Pro-inflammatory cytokines and psychotherapy in depression: Results from a randomized clinical trial

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.

Folic Acid Ameliorates Anxiety- and Depressive-Like Behavior Induced by Nicotine Withdrawal Through Restoration of Behavioral and Biochemical Alterations in Adolescent Male Rats

BACKGROUND

The present study aimed to assess the efficacy of folic acid (FA) on withdrawal following nicotine (Nic) administration in adolescent male rats.

AIMS AND METHODS

Adolescent male rats were divided into two groups: (1) vehicle and (2) Nic (Nic-2 mg/kg), and were under treatment from 21 to 42 days of age. After that, they continued the experiment without treatment and returned to a regular diet, except for one of those who received Nic. The rats were divided into four groups where they were treated with different doses of FA (5, 10, and 15 mg/kg) and bupropion (Bup) by oral gavage, and the final group included normal rats that received only FA (15 mg/kg) from 42 days of age for three weeks during which withdrawal occurred.

RESULTS

Results showed that adolescent Nic exposure exacerbated the behavioral indices of anxiety- and depression-like behaviors, while FA attenuated the effects of Nic withdrawal on anxiety and depression as well as Bup. In support, the biochemical results demonstrated a balance between oxidant and antioxidant mediators in addition to the increase and decrease of serotonin and monoamine oxidase (MAO) activity in cortical tissue. TNF-α as an inflammatory agent was decreased, whereas IL-10 as an anti-inflammatory parameter was increased.

CONCLUSIONS

The present findings suggest anxiety and depression caused by Nic withdrawal were attenuated by FA more likely through the reduction activity of MAO, the important enzyme responsible for serotonin metabolism along with balance between oxidant/antioxidant and pro-inflammatory/anti-inflammatory mediators. However, various mechanisms might be involved, which requires further investigation.

IMPLICATIONS

Nic withdrawal-induced depression and anxiety like behavior in rats followed by neuro-oxidative damage and neuro-inflammation. FA supplementation as well as Bup improved cognitive disorders induced by Nic withdrawal by increasing neuro-inflammation and neuro-oxidative damage.

Emerging roles of SIRT1 activator, SRT2104, in disease treatment

Silent information regulator 1 (SIRT1) is a NAD+-dependent class III deacetylase that plays important roles in the pathogenesis of numerous diseases, positioning it as a prime candidate for therapeutic intervention. Among its modulators, SRT2104 emerges as the most specific small molecule activator of SIRT1, currently advancing into the clinical translation phase. The primary objective of this review is to evaluate the emerging roles of SRT2104, and to explore its potential as a therapeutic agent in various diseases. In the present review, we systematically summarized the findings from an extensive array of literature sources including the progress of its application in disease treatment and its potential molecular mechanisms by reviewing the literature published in databases such as PubMed, Web of Science, and the World Health Organization International Clinical Trials Registry Platform. We focuses on the strides made in employing SRT2104 for disease treatment, elucidating its potential molecular underpinnings based on preclinical and clinical research data. The findings reveal that SRT2104, as a potent SIRT1 activator, holds considerable therapeutic potential, particularly in modulating metabolic and longevity-related pathways. This review establishes SRT2104 as a leading SIRT1 activator with significant therapeutic promise.

Short-term Psychodynamic Psychotherapy in Addition to Standard Medical Therapy Increases Clinical Remission in Adolescents and Young Adults with Inflammatory Bowel Disease: a Randomised Controlled Trial

BACKGROUND

Inflammatory bowel diseases [IBD] are chronic and pervasive conditions of the gastrointestinal tract with a rising incidence in paediatric and young adult populations. Evidence suggests that psychological disorders might be associated with relapse of disease activity. This study aims to evaluate the efficacy of short-term psychodynamic psychotherapy [STPP] in addition to standard medical therapy [SMT] in maintaining clinical remission in adolescents and young adults [AYA] with quiescent IBD, compared with SMT alone.

METHODS

A two-arm, single-centre, randomised, controlled trial was conducted in 60 IBD AYA in clinical remission. Patients were randomised to receive an 8-week STPP + SMT [n = 30] or SMT alone [n = 30]. The primary outcome was the steroid-free remission rate at 52 weeks after treatment. Secondary outcomes included the overall hospitalisation rate within 52 weeks after treatment, and medication adherence obtained from patient's electronic medical records.

RESULTS

Intention-to-treat analysis showed significant improvement in maintaining disease remission rates in the 8-week STPP + SMT group compared with the control one. The proportion of patients maintaining steroid-free remission at 52 weeks was higher in patients in STTP group [93.1%] compared with patients randomised to control group [64.3%; p = 0.01]. There were no significant differences in secondary outcomes, except for depression reduction in STPP + SMT group.

CONCLUSIONS

An 8-week STPP intervention in addition to SMT effectively increases the steroid-free remission rates in AYA with quiescent IBD. Results do not support effects for other secondary outcomes, except for depression reduction.

Ego-defense mechanisms and brief psychotherapies for the management of major depressive disorder in adults: A longitudinal and quasi-experimental study

OBJECTIVE

To evaluate the effect of psychotherapies on ego defense mechanisms and the reduction of depressive symptoms in a 12-month follow-up period.

METHODS

This longitudinal and quasi-experimental study nested within a randomized clinical trial included a clinical sample of adults (18-60 years) diagnosed with major depressive disorder using the Mini-International Neuropsychiatric Interview. Two models of psychotherapy were used: Supportive Expressive Dynamic Psychotherapy (SEDP) and Cognitive Behavioral Therapy (CBT). Defense Style Questionnaire 40 was used to analyze defense mechanisms and the Beck Depression Inventory was used to measure the depressive symptoms.

RESULTS

The total sample comprised 195 patients (113 SEDP and 82 CBT), with the mean age was 35.63 (11.44) years. After adjustments, increased mature defenses was significantly associated with reduced depressive symptoms at all follow-up times (p < 0.001) and the decrease in immature defenses was significantly associated with the reduction of depressive symptoms at all follow-up times (p < 0.001). While neurotic defenses were not associated with a reduction in depressive symptoms at any time of follow-up (p > 0.05).

CONCLUSION

Both models of psychotherapy were effective in increasing mature defenses and decreasing immature ones, as well as decreasing depressive symptoms at all evaluation times. With this, it is understood that a greater understanding of these interactions will allow a more adequate diagnostic and prognostic evaluation and the design of useful strategies that adapt to the patient's reality.

