Relationship of PTSD Symptoms With Combat Exposure, Stress, and Inflammation in American Soldiers

Exploring the dissociative subtype of PTSD: The role of early-life trauma, cortisol, and inflammatory profiles

Post-traumatic stress disorder (PTSD) is a heterogeneous mental health condition, characterized by diverse symptom profiles and biological underpinnings. A dissociative subtype of PTSD has been identified, though the potential risk factors and underlying neurobiology are yet to be understood. The current study comprised Canadian Armed Forces (CAF) members and Veterans with a history of deployment, and with diagnoses of non-dissociative (n = 31) and dissociative subtypes of PTSD (n = 19), in addition to non-deployed healthy controls (n = 14). Participants completed questionnaires assessing clinical symptoms and experiences of trauma, and provided saliva and blood samples for cortisol and inflammatory marker assessments. Individuals with dissociative PTSD displayed elevated PTSD and depression symptom severity, and greater reports of specific forms of childhood trauma compared to individuals with non-dissociative PTSD and controls. Morning cortisol was elevated in both PTSD groups compared to controls, however the PTSD groups did not differ from one another. Evening cortisol concentrations were elevated in both PTSD groups compared to controls, and in the dissociative PTSD subtype compared to the non-dissociative PTSD subtype when controlling for depression symptoms. PTSD diagnostic group moderated the relationship between awakening cortisol levels and PTSD symptom severity, such that the non-dissociative PTSD group displayed a negative correlation between awakening cortisol levels and PTSD symptom severity, while no significant relation was identified in the dissociative PTSD group. C-reactive protein (CRP) levels did not differ across diagnostic groups when accounting for body mass index (BMI). However, CRP positively correlated with depressive symptoms only among individuals with dissociative PTSD. Together, examining PTSD subtypes may help inform more effective and personalized treatment strategies in the future.

Stress-induced increase in heart-rate during sleep as an indicator of PTSD risk among combat soldiers

STUDY OBJECTIVES

Discerning the differential contribution of sleep behavior and sleep physiology to the subsequent development of posttraumatic-stress-disorder (PTSD) symptoms following military operational service among combat soldiers.

METHODS

Longitudinal design with three measurement time points: during basic training week (T1), during intensive stressed training week (T2), and following military operational service (T3). Participating soldiers were all from the same unit, ensuring equivalent training schedules and stress exposures. During measurement weeks soldiers completed the Depression Anxiety and Stress Scale (DASS) and the PTSD Checklist for DSM-5 (PCL-5). Sleep physiology (sleep heart-rate) and sleep behavior (duration, efficiency) were monitored continuously in natural settings during T1 and T2 weeks using wearable sensors.

RESULTS

Repeated measures ANOVA revealed a progressive increase in PCL-5 scores from T1 and T2 to T3, suggesting an escalation in PTSD symptom severity following operational service. Hierarchical linear regression analysis uncovered a significant relation between the change in DASS stress scores from T1 to T2 and subsequent PCL-5 scores at T3. Incorporating participants' sleep heart-rate markedly enhanced the predictive accuracy of the model, with increased sleep heart-rate from T1 to T2 emerging as a significant predictor of elevated PTSD symptoms at T3, above and beyond the contribution of DASS stress scores. Sleep behavior did not add to the accuracy of the model.

CONCLUSION

Findings underscore the critical role of sleep physiology, specifically elevated sleep heart-rate following stressful military training, in indicating subsequent PTSD risk following operational service among combat soldiers. These findings may contribute to PTSD prediction and prevention efforts.

