Adverse childhood experiences and reoccurrence of illness impact the gut microbiome, which affects suicidal behaviours and the phenome of major depression: towards enterotypic phenotypes

Exploring the association between urticaria subtypes, anxiety, and depression and potential role of gut microbiota

AIMS

In observational studies, the causal relationship between urticaria and the risk of psychiatric disorders (anxiety and depression) remains inconclusive. Furthermore, there is growing evidence that gut microbiota (GM) contributes to the pathogenesis of urticaria. This study aimed to assess the causal relationships between the genetically predicted urticaria subtypes and psychiatric disorders and further examined the role of GM in influencing the risk of these urticaria subtypes.

METHODS

We conducted a meta-analysis of observational studies identified from four databases to evaluate the associations between urticaria, anxiety, and depression over the past decade. In addition, we estimated the genetic correlation and causality between genetically predicted urticaria subtypes and psychiatric disorders using linkage disequilibrium score regression and Mendelian Randomization (MR) analyses. Finally, univariable two-sample MR and multivariable MR analyses were employed to evaluate the combined and independent effects of GM from two datasets on urticaria subtypes associated with psychiatric disorders.

RESULTS

Thirteen observational studies comprising 7321 participants were included in the meta-analysis. There was a positive association between urticaria and anxiety risk (n = 13, OR: 3.96; 95%CI: 2.90-5.41) as well as depression risk (n = 12, OR: 3.03; 95%CI: 2.30-4.01). The MR results indicated that idiopathic urticaria increased the risk of anxiety (OR = 1.14; 95%CI = 1.01-1.28; P = 3.31 × 10-2), while allergic urticaria increased the risk of major depressive disorder (OR = 1.07; 95%CI = 1.02-1.13; P = 6.65 × 10-3). Our analysis identified nineteen gut bacterial taxa that were causally associated with idiopathic and allergic urticaria. Notably, Intestinibacter and Victivallales were strongly associated with an increased risk of allergic urticaria, even after accounting for the effect of smoking or alcohol consumption in the multivariable MR analysis. FamilyXIIIAD3011group and Bacteroides vulgatus were found to exert protective roles in idiopathic urticaria.

CONCLUSIONS

The study provides evidence for the association between urticaria subtypes and psychiatric disorders, complementing existing observational studies. In addition, our study implies the involvement of gut microbiota in idiopathic and allergic urticaria. However, the specific mechanisms of bacterial action remain to be clarified.

Characterization of Gut Microbiome Composition in Depression and Completed Suicide

Growing evidence supports a bidirectional relationship between the gut microbiome and mental health. This study investigated the association between gut microbiota, depression, and suicidal behavior by analyzing fecal samples from 35 individuals with varying depression levels and 36 completed suicide cases. Standardized psychometric assessments were used for depression evaluation. Analysis revealed significant taxonomic differences between groups, with increased abundance of Firmicutes, Clostridia, Lachnospiraceae, Blautia, and Dorea in suicide cases, which also positively correlated with depression severity. Metabolic pathway analysis demonstrated a notable dichotomy: suicide cases showed elevated pathways related to infection processes, inflammation, and antibiotic resistance, while the control group exhibited higher energy metabolism and vitamin synthesis pathways. The findings establish specific microbiome profiles associated with both depression symptoms and suicidal behavior, suggesting that gut dysbiosis may influence mental health through altered energy metabolism and inflammatory processes, potentially offering new perspectives for diagnostic and therapeutic approaches.

Lipid profiles in major depression, both with and without metabolic syndrome: associations with suicidal behaviors and neuroticism

BACKGROUND

Significant associations exist between major depressive disorder (MDD), metabolic syndrome (MetS), and cardiovascular disease, potentially attributable to heightened atherogenicity. This study aimed to ascertain if MDD, depression severity, suicidal behaviors, and neuroticism associate with elevated pro-atherogenic indices and reduced anti-atherogenic indices, including a reverse cholesterol transport (RCT) index.

METHODS

This study comprised 34 healthy controls and 33 MDD patients without MetS, and 35 controls and 31 MDD patients with MetS. It assessed total cholesterol (TC) and free cholesterol (FC), high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol (LDLc), triglycerides (TG), apolipoprotein (ApoA), ApoB, cholesterol esterification rate, and a RCT composite.

