Association of CRP genetic variation and CRP level with elevated PTSD symptoms and physiological responses in a civilian population with high levels of trauma

Cannabidiol ameliorates PTSD-like symptoms by inhibiting neuroinflammation through its action on CB2 receptors in the brain of male mice

Post-traumatic stress disorder (PTSD) is a debilitating mental health disease related to traumatic experience, and its treatment outcomes are unsatisfactory. Accumulating research has indicated that cannabidiol (CBD) exhibits anti-PTSD effects, however, the underlying mechanism of CBD remains inadequately investigated. Although many studies pertaining to PTSD have primarily focused on aberrations in neuronal functioning, the present study aimed to elucidate the involvement and functionality of microglia/macrophages in PTSD while also investigated the modulatory effects of CBD on neuroinflammation associated with this condition. We constructed a modified single-prolonged stress (SPS) mice PTSD model and verified the PTSD-related behaviors by various behavioral tests (contextual freezing test, elevated plus maze test, tail suspension test and novel object recognition test). We observed a significant upregulation of Iba-1 and alteration of microglial/macrophage morphology within the prefrontal cortex and hippocampus, but not the amygdala, two weeks after the PTSD-related stress, suggesting a persistent neuroinflammatory phenotype in the PTSD-modeled group. CBD (10 mg/kg, i.p.) inhibited all PTSD-related behaviors and reversed the alterations in both microglial/macrophage quantity and morphology when administered prior to behavioral assessments. We further found increased pro-inflammatory factors, decreased PSD95 expression, and impaired synaptic density in the hippocampus of the modeled group, all of which were also restored by CBD treatment. CBD dramatically increased the level of anandamide, one of the endocannabinoids, and cannabinoid type 2 receptors (CB2Rs) transcripts in the hippocampus compared with PTSD-modeled group. Importantly, we discovered the expression of CB2Rs mRNA in Arg-1-positive cells in vivo and found that the behavioral effects of CBD were diminished by CB2Rs antagonist AM630 (1 mg/kg, i.p.) and both the behavioral and molecular effects of CBD were abolished in CB2Rs knockout mice. These findings suggest that CBD would alleviate PTSD-like behaviors in mice by suppressing PTSD-related neuroinflammation and upregulation and activation of CB2Rs may serve as one of the underlying mechanisms for this therapeutic effect. The present study offers innovative experimental evidence supporting the utilization of CBD in PTSD treatment from the perspective of its regulation of neuroinflammation, and paves the way for leveraging the endocannabinoid system to regulate neuroinflammation as a potential therapeutic approach for psychiatric disorders.

Salivary inflammatory biomarkers as a predictor of post-traumatic stress disorder and depressive symptom severity in trauma patients: A prospective study

BACKGROUND

Although post-traumatic stress disorder (PTSD) and depression screening are recommended for traumatic injury patients, routine screening is still uncommon. Salivary inflammatory biomarkers have biological plausibility and potential feasibility and acceptability for screening. This study tested prospective associations between several salivary inflammatory biomarkers (proinflammatory cytokines interleukin-1β, interleukin-6, tumor necrosis factor-α; and C-reactive protein), collected during hospitalization and PTSD and depressive symptoms at 5-month follow-up.

METHODS

Adult traumatic injury patients (N = 696) at a major urban Level 1 trauma center provided salivary samples and completed PTSD and depressive symptom measures during days 0-13 of inpatient hospitalization. At 5-month follow-up, 368 patients (77 % male, 23 % female) completed the Clinician-Administered PTSD Scale for DSM-IV and the Self-rated Inventory of Depressive Symptomatology. Analyses focused on a latent inflammatory cytokine factor and C-reactive protein at baseline predicting 5-month PTSD and depression symptom outcomes and included baseline symptom levels as covariates.

RESULTS

A latent factor representing proinflammatory cytokines was not related to 5-month PTSD or depressive symptom severity. Higher salivary CRP was related to greater PTSD symptom severity (β = .10, p = .03) at 5-month follow-up and more severity in the following depressive symptoms: changes in weight and appetite, bodily complaints, and constipation/diarrhea (β's from .14 to .16, p's from .004 -.03).

CONCLUSION

In a primarily Latine and Black trauma patient sample, salivary CRP measured after traumatic injury was related to greater PTSD symptom severity and severity in several depressive symptom clusters. Our preliminary findings suggest that salivary or systemic CRP may be useful to include in models predicting post-trauma psychopathology.

Effects of genetically predicted posttraumatic stress disorder on autoimmune phenotypes

Observational studies suggest that posttraumatic stress disorder (PTSD) increases risk for various autoimmune diseases. Insights into shared biology and causal relationships between these diseases may inform intervention approaches to PTSD and co-morbid autoimmune conditions. We investigated the shared genetic contributions and causal relationships between PTSD, 18 autoimmune diseases, and 3 immune/inflammatory biomarkers. Univariate MiXeR was used to contrast the genetic architectures of phenotypes. Genetic correlations were estimated using linkage disequilibrium score regression. Bi-directional, two-sample Mendelian randomization (MR) was performed using independent, genome-wide significant single nucleotide polymorphisms; inverse variance weighted and weighted median MR estimates were evaluated. Sensitivity analyses for uncorrelated (MR PRESSO) and correlated horizontal pleiotropy (CAUSE) were also performed. PTSD was considerably more polygenic (10,863 influential variants) than autoimmune diseases (median 255 influential variants). However, PTSD evidenced significant genetic correlation with nine autoimmune diseases and three inflammatory biomarkers. PTSD had putative causal effects on autoimmune thyroid disease (p = 0.00009) and C-reactive protein (CRP) (p = 4.3 × 10-7). Inferences were not substantially altered by sensitivity analyses. Additionally, the PTSD-autoimmune thyroid disease association remained significant in multivariable MR analysis adjusted for genetically predicted inflammatory biomarkers as potential mechanistic pathway variables. No autoimmune disease had a significant causal effect on PTSD (all p values > 0.05). Although causal effect models were supported for associations of PTSD with CRP, shared pleiotropy was adequate to explain a putative causal effect of CRP on PTSD (p = 0.18). In summary, our results suggest a significant genetic overlap between PTSD, autoimmune diseases, and biomarkers of inflammation. PTSD has a putative causal effect on autoimmune thyroid disease, consistent with existing epidemiologic evidence. A previously reported causal effect of CRP on PTSD is potentially confounded by shared genetics. Together, results highlight the nuanced links between PTSD, autoimmune disorders, and associated inflammatory signatures, and suggest the importance of targeting related pathways to protect against disease and disability.

The Toxic Stress of Racism and Its Relationship to Frailty

Significant morbidity and mortality from COVID-19-related illnesses have been observed among people of color within the United States. While theories involving healthcare inequity and political division have emerged to explain this observation, the role of chronic stress and inflammation is also being explored. Toxic stress is experienced disproportionately by race, ethnicity, and socioeconomic status and increases frailty and vulnerability to diseases such as COVID-19. C-reactive protein (CRP) is a biomarker associated with the inflammatory response that is typically elevated due to exposure to acute or chronic traumatic stress, as well as COVID-19. This study explored the relationship between CRP and Hispanic/non-Hispanic ethnicity among adults hospitalized with COVID-19 via a secondary analysis of retrospective electronic health record (EHR) data collected from a community healthcare system in Southern California. A total of 1,744 cases representing hospitalized adults with COVID-19 were reviewed. Data were extracted from the EHR to reflect demographics, medical diagnoses, medications, CRP, and comorbidity burden. Frequencies, percentages, and measures of central tendency were assessed to understand the distribution of data. Associations were conducted using Pearson's r and the chi-square test of independence. Differences between groups were examined via independent samples t-tests. The sample was 52% Hispanic, 56% male, and the mean age was 62 years (SD = 16.1). The mean age of Hispanic cases was younger than non-Hispanic cases (p < .001, η = 0.289). Serum CRP was significantly higher in the Hispanic cases, with a high degree of association (p < .001, η = 0.472). In addition, higher CRP levels were significantly associated with the need for mechanical ventilation (p < .001, φc = 0.216). No significant relationships were found between CRP and age, body mass index (BMI), or comorbidity burden. Findings challenge the assumption that the disproportionate morbidity and mortality suffered by the Hispanic population due to COVID-19 was due to age, BMI, or comorbidities such as metabolic syndrome or heart disease. CRP in the Hispanic population should be further investigated to understand its relationship to chronic stress, frailty, and risk for COVID-19 in this population.