The neurohormone tyramine stimulates the secretion of an insulin-like peptide from the Caenorhabditis elegans intestine to modulate the systemic stress response

The DAF-2/insulin/insulin-like growth factor signaling (IIS) pathway plays an evolutionarily conserved role in regulating reproductive development, life span, and stress resistance. In Caenorhabditis elegans, DAF-2/IIS signaling is modulated by an extensive array of insulin-like peptides (ILPs) with diverse spatial and temporal expression patterns. However, the release dynamics and specific functions of these ILPs in adapting to different environmental conditions remain poorly understood. Here, we show that the ILP, insulin-3 (INS-3), plays a crucial role in modulating the response to various environmental stressors in C. elegans. ins-3 mutants display increased resistance to heat, oxidative stress, and starvation; however, this advantage is countered by slower reproductive development under favorable conditions. We find that ins-3 expression is downregulated in response to environmental stressors, whereas, the neurohormone tyramine, which is released during the acute flight response, increases ins-3 expression. We show that tyramine induces intestinal calcium (Ca2+) transients through the activation of the TYRA-3 receptor. Our data support a model in which tyramine negatively impacts environmental stress resistance by stimulating the release of INS-3 from the intestine via the activation of a TYRA-3-Gαq-IP3 pathway. The release of INS-3 systemically activates the DAF-2 pathway, resulting in the inhibition of cytoprotective mechanisms mediated by DAF-16/FOXO. These studies offer mechanistic insights into a brain-gut communication pathway that weighs adaptive strategies to respond to acute and long-term stressors.

The Moderating Effect of Resilience on the Relationship Between the Relevance to Victims With Post-Trauma Psychiatric Symptoms of Community Residents After Seoul Halloween Crowd Crush

OBJECTIVE

This study aimed to examine the psychiatric impact of the Seoul Halloween crowd crush on individuals related to the victims compared to the general population. It also explores the moderating effect of resilience on the relationship between trauma exposure and psychiatric symptoms.

METHODS

In total, 2,220 participants completed various post-incident questionnaires (Patient Health Questionnaire-9, Generalized Anxiety Disorder-7, Hwa-byung symptom scale, post-traumatic stress disorder checklist for DSM-5, and Brief Resilience Scale) 30 days after the incident. Moderation analyses were conducted using the PROCESS macro in the statistical package for the social sciences.

RESULTS

Individuals related to the victims exhibited higher symptom severity and a greater risk for clinically significant levels of depression, anxiety, anger, and post-traumatic stress disorder (PTSD) (odds ratio=3.28, 3.33, 1.51, and 4.39 respectively). The impact of relevance to victims on anxiety and PTSD symptoms was moderated by resilience, with a stronger effect observed for individuals with low resilience (β=3.51, 95% confidence interval [CI] 2.78-4.24 for anxiety and β=14.53, 95% CI 12.43-16.63 for PTSD) than for those with high resilience (β=1.69, 95% CI 0.72-2.65 for anxiety and β=8.33, 95% CI 5.56-11.09 for PTSD).

CONCLUSION

When related to the victims, it was found that not only PTSD, but also depression, anxiety, and anger could intensify. Resilience emerged as a potential buffer against these adverse effects, emphasizing its significance in mitigating the psychiatric impact of community trauma.

Is inflammatory change associated with psychological risk and resilience in high-risk military personnel?

INTRODUCTION

In military populations, the potential for under-reporting of Post-traumatic Stress Disorder (PTSD) symptoms and challenges in recognising early changes can make it difficult to detect an emerging disorder. However, early identification of PTSD symptoms would improve opportunities for intervention, and potentially reduce the likelihood of chronic mental health problems.

METHOD

This study explored if changes in levels of inflammation, measured by C reactive protein (CRP) and interleukin 6 (IL-6), were associated with the onset of psychological symptoms associated with PTSD. It also examined if changes in inflammation over time contributed to psychological risk and resilience, which was defined by psychological reactivity to deployment-related combat exposures. Participants were special forces personnel who completed psychological self-report questionnaires and had measures of CRP and IL-6 taken pre and post deployment. Regression analysis was used to examine how psychological symptoms predicted change in inflammation, and Analysis of Variance (ANOVA) were used to examine differences between identified subgroups.