RESULTS

No significant associations between MDD and lipids were seen in the total study group that combined individuals with and without MetS. In individuals devoid of MetS, MDD is significantly correlated with (a) elevated FC, TG, ApoB, Castelli risk index 1, and ApoB/ApoA, and (b) diminished HDLc, ApoA, and RCT index. In individuals without MetS, there are notable correlations between the severity of depression, suicidal tendencies, neuroticism, and ApoB/ApoA, Castelli risk, and RCT indices.

CONCLUSIONS

The link between lipids and MDD features cannot be adequately estimated by combining participants with and without MetS. It should be examined in a study sample that excludes subjects with MetS. The depression phenome, suicidal behaviors, and neuroticism correlate with diminished RCT and heightened atherogenicity, which are likely implicated in the pathophysiology of MDD. Increased atherogenicity and lowered RCT may represent novel drug targets for the treatment and prevention of MDD, neuroticism, and suicidal behaviors.

Polysorbate 80 and carboxymethylcellulose: A different impact on epithelial integrity when interacting with the microbiome

The consumption of dietary emulsifiers, including polysorbate 80 (P80) and sodium carboxymethylcellulose (CMC), has raised safety concerns due to its interaction with the intestinal microbiome. This study demonstrated that increasing concentrations of P80 and CMC added to a dynamic four-stage gut microbiota model (BFBL gut simulator) altered the microbiome composition and impacted epithelial integrity in a dose-dependent manner. 16S rDNA amplicon-based metagenomics analysis revealed that these emulsifiers increased microbial groups with proinflammatory capacities while decreasing microbial taxa known to enhance barrier function. Increasing doses of P80 significantly decreased Bacteroides dorei and Akkermansia, taxa associated with anti-inflammatory potential, while increasing doses of CMC were linked to a higher abundance of Ruminococcus torques and Hungatella, which negatively impact barrier function. Both emulsifiers displayed a different impact on epithelial integrity when interacting with the microbiome. On one hand, supernatants from the BFBL simulator fed with P80 disrupted epithelial integrity to a lesser extent than the additive alone. On the other hand, both the microbiota and the supernatants from the BFBL simulator fed with CMC diminished the epithelial integrity, though the additive itself did not. These findings highlight the need to incorporate the gut microbiome in the risk assessment of these additives.

Major depressive disorder, neuroticism, suicidal behaviors, and depression severity are associated with cytokine networks and their intricate interactions with metabolic syndrome

OBJECTIVES

To identify alterations in the immune profiles in outpatients with major depression (MDD), and its associations with key features, such as suicidal ideation, neuroticism, cognitive symptoms, and the depression phenome while accounting for metabolic syndrome (MetS).

METHODS

In this case-control study, we assayed 48 serum cytokines, chemokines, and growth factors in 67 healthy controls and 66 MDD outpatients. Around 50 % of the outpatient MDD and control participants had a diagnosis of MetS.

RESULTS

Ten differentially expressed proteins (DEPs) were upregulated in outpatient MDD (i.e., CXCL12, tumor necrosis factor [TNF]β, platelet-derived growth factor [PDGF], CCL11, interleukins [IL]9, IL4, CCL5, CCL2, CCL4, IL1 receptor antagonist [IL1RN]), indicating an immune and defense response. Six DEPs were downregulated (vascular endothelial growth factor A [VEGFA], IL12, CCL3, colony stimulating factor [CSF]1, IL1B, nerve growth factor [NGF]), indicating lowered neurogenesis and neuron death regulation. Significant interactions between outpatient MDD and MetS caused a) substantial increases in IL4, IL17, TNF, TNFB, CCL2, CCL5, PDGF, IL1RN; and b) downregulation of VEGFA and FGF. A large part of the variance in neuroticism (26 %), suicidal behaviors (23 %), and the MDD phenome (31 %) was predicted by immunological data and interactions between MetS and CCL5, TNFB or VEGFA.

CONCLUSION

Outpatient MDD is characterized by a cytokine profile with neurotoxic potential which partly explains neuroticism, suicidal behaviors, and the phenome's severity. Lowered IL-10 and activated cytokine profiles with neurotoxic potential are characteristics of outpatient MDD and other depression phenotypes, including severe first-episode inpatient MDD. The presence of MetS in outpatient MDD considerably activates immune profiles with neurotoxic potential. Consequently, immune studies in MDD should always be performed in subjects with and without MetS.

