis is a new theory that has gradually become popular abroad in recent years and has a profound impact in the field of insomnia. In recent years, traditional Chinese medicine (TCM) has played an increasingly important role in the treatment of insomnia, especially acupuncture and Chinese herbal medicine. It is the main method of TCM in the treatment of insomnia. This paper mainly reviews the combination degree of "microorganism-gut-brain axis" theory with TCM and acupuncture under the system of TCM. To explore the mechanism of TCM and acupuncture in the treatment of insomnia under the guidance of "microorganism-gut-brain axis" theory, in order to provide a new idea for the diagnosis and treatment of insomnia.

Comprehensive Exploration of the Neuroprotective Mechanisms of Ginkgo biloba Leaves in Treating Neurological Disorders

Neurological disorders (NDs) are diseases that seriously affect the health of individuals worldwide, potentially leading to a significant reduction in the quality of life for patients and their families. Herbal medicines have been widely used in the treatment of NDs due to their multi-target and multi-pathway features. Ginkgo biloba leaves (GBLs), one of the most popular herbal medicines in the world, have been demonstrated to present therapeutic effects on NDs. However, the pharmacological mechanisms of GBLs in the treatment of neurological disorders have not been systematically summarized. This study aimed to summarize the molecular mechanism of GBLs in treating NDs from the cell models, animal models, and clinical trials of studies. Four databases, i.e., PubMed, Google Scholar, CNKI, and Web of Science were searched using the following keywords: "Ginkgo biloba", "Ginkgo biloba extract", "Ginkgo biloba leaves", "Ginkgo biloba leaves extract", "Neurological disorders", "Neurological diseases", and "Neurodegenerative diseases". All items meeting the inclusion criteria on the treatment of NDs with GBLs were extracted and summarized. Additionally, PRISMA 2020 was performed to independently evaluate the screening methods. Out of 1385 records in the database, 52 were screened in relation to the function of GBLs in the treatment of NDs; of these 52 records, 39 were preclinical trials and 13 were clinical studies. Analysis of pharmacological studies revealed that GBLs can improve memory, cognition, behavior, and psychopathology of NDs and that the most frequently associated GBLs are depression, followed by Alzheimer's disease, stroke, Huntington's disease, and Parkinson's disease. Additionally, the clinical studies of depression, AD, and stroke are the most common, and most of the remaining ND data are available from in vitro or in vivo animal studies. Moreover, the possible mechanisms of GBLs in treating NDs are mainly through free radical scavenging, anti-oxidant activity, anti-inflammatory response, mitochondrial protection, neurotransmitter regulation, and antagonism of PAF. This is the first paper to systematically and comprehensively investigate the pharmacological effects and neuroprotective mechanisms of GBLs in the treatment of NDs thus far. All findings contribute to a better understanding of the efficacy and complexity of GBLs in treating NDs, which is of great significance for the further clinical application of this herbal medicine.

The Underlying Neurobiological Mechanisms of Psychosis: Focus on Neurotransmission Dysregulation, Neuroinflammation, Oxidative Stress, and Mitochondrial Dysfunction

Psychosis, defined as a set of symptoms that results in a distorted sense of reality, is observed in several psychiatric disorders in addition to schizophrenia. This paper reviews the literature relevant to the underlying neurobiology of psychosis. The dopamine hypothesis has been a major influence in the study of the neurochemistry of psychosis and in development of antipsychotic drugs. However, it became clear early on that other factors must be involved in the dysfunction involved in psychosis. In the current review, it is reported how several of these factors, namely dysregulation of neurotransmitters [dopamine, serotonin, glutamate, and γ-aminobutyric acid (GABA)], neuroinflammation, glia (microglia, astrocytes, and oligodendrocytes), the hypothalamic-pituitary-adrenal axis, the gut microbiome, oxidative stress, and mitochondrial dysfunction contribute to psychosis and interact with one another. Research on psychosis has increased knowledge of the complexity of psychotic disorders. Potential new pharmacotherapies, including combinations of drugs (with pre- and probiotics in some cases) affecting several of the factors mentioned above, have been suggested. Similarly, several putative biomarkers, particularly those related to the immune system, have been proposed. Future research on both pharmacotherapy and biomarkers will require better-designed studies conducted on an all stages of psychotic disorders and must consider confounders such as sex differences and comorbidity.

Sex Differences in the Association of Depression Symptoms and Cardiovascular Disease in Adults in the United States

PURPOSE

This study explores the relationship between depression and cardiovascular disease (CVD) in the US adult population, focusing on sex differences.