Pro-inflammatory markers are related to cortical network connectivity in women exposed to interpersonal trauma with PTSD

Exposure to interpersonal violence affects a significant number of individuals each year and further increases the risk for developing Posttraumatic Stress Disorder (PTSD). A growing body of research suggests that immune system dysfunction, in particular elevated inflammation, may contribute to the pathophysiology of PTSD. However, few studies have examined the neurobiological correlates of inflammation in women with PTSD using resting-state fMRI. The present study explored the relationship between pro-inflammatory cytokine levels, C-reactive protein (CRP), tumor necrosis factor alpha TNF-alpha), and interleukin-6 (IL-6), and resting-state functional connectivity patterns in three major cortical networks (default mode network (DMN), central executive network (CEN), and salience network (SN)) in a sample of women (N=18) exposed to interpersonal violence with PTSD. Results indicated that higher CRP levels were associated with stronger functional connectivity between the SN and visual areas, but weaker functional connectivity between the CEN and visual areas. These findings suggest that pro-inflammatory markers are related to connectivity of task-positive networks in women with PTSD. Further, our results provide evidence for potential neurobiological markers of inflammation in PTSD.

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.

Inflammation in Posttraumatic Stress Disorder: Dysregulation or Recalibration?

Despite ample experimental data indicating a role of inflammatory mediators in the behavioral and neurobiological manifestations elicited by exposure to physical and psychologic stressors, causative associations between systemic low-grade inflammation and central nervous system inflammatory processes in posttraumatic stress disorder (PTSD) patients remain largely conceptual. As in other stress-related disorders, pro-inflammatory activity may play an equivocal role in PTSD pathophysiology, one that renders indiscriminate employment of anti-inflammatory agents of questionable relevance. In fact, as several pieces of preclinical and clinical research convergingly suggest, timely and targeted potentiation rather than inhibition of inflammatory responses may actually be beneficial in patients who are characterized by suppressed microglia function in the face of systemic low-grade inflammation. The deleterious impact of chronic stress-associated inflammation on the systemic level may, thus, need to be held in context with the - often not readily apparent - adaptive payoffs of low-grade inflammation at the tissue level.

A network analysis investigating the associations between posttraumatic stress symptoms, markers of inflammation and metabolic syndrome

Chronic systemic inflammation has been implicated in trauma exposure, independent of a psychiatric diagnosis, and in posttraumatic stress disorder (PTSD) and its highly comorbid conditions, such as metabolic syndrome (MetS). The present study used network analysis to examine the interacting associations between pro-inflammatory cytokines, posttraumatic stress (PTS) symptoms and symptom clusters, and individual components of MetS, in a cohort of 312 participants (n = 139 PTSD cases, n = 173 trauma-exposed controls). Pro-inflammatory cytokines were measured in serum samples using immunoturbidimetric and multiplex assays. Three network models were assessed, and the decision on which model to use was guided by network stability estimates and denseness. Weak negative associations were observed between interleukin one beta (IL-1β) and detachment (D6) and irritability (E1); tumour necrosis factor alpha (TNFα) and hypervigilance (E3); and C-reactive protein (CRP) and emotional cue reactivity (B4), which could be due to high cortisol levels present in a female-majority cohort. Network models also identified positive associations between CRP and waist circumference, blood pressure, and high-density lipoprotein cholesterol (HDL-C). The strongest association was observed between CRP and waist circumference, providing evidence that central obesity is an important inflammatory component of MetS. Some networks displayed high instability, which could be due to the small pool of participants with viable cytokine data. Overall, this study provides evidence for associations between inflammation, PTS symptoms and components of MetS. Future longitudinal studies measuring pro-inflammatory cytokines in the immediate aftermath of trauma are required to gain better insight into the role of inflammation in trauma-exposure and PTSD.

The impact of forced displacement: trauma, increased levels of inflammation and early presentation of diabetes in women Syrian refugees

BACKGROUND

Forced displacement and war trauma cause high rates of post-traumatic stress, anxiety disorders and depression in refugee populations. We investigated the impact of forced displacement on mental health status, gender, presentation of type 2 diabetes (T2D) and associated inflammatory markers among Syrian refugees in Lebanon.

METHODS

Mental health status was assessed using the Harvard Trauma Questionnaire (HTQ) and the Hopkins Symptom Checklist-25 (HSCL-25). Additional metabolic and inflammatory markers were analyzed.

RESULTS

Although symptomatic stress scores were observed in both men and women, women consistently displayed higher symptomatic anxiety/depression scores with the HSCL-25 (2.13 ± 0.58 versus 1.95 ± 0.63). With the HTQ, however, only women aged 35-55 years displayed symptomatic post-traumatic stress disorder (PTSD) scores (2.18 ± 0.43). Furthermore, a significantly higher prevalence of obesity, prediabetes and undiagnosed T2D were observed in women participants (23.43, 14.91 and 15.18%, respectively). Significantly high levels of the inflammatory marker serum amyloid A were observed in women (11.90 ± 11.27 versus 9.28 ± 6.93, P = 0.036).

CONCLUSIONS

Symptomatic PTSD, anxiety/depression coupled with higher levels of inflammatory marker and T2D were found in refugee women aged between 35 and 55 years favoring the strong need for psychosocial therapeutic interventions in moderating stress-related immune dysfunction and development of diabetes in this subset of female Syrian refugees.

Assessing and Modelling of Post-Traumatic Stress Disorder Using Molecular and Functional Biomarkers

Post-traumatic stress disorder (PTSD) is a complex psychological disorder that develops following exposure to traumatic events. PTSD is influenced by catalytic factors such as dysregulated hypothalamic-pituitary-adrenal (HPA) axis, neurotransmitter imbalances, and oxidative stress. Genetic variations may act as important catalysts, impacting neurochemical signaling, synaptic plasticity, and stress response systems. Understanding the intricate gene networks and their interactions is vital for comprehending the underlying mechanisms of PTSD. Focusing on the catalytic factors of PTSD is essential because they provide valuable insights into the underlying mechanisms of the disorder. By understanding these factors and their interplay, researchers may uncover potential targets for interventions and therapies, leading to more effective and personalized treatments for individuals with PTSD. The aforementioned gene networks, composed of specific genes associated with the disorder, provide a comprehensive view of the molecular pathways and regulatory mechanisms involved in PTSD. Through this study valuable insights into the disorder's underlying mechanisms and opening avenues for effective treatments, personalized interventions, and the development of biomarkers for early detection and monitoring are provided.

Suicidality in civilian women with PTSD: Possible link to childhood maltreatment, proinflammatory molecules, and their genetic variations

Background

Posttraumatic stress disorder (PTSD) is a robust risk factor for suicide. Studies have suggested an association between suicide and elevated inflammatory markers, although such evidence in PTSD is scarce. Suicide risk, PTSD, and inflammatory molecules are all shown to be associated with childhood maltreatment and genetic factors.

Methods

We examined the association between suicidal ideation/risk and inflammatory markers in 83 civilian women with PTSD, and explored the possible influence of childhood maltreatment and inflammatory genes. Suicidal ideation and risk were assessed using the Beck Depression Inventory-II and the Mini-International Neuropsychiatric Interview. Childhood maltreatment history was assessed with the Childhood Trauma Questionnaire (CTQ). Blood levels of high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6) and high-sensitivity tumor necrosis factor-α were measured. Genetic polymorphisms of CRP rs2794520 and IL6 rs1800796 were genotyped.

Results

Suicidal ideation was significantly positively correlated with hsCRP (p = 0.002) and IL-6 (p = 0.015) levels. Suicide risk weighted score was significantly positively correlated with hsCRP (p = 0.016) levels. The risk alleles of CRP rs2794520 and IL6 rs1800796 leading to increased respective protein levels were dose-dependently associated with higher risk of suicide (p = 0.007 and p = 0.029, respectively). The CTQ total score was significantly correlated with suicidal ideation and risk, but not with inflammatory marker levels. Furthermore, a multivariate regression analysis controlling for PTSD severity and potential confounders revealed that rs2794520 and rs1800796, but not hsCRP or IL-6 levels, significantly predicted suicidal ideation (p < 0.001) and risk (p = 0.007), respectively.

Conclusion

Genetic variations within inflammatory genes might be useful in detecting PTSD patients at high risk of suicide.

Development and feasibility testing of an integrated PTSD and adherence intervention cognitive processing therapy-life steps (CPT-L) to improve HIV outcomes: Trial protocol

Despite high rates of Post-Traumatic Stress Disorder (PTSD) in persons living with HIV (PLWH) and poor HIV-related health outcomes associated with PTSD, an effective evidence-based treatment for PTSD symptoms in PLWH does not exist. Negative reinforcement conceptual models posit that avoidant behavior (hallmark symptom of PTSD) demonstrated by PLWH with co-occurring PTSD can contribute to poor antiretroviral therapy (ART) adherence. However, research evaluating the impact of evidence-based treatment for PTSD among HIV infected populations on HIV outcomes is scarce. The Cognitive Processing Therapy (CPT) protocol is an evidence-based PTSD treatment that may address internalized stigma with targeted modifications and improve ART adherence and subsequent viral suppression through reduction of avoidant coping. This study will be the first pilot open-label randomized control trial (RCT) to test feasibility of an integrated evidence-based PTSD treatment (CPT) with an adherence intervention (Lifesteps) delivered in a Ryan White clinic to improve PTSD symptoms, adherence to ART, and retention in HIV care. Primary aims are to (1) conduct theater testing of the CPT and Lifesteps research protocol and evaluate acceptability (n = 12) and (2) deliver a modified CPT protocol (CPT-Lifesteps, or CPT-L) in 60 PLWH/PTSD exploring impact of CPT-L on PTSD symptoms and HIV outcomes compared to a Lifesteps + Standard of Care condition. This innovative research extends PTSD treatment approaches as a paradigm to reduce barriers to ART adherence. Findings of this innovative study are significant because they support the Undetectable = Untransmittable (U[bond, double bond]U) campaign and can help prevent the transmission of HIV infection through increased viral suppression.