Prenatal Stress and Ethanol Exposure: Microbiota-Induced Immune Dysregulation and Psychiatric Risks

Changes in maternal gut microbiota due to stress and/or ethanol exposure can have lasting effects on offspring's health, particularly regarding immunity, inflammation response, and susceptibility to psychiatric disorders. The literature search for this review was conducted using PubMed and Scopus, employing keywords and phrases related to maternal stress, ethanol exposure, gut microbiota, microbiome, gut-brain axis, diet, dysbiosis, progesterone, placenta, prenatal development, immunity, inflammation, and depression to identify relevant studies in both preclinical and human research. Only a limited number of reviews were included to support the arguments. The search encompassed studies from the 1990s to the present. This review begins by exploring the role of microbiota in modulating host health and disease. It then examines how disturbances in maternal microbiota can affect the offspring's immune system. The analysis continues by investigating the interplay between stress and dysbiosis, focusing on how prenatal maternal stress influences both maternal and offspring microbiota and its implications for susceptibility to depression. The review also considers the impact of ethanol consumption on gut dysbiosis, with an emphasis on the effects of prenatal ethanol exposure on both maternal and offspring microbiota. Finally, it is suggested that maternal gut microbiota dysbiosis may be significantly exacerbated by the combined effects of stress and ethanol exposure, leading to immune system dysfunction and chronic inflammation, which could increase the risk of depression in the offspring. These interactions underscore the potential for novel mental health interventions that address the gut-brain axis, especially in relation to maternal and offspring health.

The recurrence of illness (ROI) index is a key factor in major depression that indicates increasing immune-linked neurotoxicity and vulnerability to suicidal behaviors

In this study, we aimed to investigate the associations between the recurrence of illness (ROI) and biomarkers related to an activated immune network, immune-linked neurotoxicity (INT), and a combined INT and atherogenicity index (METAMMUNE). The study involved 67 healthy controls and 66 outpatient MDD (OMDD) participants. We utilized a Multiplex method to measure 48 cytokines and examined INT and METAMMUNE composite scores in association with different ROI indices. Our findings revealed that a ROI index was successfully created by extracting a validated principal component, from the physician-rated or self-declared number of depressive episodes, the frequency of lifetime suicidal ideation and attempts. ROI was significantly associated with INT and METAMMUNE indices, neuroticism, lifetime and current suicidal behaviors, and the phenome. Our analysis also revealed that a significant portion of the variance in the OMDD phenome, which includes current suicidal behaviors, anxiety, and depression, can be accounted for by the regression on INT, ROI, and emotional neglect and abuse. A validated latent construct was successfully extracted from the three ROI components, INT and METAMMUNE indices. The results indicate that increasing ROI indicates heightened immune-metabolic abnormalities, increased risk of suicidal behaviors, and elevated severity of lifetime and current phenome features.

Increased malondialdehyde and nitric oxide formation, lowered total radical trapping capacity coupled with psychological stressors are strongly associated with the phenome of first-episode mild depression in undergraduate students

Undergraduate students are frequently afflicted by major depressive disorder (MDD). Oxidative and nitrosative stress (O&NS) has been implicated in the pathophysiology of MDD. There is no information regarding whether mild outpatient MDD (SDMD) and first episode SDMD (FE-SDMD) are accompanied by O&NS. The current study compared lipid hydroperoxides (LOOH), malondialdehyde (MDA), advanced protein oxidation products, nitric oxide metabolites (NOx), thiol groups, plasma total antioxidant potential (TRAP), and paraoxonase 1 activities among SDMD and FE-SDMD patients versus healthy controls. We found that SDMD and FE-SDMD exhibit elevated MDA and NOx, and decreased TRAP and LOOH as compared with controls. There was a significant and positive correlation between O&NS biomarkers and adverse childhood experiences (ACEs), and negative life events (NLEs). O&NS pathways, NLEs and ACEs accounted for 51.7 % of the variance in the phenome of depression, and O&NS and NLS explained 42.9 % of the variance in brooding. Overall, these results indicate that SDMD and FE-SDMD are characterized by reduced total antioxidant defenses and increased aldehyde and NOx production. The combined effects of oxidative and psychological stressors are substantially associated with the manifestation of SDMD.