RESULTS

Results identify this population as having high levels of combat and trauma exposures, with low-level psychological symptoms. The results also identified a decrease in CRP and an increase in IL-6 over time. A significant difference in inflammation was identified between subgroups (p<0.05). An association between inflammatory markers and subthreshold symptoms related to anger (p<0.01) and sleep (p<0.05) was also identified.

CONCLUSION

These preliminary findings suggest inflammatory markers may help to identify adaptive responses post deployment. In addition, low-level increases in inflammatory markers may be associated with subthreshold PTSD symptoms. These findings offer potential insights for prevention, early identification and treatment in military and veteran populations.

Perceived stress and personal growth following the transition to military service: The role of sense of coherence and perceived social support

Relying on personal growth and structuration theories, we aimed to examine the internal (sense of coherence/SOC and help-seeking/HS) and external (perceived social support) resources that contribute to soldiers' personal growth following the transition to military service. We also investigated the role that perceived social support plays in moderating the relationship between SOC and personal growth, and between HS and personal growth. Two-hundred-and-seventy-one compulsory service soldiers (of whom 135 were men and 136 were women) completed self-report questionnaires between 6 and 12 months post-recruitment. The results showed both linear and curvilinear associations between soldiers' perceived stress and personal growth; SOC, HS, and perceived social support were positively correlated with personal growth; and perceived social support moderated both SOC and HS correlations with personal growth. Empirical evidence of personal growth in the transition to military service has been scant. Transitioning from civilian life to military service can be stressful and even traumatic but it can also provide opportunities for personal development. Our findings shed light on contributors to personal growth in the transition to military service, with both internal and external resources found to help one gain personal growth. It is evident that in order for soldiers to thrive, both perceived social support and active help-seeking are key factors.

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.

The neurohormone tyramine stimulates the secretion of an Insulin-Like Peptide from the intestine to modulate the systemic stress response in C. elegans

The DAF-2/insulin/insulin-like growth factor signaling (IIS) pathway plays an evolutionarily conserved role in regulating reproductive development, lifespan, and stress resistance. In C. elegans , DAF-2/IIS signaling is modulated by an extensive array of insulin-like peptides (ILPs) with diverse spatial and temporal expression patterns. However, the release dynamics and specific functions of these ILPs in adapting to different environmental conditions remain poorly understood. Here, we show that the ILP, INS-3, plays a crucial role in modulating the response to different types of stressors in C. elegans . ins-3 mutants display increased resistance to both heat and oxidative stress; however, under favorable conditions, this advantage is countered by slower reproductive development. ins-3 expression in both neurons and the intestine is downregulated in response to environmental stressors. Conversely, the neurohormone tyramine, which is released during the acute flight response, triggers an upregulation in ins-3 expression. Moreover, we found that tyramine negatively impacts environmental stress resistance by stimulating the release of INS-3 from the intestine. The subsequent release of INS-3 systemically activates the DAF-2 pathway, resulting in the inhibition of cytoprotective mechanisms mediated by DAF-16/FOXO and HSF-1. These studies offer mechanistic insights into the brain-gut communication pathway that weighs adaptive strategies to respond to acute and long-term stress scenarios.

Post-traumatic stress, prevalence of temporomandibular disorders in war veterans: Systematic review with meta-analysis

INTRODUCTION

The physical and psychological effects of war are not always easy to detect, but they can be far-reaching and long-lasting. One of the physical effects that may result from war stress is temporomandibular disorder (TMD).

OBJECTIVE

To evaluate the prevalence of TMD sign and symptoms among war veterans diagnosed with PTSD.

METHODS

We systematically searched in Web of Science, PubMed and Lilacs for articles published from the inception until 30 December 2022. All documents were assessed for eligibility based on the following Population, Exposure, Comparator and Outcomes (PECO) model: (P) Participants consisted of human subjects. (E) The Exposure consisted of exposition to war. (C) The Comparison was between war veterans (subjects exposed to war) and subjects not exposed to war. (O) The Outcome consisted of presence of temporomandibular disorders sign or symptoms (we considered pain to muscle palpation in war veterans).