Echinacoside exerts antidepressant-like effects through enhancing BDNF-CREB pathway and inhibiting neuroinflammation via regulating microglia M1/M2 polarization and JAK1/STAT3 pathway

The present study was performed to investigate the antidepressant effect of echinacoside (ECH) using chronic unpredictable mild stress (CUMS) induced depression mice and lipopolysaccharide (LPS)-stimulated N9 microglial cells. CUMS treatment was performed on C57BL/6 mice for 28 days, followed by gavaging with different doses of echinacoside (15 and 60 mg/kg) for 21 consecutive days. Sucrose preference test (SPT), open field test (OFT), tail suspension test (TST), and forced swimming test (FST) were measured to assess the effects of echinacoside on CUMS-Induced Depressive-Like Behaviors. After that, the pathological changes of hippocampus were determined by Hematoxylin and eosin (HE) staining and Nissl staining; the neurotransmitters, pro-inflammatory cytokines and indoleamine 2,3-dioxygenase (IDO) levels, and the hypothalamic-pituitary-adrenal (HPA) axis activity were determined by enzyme linked immunosorbent assay (ELISA); Iba 1were evaluated by Immunofluorescence assay; Key protein expression levels of CREB/BDNF signal pathway were measured by western blotting. Subsequently, N9 cells were stimulated with 1 μg/ml LPS to induce N9 microglia activation, and were treated with 5-20 μM of echinacoside for 24 h. After that, the levels of NO, interleukin (IL)-1β, IL-6, tumor necrosis factor alpha (TNF-α), IL-4, IL-10, and transforming growth factor beta (TGF-β) in N9 cell culture supernatants were measured by enzyme-linked immunosorbent assay (ELISA) kits; morphology and Iba 1 expression level were observed by high-content screening assay; the M1 markers of CD11b, CD86 and M2 markers of CD206 were analyzed by imaging flow cytometry. Results show that treatment with echinacoside reversed CUMS-increased immobility time in OFT, TST, FST and reversed CUMS-reduced sucrose preference in SPT. In addition, echinacoside reduced the levels of pro-inflammatory cytokines and Iba 1. Moreover, echinacoside significantly increased p-CREB/CREB ratio and BDNF level in hippocampus. Furthermore, echinacoside reduced the secretion of inflammatory factors and inhibited microglia M1 polarization in N9 cells. In conclusion, echinacoside may be beneficial for the treatment of depression diseases through regulating the microglia balance by inhibiting the polarization of microglia to M1 phenotype, and improving hippocampal neurogenesis by the CREB-BDNF signaling pathway.

How does IL-6 change after combined treatment in MDD patients? A systematic review

A growing amount of research suggests that inflammatory responses have a crucial role in the complex pathophysiology of Major Depressive Disorder (MDD), a disabling medical condition. The present review has two primary goals. Firstly, to highlight and summarize results from studies that investigated the changes of IL-6 in MDD patients before and after combined treatment. The second aim is to enlighten the need for further research on the difference in the concentration of the pro-inflammatory cytokines between MDD and Treatment-Resistant MDD. The protocol of this study was written using PRISMA, and it is registered at PROSPERO (identification: CRD42021289233). We searched the following bibliographic databases to identify potentially eligible articles without any time limit until September 2021: Pubmed, Web of Science, Scopus, PsycINFO. As they met the eligibility criteria, 14 articles were included in this systematic review. The selected studies assessed twelve different elements as an adjunction to the standard pharmacotherapy (ECT, Ketamine, CBT, NCT, Ketoprofene, Lithium, Celecoxib, Metformin tDCS, Pentoxifylline, ethyl-EPA, Zinc). Significant results were found in the studies that analyzed the impact of combined treatment with the adjunction of the following elements: ECT, Ketamine, CBT, NCT, Celecoxib, Metformin, and Pentoxifylline. Overall, this systematic review identifies several potentially beneficial combined treatments for MDD patients. Further evidence is needed to confirm the efficacy of reducing IL-6 levels in patients with Treatment-Resistant MDD.

Psychogenic non-epileptic seizures (PNES) in the COVID-19 pandemic era: A systematic review with individual patients' analysis

OBJECTIVE

Psychogenic non-epileptic seizures (PNES) resemble epileptic seizures but are not due to underlying epileptic activity and in some cases coexist alongside epilepsy. We described the clinical characteristics of patients with PNES as reported in the literature from the outbreak of the COVID-19 pandemic. We evaluated differences between patients with a diagnosis made immediately before the pandemic (pPNES) and those newly diagnosed during it (nPNES).

METHODS

A systematic search with individual patient analysis of PNES cases published since the COVID-19 pandemic outbreak was performed. Differences between pPNES and nPNES were analyzed using Chi-square or Fisher exact test.

RESULTS

Eleven articles were included, with 133 patients (106 pPNES and 27 nPNES). In the pPNES group, PNES frequency increased during the pandemic in 20/106 patients, whereas in 78/106, the frequency remained stable or decreased. nPNES was associated with higher risks of SARS-CoV-2 infection and epilepsy diagnosis, whereas psychiatric comorbidities were less frequent.

CONCLUSIONS

During the pandemic, most patients with pPNES remained stable or improved, whereas nPNES was associated with a lower burden of psychiatric comorbidities. These intriguing findings suggest that, at least in some patients, the COVID-19 pandemic may not necessarily lead to worsening in the frequency of PNES and quality of life.

Current Perspectives on Pharmacological and Non-Pharmacological Interventions for the Inflammatory Mechanism of Unipolar Depression

Since depression remains a major public health issue there is a constant need for new and more efficient therapeutic strategies based on the mechanisms involved in the aetiology of depression. Thus, the pathogenic link between depression and inflammation is considered to play a potential key role in the development of such therapies. This review summarizes the results of various pharmacological (non-steroidal anti-inflammatory drugs, aspirin, cyclooxygenase inhibitors, cytokine inhibitors, corticosteroids, statins, minocycline, N-acetyl cysteine, omega-3 fatty acids and probiotics) and non-pharmacological interventions (electroconvulsive therapy, physical exercise and psychological therapy) and outlines their efficacy and discusses potential challenges. Both conventional and non-conventional anti-inflammatory drugs showed promising results according to the specific group of patients. The pre-existing pro-inflammatory status was, in most cases, a predictor for clinical efficacy and, in some cases, a correlation between clinical improvement and changes in various biomarkers was found. Some of the non-pharmacological interventions (physical exercise and electroconvulsive therapy) have also showed beneficial effects for depressive patients with elevated inflammatory markers. Treatments with anti-inflammatory action may improve clinical outcomes in depression, at least for some categories of patients, thus opening the way for a future personalised approach to patients with unipolar depression regarding the inflammation-related mechanism.