DESIGN

Cross-sectional study.

SETTING

National Health and Nutrition Examination Survey data (2013-2018).

PARTICIPANTS

A total of 14 699 community-dwelling adults (≥20 years).

MEASURE

The Patient Health Questionnaire (PHQ-9) depression screening tool assessed depressive symptoms. CVD events included heart failure, coronary heart disease, angina, heart attack, or stroke.

ANALYSIS

Adjusted prevalence ratios were estimated using a Poisson regression model.

RESULTS

The study finds a positive association between CVD incidents and both mild to moderate depressive symptoms (aPR:1.42, P = .002) and moderately severe to severe depression (aPR:1.72, P = .024). Overall, females exhibit a 47% lower likelihood of CVD incidents compared to males. However, in a subgroup analysis, increased depressive symptoms correlate with higher CVD incidents in females (aPRs range: 2.09 to 3.43, P < .001) compared to males (aPRs range: 1.45 to 1.77, P < .001).

CONCLUSION

Depression is associated with increased cardiovascular disease (CVD) risk. Females generally have a lower CVD risk than males, but more severe depressive symptoms elevate CVD risk in females. These findings emphasize the significance of considering sex differences. Further research is needed to understand the underlying mechanisms.

Risk of major depressive increases with increasing frequency of alcohol drinking: a bidirectional two-sample Mendelian randomization analysis

Introduction

A growing body of evidence suggests that alcohol use disorders coexist with depression. However, the causal relationship between alcohol consumption and depression remains a topic of controversy.

Methods

We conducted a two-sample two-way Mendelian randomization analysis using genetic variants associated with alcohol use and major depressive disorder from a genome-wide association study.

Results

Our research indicates that drinking alcohol can reduce the risk of major depression (odds ratio: 0.71, 95% confidence interval: 0.54~0.93, p = 0.01), while increasing the frequency of drinking can increase the risk of major depression (odds ratio: 1.09, 95% confidence interval: 1.00~1.18, p = 0.04). Furthermore, our multivariate MR analysis demonstrated that even after accounting for different types of drinking, the promoting effect of drinking frequency on the likelihood of developing major depression still persists (odds ratio: 1.13, 95% confidence interval: 1.04~1.23, p = 0.005). Additionally, mediation analysis using a two-step MR approach revealed that this effect is partially mediated by the adiposity index, with a mediated proportion of 37.5% (95% confidence interval: 0.22 to 0.38).

Discussion

In this study, we found that alcohol consumption can alleviate major depression, while alcohol intake frequency can aggravate it.These findings have important implications for the development of prevention and intervention strategies targeting alcohol-related depression.

Effect of Integrated Yoga as an add-on therapy in adults with clinical depression - A randomized controlled trial

BACKGROUND

Depression is a leading cause of disability and the conventional management has several limitations. Recent studies demonstrated the benefits of yoga in psychological disorders.

AIMS

To evaluate the efficacy of the Integrated Yoga Module (IYM) to standard care with added yogic education on lifestyle modification (YELM) in patients with clinical depression.

METHODS

A PROBE trial was conducted at a single tertiary care hospital in India. Adults aged 18 to 64 with clinical depression were randomized to either an IYM or an active control group using a computer-generated mixed block randomization sequence. Both groups received YELM in addition to standard care and the intervention group practiced IYM, for 8 weeks. The primary outcome was the reduction in depression symptoms assessed using the Beck Depression Inventory (BDI-II), and secondary outcomes involved self-compassion, brief resilience, positive and negative experiences, and quality of life, evaluated at 8 weeks.

RESULTS

The mean ± SD age of participants was 32.2 ± 10.0 and 54.3% were females. The IYM group showed statistically significant improvements in BDI-II scores β = -6.7 (95% CI [-10.8, -2.5]; p = .001), resilience β = 0.4 (95% CI [0.02, 0.80]; p = .037), physical health domain of WHOQOL - BREF β = 10.1 (95% CI [0.7, 19.5]; p = .035) and negative emotions (SPANE-N) β = 2.8 (95% CI [0.1, 5.4]; p = .037). However, no significant differences were found in SCS-SF β = -0.3 (95% CI [-0.7, 0.0]; p = .053).

CONCLUSIONS

IYM as an adjunct is superior to conventional medical management in reducing symptoms and improving positive psychological resources in clinical depression.