RESULTS

Forty studies were identified at the end of the research. We chose only four study to draw up the present systematic study. The included subjects were 596. Among them, 274 were exposed to war, whereas the remaining 322 were not exposed to war stress. Among those exposed to war, 154 presented sign/symptoms of TMD (56.2%) whereas only 65 of those not exposed to war (20.18%). The overall effect revealed that subjects exposed to war and diagnosed with PTSD had a higher prevalence of TMD signs (pain at muscle palpation) than controls (RR 2.21; 95% CI: 1.13-4.34), showing an association PTSD war-related and TMD.

CONCLUSIONS

War can cause lasting physical and psychological damage that can lead to chronic diseases. Our results clearly demonstrated that war exposure, directly or indirectly, increases the risk of developing TMJ dysfunction and TMD sign/symptoms.

Emphasizing the Crosstalk Between Inflammatory and Neural Signaling in Post-traumatic Stress Disorder (PTSD)

Post-traumatic stress disorder (PTSD) is a chronic incapacitating condition with recurrent experience of trauma-related memories, negative mood, altered cognition, and hypervigilance. Agglomeration of preclinical and clinical evidence in recent years specified that alterations in neural networks favor certain characteristics of PTSD. Besides the disruption of hypothalamus-pituitary-axis (HPA) axis, intensified immune status with elevated pro-inflammatory cytokines and arachidonic metabolites of COX-2 such as PGE2 creates a putative scenario in worsening the neurobehavioral facet of PTSD. This review aims to link the Diagnostic and Statistical Manual of mental disorders (DSM-V) symptomology to major neural mechanisms that are supposed to underpin the transition from acute stress reactions to the development of PTSD. Also, to demonstrate how these intertwined processes can be applied to probable early intervention strategies followed by a description of the evidence supporting the proposed mechanisms. Hence in this review, several neural network mechanisms were postulated concerning the HPA axis, COX-2, PGE2, NLRP3, and sirtuins to unravel possible complex neuroinflammatory mechanisms that are obscured in PTSD condition.

Purinergic P2X7 receptor-mediated inflammation precedes PTSD-related behaviors in rats

Clinical evidence has linked increased peripheral pro-inflammatory cytokines with post-traumatic stress disorder (PTSD) symptoms. However, whether inflammation contributes to or is a consequence of PTSD is still unclear. Previous research shows that stress can activate purinergic P2X7 receptors (P2X7Rs) on microglia to induce inflammation and behavioral changes. In this investigation, we examined whether P2X7Rs contribute to the development of PTSD-like behaviors induced by single prolonged stress (SPS) exposure in rats. Consistent with the literature, exposing adult male and female rats to SPS produced a PTSD-like phenotype of impaired fear extinction and extinction of cue-induced center avoidance one week after exposure. Next, we examined if inflammation precedes the behavioral manifestations. Three days after SPS exposure, increased inflammatory cytokines were found in the blood and hippocampal microglia showed increased expression of the P2X7R, IL-1β, and TNF-α, suggesting increased peripheral and central inflammation before the onset of impaired fear extinction. In addition, SPS-exposed animals with impaired fear extinction recall also had more Iba1-positive microglia expressing the P2X7R in the ventral hippocampus. To determine whether P2X7Rs contribute to the PTSD-related behaviors induced by SPS exposure, we gave ICV infusions of the P2X7R antagonist, A-438079, for one week starting the day of SPS exposure. Blocking P2X7Rs prevented the SPS-induced impaired fear extinction and extinction of cue-induced center avoidance in male and female rats, suggesting that SPS activates P2X7Rs which increase inflammation to produce a PTSD-like phenotype.