IL-6 and hsCRP in Somatic Symptom Disorders and related disorders

Interleukin 6 (IL-6) and high-sensitivity C-reactive protein (hsCRP) are biomarkers of systemic low-grade inflammation (SLI) in depression and anxiety. The question if SLI in those conditions is related to comorbid chronic medical conditions has not been resolved. DSM-5 Somatic symptom disorders and related disorders (SSRD) are conditions with serious distress related to physical symptoms as main criterion. They can occur in patients with medically unexplained symptoms (MUS) and in patients with known comorbid chronic medical conditions. Often, comorbid depression and anxiety are present. SSRDs offer the opportunity to explore the role of SLI in relation to mental distress, including trauma, MUS, chronic medical conditions and comorbid mental disorder.

AIM

We hypothesized that increased IL-6 and hsCRP may be directly linked to SLI in SSRD, and that comorbid chronic medical conditions, childhood trauma, current stress and comorbid depression and anxiety may be risk factors that account for some of the variance of SLI in SSRD.

METHODS

We explored these relationships in a large sample of 241 consecutive outpatients with SSRD.

RESULTS

Mean hsCRP level was 3.66 ​mg/l, and mean IL-6 level was 3.58 ​pg/ml. IL-6 and hsCRP levels were associated with each other: τ ​= ​0.249, p ​< ​.001; a medium size correlation. Comorbid chronic medical conditions, adverse childhood events other than sexual trauma, and current stress levels were not associated with IL-6 or hsCRP levels.

CONCLUSION

IL-6 and hsCRP are elevated in SSRD, indicating SLI in SSRD independently of comorbid chronic medical conditions. In clinical research, elevated IL-6 and hsCRP can be used as biomarkers of SLI and can indicate risk for childhood sexual abuse in SSRD. Elevated hsCRP may be a biomarker indicating risk for comorbid depression or high pain levels in SSRD as well.

The Relationship Between the Gut Microbiome-Immune System-Brain Axis and Major Depressive Disorder

Major depressive disorder (MDD) is a prominent cause of disability worldwide. Current antidepressant drugs produce full remission in only about one-third of MDD patients and there are no biomarkers to guide physicians in selecting the best treatment for individuals. There is an urgency to learn more about the etiology of MDD and to identify new targets that will lead to improved therapy and hopefully aid in predicting and preventing MDD. There has been extensive interest in the roles of the immune system and the gut microbiome in MDD and in how these systems interact. Gut microbes can contribute to the nature of immune responses, and a chronic inflammatory state may lead to increased responsiveness to stress and to development of MDD. The gut microbiome-immune system-brain axis is bidirectional, is sensitive to stress and is important in development of stress-related disorders such as MDD. Communication between the gut and brain involves the enteric nervous system (ENS), the autonomic nervous system (ANS), neuroendocrine signaling systems and the immune system, and all of these can interact with the gut microbiota. Preclinical studies and preliminary clinical investigations have reported improved mood with administration of probiotics and prebiotics, but large, carefully controlled clinical trials are now necessary to evaluate their effectiveness in treating MDD. The roles that several gut microbe-derived molecules such as neurotransmitters, short chain fatty acids and tryptophan play in MDD are reviewed briefly. Challenges and potential future directions associated with studying this important axis as it relates to MDD are discussed.

Immunological Effects of an Add-On Physical Exercise Therapy in Depressed Adolescents and Its Interplay with Depression Severity

BACKGROUND

Pro-inflammatory cytokines (PICs) have gained attention in the pathophysiology and treatment of depressive disorders. At the same time, the therapeutic effect of physical activity seems to work via immunomodulatory pathways. The interventional study "Mood Vibes" analyzed the influence of exercise on depression severity (primary endpoint) in depressive adolescents; the influence of PICs on the clinical outcome was analyzed as a secondary endpoint.

METHODS

Clinically diagnosed depressed adolescents (N = 64; 28.1% male; mean age = 15.9; mean BMI = 24.6) were included and participated either in Whole Body Vibration (WBV) (n = 21) or bicycle ergometer training (n = 20) in addition to treatment-as-usual (TAU). Patients in the control treatment group received TAU only (n = 23). The PICs (interleukin-6-IL-6 and tumor necrosis factor-α-TNF-α) were analyzed before intervention, after 6 weeks of training (t1), and 8 weeks post-intervention (t2). The effects of the treatment on depression severity were rated by self-rating "Depression Inventory for Children and Adolescents" (DIKJ).

RESULTS

Basal IL-6 decreased in all groups from t0 to t1, but it increased again in WBV and controls at t2. TNF-α diminished in ergometer and controls from baseline to t1. PIC levels showed no correlation with depression severity at baseline. The influence on DIKJ scores over time was significant for IL-6 in the WBV group (p = 0.008). Sex had an impact on TNF-α (p < 0.001), with higher concentrations in male patients. Higher body mass index was associated with higher IL-6 concentrations over all measurement points (p < 0.001).

CONCLUSIONS

The positive effects of an intensive add-on exercise therapy on adolescent depression seem to be partly influenced by immunomodulation. A small sample size and non-randomized controls are limitations of this study.

Results of the Optimune trial: A randomized controlled trial evaluating a novel Internet intervention for breast cancer survivors

INTRODUCTION

After the acute treatment phase, breast cancer patients often experience low quality of life and impaired mental health, which could potentially be improved by offering cognitive behavioural therapy (CBT) and addressing exercise and dietary habits. However, CBT and other behavioural interventions are rarely available beyond the acute treatment phase. Internet-based interventions could bridge such treatment gaps, given their flexibility and scalability. In this randomized controlled trial (RCT), we investigated the effects of such an intervention ("Optimune") over three months.