Psilocybin for dementia prevention? The potential role of psilocybin to alter mechanisms associated with major depression and neurodegenerative diseases

Major depression is an established risk factor for subsequent dementia, and depression in late life may also represent a prodromal state of dementia. Considering current challenges in the clinical development of disease modifying therapies for dementia, the focus of research is shifting towards prevention and modification of risk factors to alter the neurodegenerative disease trajectory. Understanding mechanistic commonalities underlying affective symptoms and cognitive decline may reveal biomarkers to aid early identification of those at risk of progressing to dementia during the preclinical phase of disease, thus allowing for timely intervention. Adult hippocampal neurogenesis (AHN) is a phenomenon that describes the birth of new neurons in the dentate gyrus throughout life and it is associated with spatial learning, memory and mood regulation. Microglia are innate immune system macrophages in the central nervous system that carefully regulate AHN via multiple mechanisms. Disruption in AHN is associated with both dementia and major depression and microgliosis is a hallmark of several neurodegenerative diseases. Emerging evidence suggests that psychedelics promote neuroplasticity, including neurogenesis, and may also be immunomodulatory. In this context, psilocybin, a serotonergic agonist with rapid-acting antidepressant properties has the potential to ameliorate intersecting pathophysiological processes relevant for both major depression and neurodegenerative diseases. In this narrative review, we focus on the evidence base for the effects of psilocybin on adult hippocampal neurogenesis and microglial form and function; which may suggest that psilocybin has the potential to modulate multiple mechanisms of action, and may have implications in altering the progression from major depression to dementia in those at risk.

Biomarker triterpenoids of Centella asiatica as potential antidepressant agents: Combining in vivo and in silico studies

Although there are various treatments available for depression, some patients may experience resistance to treatment or encounter adverse effects. Centella asiatica (C. asiatica) is an ancient medicinal herb used in Ayurvedic medicine for its rejuvenating, neuroprotective and psychoactive properties. This study aims to explore the antidepressant-like effects of the major constituents found in C. asiatica, i.e., asiatic acid, asiaticoside, madecassic acid, and madecassoside at three doses (1.25, 2.5, and 5 mg/kg, i.p), on the behavioural and cortisol level of unpredictable chronic stress (UCS) zebrafish model. Based on the findings from the behavioural study, the cortisol levels in the zebrafish body after treatment with the two most effective compounds were measured using enzyme-linked immunosorbent assay (ELISA). Furthermore, a molecular docking study was conducted to predict the inhibitory impact of the triterpenoid compounds on serotonin reuptake. The in vivo results indicate that madecassoside (1.25, 2.5, and 5 mg/kg), asiaticoside and asiatic acid (5 mg/kg) activated locomotor behaviour. Madecassoside at all tested doses and asiaticoside at 2.5 and 5 mg/kg significantly decreased cortisol levels compared to the stressed group, indicating the potential regulation effect of madecassoside and asiaticoside on the hypothalamic-pituitary-adrenal axis overactivity. This study highlights the potential benefits of madecassoside and asiaticoside in alleviating depressive symptoms through their positive effects on behaviour and the hypothalamic-pituitary-adrenal (HPA)- axis in a chronic unpredictable stress zebrafish model. Furthermore, the in silico study provided additional evidence to support these findings. These promising results suggest that C. asiatica may be a valuable and cost-effective therapeutic option for depression, and further research should be conducted to explore its potential benefits.

Human Gut Microbiota for Diagnosis and Treatment of Depression

Nowadays, depressive disorder is spreading rapidly all over the world. Therefore, attention to the studies of the pathogenesis of the disease in order to find novel ways of early diagnosis and treatment is increasing among the scientific and medical communities. Special attention is drawn to a biomarker and therapeutic strategy through the microbiota-gut-brain axis. It is known that the symbiotic interactions between the gut microbes and the host can affect mental health. The review analyzes the mechanisms and ways of action of the gut microbiota on the pathophysiology of depression. The possibility of using knowledge about the taxonomic composition and metabolic profile of the microbiota of patients with depression to select gene compositions (metagenomic signature) as biomarkers of the disease is evaluated. The use of in silico technologies (machine learning) for the diagnosis of depression based on the biomarkers of the gut microbiota is given. Alternative approaches to the treatment of depression are being considered by balancing the microbial composition through dietary modifications and the use of additives, namely probiotics, postbiotics (including vesicles) and prebiotics as psychobiotics, and fecal transplantation. The bacterium Faecalibacterium prausnitzii is under consideration as a promising new-generation probiotic and auxiliary diagnostic biomarker of depression. The analysis conducted in this review may be useful for clinical practice and pharmacology.

