A genome-wide association study of emotion dysregulation: Evidence for interleukin 2 receptor alpha

Underlying biological mechanisms of emotion dysregulation in bipolar disorder

Difficulties with emotion regulation (ER) are a key feature of bipolar disorder (BD) contributing to poor psychosocial and functional outcomes. Abnormalities within emotion processing and regulation thus provide key targets for treatment strategies and have implications for treatment response. Although biological mechanisms and ER are typically studied independently, emergent findings in BD research suggest that there are important ties between biological mechanisms and the disturbances in ER observed in BD. Therefore, in this narrative review, we provide an overview of the literature on biological mechanisms underlying emotional dysregulation in BD including genetic and epigenetic mechanisms, neuroimaging findings, inflammation, hypothalamic-pituitary-adrenal (HPA) axis dysfunction, neuroplasticity and brain-derived neurotrophic factor (BDNF), and circadian rhythm disturbances. Finally, we discuss the clinical relevance of the findings and provide future directions for research. The continued exploration of underlying biological mechanisms in ED in BD may not only elucidate fundamental neurobiological mechanisms but also foster advancements in current treatment strategies and the development of novel targeted treatments.

Reveal the potent antidepressant effects of Zhi-Zi-Hou-Pu Decoction based on integrated network pharmacology and DDI analysis by deep learning

Background and objective

The multi-targets and multi-components of Traditional Chinese medicine (TCM) coincide with the complex pathogenesis of depression. Zhi-Zi-Hou-Pu Decoction (ZZHPD) has been approved in clinical medication with good antidepression effects for centuries, while the mechanisms under the iceberg haven't been addressed systematically. This study explored its inner active ingredients - potent pharmacological mechanism - DDI to explore more comprehensively and deeply understanding of the complicated TCM in treatment.

Methods

This research utilized network pharmacology combined with molecular docking to identify pharmacological targets and molecular interactions between ZZHPD and depression. Verification of major active compounds was conducted through UPLC-Q-TOF-MS/MS and assays on LPS-induced neuroblastoma cells. Additionally, the DDIMDL model, a deep learning-based approach, was used to predict DDIs, focusing on serum concentration, metabolism, effectiveness, and adverse reactions.

Results

The antidepressant mechanisms of ZZHPD involve the serotonergic synapse, neuroactive ligand-receptor interaction, and dopaminergic synapse signaling pathways. Eighteen active compounds were identified, with honokiol and eriocitrin significantly modulating neuronal inflammation and promoting differentiation of neuroimmune cells through genes like COMT, PI3KCA, PTPN11, and MAPK1. DDI predictions indicated that eriocitrin's serum concentration increases when combined with hesperidin, while hesperetin's metabolism decreases with certain flavonoids. These findings provide crucial insights into the nervous system's effectiveness and potential cardiovascular or nervous system adverse reactions from core compound combinations.

Conclusions

This study provides insights into the TCM interpretation, drug compatibility or combined medication for further clinical application or potential drug pairs with a cost-effective method of integrated network pharmacology and deep learning.

Prominent genetic variants and epigenetic changes in post-traumatic stress disorder among combat veterans

Post-traumatic stress disorder (PTSD) is one of the most widespread and disabling psychiatric disorders among combat veterans. Substantial interindividual variability in susceptibility to PTSD suggests the presence of different risk factors for this disorder. Twin and family studies confirm genetic factors as important risk factors for PTSD. In addition to genetic factors, epigenetic factors, especially DNA methylation, can be considered as a potential mechanism in changing the risk of PTSD. So far, many genetic and epigenetic association studies have been conducted in relation to PTSD. In genetic studies, many single nucleotide polymorphisms have been identified as PTSD risk factors. Meanwhile, the variations in catecholamines-related genes, serotonin transporter and receptors, brain-derived neurotrophic factor, inflammatory factors, and apolipoprotein E are the most prominent candidates. CpG methylation in the upstream regions of many genes is also considered a PTSD risk factor. Accurate identification of genetic and epigenetic changes associated with PTSD can lead to the presentation of suitable biomarkers for susceptible individuals to this disorder. This study aimed to delineate prominent genetic variations and epigenetic changes associated with post-traumatic stress disorder in military veterans who have experienced combat, focusing on genetic and epigenetic association studies.