From human herpes virus-6 reactivation to autoimmune reactivity against tight junctions and neuronal antigens, to inflammation, depression, and chronic fatigue syndrome due to Long COVID

Inflammation and autoimmune responses contribute to the pathophysiology of Long COVID, and its affective and chronic fatigue syndrome symptoms, labeled "the physio-affective phenome." To investigate whether Long COVID and its physio-affective phenome are linked to autoimmunity to the tight junction proteins, zonulin and occludin (ZOOC), and immune reactivity to lipopolysaccharides (LPS), and whether the latter are associated with signs of human herpes virus-6 (HHV-6) reactivation, autoimmunity directed against oligodendrocyte and neuronal proteins, including myelin basic protein. IgA/IgM/IgG responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), HHV-6, ZOOC, and neuronal proteins, C-reactive protein (CRP), and advanced oxidation protein products (AOPPs), were measured in 90 Long COVID patients and 90 healthy controls. The physio-affective phenome was conceptualized as a factor extracted from physical and affective symptom domains. Neural network identified IgA directed to LPS (IgA-LPS), IgG-ZOOC, IgG-LPS, and IgA-ZOOC as important variables associated with Long COVID diagnosis with an area under the ROC curve of 0.755. Partial Least Squares analysis showed that 40.9% of the variance in the physio-affective phenome was explained by CRP, IgA-myelin basic protein (MBP), and IgG-MBP. A large part of the variances in both autoimmune responses to MBP (36.3%-39.7%) was explained by autoimmunity (IgA and IgG) directed to ZOOC. The latter was strongly associated with indicants of HHV-6 reactivation, which in turn was associated with increased IgM-SARS-CoV-2. Autoimmunity against components of the tight junctions and increased bacterial translocation may be involved in the pathophysiology of Long COVID's physio-affective phenome.

Complex Intersections Between Adverse Childhood Experiences and Negative Life Events Impact the Phenome of Major Depression

Background

There is evidence that adverse childhood experiences (ACEs) and negative life events (NLEs) are associated with major depression (MDD).

Purpose

To determine whether ACEs affect all features of mild MDD, including suicidal tendencies, brooding, neuroticism, insomnia, cognitive deficits, severity of depression and anxiety, and cognitive deficits, and whether NLEs mediate these effects.

Sample of the Study and Methods

This study examines a cohort of 118 academic students, namely 74 students who satisfied the DSM-5-TR criteria for MDD and 44 normal control students. We assessed brooding, neuroticism, suicidal ideation and attempts, and the severity of depression, anxiety, insomnia, and the Stroop tests.

Results

One validated factor could be extracted from brooding, neuroticism, current suicidal behaviors, and the severity of depression, anxiety, and insomnia, labeled the phenome of depression. A large part of the variance in the phenome of depression (55.0%) was explained by the combined effects of self-, relationships, and academic-related NLEs in conjunction with ACEs, including family dysfunction and abuse and neglect (both physical and emotional). The latter ACEs significantly interacted (moderating effect) with NLEs to impact the depression phenome. Although sexual abuse did not have direct effects on the phenome, its effects were mediated by NLEs. We discovered that increased sexual abuse, physical and emotional abuse and neglect, and ACEs related to family dysfunction predicted 22.5% of the variance in NLEs. Up to 18.5% of the variance in the Stroop test scores was explained by sexual abuse and the phenome of depression. The latter mediated the effects of NLEs and abuse, neglect, and family dysfunction on the Stroop test scores.

Conclusion

Complex intersections between ACEs and NLEs impact the phenome of depression, which comprises neuroticism, brooding, suicidal tendencies, and the severity of insomnia, anxiety, and depression, while sexual abuse together with other ACEs and NLEs may impact cognitive interference inhibition.

Adverse childhood experience and depression: the role of gut microbiota

Depression is the most common psychiatric disorder that burdens modern society heavily. Numerous studies have shown that adverse childhood experiences can increase susceptibility to depression, and depression with adverse childhood experiences has specific clinical-biological features. However, the specific neurobiological mechanisms are not yet precise. Recent studies suggest that the gut microbiota can influence brain function and behavior associated with depression through the "microbe-gut-brain axis" and that the composition and function of the gut microbiota are influenced by early stress. These studies offer a possibility that gut microbiota mediates the relationship between adverse childhood experiences and depression. However, few studies directly link adverse childhood experiences, gut microbiota, and depression. This article reviews recent studies on the relationship among adverse childhood experiences, gut microbiota, and depression, intending to provide insights for new research.