Unraveling the Role of the Blood-Brain Barrier in the Pathophysiology of Depression: Recent Advances and Future Perspectives

Depression is a highly prevalent psychological disorder characterized by persistent dysphoria, psychomotor retardation, insomnia, anhedonia, suicidal ideation, and a remarkable decrease in overall well-being. Despite the prevalence of accessible antidepressant therapies, many individuals do not achieve substantial improvement. Understanding the multifactorial pathophysiology and the heterogeneous nature of the disorder could lead the way toward better outcomes. Recent findings have elucidated the substantial impact of compromised blood-brain barrier (BBB) integrity on the manifestation of depression. BBB functions as an indispensable defense mechanism, tightly overseeing the transport of molecules from the periphery to preserve the integrity of the brain parenchyma. The dysfunction of the BBB has been implicated in a multitude of neurological disorders, and its disruption and consequent brain alterations could potentially serve as important factors in the pathogenesis and progression of depression. In this review, we extensively examine the pathophysiological relevance of the BBB and delve into the specific modifications of its components that underlie the complexities of depression. A particular focus has been placed on examining the effects of peripheral inflammation on the BBB in depression and elucidating the intricate interactions between the gut, BBB, and brain. Furthermore, this review encompasses significant updates on the assessment of BBB integrity and permeability, providing a comprehensive overview of the topic. Finally, we outline the therapeutic relevance and strategies based on BBB in depression, including COVID-19-associated BBB disruption and neuropsychiatric implications. Understanding the comprehensive pathogenic cascade of depression is crucial for shaping the trajectory of future research endeavors.

An analysis of POMC gene methylation and expression in patients with schizophrenia

Schizophrenia is a chronic mental disorder that affects millions of people and is believed to be caused by both environmental and genetic factors. Despite extensive research, the exact mechanisms underlying schizophrenia are still unclear. Studies have shown that numerous psychiatric disorders are associated with methylation of the POMC gene, which encodes adrenocorticotropic hormone, a critical player in the hypothalamic-pituitary-adrenal axis. However, the association between DNA methylation in POMC patients and schizophrenia remains unclear. In this study, we evaluated three fragments of the POMC promoter region, including 51 CpG sites, in the peripheral blood of schizophrenia patients and healthy controls. The POMC protein level was measured via enzyme-linked immunosorbent assay (ELISA). The schizophrenia group exhibited significantly greater levels of methylation of the POMC gene than those in the control group. The methylation level of the POMC-2 fragment was significantly greater in the patient group than in the control group. There were 17 significantly hypermethylated CpG sites in the patient group. After stratification by sex, POMC methylation levels were found to be significantly greater in male schizophrenia patients than in healthy controls; the methylation levels of POMC-2 fragments were greater in the male patient group; nine CpG sites were significantly hypermethylated in the male patient group; and only one CpG site was significantly hypermethylated in the female patient group. The POMC protein level in patients was significantly lower than that in healthy controls. These findings demonstrate that the DNA methylation of POMC might be associated with the pathophysiology of schizophrenia. Overall, studying the correlation between POMC methylation and schizophrenia may contribute to the diagnosis and evaluation of neuropsychiatric disorders.

Alzheimer Disease-Link With Major Depressive Disorder and Efficacy of Antidepressants in Modifying its Trajectory

Alzheimer disease (AD) is a devastating neurodegenerative disorder that affects millions of individuals worldwide, with no effective cure. The main symptoms include learning and memory loss, and the inability to carry out the simplest tasks, significantly affecting patients' quality of life. Over the past few years, tremendous progress has been made in research demonstrating a link between AD and major depressive disorder (MDD). Evidence suggests that MDD is commonly associated with AD and that it can serve as a precipitating factor for this disease. Antidepressants such as selective serotonin reuptake inhibitors, which are the first line of treatment for MDD, have shown great promise in the treatment of depression in AD, although their effectiveness remains controversial. The goal of this review is to summarize current knowledge regarding the association between AD, MDD, and antidepressant treatment. It first provides an overview of the interaction between AD and MDD at the level of genes, brain regions, neurotransmitter systems, and neuroinflammatory markers. The review then presents current evidence regarding the effectiveness of various antidepressants for AD-related pathophysiology and then finally discusses current limitations, challenges, and future directions.