Association of pro-inflammatory cytokines with trauma and post-traumatic stress disorder visiting a tertiary care hospital in Kathmandu

Post-traumatic stress disorder (PTSD) is a mental disorder that can occur after trauma. Although inflammatory markers such as cytokines are found altered in trauma and PTSD, there is no consensus regarding which can be considered as biomarkers. Studies from South Asia region is also rare. We studied cytokines among trauma affected patients and matched healthy controls. Fifty patients (cases) with trauma, visiting the University hospital in Kathmandu and thirty-nine healthy controls were selected, and the levels of cytokines were determined using a Luminex IS 200. We compared the levels of the cytokines in thirty-four age and gender matched pairs of case and control among three groups: healthy volunteers, cases diagnosed as PTSD, and cases without PTSD. Among the 34 pair-matched cases and controls, IL-6 was significantly higher in both PTSD positive cases [2.43 (0.00-14.54) pg/ml; p = 0.004] and PTSD negative cases [3.00 (0.92-3.86) pg/ml; p = 0.005], than in controls [0.39 (0.00-11.38) pg/ml]. IL-1β was significantly higher in PTSD positive cases [0.17 (0.00-5.27) pg/ml; p = 0.011] than in controls 0.00 (0.00-0.12) pg/ml. Other cytokines did not show significant differences. IL-6 was higher in both the trauma affected groups and IL-1β was higher in the trauma affected group with PTSD when compared to healthy controls. This supports the immune system activation hypothesis after trauma.

The use of biochemical indexes in hair for clinical studies of psychiatric diseases: What can we learn about mental disease from hair?

Analysis of hair samples provides unique advantages, including non-invasive sampling, sample stability, and the possibility of additional optimization of high sensitivity detection methods. Hair sample analysis is often used in psychiatric disease research to evaluate previous periods of stress encountered by patients. Glucocorticoid analysis is the most frequently tested indicator of stress. Furthermore, the hypothalamus-pituitary-gonad axis and endocannabinoid system also are involved in the occurrence and development of mental disorders. The endocannabinoid and sex hormone levels in patients experiencing mental illness are considerably different from levels observed in healthy individuals. Nevertheless, due to the different methods used to assess the degree of disease and the range of analytical methods involved in clinical research, the trends in changes for these biomarkers are not uniform. The correlations between changes in biomarker concentrations and illness severity also are not clear. The observed alterations suggest these biochemical substances in hair have potential as biomarkers for diagnosis or predictive treatment. However, the variable results obtained thus far could hamper further development of hair samples for clinical assessment in psychiatric disorders. This article summarizes the published reports documenting the changes in the content of relevant substances in hair in individuals experiencing mental illness and the degree of correlation. In the discussion section, we proposed several issues that should be considered in future studies of hair samples obtained from patients with mental disorders to promote the use of hair sample assessment as an aid in diagnosis or predictive treatment.

Sex-dependent effects of microglial reduction on impaired fear extinction induced by single prolonged stress

Single prolonged stress (SPS) is a preclinical rodent model for studying post-traumatic stress disorder (PTSD)-like behaviors. Previously we found that increased expression of the microglial marker Iba-1 in the ventral hippocampus after SPS exposure was associated with impaired fear extinction, suggesting that microglial activity contributed to the SPS-induced behavioral changes. To test this, we examined whether reducing microglia with the colony-stimulating factor 1 receptor blocker, PLX3397, in the diet would prevent the SPS-induced extinction impairment. Male rats exposed to SPS showed enhanced fear acquisition and impaired fear extinction memory. Adding PLX3397 to the diet prevented these behavioral changes. In contrast, PLX3397 did not prevent SPS from impairing fear extinction memory in the female rats. Despite the sex-dependent behavioral effects, we found a reduced number and area fraction of Iba-1+ microglia in both male and female rats suggesting that PLX3397 had similar effects on microglia in both sexes. Altogether, these results suggest that microglia contribute to the behavioral changes induced by SPS in male but not female rats.

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.