Maternal Adversity and Epigenetic Age Acceleration Predict Heightened Emotional Reactivity in Offspring: Implications for Intergenerational Transmission of Risk

Black American women are disproportionately exposed to adversities that may have an intergenerational impact on mental health. The present study examined whether maternal exposure to adversity and epigenetic age acceleration (EAA; a biomarker of stress exposure) predicts the socioemotional health of her offspring. During pregnancy, 180 Black American women self-reported experiences of childhood adversity and marginalization-related adversity (i.e., racial discrimination and gendered racial stress) and provided a blood sample for epigenetic assessment. At a three-year follow-up visit, women reported their offspring's emotional reactivity (an early indicator of psychopathology) via the CBCL/1.5-5. After adjusting for maternal education and offspring sex, results indicated that greater maternal experiences of childhood trauma (β = 0.21, SE(β) = 0.01; p = 0.01) and racial discrimination (β = 0.14, SE(β) = 0.07; p = 0.049) predicted greater offspring emotional reactivity, as did maternal EAA (β = 0.17, SE(β) = 0.09, p = 0.046). Our findings suggest that maternal EAA could serve as an early biomarker for intergenerational risk conferred by maternal adversity, and that 'maternal adversity' must be defined more broadly to include social marginalization, particularly for Black Americans.

Emotional dysregulation, alexithymia and neuroticism: a systematic review on the genetic basis of a subset of psychological traits

Neuroticism, alexithymia and emotion dysregulation are key traits and known risk factors for several psychiatric conditions. In this systematic review, the aim is to evaluate the genetic contribution to these psychological phenotypes. A systematic review of articles found in PubMed was conducted. Search terms included 'genetic', 'GWAS', 'neuroticism', 'alexithymia' and 'emotion dysregulation'. Risk of bias was assessed utilizing the STREGA checklist. Two hundred two papers were selected from existing literature based on the inclusion and exclusion criteria. Among these, 27 were genome-wide studies and 175 were genetic association studies. Single gene association studies focused on selected groups of genes, mostly involved in neurotransmission, with conflicting results. GWAS studies on neuroticism, on the other hand, found several relevant and replicated intergenic and intronic loci affecting the expression and regulation of crucial and well-known genes (such as DRD2 and CRHR1). Mutations in genes coding for trascriptional factors were also found to be associated with neuroticism (DCC, XKR6, TCF4, RBFOX1), as well as a noncoding regulatory RNA (LINC00461). On the other hand, little GWAS data are available on alexythima and emotional dysregulation.

Investigating the effects of emotion dysregulation and repetitive negative thinking on alcohol hangover anxiety and depression

INTRODUCTION

Underlying factors associated with alcohol hangover psychological symptoms, such as anxiety and depression, have not been identified. Emotion dysregulation and repetitive negative thinking (RNT) are transdiagnostic factors associated with psychopathology, including non-hangover anxiety and depression. The current study prospectively examined the role of emotion dysregulation on subsequent alcohol hangover anxiety and depression symptoms, as well as the moderating role of RNT on this relation among university students.

METHODS

One hundred thirty-six participants completed baseline assessments of emotion dysregulation (DERS-16) and non-hangover anxiety and depression (DASS-21). Thirty-nine participants reported experiencing alcohol hangover at 2-week follow up and completed assessments of RNT (PTQ) and hangover anxiety and depression (modified DASS-21). Two independent regression-based moderation analyses were conducted to examine the relation of baseline emotion dysregulation, 2-week follow-up RNT, and hangover anxiety and depression symptoms after accounting for baseline non-hangover anxiety and depression symptoms.

RESULTS

Among those experiencing alcohol hangover (n = 39), emotion dysregulation and RNT were not associated with hangover related anxiety beyond non-hangover anxiety. Emotion dysregulation significantly predicted hangover depression but was rendered non-significant by the addition of RNT, which was significantly associated with hangover depression. RNT moderated the emotion dysregulation-hangover depression relation such that emotion dysregulation was not associated with future hangover depression at low levels of RNT but was positively associated with hangover depression at moderate to high levels of RNT.