Eveningness chronotype and depressive affective temperament associated with higher high-sensitivity C-reactive protein in unipolar and bipolar depression

BACKGROUND

Several studies investigated the role of inflammation in the etiopathogenesis of mood disorders. The aim of our cross-sectional study is evaluating baseline high-sensitivity C-reactive-protein (hsCRP) levels in a cohort of unipolar and bipolar depressive inpatients, in relation with psychopathological, temperamental and chronotype features.

METHODS

Among 313 screened inpatients, we retrospectively recruited 133 moderate-to-severe depressive patients who were assessed for hsCRP levels, chronotype with Morningness-Eveningness Questionnaire (MEQ) and affective temperament with Temperament Evaluation of Memphis, Pisa, Paris and San Diego (TEMPS).

LIMITATIONS

The cross-sectional and retrospective design of the study, the small sample size, the exclusion of hypomanic, maniac and euthymic bipolar patients.

RESULTS

hsCRP levels were significantly higher among those with previous suicide attempt (p = 0.05), death (p = 0.018) and self-harm/self-injury thoughts (p = 0.011). Linear regression analyses, adjusted for all covariates, demonstrated that higher scores at the TEMPS-M depressive, while lower scores at the hyperthymic and irritable affective temperaments [F = 88.955, R² = 0.710, p < 0.001] and lower MEQ scores [F = 75.456, R² = 0.405, p < 0.001] statistically significantly predicted higher hsCRP.

CONCLUSION

Eveningness chronotype and a depressive affective temperament appeared to be associated with higher hsCRP levels during moderate-to-severe unipolar and bipolar depression. Further longitudinal and larger studies should better characterise patients with mood disorders by investigating the influence of chronotype and temperament.

Two-year impact of COVID-19 pandemic on hospitalized patients with skin diseases in China

To investigate the clinical characteristics of skin disorders among hospitalized patients before and during the coronavirus disease 2019 (COVID-19) pandemic, a retrospective study was conducted based on hospitalized patients with skin diseases from Xiangya Hospital of Central South University, the largest hospital in the south-central region of China, between January 1, 2018, and December 31, 2021. A total of 3039 hospitalized patients were enrolled in the study, including 1681 patients in the prepandemic group and 1358 patients in the pandemic group. The total number of hospitalized patients in the pandemic group decreased by 19.2%, with an increased proportion of patients over 60 years of age (39.8% vs. 35.8%). Moreover, compared with the prepandemic group, there were decreases in the occurrence of most skin diseases in the pandemic group, but the proportions of keratinolytic carcinoma (6.6% vs. 5.2%), dermatitis (24.0% vs. 18.9%), and psoriasis (18.0% vs. 14.8%) were higher in the pandemic group. In addition, longer hospital stays (β = 0.07, SE = 0.02, P = 1.35 × 10^-3 ) and higher hospital costs (β = 0.06, SE = 0.03, p = 0.031) were found in the pandemic group through general linear models, even after the corresponding adjustment. In summary, the COVID-19 pandemic has had a lasting impact on patients with skin diseases, with fewer hospitalized patients, increased proportions of older patients, longer hospital stays, and increased hospital costs. These findings will facilitate better preparation for the most effective response to future pandemics.

Single Prolonged Stress Decreases the Level of Adult Hippocampal Neurogenesis in C57BL/6, but Not in House Mice

Many people experience traumatic events during their lives, but not all of them develop severe mental pathologies, characterized by high levels of anxiety that persists for more than a month after psychological trauma, such as posttraumatic stress disorder (PTSD). We used a single prolonged stress protocol in order to model PTSD in long-inbred C57BL/6 and wild-derived (house) female mice. The susceptibility of mice to single prolonged stress was assessed by behavior phenotyping in the Open Field and Elevated Plus Maze, the level of neuroinflammation in the hippocampus was estimated by real-time PCR to TNFα, IL-1β, IL-6, IL-10, Iba1 and GFAP, as well as immunohistochemical analysis of microglial morphology and mean fluorescence intensity for GFAP+ cells. The level of neurogenesis was analyzed by real-time PCR to Ki67, Sox2 and DCX as well as immunohistochemistry to Ki67. We showed that long-inbread C57BL/6 mice are more susceptible to a single prolonged stress protocol compared to wild-derived (house) mice. Stressed C57BL/6 mice demonstrated elevated expression levels of proinflammatory cytokines TNFα, IL-1β, and IL-6 in the hippocampus, while in house mice no differences in cytokine expression were detected. Expression levels of Iba1 in the hippocampus did not change significantly after single prolonged stress, however GFAP expression increased substantially in stressed C57BL/6 mice. The number of Iba+ cells in the dentate gyrus also did not change after stress, but the morphology of Iba+ microglia in C57BL/6 animals allowed us to suggest that it was activated; house mice also had significantly more microglia than C57BL/6 animals. We suppose that decreased microglia levels in the hippocampus of C57BL/6 compared to house mice might be one of the reasons for their sensitivity to a single prolonged stress. Single prolonged stress reduced the number of Ki67+ proliferating cells in the dentate gyrus of the hippocampus but only in C57BL/6 mice, not in house mice, with the majority of cells detected in the dorsal (septal) hippocampus in both. The increase in the expression level of DCX might be a compensatory reaction to stress; however, it does not necessarily mean that these immature neurons will be functionally integrated, and this issue needs to be investigated further.

C-Reactive Protein (CRP): A Potent Inflammation Biomarker in Psychiatric Disorders

An increasing number of studies have investigated the role of inflammation in psychiatric disorders, by demonstrating how an altered/dysfunctional immunological and inflammatory system may underpin a psychiatric condition. Particularly, several studies specifically investigated the role of a neuroinflammatory biomarker, named C-reactive protein (CRP), in psychiatric disorders. Overall, even though scientific literature so far published still does not appear definitive, CRP is more likely reported to be elevated in several psychiatric disorders, including schizophrenia, mood disorders, anxiety disorders and post-traumatic stress disorder. Moreover, a low-grade inflammation (CRP >3 mg/L) has been more likely observed in a subgroup of patients affected with a more severe psychopathological symptomatology, more treatment resistance and worst clinical mental illness course, strengthening the hypothesis of the need for a different clinical and prognostic characterization based on this concomitant neuroinflammatory predisposition. However, even though further research studies are needed to confirm this preliminary evidence, CRP may represent a potential clinical routine biomarker which could be integrated in the clinical routine practice to better characterize clinical picture and course as well as address clinicians towards a personalized treatment.

Early Life Stress, Neuroinflammation, and Psychiatric Illness of Adulthood

Stress exposure during early stages of life elevates the risk of developing psychopathologies and psychiatric illness in later life. The brain and immune system are not completely developed by birth and therefore continue develop after birth; this post birth development is influenced by several psychosocial factors; hence, early life stress (ELS) exposure can alter brain structural development and function. A growing number of experimental animal and observational human studies have investigated the link between ELS exposure and increased risk of psychopathology through alternations in the immune system, by evaluating inflammation biomarkers. Recent studies, including brain imaging, have also shed light on the mechanisms by which both the innate and adaptive immune systems interact with neural circuits and neurotransmitters, which affect psychopathology. Herein, we discuss the link between the experience of stress in early life and lifelong alterations in the immune system, which subsequently lead to the development of various psychiatric illnesses.