Stress-free blood sampling in minipigs: A novel method for assessing 24-h cortisol profiles and drug effects on diurnal and ultradian rhythms

We developed a novel, stress-free blood sampling method for minipigs, allowing continuous cortisol monitoring over 24 h. Baseline cortisol levels exhibited both ultradian and diurnal rhythms. During nighttime, smaller ultradian rhythms overlaid a lower baseline cortisol, which increased in sleeping pigs before lights were turned on. Additionally, we developed an analytical tool based on the R package "pracma" to quantify ultradian peak and circadian components of the cortisol profiles. To validate our model, we investigated the effects of Verucerfont, a CRH receptor antagonist, and Venlafaxine, a serotonin-norepinephrine reuptake inhibitor. Verucerfont reduced cortisol levels during the first 9 h without affecting diurnal rhythm. Cortisol peak parameters decreased, with a 31% reduction in overall area under the curve (AUC) and a 38% reduction in ultradian average AUC. Ultradian peaks decreased from 7 to 4.5, with 34% lower amplitude. Venlafaxine maintained plasma concentrations within the targeted human effective range. This method enables us to enhance our understanding of cortisol regulation and provide valuable insights for the impact of investigation drugs on the diurnal and ultradian rhythms of cortisol.

St. John's wort extract Ze 117 alters the membrane fluidity of C6 glioma cells by influencing cellular cholesterol metabolism

Chronic stress is associated with major depressive disorder (MDD). Increased glucocorticoid levels caused by uncontrolled release through the hypothalamic‒pituitary‒adrenal (HPA) axis can cause changes in the lipid content of the cellular plasma membrane. These changes are suspected to be involved in the development of depressive disorders. St. John's wort extract (SJW) Ze 117 has long been used as an alternative to synthetic antidepressants. Part of its effect may be due to an effect on the cellular lipid composition and thus on the properties of plasma membranes and receptor systems embedded therein. In this study, we investigated the effect of Ze 117 on that of dexamethasone and simvastatin. Dexamethasone increases the fluidity of C6 cell plasma membranes. This effect is counteracted by administration of Ze 117. Here we demonstrate that this is not due to a change in C16:1/16:0 and C18:1/18:0 ratios in C6 cell fatty acids. On the other hand, Ze 117 increased the cellular cholesterol content by 42.5%, whereas dexamethasone reduced cholesterol levels similarly to simvastatin. Lowering cholesterol levels by dexamethasone or simvastatin resulted in decreased β-arrestin 2 recruitment to the 5-HT1a receptor. This effect was counterbalanced by Ze 117, whereas the SJW extract had little effect on β-arrestin 2 recruitment in non-stressed cells. Taken together, in C6 cells, Ze 117 induces changes in membrane fluidity through its effect on cellular cholesterol metabolism rather than by affecting fatty acid saturation. This effect is reflected in an altered signal transduction of the 5-HT1a receptor under Ze 117 administration. The current in vitro results support the hypothesis that Ze 117 addresses relevant parts of the cellular lipid metabolism, possibly explaining some of the antidepressant actions of Ze 117.

Implications of Kynurenine Pathway Metabolism for the Immune System, Hypothalamic-Pituitary-Adrenal Axis, and Neurotransmission in Alcohol Use Disorder

In recent years, there has been a marked increase in interest in the role of the kynurenine pathway (KP) in mechanisms associated with addictive behavior. Numerous reports implicate KP metabolism in influencing the immune system, hypothalamic-pituitary-adrenal (HPA) axis, and neurotransmission, which underlie the behavioral patterns characteristic of addiction. An in-depth analysis of the results of these new studies highlights interesting patterns of relationships, and approaching alcohol use disorder (AUD) from a broader neuroendocrine-immune system perspective may be crucial to better understanding this complex phenomenon. In this review, we provide an up-to-date summary of information indicating the relationship between AUD and the KP, both in terms of changes in the activity of this pathway and modulation of this pathway as a possible pharmacological approach for the treatment of AUD.

The mediating effect of internet addiction and the moderating effect of physical activity on the relationship between alexithymia and depression

There is a certain relationship between alexithymia and depression, but further investigation is needed to explore their underlying mechanisms. The aims of this study was to explore the mediating role of internet addiction between alexithymia and depression and the moderating role of physical activity. A total of 594 valid responses were included in the analysis, with a mean age of 18.72 years (SD = 1.09). The sample comprised 250 males (42.09%) and 344 females (57.91%). These responses were utilized for descriptive analysis, correlation analysis, regression analysis, and the development of mediation and moderation models. Alexithymia showed positive correlations with depression and internet addiction, and physical activity was negatively correlated with internet addiction and depression. Internet addiction partially mediated the relationship between alexithymia and depression, while physical activity weakened the association between internet addiction and depression, acting as a moderator. Our findings suggest that excessive Internet engagement may mediate the relationship between alexithymia and depression as an emotional regulatory coping strategy, and that physical activity attenuates the predictive effect of Internet addiction on depression.