In major dysmood disorder, physiosomatic, chronic fatigue and fibromyalgia symptoms are driven by immune activation and increased immune-associated neurotoxicity

Major depressive disorder (MDD) is accompanied by activated neuro-immune pathways, increased physiosomatic and chronic fatigue-fibromyalgia (FF) symptoms. The most severe MDD phenotype, namely major dysmood disorder (MDMD), is associated with adverse childhood experiences (ACEs) and negative life events (NLEs) which induce cytokines/chemokines/growth factors. To delineate the impact of ACE + NLEs on physiosomatic and FF symptoms in first episode (FE)-MDMD, and examine whether these effects are mediated by immune profiles. ACEs, NLEs, physiosomatic and FF symptoms, and 48 cytokines/chemokines/growth factors were measured in 64 FE-MDMD patients and 32 normal controls. Physiosomatic, FF and gastro-intestinal symptoms belong to the same factor as depression, anxiety, melancholia, and insomnia. The first factor extracted from these seven domains is labeled the physio-affective phenome of depression. A part (59.0%) of the variance in physiosomatic symptoms is explained by the independent effects of interleukin (IL)-16 and IL-8 (positively), CCL3 and IL-1 receptor antagonist (inversely correlated). A part (46.5%) of the variance in physiosomatic (59.0%) symptoms is explained by the independent effects of interleukin (IL)-16, TNF-related apoptosis-inducing ligand (TRAIL) (positively) and combined activities of negative immunoregulatory cytokines (inversely associated). Partial least squares analysis shows that ACE + NLEs exert a substantial influence on the physio-affective phenome which are partly mediated by an immune network composed of interleukin-16, CCL27, TRAIL, macrophage-colony stimulating factor, and stem cell growth factor. The physiosomatic and FF symptoms of FE-MDMD are partly caused by immune-associated neurotoxicity due to T helper (Th)-1 polarization and M1 macrophage activation and relative lowered compensatory immunoregulatory protection.

Predictors of increased affective symptoms and suicidal ideation during the COVID-19 pandemic: results from a large-scale study of 14 271 Thai adults

BACKGROUND

Increasing data suggest emergent affective symptoms during the COVID-19 pandemic.

OBJECTIVES

To study the impact of the COVID-19 pandemic on affective symptoms and suicidal ideation in Thai adults.

METHODS

The Collaborative Outcomes Study on Health and Functioning during Infection Times uses non-probability sampling (chain referring and voluntary response sampling) and stratified probability sampling to identify risk factors of mental health problems and potential treatment targets to improve mental health outcomes during pandemics.

FINDINGS

Analysing 14 271 adult survey participants across all four waves of the COVID-19 pandemic in Thailand, covering all 77 provinces from 1 June 2020 to 30 April 2022, affective symptoms and suicidality increased during COVID-19 pandemic. Affective symptoms were strongly predicted by pandemic (feelings of isolation, fear of COVID-19, loss of social support, financial loss, lack of protective devices) and non-pandemic (female sex, non-binary individuals, adverse childhood experiences (ACEs), negative life events, student status, multiple mental health and medical conditions, physical pain) risk factors. ACEs, prior mental health conditions and physical pain were the top three risk factors associated with both increased affective symptoms and suicidal ideation during the COVID-19 pandemic. Partial least squares analysis showed that ACEs were the most important risk factor as they impacted most pandemic and non-pandemic risk factors.

CLINICAL IMPLICATIONS

Rational policymaking during a pandemic should aim to identify the groups at highest risk (those with ACEs, psychiatric and medical disease, women, non-binary individuals) and implement both immediate and long-term strategies to mitigate the impact of ACEs, while effectively addressing associated psychiatric and medical conditions.

Mood and microbes: a comprehensive review of intestinal microbiota's impact on depression

Depression is considered a multifaceted and intricate mental disorder of growing concern due to its significant impact on global health issues. The human gut microbiota, also known as the "second brain," has an important role in the CNS by regulating it through chemical, immunological, hormonal, and neurological processes. Various studies have found a significant bidirectional link between the brain and the gut, emphasizing the onset of depression therapies. The biological and molecular processes underlying depression and microbiota are required, as the bidirectional association may represent a novel study. However, profound insights into the stratification and diversity of the gut microbiota are still uncommon. This article investigates the emerging evidence of a bacterial relationship between the gut and the brain's neurological system and its potential pathogenicity and relevance. The interplay of microbiota, immune system, nervous system neurotransmitter synthesis, and neuroplasticity transitions is also widely studied. The consequences of stress, dietary fibers, probiotics, prebiotics, and antibiotics on the GB axis are being studied. Multiple studies revealed the processes underlying this axis and led to the development of effective microbiota-based drugs for both prevention and treatment. Therefore, the results support the hypothesis that gut microbiota influences depression and provide a promising area of research for an improved knowledge of the etiology of the disease and future therapies.