Efficacy and underlying mechanisms of acupuncture therapy for PTSD: evidence from animal and clinical studies

As a major public health problem, posttraumatic stress disorder (PTSD) has a substantial impact on individuals and society. The total excess economic burden of PTSD in the US is estimated to be more than $232.2 billion a year. Acupuncture is widely used in patients with PTSD, and an increasing number of studies have been undertaken to assess the efficacy and underlying mechanisms of acupuncture for the treatment of individuals with PTSD. However, there has not yet been a review that simultaneously elucidates the therapeutic efficacy and biological mechanisms of acupuncture. We wished to examine the efficacy and underlying mechanisms of acupuncture for the treatment of individuals with PTSD. We conducted this review in three sections as follows: a meta-analysis, an acupoint analysis, and mechanism research. PubMed, Web of Science, Embase, Cochrane Library, China National Knowledge Infrastructure Database (CNKI), WanFang Database, China Biology Medicine Database (CBM), Chinese Science and Technology Journals Database (VIP), and other databases were searched from 1 January 2012 to 27 November 2022. Based on the included studies, we first determined whether acupuncture is more effective than psychological treatment or pharmacological treatment for treating and improving the quality of life of individuals with PTSD by meta-analysis. Second, the most commonly used acupoints and parameters of acupuncture were summarized based on animal and clinical studies. Third, we attempt to summarize the current mechanisms of acupuncture in the treatment of PTSD. Finally, 56 acupoint analyses, eight meta-analyses, and 33 mechanistic studies were included. Acupuncture outperformed pharmacotherapy treatment in improving symptom scores by CAPS, HAMA, HAMD, PCL-C, and SCL-90 somatization for PTSD and outperformed psychotherapy treatment in improving symptom scores by CAPS PCL-C and HAMD, according to the meta-analysis. GV20 was the most frequently used acupuncture point in clinical studies and animal studies, with a 78.6% application rate. Acupuncture may be effective in treating PTSD by regulating the structure and components of several brain areas, regulating the neuroendocrine system, and involving signaling pathways. In conclusion, this finding indicates that acupuncture has promising potential for treating PTSD.

PTSD, Immune System, and Inflammation

Posttraumatic stress disorder (PTSD) is a severe trauma and stress-related disorder associated with different somatic comorbidities, especially cardiovascular and metabolic disorders, and with chronic low-grade inflammation. Altered balance of the hypothalamic-pituitary-adrenal (HPA) axis, cytokines and chemokines, C-reactive protein, oxidative stress markers, kynurenine pathways, and gut microbiota might be involved in the alterations of certain brain regions regulating fear conditioning and memory processes, that are all altered in PTSD. In addition to the HPA axis, the gut microbiota maintains the balance and interaction of the immune, CNS, and endocrine pathways forming the gut-brain axis. Disbalance in the HPA axis, gut-brain axis, oxidative stress pathways and kynurenine pathways, altered immune signaling and disrupted homeostasis, as well as the association of the PTSD with the inflammation and disrupted cognition support the search for novel strategies for treatment of PTSD. Besides potential anti-inflammatory treatment, dietary interventions or the use of beneficial bacteria, such as probiotics, can potentially improve the composition and the function of the bacterial community in the gut. Therefore, bacterial supplements and controlled dietary changes, with exercise, might have beneficial effects on the psychological and cognitive functions in patients with PTSD. These new treatments should be aimed to attenuate inflammatory processes and consequently to reduce PTSD symptoms but also to improve cognition and reduce cardio-metabolic disorders associated so frequently with PTSD.

Association of day-of-injury plasma glial fibrillary acidic protein concentration and six-month posttraumatic stress disorder in patients with mild traumatic brain injury

Several proteins have proven useful as blood-based biomarkers to assist in evaluation and management of traumatic brain injury (TBI). The objective of this study was to determine whether two day-of-injury blood-based biomarkers are predictive of posttraumatic stress disorder (PTSD). We used data from 1143 individuals with mild TBI (mTBI; defined as admission Glasgow Coma Scale [GCS] score 13-15) enrolled in TRACK-TBI, a prospective longitudinal study of level 1 trauma center patients. Plasma glial fibrillary acidic protein (GFAP) and serum high sensitivity C-reactive protein (hsCRP) were measured from blood collected within 24 h of injury. Two hundred and twenty-seven (19.9% of) patients had probable PTSD (PCL-5 score ≥ 33) at 6 months post-injury. GFAP levels were positively associated (Spearman's rho = 0.35, p < 0.001) with duration of posttraumatic amnesia (PTA). There was an inverse association between PTSD and (log)GFAP (adjusted OR = 0.85, 95% CI 0.77-0.95 per log unit increase) levels, but no significant association with (log)hsCRP (adjusted OR = 1.11, 95% CI 0.98-1.25 per log unit increase) levels. Elevated day-of-injury plasma GFAP, a biomarker of glial reactivity, is associated with reduced risk of PTSD after mTBI. This finding merits replication and additional studies to determine a possible neurocognitive basis for this relationship.

The Influence of HLA Alleles on the Affective Distress Profile

(1) Background: Affective distress can be triggered by aggressive stimuli with an unfavorable role for the individual. Some of the factors that lead to the development and evolution of a mental disorder can be genetic. The aim of this study is to determine some correlations between the human leukocyte antigen (HLA) genes and the affective distress profile (PDA). (2) Methods: A psychological assessment and testing tool for anxiety was applied to 115 people. The low-resolution HLA alleles of class I (HLA-A, HLA-B, and HLA-C) and class II (HLA-DRB1 and HLA-DQB1) were identified by the PCR technique after DNA extraction from the blood. Depending on the PDA, the subjects were divided into two groups: a group with a low PDA and another one with a medium and high PDA. The IBM SPSS software was used to compare the frequency of HLA alleles between the two groups. (3) Results: The univariate analysis revealed a significant association of the HLA-A locus (A*01, A*30), HLA-B (B*08), and HLA-DRB1 (DRB1*11) with the low PDA group and of the HLA-A locus (A*32), HLA-B (B*52), and HLA-C (C*12) with the medium and high PDA group. (4) Conclusions: The present study highlighted potential associations between HLA alleles and anxiety disorders.

Inflammation, amygdala-ventromedial prefrontal functional connectivity and symptoms of anxiety and PTSD in African American women recruited from an inner-city hospital: Preliminary results

Inflammatory stimuli have been shown to impact brain regions involved in threat detection and emotional processing including amygdala and ventromedial prefrontal cortex (vmPFC), and to increase anxiety. Biomarkers of endogenous inflammation, including inflammatory cytokines and C-reactive protein (CRP), are reliably elevated in a subset of patients with depression and anxiety-related disorders such as post-traumatic stress disorder (PTSD), and have been associated with high anxiety in population studies. We previously reported that plasma CRP and cytokines in patients with depression were negatively correlated with resting-state functional connectivity (FC) between right amygdala and vmPFC, as assessed using both ROI to voxel-wise and targeted FC approaches, in association with symptoms of anxiety, particularly in patients with comorbid anxiety disorders or PTSD. To determine whether relationships between inflammation, right amygdala-vmPFC FC, and anxiety are reproducible across patient samples and research settings, we employed an a priori, hypothesis-driven approach to examine relationships between inflammation, targeted right amygdala-vmPFC FC and anxiety in a cohort of African American (AA) women (n = 54) recruited from an inner-city hospital population reliably found to have higher levels of inflammation (median CRP ∼ 4 mg/L) as well as symptoms of anxiety, depression and PTSD. Higher concentrations of plasma CRP were associated with lower right amygdala-vmPFC FC (r = -0.32, p = 0.017), and this relationship remained significant when controlling for age, body mass index and number of lifetime trauma events experienced, as well as severity of PTSD and depression symptoms (all p < 0.05). This amygdala-vmPFC FC was similarly associated with a composite score of three inflammatory cytokines in a subset of women where plasma was available for analysis (n = 33, r = -0.33, p = 0.058; adjusted r = -0.43, p = 0.026 when controlling for covariates including PTSD and depression symptom severity). Lower right amygdala-vmPFC FC was in turn associated with higher levels of anxiety reported to be generally experienced on the State-Trait Anxiety Inventory, trait component (adjusted r = -0.32, p = 0.039 when controlling for covariates). Exploratory analyses also revealed a negative correlation between severity of childhood maltreatment and right amygdala-vmPFC FC (r = -0.32, p = 0.018) that was independent of CRP and its association with FC, as well as an association between low amygdala-vmPFC FC and severity of PTSD symptoms, specifically the re-experiencing/intrusive symptom subscale (adjusted r = -0.32, p = 0.028 when controlling for covariates). While CRP was not linearly associated with either anxiety or PTSD symptoms, CRP concentrations were higher in women reporting clinically significant anxiety or PTSD symptom severity when these symptoms were considered together (both p < 0.05), but with no interaction. These results support our primary hypothesis that higher inflammation was associated with lower amygdala-vmPFC FC, a relationship that was detected using a hypothesis-driven, targeted approach. Findings also support that this phenotype of high CRP and low vmPFC FC was observed in association with anxiety in primary analyses, as well as symptoms of PTSD in exploratory analyses, in a cohort recruited from an inner-city population of AA women enriched for high inflammation, history of trauma exposure, and symptom severity. Larger, longitudinal samples are required to fully tease apart causal relationships between inflammatory biomarkers, FC and PTSD-related symptoms in future studies.