Social stress-induced depressive-like symptoms and changes in gut microbial and lipidomic profiles are prevented by pharmacological inhibition of FAAH activity in male rats

Pharmacological inhibition of fatty acid amide hydrolase (FAAH) activity has antidepressant-like effects in preclinical models of stress. In this study, we investigated whether the antidepressant-like effects of FAAH inhibition are associated with corresponding changes in gut microbial and lipidomic profiles, which are emerging as critical components in the pathophysiology of depression. Adult male Wistar rats experienced five weeks of repeated social defeat or control procedure and were treated with the FAAH inhibitor URB694 (0.3 mg/kg/day, i.p.) or vehicle starting from the third week. Repeated social defeat induced the emergence of depressive-like behavioral (sucrose preference reduction and passive coping behaviors in the forced swim test) and neuroendocrine (increased corticosterone levels) changes, which were prevented by URB694 treatment. Repeated social defeat also provoked a significant variation in gut microbiota (changes in the relative abundance of 14 bacterial taxa) and lipidic (e.g., glycerophospholipids) composition. These stress-induced changes were prevented by URB694 treatment. These findings indicate that inhibition of FAAH activity with URB694 blocks the co-occurrence of depressive-like behavioral and neuroendocrine changes and alterations in gut microbial and lipid composition in rats exposed to repeated social defeat. In conclusion, these results suggest that the gut microbiota-lipid crosstalk may represent a novel biological target for FAAH inhibitors to enhance stress resilience.

Sex-Specific Differences and the Role of Environmental Enrichment in the Expression of Hippocampal CB1 Receptors following Chronic Unpredictable Stress

Stress-related mental disorders have become increasingly prevalent, thus endangering mental health worldwide. Exploring stress-associated brain alterations is vital for understanding the possible neurobiological mechanisms underlying these changes. Based on existing evidence, the brain endogenous cannabinoid system (ECS) plays a significant role in the stress response, and disruptions in its function are associated with the neurobiology of various stress-related disorders. This study primarily focuses on investigating the impact of chronic unpredictable stress (CUS) on the expression of hippocampal cannabinoid type 1 (CB1) receptors, part of the ECS, in adult male and female Wistar rats. Additionally, it explores whether environmental enrichment (EE) initiated during adolescence could mitigate the CUS-associated alterations in CB1 expression. Wistar rats, shortly after weaning, were placed in either standard housing (SH) or EE conditions for a duration of 10 weeks. On postnatal day 66, specific subgroups of SH or EE animals underwent a 4-week CUS protocol. Western blot (WB) analysis was conducted in the whole hippocampus of the left brain hemisphere to assess total CB1 protein expression, while immunohistochemistry (IHC) was performed on the right hemisphere to estimate the expression of CB1 receptors in certain hippocampal areas (i.e., CA1, CA3 and dentate gyrus-DG). The WB analysis revealed no statistically significant differences in total CB1 protein levels among the groups; however, reduced CB1 expression was found in specific hippocampal sub-regions using IHC. Specifically, CUS significantly decreased CB1 receptor expression in the CA1 and DG of both sexes, whereas in CA3 the CUS-associated decrease was limited to SH males. Interestingly, EE housing proved protective against these reductions. These findings suggest a region and sex-specific endocannabinoid response to chronic stress, emphasizing the role of positive early experiences in the protection of the adolescent brain against adverse conditions later in life.