Stress- and drug-induced neuroimmune signaling as a therapeutic target for comorbid anxiety and substance use disorders

Stress and substance use disorders remain two of the most highly prevalent psychiatric conditions and are often comorbid. While individually these conditions have a debilitating impact on the patient and a high cost to society, the symptomology and treatment outcomes are further exacerbated when they occur together. As such, there are few effective treatment options for these patients, and recent investigation has sought to determine the neural processes underlying the co-occurrence of these disorders to identify novel treatment targets. One such mechanism that has been linked to stress- and addiction-related conditions is neuroimmune signaling. Increases in inflammatory factors across the brain have been heavily implicated in the etiology of these disorders, and this review seeks to determine the nature of this relationship. According to the "dual-hit" hypothesis, also referred to as neuroimmune priming, prior exposure to either stress or drugs of abuse can sensitize the neuroimmune system to be hyperresponsive when exposed to these insults in the future. This review completes an examination of the literature surrounding stress-induced increases in inflammation across clinical and preclinical studies along with a summarization of the evidence regarding drug-induced alterations in inflammatory factors. These changes in neuroimmune profiles are also discussed within the context of their impact on the neural circuitry responsible for stress responsiveness and addictive behaviors. Further, this review explores the connection between neuroimmune signaling and susceptibility to these conditions and highlights the anti-inflammatory pharmacotherapies that may be used for the treatment of stress and substance use disorders.

Impact of Web-Based Cognitive Behavioral Therapy for Insomnia on Stress, Health, Mood, Cognitive, Inflammatory, and Neurodegenerative Outcomes in Rural Dementia Caregivers: Protocol for the NiteCAPP CARES and NiteCAPP SHARES Randomized Controlled Trial

BACKGROUND

Chronic insomnia affects up to 63% of family dementia caregivers. Research suggests that chronic insomnia prompts changes in central stress processing that have downstream negative effects on health and mood, as well as on cognitive, inflammatory, and neurodegenerative functioning. We hypothesize that cognitive behavioral therapy for insomnia (CBT-I) will reverse those downstream effects by improving insomnia and restoring healthy central stress processing. Rural caregivers are particularly vulnerable, but they have limited access to CBT-I; therefore, we developed an accessible digital version using community input (NiteCAPP CARES).

OBJECTIVE

This trial will evaluate the acceptability, feasibility, and short-term and long-term effects of NiteCAPP CARES on the sleep and stress mechanisms underlying poor caregiver health and functioning.

METHODS

Dyads (n=100) consisting of caregivers with chronic insomnia and their coresiding persons with dementia will be recruited from Columbia and surrounding areas in Missouri, United States. Participant dyads will be randomized to 4 weeks (plus 4 bimonthly booster sessions) of NiteCAPP CARES or a web-based sleep hygiene control (NiteCAPP SHARES). Participants will be assessed at baseline, after treatment, and 6- and 12-month follow-ups. The following assessments will be completed by caregivers: 1 week of actigraphy and daily diaries measuring sleep, Insomnia Severity Index, arousal (heart rate variability), inflammation (blood-derived biomarkers: interleukin-6 and C-reactive protein), neurodegeneration (blood-derived biomarkers: plasma amyloid beta [Aβ40 and Aβ42], total tau, and phosphorylated tau [p-tau181 and p-tau217]), cognition (Joggle battery, NIH Toolbox for Assessment of Neurological and Behavioral Function, and Cognitive Failures Questionnaire), stress and burden, health, and mood (depression and anxiety). Persons with dementia will complete 1 week of actigraphy at each time point.

RESULTS

Recruitment procedures started in February 2022. All data are expected to be collected by 2026. Full trial results are planned to be published by 2027. Secondary analyses of baseline data will be subsequently published.

CONCLUSIONS

This randomized controlled trial tests NiteCAPP CARES, a web-based CBT-I for rural caregivers. The knowledge obtained will address not only what outcomes improve but also how and why they improve and for how long, which will help us to modify NiteCAPP CARES to optimize treatment potency and support future pragmatic testing and dissemination.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04896775; https://clinicaltrials.gov/ct2/show/NCT04896775.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/37874.

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.