Impact of Toxoplasma gondii and Human Microbiome on Suicidal Behavior: A Systematic Review

BACKGROUND

Suicide remains a persistent global health challenge, resisting widespread prevention efforts. According to previous findings, toxoplasmosis is particularly associated with altered decision making, which could lead to risk-taking behavior, thereby increasing the likelihood for suicidal behavior (SB). In addition, discussion about the role of microbiome in psychiatric disorders has emerged lately, which also makes it relevant to investigate its role in the context of SB. Therefore, two systematic reviews are integrated in this paper, and the existing knowledge is comprehensively summarized regarding the association between microbial pathogens and SB.

METHODS

We conducted a systematic search with keywords including SB and Toxoplasma gondii (Suicid* AND Toxoplasm*) and microbiome (Suicid* AND Microbiome AND Microbiota) throughout PubMed and Scopus to retrieve related studies up to 9 November 2023, identifying 24 eligible records. The subjects of the included studies had to have fulfilled the criteria of an SB disorder as defined by DSM-5, and death cases needed to have been defined as suicide.

RESULTS

Most studies reported significant association between toxoplasmosis and SB, suggesting a higher likelihood of SB in the infected population. Regarding the microbiome, only very few studies investigated an association between SB and alterations in the microbiome. Based on six included studies, there were some indications of a link between changes in the microbiome and SB.

CONCLUSION

The cognitive aspects of decision making in T. gondii-infected individuals with SB should be further investigated to unravel the underlying mechanisms. Further sufficiently powered studies are needed to establish a link between SB and alterations in the microbiome.

Lower Nerve Growth Factor Levels in Major Depression and Suicidal Behaviors: Effects of Adverse Childhood Experiences and Recurrence of Illness

Major depressive disorder (MDD) and its severe subtype, major dysmood disorder (MDMD), are distinguished by activation of inflammatory and growth factor subnetworks, which are associated with recurrence of illness (ROI) and adverse childhood experiences (ACEs). Nerve growth factor (NGF) plays a crucial role in facilitating neuro-immune communications and may regulate the inflammatory response.

METHODS

The present study examined the effects of ACEs and ROI on culture supernatant NGF, stem cell factor (SCF), stem cell GF (SCGF), hepatocyte GF (HGF), and macrophage colony-stimulating factor (M-CSF), in relation to a neurotoxicity (NT) cytokine profile.

RESULTS

NGF levels are lower in MDD (p = 0.003), particularly MDMD (p < 0.001), as compared with normal controls. ROI and ACE were significantly and inversely associated with NGF (≤0.003) and the NGF/NT ratio (≤0.001), whereas there are no effects of ACEs and ROI on SCF, SCGF, HGF, or M-CSF. Lowered NGF (p = 0.003) and the NGF/NT ratio (p < 0.001) are highly significantly and inversely associated with the severity of the current depression phenome, conceptualized as a latent vector extracted from the current severity of depression, anxiety, and suicidal behaviors. We found that one validated and replicable latent vector could be extracted from NGF, ROI, and the depression phenome, which therefore constitutes a novel ROI-NGF-pathway-phenotype. ACEs explained 59.5% of the variance in the latter pathway phenotype (p < 0.001).

CONCLUSIONS

The imbalance between decreased NGF and increased neurotoxic cytokines during the acute phase of severe depression may contribute to decreased neuroprotection, increased neuro-affective toxicity, and chronic mild inflammation.

Fight the Fire: Association of Cytokine Genomic Markers and Suicidal Behavior May Pave the Way for Future Therapies

The fight against suicide is highly challenging as it may be one of the most complex and, at the same time, most threatening among all psychiatric phenomena. In spite of its huge impact, and despite advances in neurobiology research, understanding and predicting suicide remains a major challenge for both researchers and clinicians. To be able to identify those patients who are likely to engage in suicidal behaviors and identify suicide risk in a reliable and timely manner, we need more specific, novel biological and genetic markers/indicators to develop better screening and diagnostic methods, and in the next step to utilize these molecules as intervention targets. One such potential novel approach is offered by our increasing understanding of the involvement of neuroinflammation based on multiple observations of increased proinflammatory states underlying various psychiatric disorders, including suicidal behavior. The present paper overviews our existing understanding of the association between suicide and inflammation, including peripheral and central biomarkers, genetic and genomic markers, and our current knowledge of intervention in suicide risk using treatments influencing inflammation; also overviewing the next steps to be taken and obstacles to be overcome before we can utilize cytokines in the treatment of suicidal behavior.