Effects of Psychological Stress on Spontaneous Itch and Mechanical Alloknesis of Atopic Dermatitis

Atopic dermatitis (AD), a chronic inflammatory skin disease, manifests as an intractable itch. Psychological stress has been suggested to play a role in the onset and worsening of AD symptoms. However, the pathophysiological relationships between psychological stressors and cutaneous manifestations remain unclear. To elucidate the mechanisms underlying the stress-related exacerbation of itch, we investigated the effects of water stress, restraint stress and repeated social defeat stress on itch-related scratching behaviour, mechanical alloknesis and dermatitis in male NC/Nga mice with AD-like symptoms induced by the repeated application of ointment containing Dermatophagoides farina body. NC/Nga mice with AD-like symptoms were subjected to water stress, restraint stress and repeated social defeat stress, and their scratching behaviour, sensitivity to mechanical stimuli (mechanical alloknesis) and severity of  dermatitis were evaluated. Social defeat stress+ Dermatophagoides farina body-treated mice exposed to stress showed slower improvements in or the exacerbation of AD-like symptoms, including dermatitis and itch. In the mechanical alloknesis assay, the mechanical alloknesis scores of social defeat stress+ Dermatophagoides farina body-treated mice exposed to stress were significantly higher than those of non-exposed social defeat stress+ Dermatophagoides farina body- and social defeat stress-treated mice. These results suggest that psychological stress delays improvements in dermatitis by exacerbating itch hypersensitivity in AD.

Quercetin alleviates chronic unpredictable mild stress-induced depression-like behavior by inhibiting NMDAR1 with α2δ-1 in rats

BACKGROUND

Depression is a serious mental disorder and the most prevalent cause of disability and suicide worldwide. Chronic unpredictable mild stress (CUMS) can lead to a significant acceleration of depression development. Quercetin (Que) is a flavonoid compound with a wide range of pharmacological effects. Recent studies have shown that quercetin can improve CUMS-induced depression-like behavior, but the mechanism of its improvement is still unclear. α2δ-1 is a regulatory subunit of voltage-gated calcium channel, which can interact with N-methyl-D-aspartate receptor (NMDAR) to form a complex.

OBJECTIVE

In this study, we found that Que could inhibit the increase of α2δ-1 and NMDAR expression in rat hypothalamus induced by CUMS. In pain, chronic hypertension and other studies have shown that α2δ-1 interacts with the NMDAR to form a complex, which subsequently affects the expression level of NMDAR. Consequently, the present study aimed to investigate the antidepressant effect of Que in vivo and in vitro and to explore its mechanism of action in terms of the interaction between α2δ-1 and NMDAR.

METHODS

Rats were randomly exposed to two stressors every day for 4 weeks to establish a CUMS rat model, then sucrose preference test (SPT), forced swimming test (FST), tail suspension test (TST), and open field test (OFT) were performed to detect the behavior of CUMS rats, so as to evaluate whether the CUMS rat model was successfully established and the improvement effect of Que on CUMS-induced depression-like behavior in rats. Experimental techniques such as serum enzyme-linked immunosorbent assay (ELISA), immunofluorescence, Western blot, and co-immunoprecipitation, as well as in vitro experiments, were used to investigate the mechanisms by which Que exerts its antidepressant effects.

RESULTS

Behavioral and ELISA test results showed that Que could produce a reduction in the excitability of the hypothalamic-pituitary-adrenal (HPA) axis in CUMS rats and lead to significant improvements in their depressive behavior. Western blot, immunofluorescence, and co-immunoprecipitation experiments showed that Que produced a decrease in NMDAR1 and α2δ-1 expression levels and interfered with α2δ-1 and NMDAR1 binding. In addition, the neural regulation mechanism of Que on antidepressant effect in PC12 cells knocked out α2δ-1 gene was further verified. Cellular experiments demonstrated that Que led to a reversal of up-regulation of NMDAR1 and α2δ-1 expression levels in corticosterone-injured PC12 cells, while Que had no effects on NMDAR1 expression in PC12 cells with the α2δ-1 gene knockout.

CONCLUSIONS

Que has a good antidepressant effect and can significantly improve the depression-like behavior caused by CUMS. It exerts antidepressant effects by inhibiting the expression level of α2δ-1, interfering with the interaction between α2δ-1 and NMDAR, and then reducing the excitability of the HPA axis.

Exploring clinical applications and long-term effectiveness of benzodiazepines: An integrated perspective on mechanisms, imaging, and personalized medicine

Benzodiazepines have been long-established treatments for various conditions, including anxiety disorders and insomnia. Recent FDA warnings emphasize the risks of misuse and dependence associated with benzodiazepines. This article highlights their benefits and potential drawbacks from various perspectives. It achieves this by explaining how benzodiazepines work in terms of neuroendocrinology, immunomodulation, sleep, anxiety, cognition, and addiction, ultimately improving their clinical effectiveness. Benzodiazepines play a regulatory role in the HPA axis and impact various systems, including neuropeptide Y and cholecystokinin. Benzodiazepines can facilitate sleep-dependent memory consolidation by promoting spindle wave activity, but they can also lead to memory deficits in older individuals due to reduced slow-wave sleep. The cognitive effects of chronic benzodiazepines use remain uncertain; however, no adverse findings have been reported in clinical imaging studies. This article aims to comprehensively review the evidence on benzodiazepines therapy, emphasizing the need for more clinical studies, especially regarding long-term benzodiazepines use.