Involvement of the brain-heart axis in the link between PTSD and cardiovascular disease

Posttraumatic stress disorder (PTSD) has long been associated with a heightened risk of cardiovascular disease (CVD). A number of mechanisms have been implicated to underlie this brain-heart axis relationship, such as altered functioning of the autonomic nervous system and increased systemic inflammation. While neural alterations have repeatedly been observed in PTSD, they are rarely considered in the PTSD-CVD link. The brain-heart axis is a pathway connecting frontal and limbic brain regions to the brainstem and periphery via the autonomic nervous system and it may be a promising model for understanding CVD risk in PTSD given its overlap with PTSD neural deficits. We first provide a summary of the primary mechanisms implicated in the association between PTSD and CVD. We then review the brain-heart axis and its relevance to PTSD, as well as findings from PTSD trials demonstrating that a number of PTSD treatments have effects on areas of the brain-heart axis. Finally, we discuss sex considerations in the PTSD-CVD link. A critical next step in this study is to determine if PTSD treatments that affect the brain-heart axis (e.g., brain stimulation that improves autonomic function) also reduce the risk of CVD.

The role of the immune system in posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) develops in a subset of individuals upon exposure to traumatic stress. In addition to well-defined psychological and behavioral symptoms, some individuals with PTSD also exhibit elevated concentrations of inflammatory markers, including C-reactive protein, interleukin-6, and tumor necrosis factor-α. Moreover, PTSD is often co-morbid with immune-related conditions, such as cardiometabolic and autoimmune disorders. Numerous factors, including lifetime trauma burden, biological sex, genetic background, metabolic conditions, and gut microbiota, may contribute to inflammation in PTSD. Importantly, inflammation can influence neural circuits and neurotransmitter signaling in regions of the brain relevant to fear, anxiety, and emotion regulation. Given the link between PTSD and the immune system, current studies are underway to evaluate the efficacy of anti-inflammatory treatments in those with PTSD. Understanding the complex interactions between PTSD and the immune system is essential for future discovery of diagnostic and therapeutic tools.

Posttraumatic Stress Disorder Mediates the Association between Traumatic World Trade Center Dust Cloud Exposure and Ongoing Systemic Inflammation in Community Members

Exposure to World Trade Center (WTC) dust/fumes and traumas on 11 September 2001 has been reported as a risk factor for post-traumatic stress disorder (PTSD) and other mental/physical health symptoms in WTC-affected populations. Increased systemic inflammation and oxidative stress from the exposure and subsequent illnesses have been proposed as contributors to the underlying biological processes. Many blood-based biomarkers of systemic inflammation, including C-reactive protein (CRP), are useful for non-invasive diagnostic and monitoring of disease process, and also potential targets for therapeutic interventions. Twenty years after 9/11, however, the relationships between WTC exposure, chronic PTSD, and systemic inflammation are only beginning to be systematically investigated in the WTC-affected civilian population despite the fact that symptoms of PTSD and systemic inflammation are still common and persistent. This paper aims to address this knowledge gap, using enrollees of the WTC Environmental Health Center (EHC), a federally designated treatment and surveillance program for community members (WTC Survivors) exposed to the 9/11 terrorist attack. We conducted a mediation analysis to investigate the association between acute WTC dust cloud traumatic exposure (WDCTE) on 9/11, chronic PTSD symptoms, and levels of systemic inflammation. The data indicate that the chronic PTSD symptoms and some specific symptom clusters of PTSD significantly mediate the WDCTE on systemic inflammation, as reflected by the CRP levels. As both chronic PTSD and systemic inflammation are long-term risk factors for neurodegeneration and cognitive decline, further research on the implications of this finding is warranted.

Involvement of Nuclear Factor-κB in Inflammation and Neuronal Plasticity Associated with Post-Traumatic Stress Disorder

Post-traumatic stress disorder (PTSD) is a debilitating psychiatric condition which develops either due to stress or witnessing a traumatic situation. PTSD is characterized by acute and chronic stress response exhibit anxiety, fear, and an increased inflammatory etiology. Inflammation contributes a critical role in several parts of the brain that control fear and flashback cognatic function. It is known that impairment of the neurological circuit leads to the development of PTSD. Evidence has suggested that dysregulation of the sympathetic nervous system and hypothalamic-pituitary adrenal (HPA) axis and inflammatory responsiveness are pivotal and a greater risk in PTSD. NF-κB, a master regulator for inflammation, has been showed to modulate memory reconsolidation and synaptic plasticity; however, NF-κB’s association with PTSD remain elusive. In this review, we provide relevant findings regarding NF-κB activity in various components of brain and describe a potential mechanism linking PTSD using preclinical and clinical models. We envisage NF-κB signaling as a crucial mediator for inflammation, cognitive function, memory restoration and behavioral actions of stress and suggest that it could be used for therapeutic intervention in PTSD.

Genetic and Epigenetic Association of Hepatocyte Nuclear Factor-1α with Glycosylation in Post-Traumatic Stress Disorder

Post-traumatic stress disorder (PTSD) is a complex trauma-related disorder, the etiology and underlying molecular mechanisms of which are still unclear and probably involve different (epi)genetic and environmental factors. Protein N-glycosylation is a common post-translational modification that has been associated with several pathophysiological states, including inflammation and PTSD. Hepatocyte nuclear factor-1α (HNF1A) is a transcriptional regulator of many genes involved in the inflammatory processes, and it has been identified as master regulator of plasma protein glycosylation. The aim of this study was to determine the association between N-glycan levels in plasma and immunoglobulin G, methylation at four CpG positions in the HNF1A gene, HNF1A antisense RNA 1 (HNF1A-AS1), rs7953249 and HNF1A rs735396 polymorphisms in a total of 555 PTSD and control subjects. We found significant association of rs7953249 and rs735396 polymorphisms, as well as HNF1A gene methylation at the CpG3 site, with highly branched, galactosylated and sialyated plasma N-glycans, mostly in patients with PTSD. HNF1A-AS1 rs7953249 polymorphism was also associated with PTSD; however, none of the polymorphisms were associated with HNF1A gene methylation. These results indicate a possible regulatory role of the investigated HNF1A polymorphisms with respect to the abundance of complex plasma N-glycans previously associated with proinflammatory response, which could contribute to the clinical manifestation of PTSD and its comorbidities.

Central and Peripheral Immune Dysregulation in Posttraumatic Stress Disorder: Convergent Multi-Omics Evidence

Posttraumatic stress disorder (PTSD) is a chronic and multifactorial disorder with a prevalence ranging between 6–10% in the general population and ~35% in individuals with high lifetime trauma exposure. Growing evidence indicates that the immune system may contribute to the etiology of PTSD, suggesting the inflammatory dysregulation as a hallmark feature of PTSD. However, the potential interplay between the central and peripheral immune system, as well as the biological mechanisms underlying this dysregulation remain poorly understood. The activation of the HPA axis after trauma exposure and the subsequent activation of the inflammatory system mediated by glucocorticoids is the most common mechanism that orchestrates an exacerbated immunological response in PTSD. Recent high-throughput analyses in peripheral and brain tissue from both humans with and animal models of PTSD have found that changes in gene regulation via epigenetic alterations may participate in the impaired inflammatory signaling in PTSD. The goal of this review is to assess the role of the inflammatory system in PTSD across tissue and species, with a particular focus on the genomics, transcriptomics, epigenomics, and proteomics domains. We conducted an integrative multi-omics approach identifying TNF (Tumor Necrosis Factor) signaling, interleukins, chemokines, Toll-like receptors and glucocorticoids among the common dysregulated pathways in both central and peripheral immune systems in PTSD and propose potential novel drug targets for PTSD treatment.

Post-traumatic stress disorder: clinical and translational neuroscience from cells to circuits

Post-traumatic stress disorder (PTSD) is a maladaptive and debilitating psychiatric disorder, characterized by re-experiencing, avoidance, negative emotions and thoughts, and hyperarousal in the months and years following exposure to severe trauma. PTSD has a prevalence of approximately 6-8% in the general population, although this can increase to 25% among groups who have experienced severe psychological trauma, such as combat veterans, refugees and victims of assault. The risk of developing PTSD in the aftermath of severe trauma is determined by multiple factors, including genetics - at least 30-40% of the risk of PTSD is heritable - and past history, for example, prior adult and childhood trauma. Many of the primary symptoms of PTSD, including hyperarousal and sleep dysregulation, are increasingly understood through translational neuroscience. In addition, a large amount of evidence suggests that PTSD can be viewed, at least in part, as a disorder that involves dysregulation of normal fear processes. The neural circuitry underlying fear and threat-related behaviour and learning in mammals, including the amygdala-hippocampus-medial prefrontal cortex circuit, is among the most well-understood in behavioural neuroscience. Furthermore, the study of threat-responding and its underlying circuitry has led to rapid progress in understanding learning and memory processes. By combining molecular-genetic approaches with a translational, mechanistic knowledge of fear circuitry, transformational advances in the conceptual framework, diagnosis and treatment of PTSD are possible. In this Review, we describe the clinical features and current treatments for PTSD, examine the neurobiology of symptom domains, highlight genomic advances and discuss translational approaches to understanding mechanisms and identifying new treatments and interventions for this devastating syndrome.