CONCLUSION

Results provide preliminary support for the role of emotion dysregulation and RNT in hangover depression severity.

Factors associated with mood disorders and the efficacy of the targeted treatment of functional dyspepsia: A randomized clinical trial

Background

Patients with functional dyspepsia (FD) are often accompanied by mood disorders (MDs). This study aimed to identify factors associated with MDs in patients with FD and evaluate the efficacy of targeted treatment plans.

Methods

Relevant scales were used to assess MDs. Patients with FD having MDs and acid reflux were treated with flupentixol and melitracen (FM) and acid-suppressive therapy (AST) (histamine-2 receptor antagonists (H2RAs) (group A) or proton pump inhibitors (PPIs) (group B)), and those without acid reflux (group C) did not receive AST. Patients with FD without MDs were randomly administered H2RAs (group D) or PPIs (group E). The primary endpoints were factors associated with MDs and improvement in gastrointestinal (GI) symptoms and MDs in patients with FD.

Results

A total of 362 patients with FD were enrolled in this study. Patients with FD having high GI score and low education were found prone to MDs. At week 2, the remission rate of overall GI symptoms and depression was significantly higher in group B than that in groups A and C [GI: 72.72% (32/44) vs. 47.73% (21/44) and 72.72% (32/44) vs. 38.94% (44/113), all P < 0.05; depression: 72.22% (26/36) vs. 41.67% (15/36) and 72.22% (26/36) vs. 41.57% (37/89), all P < 0.05]. Furthermore, the remission rate of overall GI symptoms was significantly higher in group E than that in group D [60.29% (41/68) vs. 42.65% (29/68), P < 0.05]. At week 8, similar efficacies and adverse reactions were observed in these groups.

Conclusion

The risk factors for MDs were high GI scores and low literacy rates. Thus, targeted treatment (FM+PPIs for patients with MDs; PPIs for patients without MDs) can improve the efficacy of patients with FD.

Clinical trial registration

www.chictr.org.cn, identifier ChiCTR2100053126.

Prediction of Probable Major Depressive Disorder in the Taiwan Biobank: An Integrated Machine Learning and Genome-Wide Analysis Approach

In light of recent advancements in machine learning, personalized medicine using predictive algorithms serves as an essential paradigmatic methodology. Our goal was to explore an integrated machine learning and genome-wide analysis approach which targets the prediction of probable major depressive disorder (MDD) using 9828 individuals in the Taiwan Biobank. In our analysis, we reported a genome-wide significant association with probable MDD that has not been previously identified: FBN1 on chromosome 15. Furthermore, we pinpointed 17 single nucleotide polymorphisms (SNPs) which show evidence of both associations with probable MDD and potential roles as expression quantitative trait loci (eQTLs). To predict the status of probable MDD, we established prediction models with random undersampling and synthetic minority oversampling using 17 eQTL SNPs and eight clinical variables. We utilized five state-of-the-art models: logistic ridge regression, support vector machine, C4.5 decision tree, LogitBoost, and random forests. Our data revealed that random forests had the highest performance (area under curve = 0.8905 ± 0.0088; repeated 10-fold cross-validation) among the predictive algorithms to infer complex correlations between biomarkers and probable MDD. Our study suggests that an integrated machine learning and genome-wide analysis approach may offer an advantageous method to establish bioinformatics tools for discriminating MDD patients from healthy controls.