METHODS

This RCT included 363 female breast cancer survivors (age range = 30-70), recruited from the community, who had completed the active treatment phase. Inclusion criteria were: breast cancer diagnosis less than 5 years ago and acute treatment completion at least 1 month ago. Participants were randomly assigned to (1) an intervention group (n = 181), in which they received care as usual (CAU) plus 12-month access to Optimune immediately after randomization, or (2) a control group (n = 182), in which they received CAU and Optimune after a delay of 3 months. Primary endpoints were quality of life (QoL), physical activity, and dietary habits at three months. We hypothesized that intervention group participants would report better QoL, more physical activity, and improved dietary habits after 3 months.

RESULTS

Intention-to-treat (ITT) analyses revealed significant effects on QoL (d = 0.27, 95% CI: 0.07-0.48) and dietary habits (d = 0.36, 95% CI: 0.15-0.56), but the effect on physical exercise was not significant (d = 0.30; 95% CI: 0.10-0.51).

DISCUSSION

These findings suggest the effectiveness of Optimune, a new CBT-based Internet intervention for breast cancer survivors, in facilitating improvements in quality of life and dietary habits. Efforts to disseminate this intervention more broadly may be warranted.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03643640. Registered August 23rd 2018, https://clinicaltrials.gov/ct2/show/NCT03643640.

Assessment of cytokines, microRNA and patient related outcome measures in conversion disorder/functional neurological disorder (CD/FND): The CANDO clinical feasibility study

BACKGROUND

Conversion disorder/functional neurological disorder (CD/FND) occurs often in neurological settings and can lead to long-term distress, disability and demand on health care services. Systemic low-grade inflammation might play a role, however, the pathogenic mechanism is still unknown.

AIM

1) To explore the feasibility to establish and assess a cohort of CD/FND with motor symptoms, involving persons with lived experience (PPI). 2) To generate proof of concept regarding a possible role for cytokines, microRNA, cortisol levels and neurocognitive symptoms in patients with motor CD/FND.

METHOD

Feasibility study.

RESULTS

The study showed active involvement of patients despite high clinical illness burden and disability, neurocognitive symptoms, childhood adverse experiences (ACE) and current life events. The study provided valuable knowledge regarding the feasibility of conducting a study in these patients that will inform future study phases. In the sample there were elevated levels of IL6, IL12, IL17A, IFNg, TNFa and VEGF-a, suggesting systemic low-grade inflammation. Also, microRNAs involved in inflammation and vascular inflammation were correlated with TNFa and VEGFa respectively, suggesting proof of concept for an epigenetic mechanism. Owing to the COVID-19 outbreak, the patient sample was limited to 15 patients.

CONCLUSION

It is a novelty that this study is conducted in the clinical setting. This innovative, translational study explores stress-related SLI in CD/FND patients and the feasibility of a larger project aiming to develop new treatments for this vulnerable population. Given the positive findings, there is scope to conduct further research into the mechanism of disease in CD/FND.

Understanding Why Post-Stroke Depression May Be the Norm Rather Than the Exception: The Anatomical and Neuroinflammatory Correlates of Post-Stroke Depression

Ischemic Stroke precedes depression. Post-stroke depression (PSD) is a major driver for poor recovery, negative quality of life, poor rehabilitation outcomes and poor functional ability. In this systematic review, we analysed the inflammatory basis of post-stroke depression, which involves bioenergetic failure, deranged iron homeostasis (calcium influx, Na influx, potassium efflux etc), excitotoxicity, acidotoxicity, disruption of the blood brain barrier, cytokine-mediated cytotoxicity, reactive oxygen mediated toxicity, activation of cyclooxygenase pathway and generation of toxic products. This process subsequently results in cell death, maladapted, persistent neuro-inflammation and deranged neuronal networks in mood-related brain regions. Furthermore, an in-depth review likewise reveals that anatomic structures related to post-stroke depression may be localized to complex circuitries involving the cortical and subcortical regions.

Personalized Medicine Using Neuroimmunological Biomarkers in Depressive Disorders

Major depressive disorder (MDD) is associated with increased suicidal risk and reduced productivity at work. Neuroimmunology, the study of the immune system and nervous system, provides further insight into the pathogenesis and outcome of MDD. Cytokines are the main modulators of neuroimmunology, and their levels are somewhat entangled in depressive disorders as they affect depressive symptoms and are affected by antidepressant treatment. The use of cytokine-derived medication as a treatment option for MDD is currently a topic of interest. Although not very promising, cytokines are also considered as possible prognostic or diagnostic markers for depression. The machine learning approach is a powerful tool for pattern recognition and has been used in psychiatry for finding useful patterns in data that have translational meaning and can be incorporated in daily clinical practice. This review focuses on the current knowledge of neuroimmunology and depression and the possible use of machine learning to widen our understanding of the topic.

Bipolar disorder: An evolutionary psychoneuroimmunological approach

Bipolar disorder is a mental health disorder characterized by extreme shifts in mood, high suicide rate, sleep problems, and dysfunction of psychological traits like self-esteem (feeling inferior when depressed and superior when manic). Bipolar disorder is rare among populations that have not adopted contemporary Western lifestyles, which supports the hypothesis that bipolar disorder results from a mismatch between Homo sapiens's evolutionary and current environments. Recent studies have connected bipolar disorder with low-grade inflammation, the malfunctioning of the internal clock, and the resulting sleep disturbances. Stress is often a triggering factor for mania and sleep problems, but stress also causes low-grade inflammation. Since inflammation desynchronizes the internal clock, chronic stress and inflammation are the primary biological mechanisms behind bipolar disorder. Chronic stress and inflammation are driven by contemporary Western lifestyles, including stressful social environments, unhealthy dietary patterns, limited physical activity, and obesity. The treatment of bipolar disorder should focus on reducing stress, stress sensitivity, and inflammation by lifestyle changes rather than just temporarily alleviating symptoms with psychopharmacological interventions.