Dysregulated TP53 Among PTSD Patients Leads to Downregulation of miRNA let-7a and Promotes an Inflammatory Th17 Phenotype

Post-traumatic stress disorder (PTSD) is a psychiatric disorder and patients diagnosed with PTSD often express other comorbid health issues, particularly autoimmune and inflammatory disorders. Our previous reports investigating peripheral blood mononuclear cells (PBMCs) from PTSD patients showed that these patients exhibit an increased inflammatory T helper (Th) cell phenotype and widespread downregulation of microRNAs (miRNAs), key molecules involved in post-transcriptional gene regulation. A combination of analyzing prior datasets on gene and miRNA expression of PBMCs from PTSD and Control samples, as well as experiments using primary PBMCs collected from human PTSD and Controls blood, was used to evaluate TP53 expression, DNA methylation, and miRNA modulation on Th17 development. In the current report, we note several downregulated miRNAs were linked to tumor protein 53 (TP53), also known as p53. Expression data from PBMCs revealed that compared to Controls, PTSD patients exhibited decreased TP53 which correlated with an increased inflammatory Th17 phenotype. Decreased expression of TP53 in the PTSD population was shown to be associated with an increase in DNA methylation in the TP53 promotor region. Lastly, the most significantly downregulated TP53-associated miRNA, let-7a, was shown to negatively regulate Th17 T cells. Let-7a modulation in activated CD4+ T cells was shown to influence Th17 development and function, via alterations in IL-6 and IL-17 production, respectively. Collectively, these studies reveal that PTSD patients could be susceptible to inflammation by epigenetic dysregulation of TP53, which alters the miRNA profile to favor a proinflammatory Th17 phenotype.

The Association between Endogenous Hair Steroid Hormones and Social Environmental Factors in a Group of Conscripts during Basic Military Training

This study aimed to analyse the association between endogenous hair steroid hormones as reliable biological indicators of an individual’s stress level and the social environmental factors experienced during military training that are manifested at the beginning of compulsory military service. Hair steroid hormone concentrations—cortisol, cortisone, dehydroepiandrosterone (DHEA), and testosterone—in a group of 185 conscripts were measured using the ultra-high performance liquid chromatography-tandem mass spectrometry method. Six subjective social environmental factors in the military—attitude towards the military and military service, adaptation to the military environment, team, task, and norm cohesion, as well as psychological (un)safety in the group—were evaluated using military-specific research questionnaires. Weak but significant negative correlations were identified between cortisol and adaptation (r = −0.176, p < 0.05), attitude (r = −0.147, p < 0.05) as well as between testosterone and task cohesion (r = −0.230, p < 0.01) levels. Additionally, a multiple forward stepwise regression analysis highlighted that cortisone variation might be partially explained by task cohesion; the DHEA—determined by psychological (un)safety in the group, attitude towards the military and military service, and norm cohesion; and the testosterone—determined by task cohesion and adaptation to the new military environment. The results of this study suggest that subjective measures of social factors can be used to predict hair steroid hormone levels as objective measures of the chronic stress perceived by conscripts during their basic military training.

Alzheimer's disease neuropathology is exacerbated following traumatic brain injury. Neuroprotection by co-administration of nanowired mesenchymal stem cells and cerebrolysin with monoclonal antibodies to amyloid beta peptide

Military personnel are prone to traumatic brain injury (TBI) that is one of the risk factors in developing Alzheimer's disease (AD) at a later stage. TBI induces breakdown of the blood-brain barrier (BBB) to serum proteins into the brain and leads to extravasation of plasma amyloid beta peptide (ΑβP) into the brain fluid compartments causing AD brain pathology. Thus, there is a need to expand our knowledge on the role of TBI in AD. In addition, exploration of the novel roles of nanomedicine in AD and TBI for neuroprotection is the need of the hour. Since stem cells and neurotrophic factors play important roles in TBI and in AD, it is likely that nanodelivery of these agents exert superior neuroprotection in TBI induced exacerbation of AD brain pathology. In this review, these aspects are examined in details based on our own investigations in the light of current scientific literature in the field. Our observations show that TBI exacerbates AD brain pathology and TiO₂ nanowired delivery of mesenchymal stem cells together with cerebrolysin-a balanced composition of several neurotrophic factors and active peptide fragments, and monoclonal antibodies to amyloid beta protein thwarted the development of neuropathology following TBI in AD, not reported earlier.