Computational analysis of deleterious single nucleotide polymorphisms in catechol O-Methyltransferase conferring risk to post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is one of the prevalent neurological disorder which is drawing increased attention over the past few decades. Major risk factors for PTSD can be categorized into environmental and genetic factors. Among the genetic risk factors, polymorphisms in the catechol-O-methyltransferase (COMT) gene is known to be associated with the risk for PTSD. In the present study, we analysed the impact of deleterious single nucleotide polymorphisms (SNPs) in the COMT gene conferring risk to PTSD using computational based approaches followed by molecular dynamic simulations. The data on COMT gene associated with PTSD were collected from several databases including Online Mendelian Inheritance in Man (OMIM) search. Datasets related to SNP were downloaded from the dbSNP database. To study the structural and dynamic effects of COMT wild type and mutant forms, we performed molecular dynamics simulations (MD simulations) at a time scale of 300 ns. Results from screening the SNPs using the computational tools SIFT and Polyphen-2 demonstrated that the SNP rs4680 (V158M) in COMT has a deleterious effect with phenotype in PTSD. Results from the MD simulations showed that there is some major fluctuations in the structural features including root mean square deviation (RMSD), radius of gyration (Rg), root mean square fluctuation (RMSF) and secondary structural elements including α-helices, sheets and turns between wild-type (WT) and mutant forms of COMT protein. In conclusion, our study provides novel insights into the deleterious effects and impact of V158M mutation on COMT protein structure which plays a key role in PTSD.

The role of gene polymorphisms, and analysis of peripheral and central levels of interleukins in suicidal behavior: A systematic review

In terms of the physiological characteristics of suicidal behavior (SB) disorder, an increase inflammation response has been reported in these individuals. Therefore, the pro-inflammatory and anti-inflammatory activities of interleukins are adequate markers to research in order to understand the pathogenesis of SB. For that reason, the aim of this systematic review was to evaluate the role of interleukins in individuals with suicidal behavior disorder. A systematic search was performed in PubMed, Scopus and EBSCO databases up to July 2019. We used the words "interleukin" AND "suicide", "interleukin" AND "suicidal", and "IL-". Articles where interleukins concentrations were measured in individuals with SB and/or genetic studies addressing interleukins genes variants as possible markers to SB were included. A total of 54 articles were included. Articles that measured interleukin levels comprised 1111 cases and 1588 controls; whereas the genetic studies comprised 3082 cases and 5148 controls. These studies evaluated the concentrations of IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-8, IL-10, sIL-2R in serum, plasma. The pro-inflammatory interleukins concentrations were higher in cases than in controls; however, we observed heterogeneity in the measurements and sample sources. Whereas, 9 polymorphisms of IL-1α, IL-1β, IL-6, IL-1β-8 genes were analyzed in association with suicide behavior disorder, though no conclusive outcomes were attained. Our results suggest that individuals with suicide risk undergo continuous stress that could trigger the release and circulation of pro-inflammatory interleukins and therefore their concentration in plasma. However, more studies are necessary in order to reach conclusively outcomes.

Gender Differences in Depression: Evidence From Genetics

Compared with men, female accounts for a larger proportion of patients with depression. Behavioral genetics researches find gender differences in genetic underpinnings of depression. We found that gender differences exist in heritability and the gene associated with depression after reviewing relevant research. Both genes and gene-environment interactions contribute to the risk of depression in a gender-specific manner. We detailed the relationships between serotonin transporter gene-linked promoter region (5-HTTLPR) and depression. However, the results of these studies are very different. We explored the reasons for the contradictory conclusions and provided some suggestions for future research on the gender differences in genetic underpinnings of depression.

A Systematic Review of DNA Methylation and Gene Expression Studies in Posttraumatic Stress Disorder, Posttraumatic Growth, and Resilience

Most people will experience a traumatic event within their lifetime. One commonly recognized response to trauma exposure is posttraumatic stress disorder (PTSD). The biological underpinnings of PTSD, including epigenetic mechanisms of DNA methylation and gene expression, have been studied intensively. However, psychological posttrauma responses vary widely and can include positive outcomes, such as posttraumatic growth (PTG) and, more commonly, resilience. The aim of this systematic review was to summarize the current DNA methylation and gene expression data with respect to three potential posttrauma responses: PTSD, PTG, and resilience. A literature search identified 486 studies, 51 of which were deemed eligible for inclusion (total N = 10,633). All included studies examined PTSD and consistently implicated DNA methylation and gene expression changes in hypothalamic-pituitary-adrenal axis and inflammatory genes. Ten studies acknowledged resilience as a posttrauma response, but only two studies examined epigenetics and gene expression using a scale to measure resilience. Low resilience was associated with gene expression patterns in immune and dopamine genes, and high resilience was associated with a blunted inflammatory response. No studies examined epigenetic or gene expression changes associated with PTG. These findings highlight a focus on pathogenic research, which has failed to adequately acknowledge and measure positive posttrauma outcomes of PTG and resilience. Future research should examine DNA methylation and gene expression changes associated with PTG and resilience in addition to PTSD in order to gain a more comprehensive picture of an individual's well-being following exposure to trauma.