Inflamed Mind: Multiple Genetic Variants of IL6 Influence Suicide Risk Phenotypes in Interaction With Early and Recent Adversities in a Linkage Disequilibrium-Based Clumping Analysis

Background: Understanding and predicting suicide remains a challenge, and a recent paradigm shift regarding the complex relationship between the immune system and the brain brought attention to the involvement of inflammation in neuropsychiatric conditions including suicide. Among cytokines, IL-6 has been most frequently implicated in suicide, yet only a few candidate gene studies and without considering the effect of stress investigated the role of IL6 in suicidal behaviour. Our study aimed to investigate the association of IL6 variation with a linkage disequilibrium-based clumping method in interaction with childhood adversities and recent stress on manifestations along the suicide spectrum. Methods: One thousand seven hundred and sixty-two participants provided information on previous suicide attempts, current suicidal ideation, thoughts of death, and hopelessness, and were genotyped for 186 variants in IL6. Early childhood adversities were recorded with an instrument adapted from the Childhood Trauma Questionnaire, recent life events were registered using the List of Threatening Life Events. Following a 3-step quality control, logistic and linear regression models were run to explore the effect of genotype and gene-environment interactions on suicide phenotypes. All regression models were followed by a clumping process based on empirical estimates of linkage disequilibrium between clumps of intercorrelated SNPs. Interaction effects of distinct types of recent life events were also analysed. Results: No clumps with significant main effects emerged, but we identified several clumps significantly interacting with childhood adversities on lifetime suicide attempts, current suicidal ideation, and current thoughts of death. We also identified clumps significantly interacting with recent negative life events on current suicidal ideation. We reported no clumps with significant effect on hopelessness either as a main effect or in interaction with childhood adversities or recent stress. Conclusion: We identified variant clumps in IL6 influencing suicidal behaviour, but only in interaction with childhood or recent adversities. Our results may bring us a step further in understanding the role of neuroinflammation and specifically of IL-6 in suicide, towards identifying novel biological markers of suicidal behaviour especially in those exposed to stressful experiences, and to fostering the adaptation of a new paradigm and identifying novel approaches and targets in the treatment of suicidal behaviour.

Blues in the Brain and Beyond: Molecular Bases of Major Depressive Disorder and Relative Pharmacological and Non-Pharmacological Treatments

Despite the extensive research conducted in recent decades, the molecular mechanisms underlying major depressive disorder (MDD) and relative evidence-based treatments remain unclear. Various hypotheses have been successively proposed, involving different biological systems. This narrative review aims to critically illustrate the main pathogenic hypotheses of MDD, ranging from the historical ones based on the monoaminergic and neurotrophic theories, through the subsequent neurodevelopmental, glutamatergic, GABAergic, inflammatory/immune and endocrine explanations, until the most recent evidence postulating a role for fatty acids and the gut microbiota. Moreover, the molecular effects of established both pharmacological and non-pharmacological approaches for MDD are also reviewed. Overall, the existing literature indicates that the molecular mechanisms described in the context of these different hypotheses, rather than representing alternative ones to each other, are likely to contribute together, often with reciprocal interactions, to the development of MDD and to the effectiveness of treatments, and points at the need for further research efforts in this field.

Role of Interleukin-6 in Depressive Disorder

Major depressive disorder (MDD), which is a leading psychiatric illness across the world, severely affects quality of life and causes an increased incidence of suicide. Evidence from animal as well as clinical studies have indicated that increased peripheral or central cytokine interleukin-6 (IL-6) levels play an important role in stress reaction and depressive disorder, especially physical disorders comorbid with depression. Increased release of IL-6 in MDD has been found to be a factor associated with MDD prognosis and therapeutic response, and may affect a wide range of depressive symptomatology. However, study results of the IL6 genetic effects in MDD are controversial. Increased IL-6 activity may cause depression through activation of hypothalamic-pituitary-adrenal axis or influence of the neurotransmitter metabolism. The important role of neuroinflammation in MDD pathogenesis has created a new perspective that the combining of blood IL-6 and other depression-related cytokine levels may help to classify MDD biological subtypes, which may allow physicians to identify the optimal treatment for MDD patients. To modulate the IL-6 activity by IL-6-related agents, current antidepressive agents, herb medication, pre-/probiotics or non-pharmacological interventions may hold great promise for the MDD patients with inflammatory features.

A longitudinal analysis of cytokines in anorexia nervosa

OBJECTIVE

Inflammation has been proposed to have a pathophysiological role in anorexia nervosa (AN) and to contribute to the maintenance of the disorder. Longitudinal cytokine research in AN has focused on only a few pro-inflammatory cytokines. We assessed a broad range of cytokines over time in people undergoing specialised treatment for AN.

METHOD

We measured serum concentrations of 27 cytokines in people with AN (n = 23). Body mass index (BMI), eating disorder (ED) symptoms and general psychopathology were assessed and blood samples were collected within four weeks of the commencement of specialised ED treatment (baseline) and at 12- and 24-week follow-ups.

RESULTS

Both BMI and ED symptoms improved over the assessment period. Linear mixed models showed that log IL-6 decreased between baseline and week 12 assessments. By week 12, log IL-6 values were comparable to levels in healthy individuals. Log IL-7 increased from week 12 to week 24.

DISCUSSION

Initially elevated IL-6 serum concentrations appear to 'normalize' during the first 3-months of specialised treatment for AN and this co-occurs with improvements in ED symptoms. Therefore, IL-6 has the potential to be a state biomarker for AN.

Protocol for the Optimune trial: a randomized controlled trial evaluating a novel Internet intervention for breast cancer survivors

INTRODUCTION

Depression and fatigue are common in breast cancer survivors, and their presence is associated with personal suffering and worse prognosis. While many women receive short-term psychological support in the acute treatment phase, this is rarely available in subsequent phases. Internet interventions for breast cancer survivors could provide additional psychological support, as they are easily accessible and may be effective. However, no trial has yet examined the effectiveness of an Internet intervention that provides cognitive behavioural therapy techniques plus lifestyle advice for this population. This trial aims to test whether Optimune, a novel Internet intervention we developed for that purpose, leads to improvements in quality of life and relevant lifestyle habits over the course of 3 to 6 months.

METHODS

This randomized controlled trial (RCT) will include 360 female breast cancer survivors who have completed the active tumour eradication phase. Participants will be recruited from various settings, including web-based advertisements and Internet forums in German-speaking countries. The main inclusion criteria are a breast cancer diagnosis less than 5 years ago and completion of acute treatment at least 1 month ago, as verified by discharge letter from an oncology treatment centre. Participants will be randomly assigned to either (1) a control group, in which they receive care as usual (CAU) and are given access to Optimune after a delay of 3 months (CAU/wait list control), or (2) a treatment group that may also use CAU and will receive 12-month access to Optimune immediately after randomization. The three primary endpoints are quality of life, physical activity and diet quality, assessed with the World Health Organization Quality of Life Questionnaire, the International Physical Activity Questionnaire and the Food Quality Questionnaire, at 3 months post-baseline; secondary outcomes include cancer-related fatigue, emotional stress, depression, anxiety, fear of progression, insomnia, usefulness of the programme and negative treatment effects. Online assessments are conducted at baseline (T0), 3 months (T1) and 6 months (T2).