How inflammation influences psychiatric disease

Recent studies highlight the strong correlation between infectious diseases and the development of neuropsychiatric disorders. In this editorial, we comment on the article "Anti-infective therapy durations predict psychological stress and laparoscopic surgery quality in pelvic abscess patients" by Zhang et al, published in the recent issue of the World Journal of Psychiatry 2023; 13 (11): 903-911. Our discussion highlighted the potential consequences of anxiety, depression, and psychosis, which are all linked to bacterial, fungal, and viral infections, which are relevant to the impact of inflammation on the sequelae in mental health as those we are observing after the coronavirus disease 2019 pandemic. We focus specifically on the immune mechanisms triggered by inflammation, the primary contributor to psychiatric complications. Importantly, pathophysiological mechanisms such as organ damage, post-injury inflammation, and infection-induced endocrine alterations, including hypocortisolism or autoantibody formation, significantly contribute to the development of chronic low-grade inflammation, promoting the emergence or development of psychiatric alterations in susceptible individuals. As inflammation can have long-term effects on patients, a multidisciplinary treatment plan can avoid complications and debilitating health issues, and it is crucial to recognize and address the mental health implications.

Review of research progress on intestinal microbiota based on metabolism and inflammation for depression

Depression is a prevalent mental illness, affecting a significant portion of the global population. Recent research has highlighted the crucial role of the gut microbiota in both metabolic and central nervous health. By reviewing literature from various databases, including Pubmed, Science Direct, Web of Science, and Scopus, spanning the years 2005-2023, a comprehensive search was conducted using keywords such as "Depression" and "Gut Microbiota". The gut microbiota acts as a "second brain" in humans and can communicate bidirectionally with the brain through the Brain-gut-microbiota axis pathway. This communication involves the immune and nervous systems. However, there are challenges in detecting and treating depression effectively. To address these limitations, researchers have been exploring the relationship between gut microbiota and depression. Studies have shown that gut microbial metabolites, such as lipopolysaccharides and short-chain fatty acids, can induce pro-inflammatory cytokines that contribute to neuroinflammation and increase the risk of depression. The kynurenine pathway, triggered by gut microbial metabolites, has also been associated with neuroinflammation. Thus, investigating these microbial metabolites can provide insights into depression treatment. This review focuses on analyzing the connection between gut microbial metabolites, inflammation, and depression. It explores novel mechanisms contributing to depression, specifically focusing on the mediation of inflammation through the release of pro-inflammatory cytokines. The objective is to provide valuable insights into the mechanisms underlying depression and to propose potential treatments.

Potential Impact of Hypoxic Astrocytes on the Aggravation of Depressive Symptoms in Parkinson's Disease

Mounting evidence suggests a significant correlation between depressive disorders and neurodegenerative conditions, encompassing Alzheimer's disease and Parkinson's disease (PD). Depression represents a substantial non-motor manifestation frequently identified in individuals with PD, posing a significant threat to patients' overall well-being and necessitating the implementation of effective management strategies. Despite its high prevalence, impacting over 40% of PD patients, the precise cellular and molecular mechanisms underlying depression and its relationship to dopaminergic system degeneration remain largely ambiguous. In this study, we presented our findings demonstrating distinct characteristics of cortical astrocytes in PD patients compared to reactivated glial cells in the substantia nigra. We identified a subset of differentially expressed genes associated with depressive disorders from PD-associated cortical astrocytes. Furthermore, we uncovered the potential involvement of the hypoxia signaling in driving cortical astrocytic dysfunctions. Through a comprehensive investigation utilizing transcriptome and chromatin accessibility analyses on cultured human astrocytes, we revealed that hypoxic treatment could induce similar expression changes observed in cortex from PD patients. Additionally, we provided evidence that activation of the HIF-1 signaling pathway suppressed the expression of key components of mitochondrial ribosomes and electron transport chain proteins COX2 and CYTB, resulting in abnormal mitochondrial membrane potential. Our results underscore the potential impact of glial metabolic abnormalities on the development of depressive disorders associated with Parkinson's disease.