Gene-level genome-wide association analysis of suicide attempt, a preliminary study in a psychiatric Mexican population

Background

Evidence suggests that liability for suicide behavior is heritable; additionally, suicide has been partly related to other psychiatric disorders. Nevertheless, most of the information reported so far address Caucasian and Asian individuals. Hence, our aim was to conduct a gene‐level association study in Mexican psychiatric individuals diagnosed with suicide attempt.

Methods

We recruited 192 individuals from two clinical centers in Mexico. All participants were born in Mexico and had Mexican parents and grandparents. Direct genotyping was performed using the commercial platform Infinium PsychArray BeadChip. A p‐value lower than 1e‐05 was considered as gene‐level significant and a p‐value lower than 1e‐04 was considered as gene‐level nominal significant.

Results

Our analyses showed that SCARA5 was associated to suicide intent at a gene‐level with statistical significance (p‐value = 1.12e‐6). Other genes were nominally associated with suicide attempt: GHSR (p‐value = 0.0004), RGS10 (p‐value = 5.13e‐5), and STK33 (p‐value = 3.62e‐5). Regarding gene variant analyses, the SNPs with a statistical association (p > .05) were rs561361616, rs1537577, rs11198999 for RGS10, and rs11041981, rs11041993, rs11041994, rs11041995, rs11041997, rs10840083, rs10769918 for STK33. For these genes, previous studies have associated SCARA5 with depression, GHSR with alcohol dependence and depression, and RGS10 with schizophrenia and depression. To date, STK33 has not been associated with any psychiatric disorder.

Conclusion

Our outcomes revealed that SCARA5, GHSR, RGS10 and STK33 could be considered as risk biomarkers for suicide attempt behavior in our Mexican psychiatric sample. We recommend to perform larger scale analyses to have conclusive results.

Genome-wide analysis of emotional lability in adult attention deficit hyperactivity disorder (ADHD)

Emotional lability is strongly associated with Attention Deficit Hyperactivity Disorder (ADHD), represents a major source of impairment and predicts poor clinical outcome in ADHD. Given that no specific genes with a role in the co-occurrence of both conditions have been described, we conducted a GWAS of emotional lability in 563 adults with ADHD. Despite not reaching genome-wide significance, the results highlighted genes related with neurotransmission, cognitive function and a wide range of psychiatric disorders that have emotional lability as common clinical feature. By constructing polygenic risk scores on mood instability in the UK Biobank sample and assessing their association with emotional lability in our clinical dataset, we found suggestive evidence of common genetic variation contributing to emotional lability in general population and in clinically diagnosed ADHD. Although not conclusive, these tentative results are in agreement with previous studies that suggest emotion dysregulation as a transdiagnostic construct and highlight the need for further investigation to disentangle the genetic basis of mood instability in ADHD and co-occurring psychiatric disorders.

Translational studies support a role for serotonin 2B receptor (HTR2B) gene in aggression-related cannabis response