DISCUSSION

Results of this RCT are expected to extend the body of knowledge with regard to the effectiveness of CBT-based Internet interventions for female breast cancer survivors.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03643640. Registered on 23 August 2018.

Depression's Unholy Trinity: Dysregulated Stress, Immunity, and the Microbiome

Depression remains one of the most prevalent psychiatric disorders, with many patients not responding adequately to available treatments. Chronic or early-life stress is one of the key risk factors for depression. In addition, a growing body of data implicates chronic inflammation as a major player in depression pathogenesis. More recently, the gut microbiota has emerged as an important regulator of brain and behavior and also has been linked to depression. However, how this holy trinity of risk factors interact to maintain physiological homeostasis in the brain and body is not fully understood. In this review, we integrate the available data from animal and human studies on these three factors in the etiology and progression of depression. We also focus on the processes by which this microbiota-immune-stress matrix may influence centrally mediated events and on possible therapeutic interventions to correct imbalances in this triune.

Cytokine Research in Depression: Principles, Challenges, and Open Questions

Cytokines have been implicated in the pathology of depression. Currently, the evidence is based on cross-sectional studies and meta-analytic research comparing blood concentrations of T helper type 1 (TH1), T helper type 2 (TH2), pro-inflammatory or anti-inflammatory cytokines of patients with a depressive disorder to those of healthy controls. Additionally, multiple longitudinal studies have investigated cytokine levels during antidepressant treatment. According to the current literature, it seems that peripheral levels of interleukin (IL)-6, IL-10, IL-12, IL-13, and tumor necrosis factor (TNF)-α are elevated and that interferon (IFN)-γ levels are lower in patients with depression compared to healthy controls. However, the overlap of cytokine values between acutely depressed patients, remitted and recovered patients and healthy controls is considerable. Thus, the discriminative power of cytokine concentrations between depressed and non-depressed people is likely weak. Treatment with certain antidepressants appears to decrease peripheral levels of IL-6, IL-10, and TNF-α. However, weight gain-inducing psychopharmacological substances, such as the antidepressant mirtazapine, have been reported to potentially increase the production of pro-inflammatory cytokines. Even though cytokines are often discussed as biomarkers for depression, they have also been shown to be altered in other psychiatric disorders. Moreover, many environmental, social, psychological, biological, and medical factors are also associated with cytokine changes. Thus, cytokine alterations seem extremely unspecific. The interpretation of the results of these studies remains a challenge because it is unknown which type of cells are most responsible for cytokine changes measured in the blood nor have the main target cells or target tissues been identified. The same cytokine can be produced by multiple cell types, and the same cell can produce various cytokines. Additionally, redundancy, synergy, antagonism, and signaling cascades of cytokine signaling must be considered. Cytokines might not be associated with the diagnosis of depression according to the currently used diagnostic manuals, but rather with specific subtypes of depression, or with depressive symptoms across different psychiatric diagnoses. Therefore, the currently available diagnostic systems may not be the ideal starting point for psychiatric cytokine research.

Translocator protein (18kDa TSPO) binding, a marker of microglia, is reduced in major depression during cognitive-behavioral therapy

Prior studies indicated that neuroinflammation might play a role in the pathophysiology of major depressive disorder (MDD). The purpose of this study was to examine changes in a microglial marker in the brain of patients with MDD during cognitive-behavioral therapy (CBT) and supportive psychotherapy (SPT). Participants were newly diagnosed patients with MDD receiving CBT (n=20) or SPT (n=20) who were compared with 20 healthy control subjects. We used [¹⁸F]-FEPPA positron emission tomography (PET) to examine translocator protein total distribution volume (TSPO V_T), a marker of microglial density and inflammation. Patients were scanned before and after CBT and SPT. Before therapy, TSPO V_T was significantly elevated in neocortical grey matter, frontal cortex, temporal cortex, and hippocampus in MDD relative to the control subjects. In the CBT group, but not in the SPT group, TSPO V_T was significantly reduced during the treatment period. Reductions in TSPO V_T were correlated with the amelioration of depressive symptoms. This correlation was consistent in the hippocampus in both CBT and SPT groups. In conclusion, CBT, when it reduced symptoms, also decreased TSPO V_T. Efficient psychosocial interventions were accompanied by the normalization of a glial marker in the brain of patients with MDD, which may indicate reduced pro-inflammatory activity.

Depression subtyping based on evolutionary psychiatry: Proximate mechanisms and ultimate functions

Major depressive disorder constitutes one of the leading causes of disability worldwide. However, it is not a unitary disease-it is a heterogeneous syndrome, with patients differing remarkably in symptom profile, pathophysiology and treatment responsiveness. Previous attempts to subtype major depressive disorder have showed limited clinical applicability. We present a classification of major depressive disorder episodes based on the proximate mechanisms that led to the original mood change that caused the depressive episode. We identify discrete depression subtypes that are induced by: 1) infection, 2) long-term stress, 3) loneliness, 4) traumatic experience, 5) hierarchy conflict, 6) grief, 7) romantic rejection, 8) postpartum events, 9) the season, 10) chemicals, 11) somatic diseases and 12) starvation. We further examine the ultimate functions of these subtypes and show that not all types of mood changes that trigger depression are adaptive. Instead, some are clearly maladaptive and some are byproducts of other adaptations. In modern societies, low mood after adverse life events may turn into a pathological depressive state. Modern lifestyle increases susceptibility to inflammatory dysregulation and chronic stress, both of which increase the amount of proinflammatory cytokines in peripheral blood, leading to low mood and sickness behaviour. Proinflammatory cytokines may aggravate the previously adaptive short-term mood changes to a chronic maladaptive depressive state by preventing the normalization of mood after adverse life events. Subtyping depression enables an effective and intelligent long-term treatment of patients in each subtype by treating the underlying causes of depression.