C-Reactive Protein: Marker of risk for post-traumatic stress disorder and its potential for a mechanistic role in trauma response and recovery

Increasing evidence indicates that inflammation plays a role in PTSD and stress disorder pathophysiology. PTSD is consistently associated with higher circulating inflammatory protein levels. Rodent models demonstrate that inflammation promotes enduring avoidance and arousal behaviors after severe stressors (e.g., predator exposure and social defeat), suggesting that inflammation may play a mechanistic role in trauma disorders. C-reactive protein (CRP) is an innate acute phase reactant produced by the liver after acute infection and chronic disease. A growing number of investigations report associations with PTSD diagnosis and elevated peripheral CRP, CRP gene mutations, and CRP gene expression changes in immune signaling pathways. CRP is reasonably established as a potential marker of PTSD and trauma exposure, but if and how it may play a mechanistic role is unclear. In this review, we discuss the current understanding of immune mechanisms in PTSD with a particular focus on the innate immune signaling factor, CRP. We found that although there is consistent evidence of an association of CRP with PTSD symptoms and risk, there is a paucity of data on how CRP might contribute to CNS inflammation in PTSD, and consequently, PTSD symptoms. We discuss potential mechanisms through which CRP could modulate enduring peripheral and CNS stress responses, along with future areas of investigation probing the role of CRP and other innate immune signaling factors in modulating trauma responses. Overall, we found that CRP likely contributes to central inflammation, but how it does so is an area for further study.

C-reactive protein as a potential biomarker in psychiatric practice: Are we there yet?

OBJECTIVES

Serum or plasma levels of C-reactive protein (CRP) and high-sensitivity CRP (hsCRP) are widely used clinical markers of inflammation in other branches of medicine, whereas its clinical use in psychiatry has been limited to research studies. We aimed to assess the possibility of using CRP/hsCRP in psychiatric practice. This is a review and evaluation of various lines of evidence supporting the concept of CRP as a biomarker for psychiatric disorders in certain conditions.

METHODS

We searched the literature for studies which assessed CRP/hsCRP levels in various psychiatric disorders.

RESULTS

The accumulating evidence from large studies and meta-analyses allows us to understand the role of CRP in major psychiatric disorders and increase our understanding of specific symptoms and subtypes of disorders. CRP may be considered a 'psychiatric biomarker' which can alert clinicians about neuroinflammation, adverse effects of medications, cardiometabolic status, co-morbidities, and may also predict clinical outcomes and guide optimal treatment.selection.

CONCLUSION

Although the underlying pathophysiological role of CRP and hsCRP is still elusive and the association between CRP and psychiatric disorders is inconsistent, CRP holds promise to become a psychiatric biomarker.

The relations between C-reactive protein and trauma exposure, PTSD and depression symptoms, and PTSD psychotherapy treatment response in treatment seeking veterans and service members

While inflammatory markers have been implicated in the link between PTSD and poor health outcomes, there is a paucity of research investigating C-reactive protein (CRP) and psychotherapy treatment response for posttraumatic stress disorder (PTSD). The present study utilized a large, well-characterized sample of veterans and service members (N = 493) engaged in intensive psychotherapy to investigate the associations between CRP, trauma exposure, related variables, and PTSD and depression, as well as investigating if CRP was associated with PTSD psychotherapy treatment response. Bivariate correlation results indicate that CRP was significantly associated with BMI (r = 0.48) and severity of experiences of childhood physical and sexual abuse (r = 0.14 and 0.15, respectively) and was not significantly associated with baseline PTSD total symptom severity, PTSD symptom clusters, or depression symptom severity (rs ranging from -0.03 to 0.04). In multivariate regression models investigating if CRP and related variables were associated with PTSD baseline symptom severity, CRP was not a significant predictor (β = -0.03). Hierarchical linear modeling did not identify CRP as a significant predictor of PTSD psychotherapy outcome. Given that findings indicate that CRP was broadly elevated in this treatment seeking sample but not associated with PTSD and depression symptom severity, results suggest CRP may not be a specific biomarker for PTSD or depression but may be elevated in psychiatric disease more generally.

Neuroprotective Effect of Acupuncture against Single Prolonged Stress-Induced Memory Impairments and Inflammation in Rat Brain via Modulation of Brain-Derived Neurotrophic Factor Expression

Posttraumatic stress disorder (PTSD) is a serious mental disorder that can appear after exposure to extreme stress. Acupuncture is an alternative therapy that is widely used to treat various neurodegenerative diseases, as well as cognitive and memory impairments. The aim of this study was to examine whether acupuncture stimulation at a specific acupoint (Shenmen or heart meridian, HT7) could improve memory defects caused by single prolonged stress (SPS) in rats. After exposure to SPS, acupuncture on the HT7 acupoint in male rats was performed, once daily for 21 days. We confirmed that this treatment improved fear memory, cognitive function, and spatial memory by modulating the neuroinflammation and expression of brain-derived neurotrophic factor (BDNF) mRNA in the brain. It also significantly inhibited the activation of proinflammatory cytokines, such as tumor necrosis factor-α and interleukin-1β and the enzyme cyclooxygenase-2 in the brain; it increased the expression of BDNF mRNA in the hippocampus. Our findings provide valuable information concerning the clinical usefulness of acupuncture in the treatment of PTSD.

Developmental Timing of Trauma in Women Predicts Unique Extracellular Vesicle Proteome Signatures

BACKGROUND

Exposure to traumatic events is a risk factor for negative physical and mental health outcomes. However, the underlying biological mechanisms that perpetuate these lasting effects are not known.

METHODS

We investigated the impact and timing of sexual trauma, a specific type of interpersonal violence, experienced during key developmental windows of childhood, adolescence, or adulthood on adult health outcomes and associated biomarkers, including circulating cell-free mitochondrial DNA levels and extracellular vesicles (EVs), in a predominantly Black cohort of women (N = 101).

RESULTS

Significant changes in both biomarkers examined, circulating cell-free mitochondrial DNA levels and EV proteome, were specific to developmental timing of sexual trauma. Specifically, we identified a large number of keratin-related proteins from EVs unique to the adolescent sexual trauma group. Remarkably, the majority of these keratin proteins belong to a 17q21 gene cluster, which suggests a potential local epigenetic regulatory mechanism altered by adolescent trauma to impact keratinocyte EV secretion or its protein cargo. These results, along with changes in fear-potentiated startle and skin conductance detected in these women, suggest that sexual violence experienced during the specific developmental window of adolescence may involve unique programming of the skin, the body's largest stress organ.

CONCLUSIONS

Together, these descriptive studies provide novel insight into distinct biological processes altered by trauma experienced during specific developmental windows. Future studies will be required to mechanistically link these biological processes to health outcomes.

Brick by Brick: Building a Transdiagnostic Understanding of Inflammation in Psychiatry

ABSTRACT

Inflammatory phenomena are found in many psychiatric disorders-notably, depression, schizophrenia, and posttraumatic stress disorder. Inflammation has been linked to severity and treatment resistance, and may both contribute to, and result from, the pathophysiology of some psychiatric illnesses. Emerging research suggests that inflammation may contribute to symptom domains of reward, motor processing, and threat reactivity across different psychiatric diagnoses. Reward-processing deficits contribute to motivational impairments in depression and schizophrenia, and motor-processing deficits contribute to psychomotor slowing in both depression and schizophrenia. A number of experimental models and clinical trials suggest that inflammation produces deficits in reward and motor processing through common pathways connecting the cortex and the striatum, which includes the nucleus accumbens, caudate nucleus, and putamen.The observed effects of inflammation on psychiatric disorders may cut across traditional conceptualizations of psychiatric diagnoses. Further study may lead to targeted immunomodulating treatments that address difficult-to-treat symptoms in a number of psychiatric disorders. In this review, we use a Research Domain Criteria framework to discuss proposed mechanisms for inflammation and its effects on the domains of reward processing, psychomotor slowing, and threat reactivity. We also discuss data that support contributing roles of metabolic dysregulation and sex differences on the behavioral outcomes of inflammation. Finally, we discuss ways that future studies can help disentangle this complex topic to yield fruitful results that will help advance the field of psychoneuroimmunology.