Cannabis use is increasing in the United States, as are its adverse effects. We investigated the genetics of an adverse consequence of cannabis use: cannabis-related aggression (CRA) using a genome-wide association study (GWAS) design. Our GWAS sample included 3269 African Americans (AAs) and 2546 European Americans (EAs). An additional 89 AA subjects from the Grady Trauma Project (GTP) were also examined using a proxy-phenotype replication approach. We identified genome-wide significant risk loci contributing to CRA in AAs at the serotonin receptor 2B receptor gene (HTR2B), and the lead SNP, HTR2B*rs17440378, showed nominal association to aggression in the GTP cohort of cannabis-exposed subjects. A priori evidence linked HTR2B to impulsivity/aggression but not to cannabis response. Human functional data regarding the HTR2B variant further supported our finding. Treating an Htr2b-/- knockout mouse with THC resulted in increased aggressive behavior, whereas wild-type mice following THC administration showed decreased aggression in the resident-intruder paradigm, demonstrating that HTR2B variation moderates the effects of cannabis on aggression. These concordant findings in mice and humans implicate HTR2B as a major locus associated with cannabis-induced aggression.

Neuroepigenetics of Post-Traumatic Stress Disorder

While diagnosis of PTSD is based on behavioral symptom clusters that are most directly associated with brain function, epigenetic studies of PTSD in humans to date have been limited to peripheral tissues. Animal models of PTSD have been key for understanding the epigenetic alterations in the brain most directly relevant to endophenotypes of PTSD, in particular those pertaining to fear memory and stress response. This chapter provides an overview of neuroepigenetic studies based on animal models of PTSD, with an emphasis on the effect of stress on fear memory. Where relevant, we also describe human-based studies with relevance to neuroepigenetic insights gleaned from animal work and suggest promising directions for future studies of PTSD neuroepigenetics in living humans that combine peripheral epigenetic measures with measures of central nervous system activity, structure and function.

Traumatic Stress Epigenetics

Purpose of Review

Traumatic stress has profound impacts on many domains of life, yet the mechanisms that confer risk for or resilience to the development of traumatic stress-related psychopathologies are still very much under investigation. The current review highlights recent developments in the field of traumatic stress epigenetics in humans.

Recent Findings

Recent results reveal traumatic stress-related epigenetic dysregulation in neural, endocrine, and immune system genes and associated networks. Emerging work combining imaging with epigenetic measures holds promise for addressing the correspondence between peripheral and central effects of traumatic stress. A growing literature is also documenting the transgenerational effects of prenatal stress exposures in humans.

Summary

Moving forward, increasing focus on epigenetic marks of traumatic stress in CNS tissue will create a clearer picture of the relevance of peripheral measures; PTSD brain banks will help in this regard. Similarly, leveraging multigenerational birth cohort data will do much to clarify the extent of transgenerational epigenetic effects of traumatic stress. Greater efforts should be made towards developing prospective studies with longitudinal design.

A BRIEF INTRODUCTION TO THE NEUROGENETICS OF COGNITION-EMOTION INTERACTIONS

Neuroscience research has demonstrated that cognition, emotion, and their dynamic interactions emerge from complex and flexible patterns of activity across distributed neural circuits. A parallel branch of research in genetics has begun to identify common variation in the human DNA sequence (i.e., genome) that may shape individual differences in cognition-emotion interactions by altering molecular and cellular pathways that modulate the activity of these neural circuits. Here we provide a brief introduction to such neurogenetics research and how it may usefully inform our understanding of the biological mechanisms through which dynamic cognition-emotion interactions emerge and, subsequently, help shape normal and abnormal behavior.

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.

Exploring the link between work and health

Purpose

The purpose of this paper is to examine if facets of workaholism are associated with a family history of metabolic diseases.

Design/methodology/approach

Data on workaholism and family history of health issues were collected, through administration of an online survey, from 194 employees.

Findings

Workaholism significantly related to a family history of metabolic diseases.

Research limitations/implications

Future researchers should collect objective disease data, examine work-related moderators as well as potential mediators, and implement longitudinal designs with much larger samples. That said, the data reveal a correlation between workaholism and family history of metabolic disease.

Practical implications

The results provide valuable information to help promote a healthy workforce and to improve employees’ health by reducing workaholic tendencies. They could also help to minimize health-related costs associated with metabolic diseases that could develop in parallel with workaholism, as well as costs in terms of a loss in productivity due absenteeism.

Originality/value

It is, the authors believe, the first study to investigate the relationship between facets of workaholism and family history of health issues that have often been associated with metabolic diseases.

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.