Effects of palmatine on rats with comorbidity of diabetic neuropathic pain and depression

Diabetic neuropathic pain (DNP) is one of the common complications of diabetes. Depression (DP) is also one of the common complications of diabetes. P2X₇ receptors play an important role in the transmission of nociceptive signal and are associated with depressive illness. In the study, the hyperalgesia, allodynia and depressive behaviours of rats with comorbidity of DNP and DP were confirmed by the thermal withdrawal latency (TWL) test, mechanical withdrawal threshold (MWT) test, sucrose preference test (SPT), immobility time of forced swimming test (IMFST) and open-field test (OFT). The change in expression of the P2X₇ receptor of the hippocampus was observed through RT-PCR, qPCR, Western blotting and immunohistochemical staining methods The results showed that palmatine treatment can alleviate the hyperalgesia, allodynia and depressive behaviours of rats with comorbidity of DNP and DP. Meanwhile, the expression of P2X₇ receptors, GFAP, TNF-α and IL-1β in the hippocampus of the rats with comorbidity of DNP and DP was significantly increased compared with the control rats, and palmatine treatment could decrease the expression. Furthermore, the enhanced phosphorylation of ERK1/2 in the hippocampus of rats with DNP and DP was decreased noticeably by palmatine treatment. The results of this study suggest that palmatine can alleviate the comorbidity of DNP and DP by inhibiting the expression of P2X₇ receptors in the hippocampus, and its action may be related to suppression of the phosphorylation of ERK1/2 and the release of TNF-α and IL-1β in the hippocampus.

Modeling consequences of prolonged strong unpredictable stress in zebrafish: Complex effects on behavior and physiology

Chronic stress is the major pathogenetic factor of human anxiety and depression. Zebrafish (Danio rerio) have become a novel popular model species for neuroscience research and CNS drug discovery. The utility of zebrafish for mimicking human affective disorders is also rapidly growing. Here, we present a new zebrafish model of clinically relevant, prolonged unpredictable strong chronic stress (PUCS). The 5-week PUCS induced overt anxiety-like and motor retardation-like behaviors in adult zebrafish, also elevating whole-body cortisol and proinflammatory cytokines - interleukins IL-1β and IL-6. PUCS also elevated whole-body levels of the anti-inflammatory cytokine IL-10 and increased the density of dendritic spines in zebrafish telencephalic neurons. Chronic treatment of fish with an antidepressant fluoxetine (0.1mg/L for 8days) normalized their behavioral and endocrine phenotypes, as well as corrected stress-elevated IL-1β and IL-6 levels, similar to clinical and rodent data. The CNS expression of the bdnf gene, the two genes of its receptors (trkB, p75), and the gfap gene of glia biomarker, the glial fibrillary acidic protein, was unaltered in all three groups. However, PUCS elevated whole-body BDNF levels and the telencephalic dendritic spine density (which were corrected by fluoxetine), thereby somewhat differing from the effects of chronic stress in rodents. Together, these findings support zebrafish as a useful in-vivo model of chronic stress, also calling for further cross-species studies of both shared/overlapping and distinct neurobiological responses to chronic stress.

Correlation between interferon γ and interleukin 6 with PTSD and resilience

Posttraumatic Stress Disorder (PTSD) is a debilitating psychiatric disorder with decreased general health prognosis and increased mortality. Inflammation has been hypothesised to be a link between PTSD and the most common co-morbid medical disorders. However, the relationship between inflammation and PTSD is not clear. Individual inflammatory markers have shown variable associations with PTSD. This study investigates the correlations between serum cytokines, PTSD and resilience in a cohort of Caucasian Vietnam combat veterans (n = 299). After correction for multiple testing, PTSD severity was correlated with small but significant decreases in interleukin 6 and interferon γ (p = 0.004, p = 0.013, respectively) whereas resilience was correlated with increased levels of interleukin 6 and interferon γ (p = 0.023; p = 0.007, respectively). Analyses of sub-symptoms of PTSD revealed that mood and arousal symptoms showed the most significant effect on interleukin 6 and interferon γ. More research is needed to further elucidate the mechanisms underlying the relationship between cytokine levels, PTSD sub-symptoms and trauma outcomes to improve the knowledge base of differences in trauma response and the biological system.

Therapeutic Strategies for Treatment of Inflammation-related Depression

BACKGROUND

Mounting evidence demonstrates enhanced systemic levels of inflammatory mediators in depression, indicating that inflammation may play a role in the etiology and course of mood disorders. Indeed, proinflammatory cytokines induce a behavioral state of conservation- withdrawal resembling human depression, characterized by negative mood, fatigue, anhedonia, psychomotor retardation, loss of appetite, and cognitive deficits. Neuroinflammation also contributes to non-responsiveness to current antidepressant (AD) therapies. Namely, response to conventional AD medications is associated with a decrease in inflammatory biomarkers, whereas resistance to treatment is accompanied by increased inflammation.

METHODS

In this review, we will discuss the utility and shortcomings of pharmacologic AD treatment strategies focused on inflammatory pathways, applied alone or as an adjuvant component to current AD therapies.

RESULTS

Mechanisms of cytokine actions on behavior involve activation of inflammatory pathways in the brain, resulting in changes of neurotransmitter metabolism, neuroendocrine function, and neuronal plasticity. Selective serotonin reuptake inhibitors exhibit the most beneficial effects in restraining the inflammation markers in depression. Different anti-inflammatory agents exhibit AD effects via modulating neurotransmitter systems, neuroplasticity markers and glucocorticoid receptor signaling. Anti-inflammatory add-on therapy in depression highlights such treatment as a candidate for enhancement strategy in patients with moderate-to-severe depression.

CONCLUSION

The interactions between the immune system and CNS are not only involved in shaping behavior, but also in responding to therapeutics. Even though, substantial evidence from animal and human research support a beneficial effect of anti-inflammatory add-on therapy in depression, further research with special attention on safety, particularly during prolonged periods of antiinflammatory co-treatments, is required.

Effect of antidepressant treatment on peripheral inflammation markers - A meta-analysis

INTRODUCTION

Major Depressive Disorder (MDD) in accordance to the inflammatory concept is associated with complex immunological disturbances in the central nervous system (CNS). This is reflected by elevated plasma levels of inflammatory cytokines in depressed subjects. Although numerous studies report significant influence of antidepressants on pro-inflammatory/anti-inflammatory cytokines balance, the available data is often inconsistent regarding specific cytokines and drugs used. We aimed to perform a comprehensive meta-analysis of the effect of antidepressant treatment on a wide array of cytokines.