Inflammation as a Pathophysiologic Pathway to Anhedonia: Mechanisms and Therapeutic Implications

Anhedonia, characterized by a lack of motivation, interest, or ability to experience pleasure, is a prominent symptom of depression and other psychiatric disorders and has been associated with poor response to standard therapies. One pathophysiologic pathway receiving increased attention for its potential role in anhedonia is inflammation and its effects on the brain. Exogenous administration of inflammatory stimuli to humans and laboratory animals has reliably been found to affect neurotransmitters and neurocircuits involved in reward processing, including the ventral striatum and ventromedial prefrontal cortex, in association with reduced motivation. Moreover, a rich literature including meta-analyses describes increased inflammation in a significant proportion of patients with depression and other psychiatric illnesses involving anhedonia, as evident by elevated inflammatory cytokines, acute phase proteins, chemokines, and adhesion molecules in both the periphery and central nervous system. This endogenous inflammation may arise from numerous sources including stress, obesity or metabolic dysfunction, genetics, and lifestyle factors, many of which are also risk factors for psychiatric illness. Consistent with laboratory studies involving exogenous administration of peripheral inflammatory stimuli, neuroimaging studies have further confirmed that increased endogenous inflammation in depression is associated with decreased activation of and reduced functional connectivity within reward circuits involving ventral striatum and ventromedial prefrontal cortex in association with anhedonia. Here, we review recent evidence of relationships between inflammation and anhedonia, while highlighting translational and mechanistic work describing the impact of inflammation on synthesis, release, and reuptake of neurotransmitters like dopamine and glutamate that affects circuits to drive motivational deficits. We will then present insight into novel pharmacological strategies that target either inflammation or its downstream effects on the brain and behavior. The meaningful translation of these concepts through appropriately designed trials targeting therapies for psychiatric patients with high inflammation and transdiagnostic symptoms of anhedonia is also discussed.

Association of serum interleukin-6 and C-reactive protein with depressive and adjustment disorders in COVID-19 inpatients

Background

Immune mechanisms are part of the pathophysiology of mental disorders, although their role remains controversial. In depressive disorders a chronic low-grade inflammatory process is observed, with higher interleukin-6 (IL-6) values. Furthermore, in SARS-CoV2 infection, which is closely related to depressive disorders, there is a proinflammatory cascade of cytokines that causes systemic inflammation.

Methods

The present study evaluates the relationship between IL-6 and C-reactive protein (CRP) serum levels and the presence of depressive and adjustment disorders in a sample of 1851 patients admitted to hospital for SARS-CoV2 infection from March to November 2020. Concentrations of IL-6 and CRP were determined within the first 72 ​h at admission and compared among groups of patients according to previous history and current presence of depression or adjustment disorders.

Results

IL-6 serum levels were significantly higher in the group of patients with depression and adjustment disorders compared to patients without such disorders (114.25 ​pg/mL (SD, 225.44) vs. 86.41 (SD, 202.97)), even after adjusting for several confounders. Similar results were obtained for CRP (103.94 ​mg/L (SD, 91.16) vs. 90.14 (SD, 85.73)). The absolute levels of IL-6 and CRP were higher than those of previous depression studies, and differences were only found for the subgroup of De Novo depressive or adjustment disorders.

Conclusions

Serum concentrations of IL-6 and CRP are higher in COVID-19 patients with De Novo but not persistent depressive or adjustment disorders. Clinical features such as fatigue, asthenia, anhedonia, or anxiety can be the basis for this finding.

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Inflammation markers are higher in COVID inpatients with affective symptoms and no previous psychiatric history.

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Sickness behavior overlaps with stress-related disorders symptomatology.

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Cytokine levels equalize in non-depressed and chronically depressed COVID inpatients.

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COVID inpatients with affective symptoms may show a worse prognosis.

Rethinking stress resilience

Resilience to stressful life events has received considerable attention in both clinical and preclinical studies. A number of neural substrates have been identified as putatively mediating resilience to stress. However, there remains considerable diversity in how resilience is defined and studied. This article aims to examine how resilience is defined and conceptualized in social psychology, public health, and related fields, to better inform the understanding of stress resilience in the neurobiological context, and to differentiate resilience from other patterns of response to stressful experiences. An understanding of resilience through the lens of clinical and applied sciences is likely to lead to the identification of more robust and reproducible neural substrates, though many challenges remain.

The emerging tale of microglia in psychiatric disorders

As the professional phagocytes of the brain, microglia orchestrate the immunological response and play an increasingly important role in maintaining homeostatic brain functions. Microglia are activated by pathological events or slight alterations in brain homeostasis. This activation is dependent on the context and type of stressor or pathology. Through secretion of cytokines, chemokines and growth factors, microglia can strongly influence the response to a stressor and can, therefore, determine the pathological outcome. Psychopathologies have repeatedly been associated with long-lasting priming and sensitization of cerebral microglia. This review focuses on the diversity of microglial phenotype and function in health and psychiatric disease. We first discuss the diverse homeostatic functions performed by microglia and then elaborate on context-specific spatial and temporal microglial heterogeneity. Subsequently, we summarize microglia involvement in psychopathologies, namely major depressive disorder, schizophrenia and bipolar disorder, with a particular focus on post-mortem studies. Finally, we postulate microglia as a promising novel therapeutic target in psychiatry through antidepressant and antipsychotic treatment.

C-Reactive Protein +1444C/T Polymorphism Is Associated with the Susceptibility to Pulmonary Tuberculosis

Objective

The T allele of C-reactive protein (CRP) +1444C/T (rs1130864) polymorphism was associated with increased risk for some inflammatory conditions. The objective of the study was to explore the association between the CRP +1444C/T polymorphism with the susceptibility to pulmonary tuberculosis (PTB) in a Chinese population.

Methods

This case-control study enrolled 480 PTB patients and 480 healthy controls. The CRP +1444C/T polymorphism was determined using Sanger sequencing. The odds ratio (OR) and 95% confidence interval (CI) were assessed to examine the strength of genetic correlation.

Results

The genotype and allele frequencies of PTB patients differed from controls (CT vs. CC, OR = 1.924, 95% CI: 1.099-3.371, adjusted P value = 0.022; T vs. C, OR = 1.884, 95% CI: 1.085-3.273, adjusted P value = 0.024). Stratified analysis by sex found that PTB patients' genotype and allele frequencies differed from controls in the male subgroup but not the female subgroup.

Conclusion

In conclusion, the minor T allele of CRP +1444C/T polymorphism was associated with increased PTB risk.

Investigation of C-reactive protein and AIM2 methylation as a marker for PTSD in Australian Vietnam veterans

Chronic inflammation is a key factor in symptomology and comorbidities of post-traumatic stress disorder (PTSD). Levels of a proinflammatory marker, C-reactive protein (CRP) are increased in individuals with PTSD but it is not clear if this is due to trauma exposure or PTSD. Our study aimed to assess the relationship between serum CRP levels, CRP SNPs, methylation, mRNA expression and PTSD in a homogenous trauma exposed Australian Vietnam veteran cohort. We hypothesized that decreased DNA methylation would be associated with increased gene expression and increased peripheral CRP levels in PTSD patients and that this would be independent of trauma. Participants were 299 Vietnam veterans who had all been exposed to trauma and approximately half were diagnosed with PTSD. We observed higher levels of serum CRP in the PTSD group compared to the non-PTSD group but after controlling for BMI and triglycerides the association did not remain significant. No association was found between CRP SNPs and PTSD or CRP levels. Absent in Melanoma 2 (AIM2) which is a mediator of inflammatory response and a determinant of CRP levels was analysed for DNA methylation and mRNA expression. We observed a trend level association between PTSD and AIM2 methylation after controlling for age, smoking, triglycerides, BMI and cell types. There was no significant interaction between PTSD and CRP levels on AIM2 methylation after controlling for covariates. We observed that as AIM2 methylation levels decreased, AIM2 mRNA expression increased. Elevated CRP levels were associated with AIM2 mRNA in the trauma exposed cohort but there was no significant interaction effect with PTSD. Our results could not confirm that CRP is a marker of PTSD independent of trauma in this group of older veterans. CRP may be a broad marker of disease risk, or a marker of PTSD in younger cohorts than those in this study.

αCaMKII in the lateral amygdala mediates PTSD-Like behaviors and NMDAR-Dependent LTD

Post-traumatic stress disorder (PTSD) is a psychiatric disorder that afflicts many individuals. However, its molecular and cellular mechanisms remain largely unexplored. Here, we found PTSD susceptible mice exhibited significant up-regulation of alpha-Ca²⁺/calmodulin-dependent kinase II (αCaMKII) in the lateral amygdala (LA). Consistently, increasing αCaMKII in the LA not only caused PTSD-like behaviors such as impaired fear extinction and anxiety-like behaviors, but also attenuated N-methyl-D-aspartate receptor (NMDAR)-dependent long-term depression (LTD) at thalamo-lateral amygdala (T-LA) synapses, and reduced GluA1-Ser845/Ser831 dephosphorylation and a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) internalization. Suppressing the elevated αCaMKII to normal levels completely rescued both PTSD-like behaviors and the impairments in LTD, GluA1-Ser845/Ser831 dephosphorylation, and AMPAR internalization. Intriguingly, deficits in GluA1-Ser845/Ser831 dephosphorylation and AMPAR internalization were detected not only after impaired fear extinction, but also after attenuated LTD. Our results suggest that αCaMKII in the LA may be a potential molecular determinant of PTSD. We further demonstrate for the first time that GluA1-Ser845/Ser831 dephosphorylation and AMPAR internalization are molecular links between fear extinction and LTD.

Immune system regulation and role of the human leukocyte antigen in posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is a debilitating condition that adversely affect mental and physical health. Recent studies have increasingly explored the role of the immune system in risk for PTSD and its related symptoms. Dysregulation of the immune system may lead to central nervous system tissue damage and impair learning and memory processes. Individuals with PTSD often have comorbid inflammatory or auto-immune disorders. Evidence shows associations between PTSD and multiple genes that are involved in immune-related or inflammatory pathways. In this review, we will summarize the evidence of immune dysregulation in PTSD, outlining the contributions of distinct cell types, genes, and biological pathways. We use the Human Leukocyte Antigen (HLA) locus to illustrate the contribution of genetic variation to function in different tissues that contribute to PTSD etiology, severity, and comorbidities.

Genetics of human startle reactivity: A systematic review to acquire targets for an anxiety endophenotype

OBJECTIVES

Startle response is an objective physiological measure integral to the human defense system and a promising target for endophenotype investigations of anxiety. Given the alterations in startle reactivity observed among anxiety and related disorders, we searched for genetic variants associated with startle reactivity as they may be further involved in pathological anxiety risk.

METHODS

A systematic literature review was performed to identify genetic variants associated with startle reactivity in humans, specifically baseline and fear- or anxiety-potentiated startle.

RESULTS

The polymorphisms Val66Met (rs6265) from brain-derived neurotrophic factor (BDNF), Val158Met (rs4680) from catechol-O-methyltransferase (COMT), and the serotonin transporter-linked polymorphic region (5-HTTLPR) from the serotonin transporter gene (SLC6A4) were most commonly studied in human startle. In addition, several other genetic variants have also been identified as potential candidates that warrant further research, especially given their novelty in in the context of anxiety.

CONCLUSIONS

Similar to psychiatric genetic studies, the studies on startle reactivity primarily focus on candidate genes and are plagued by non-replication. Startle reactivity is a promising endophenotype that requires concerted efforts to collect uniformly assessed, large, well-powered samples and hypothesis-free genome-wide strategies. To further support startle as an endophenotype for anxiety, this review suggests advanced genetic strategies for startle research.

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.

Mapping the transcriptomics landscape of post-traumatic stress disorder symptom dimensions in World Trade Center responders

Gene expression has provided promising insights into the pathophysiology of post-traumatic stress disorder (PTSD); however, specific regulatory transcriptomic mechanisms remain unknown. The present study addressed this limitation by performing transcriptome-wide RNA-Seq of whole-blood samples from 226 World Trade Center responders. The investigation focused on differential expression (DE) at the gene, isoform, and for the first time, alternative splicing (AS) levels associated with the symptoms of PTSD: total burden, re-experiencing, avoidance, numbing, and hyperarousal subdimensions. These symptoms were associated with 76, 1, 48, 15, and 49 DE genes, respectively (FDR < 0.05). Moreover, they were associated with 103, 11, 0, 43, and 32 AS events. Avoidance differed the most from other dimensions with respect to DE genes and AS events. Gene set enrichment analysis (GSEA) identified pathways involved in inflammatory and metabolic processes, which may have implications in the treatment of PTSD. Overall, the findings shed a novel light on the wide range of transcriptomic alterations associated with PTSD at the gene and AS levels. The results of DE analysis associated with PTSD subdimensions highlights the importance of studying PTSD symptom heterogeneity.

Key dimensions of post-traumatic stress disorder and endothelial dysfunction: a protocol for a mechanism-focused cohort study

INTRODUCTION

Both trauma exposure and post-traumatic stress disorder (PTSD) are associated with increased risk of cardiovascular disease (CVD), the leading cause of death in the USA. Endothelial dysfunction, a modifiable, early marker of CVD risk, may represent a physiological mechanism underlying this association. This mechanism-focused cohort study aims to investigate the relationship between PTSD (both in terms of diagnosis and underlying symptom dimensions) and endothelial dysfunction in a diverse, community-based sample of adult men and women.

METHODS AND ANALYSIS

Using a cohort design, 160 trauma-exposed participants without a history of CVD are designated to the PTSD group (n=80) or trauma-exposed matched control group (n=80) after a baseline diagnostic interview assessment. Participants in the PTSD group have a current (past month) diagnosis of PTSD, whereas those in the control group have a history of trauma but no current or past psychiatric diagnoses. Endothelial dysfunction is assessed via flow-mediated vasodilation of the brachial artery and circulating levels of endothelial cell-derived microparticles. Two higher order symptom dimensions of PTSD-fear and dysphoria-are measured objectively with a fear conditioning paradigm and attention allocation task, respectively. Autonomic imbalance, inflammation, and oxidative stress are additionally assessed and will be examined as potential pathway variables linking PTSD and its dimensions with endothelial dysfunction. Participants are invited to return for a 2-year follow-up visit to reassess PTSD and its dimensions and endothelial dysfunction in order to investigate longitudinal associations.

ETHICS AND DISSEMINATION

This study is conducted in compliance with the Helsinki Declaration and University of California, Los Angeles Institutional Review Board. The results of this study will be disseminated via articles in peer-reviewed journals and presentations at academic conferences and to community partners.

TRIAL REGISTRATION NUMBER

NCT03778307; pre-results.

Dissecting the genetic association of C-reactive protein with PTSD, traumatic events, and social support

Inflammatory markers like C-reactive protein (CRP) have been associated with post-traumatic stress disorder (PTSD) and traumatic experiences, but the underlying mechanisms are unclear. We investigated the relationship among serum CRP, PTSD, and traits related to traumatic events and social support using genetic association data from the Psychiatric Genomics Consortium (23,185 PTSD cases and 151,309 controls), the UK Biobank (UKB; up to 117,900 individuals), and the CHARGE study (Cohorts for Heart and Aging Research in Genomic Epidemiology, 148,164 individual). Linkage disequilibrium score regression, polygenic risk scoring, and two-sample Mendelian randomization (MR) analyses were used to investigate genetic overlap and causal relationships. Genetic correlations of CRP were observed with PTSD (rg = 0.16, p = 0.026) and traits related to traumatic events, and the presence of social support (-0.28 < rg < 0.20; p < 0.008). We observed a bidirectional association between CRP and PTSD (CRP → PTSD: β = 0.065, p = 0.015; PTSD → CRP: β = 0.008, p = 0.009). CRP also showed a negative association with the "felt loved as a child" trait (UKB, β = -0.017, p = 0.008). Owing to the known association of socioeconomic status (SES) on PTSD, a multivariable MR was performed to investigate SES as potential mediator. We found that household income (univariate MR: β = -0.22, p = 1.57 × 10-7; multivariate MR: β = -0.17, p = 0.005) and deprivation index (univariate MR: β = 0.38, p = 1.63 × 10-9; multivariate MR: β = 0.27, p = 0.016) were driving the causal estimates of "felt loved as a child" and CRP on PTSD. The present findings highlight a bidirectional genetic association between PTSD and CRP, also suggesting a potential role of SES in the interplay between childhood support and inflammatory processes with respect to PTSD risk.

Inflammation-driven brain and gut barrier dysfunction in stress and mood disorders

Regulation of emotions is generally associated exclusively with the brain. However, there is evidence that peripheral systems are also involved in mood, stress vulnerability vs. resilience, and emotion‐related memory encoding. Prevalence of stress and mood disorders such as major depression, bipolar disorder, and post‐traumatic stress disorder is increasing in our modern societies. Unfortunately, 30%–50% of individuals respond poorly to currently available treatments highlighting the need to further investigate emotion‐related biology to gain mechanistic insights that could lead to innovative therapies. Here, we provide an overview of inflammation‐related mechanisms involved in mood regulation and stress responses discovered using animal models. If clinical studies are available, we discuss translational value of these findings including limitations. Neuroimmune mechanisms of depression and maladaptive stress responses have been receiving increasing attention, and thus, the first part is centered on inflammation and dysregulation of brain and circulating cytokines in stress and mood disorders. Next, recent studies supporting a role for inflammation‐driven leakiness of the blood–brain and gut barriers in emotion regulation and mood are highlighted. Stress‐induced exacerbated inflammation fragilizes these barriers which become hyperpermeable through loss of integrity and altered biology. At the gut level, this could be associated with dysbiosis, an imbalance in microbial communities, and alteration of the gut–brain axis which is central to production of mood‐related neurotransmitter serotonin. Novel therapeutic approaches such as anti‐inflammatory drugs, the fast‐acting antidepressant ketamine, and probiotics could directly act on the mechanisms described here improving mood disorder‐associated symptomatology. Discovery of biomarkers has been a challenging quest in psychiatry, and we end by listing promising targets worth further investigation.