METHODS

We performed a systematic search of 6 databases, which yielded 32 studies measuring the levels of selected cytokines before and at a second time-point during antidepressant treatment. For meta-analysis of selected studies with a continuous measure we analysed variables containing the number of cases, mean and standard deviation of the level of IL-1ß, IL-2, IL-5, IL-6, IL-8, IL-10, CRP, TNF-α, IFN-γ levels observed in the different studies, in the intervention groups before and after antidepressant treatment.

RESULTS

Statistical analysis revealed significant decreases of IL-4, IL-6, and IL-10 in MDD subjects after antidepressant treatment. In case of IL-1ß the decrease was significant exclusively for SSRI drugs. We did not find any significant effect of antidepressant medication on IL-2, TNF-α IFN-γ and CRP.

CONCLUSIONS

Antidepressant treatment affects the levels of cytokines in depression. The immunological imbalance in MDD is complex and seems to be mediated by other factors yet to be elucidated. The credibility of our results is limited by high heterogeneity among studies and very few studies with a placebo-controlled design. Research with MDD subtypes, response to treatment status and cytokine associations with the kynurenine pathway taken into account pose a promising target for future studies.

Positive association between Toxoplasma gondii IgG serointensity and current dysphoria/hopelessness scores in the Old Order Amish: a preliminary study

Toxoplasma gondii (T. gondii) IgG seropositivity and serointensity have been previously associated with suicidal self-directed violence (SSDV). Although associations with unipolar depression have also been investigated, the results have been inconsistent, possibly as a consequence of high heterogeneity. We have now studied this association in a more homogeneous population, [that is (i.e.) Old Order Amish (OOA)] with previously reported high T. gondii seroprevalence. In 306 OOA with a mean age of 46.1 ± 16.7 years, including 191 (62.4%) women in the Amish Wellness Study, we obtained both T. gondii IgG titers (by enzyme-linked immunosorbent assay [ELISA]), and depression screening questionnaires (Patient Health Questionnaire [PHQ-9] [n = 280] and PHQ-2 [n = 26]). Associations between T. gondii IgG and dysphoria/hopelessness and anhedonia scores on depression screening questionnaires were analyzed using multivariable linear methods with adjustment for age and sex. Serointensity was associated with both current dysphoria/hopelessness (p = 0.045) and current combined anhedonia and dysphoria/hopelessness (p = 0.043), while associations with simple anhedonia and past/lifelong (rather than current) phenotypes were not significant. These results indicate the need for larger longitudinal studies to corroborate the association between dysphoria/hopelessness and T. gondii IgG-titers. Current hopelessness is a known risk factor for SSDV which responds particularly well to cognitive behavioral therapy, and may be a focused treatment target for T. gondii-positive individuals at high-risk for SSDV.

Genetic and serum biomarker evidence for a relationship between TNFα and PTSD in Vietnam war combat veterans

BACKGROUND

Posttraumatic stress disorder (PTSD) is associated with increased inflammation and comorbid medical conditions. However, study findings for individual inflammatory marker levels have been inconsistent. Some research suggests that resilience may play a role in decreased inflammation. A polymorphism in the promoter region of the tumor necrosis factor α gene (TNFα), TNFA -308 (rs1800629) is associated with psychiatric illness but its role in PTSD is yet to be elucidated.

OBJECTIVE

This study investigates a key inflammatory marker, TNFα, for its role in PTSD severity.

METHOD

In a cohort of trauma-exposed Vietnam War veterans (n=299; 159 cases, 140 controls) TNF α serum levels and TNFα polymorphism rs1800629 were correlated with PTSD severity and resilience scores.

RESULTS

The polymorphism was associated with PTSD severity (p=0.045). There were significant group differences between cases and controls with regards to serum TNFα levels (p=0.036). Significant correlations were found between PTSD severity and elevated TNFα levels (r=0.153; p=0.009), and between resilience and decreased TNFα levels at a trend level (p=0.08) across the entire cohort. These relationships were non-significant after controlling for covariates. In the PTSD diagnostic group, a correlation of TNFα and PTSD severity was observed on a trend level (p=0.06), the relationship between TNFα and resilience remained non-significant.

CONCLUSIONS

To our knowledge, this is the first time rs1800629 has been investigated in PTSD contributing to a growing body of literature that identifies the GG as a risk genotype for psychiatric disorders in Caucasian cohorts. However, more research is needed to replicate our results in larger, equally well-characterized cohorts. The relationship between serum TNFα levels and PTSD severity and resilience requires further investigation.

History of childhood trauma as risk factors to suicide risk in major depression

The aim of this study was to compare childhood trauma scores domains between Major Depressive Disorder (MDD) patients with and without suicide risk. This is cross-sectional study including a clinical sample of adults (18-60 years) diagnosed with MDD through the Mini International Neuropsychiatric Interview Plus version (MINI Plus). The Childhood Trauma Questionnaire (CTQ) was also used to verify types of trauma scores: abuse (emotional, physical, and sexual) and neglect (emotional and physical). Adjusted analysis was performed by linear regression. The sample was composed to 473 patients, suicide risk was observed in 16.3% of them. Suicide risk was independently associated with emotional abuse and neglect and sexual abuse, but not with physical abuse and neglect. Different domains of childhood trauma are associated with suicide risk in MDD population and emotional trauma should be considered a risk factor for suicide risk in MDD patients.

Oxidative stress: a potential link between emotional wellbeing and immune response

Emotional wellbeing is central to normal health and good living. Persistent psychological stress often disrupts emotional wellbeing and triggers onset of neuropsychiatric ailments. An integrated, multisystemic stress response involving neuroinflammatory, neuroendocrine and metabolic cascades seem to have some causative links. Of particular interest are the neuroinflammatory processes. Psychological stress has been suggested to negatively affect normal functioning of the immune system contributing to the pathophysiology of some neuropsychiatric conditions. Thus examination of the interaction between the immune system and the central nervous system is likely to reveal molecular targets critical for development of potential therapeutic and preventive measures. This review is a summarized discussion of evidence linking impact of psychological stress on the immune system, with a particular emphasis on oxidative stress mechanisms by which mental stress potentially impacts immune function leading to activation of multiple cascades resulting in subsequent manifestation of psychiatric symptomologies.