Survey of psychiatric impairment among residents exposed to environmental pollution from a petrochemical complex

PURPOSE

This study first assessed the occurrence of major depressive disorder (MDD), post-traumatic stress disorder (PTSD), symptoms of poor sleep quality and high levels of distress among residents, caused by reported long-term stress from environmental pollution emitted from the biggest petroleum chemistry factory (PCF) in the world.

METHODS

A total of 328 long-term residents (Mean age = 57.5, SD = 16.5 years, ranging from 22 to 95) were recruited randomly from a total population of 26,632 in Mailiao township in Taiwan next to the PCF. Trained assistants used the Disaster-Related Psychological Screening test, the Perception of Life Threats Caused by the SCNP questionnaire and the Sleep Quality Scale to interview the participants.

RESULTS

The results support our hypotheses that most of the residents (71%) would report life threats caused by the PCF. The residents displayed higher rates of major depressive episodes (24.1%), PTSD (24.5%) and symptoms of poor sleep quality. The more they felt threat from the PCF, the stronger the connection with MDD and PTSD symptoms.

CONCLUSION

The results indicate an increased prevalence of MDD, PTSD and symptoms of poor sleep quality in those exposed to environmental pollution from the PCF, highlighting the need for prompt prevention, diagnostic and therapeutic attention.

The neuropsychiatric manifestations of COVID-19: Interactions with psychiatric illness and pharmacological treatment

The recent outbreak of the corona virus disease (COVID-19) has had major global impact. The relationship between severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection and psychiatric diseases is of great concern, with an evident link between corona virus infections and various central and peripheral nervous system manifestations. Unmitigated neuro-inflammation has been noted to underlie not only the severe respiratory complications of the disease but is also present in a range of neuro-psychiatric illnesses. Several neurological and psychiatric disorders are characterized by immune-inflammatory states, while treatments for these disorders have distinct anti-inflammatory properties and effects. With inflammation being a common contributing factor in SARS-CoV-2, as well as psychiatric disorders, treatment of either condition may affect disease progression of the other or alter response to pharmacological treatment. In this review, we elucidate how viral infections could affect pre-existing psychiatric conditions and how pharmacological treatments of these conditions may affect overall progress and outcome in the treatment of SARS-CoV-2. We address whether any treatment-induced benefits and potential adverse effects may ultimately affect the overall treatment approach, considering the underlying dysregulated neuro-inflammatory processes and potential drug interactions. Finally, we suggest adjunctive treatment options for SARS-CoV-2-associated neuro-psychiatric symptoms.

To stress or not to stress: Brain-behavior-immune interaction may weaken or promote the immune response to SARS-CoV-2

The COVID-19 pandemic continues to strongly affect people with health disadvantages, creating a heavy burden on medical systems and societies worldwide. Research is growing rapidly and recently revealed that stress-related factors such as socio-economic status, may also play a pivotal role. However, stress research investigating the underlying psychoneuroimmune interactions is missing. Here we address the question whether stress-associated neuroendocrine-immune mechanisms can possibly contribute to an increase in SARS-CoV-2 infections and influence the course of COVID-19 disease. Additionally, we discuss that not all forms of stress (e.g. acute versus chronic) are detrimental and that some types of stress could attenuate infection-risk and -progression. The overall aim of this review is to motivate future research efforts to clarify whether psychosocial interventions have the potential to optimize neuroendocrine-immune responses against respiratory viral infections during and beyond the COVID-19 pandemic. The current state of research on different types of stress is summarized in a comprehensive narrative review to promote a psychoneuroimmune understanding of how stress and its mediators cortisol, (nor)adrenaline, neuropeptides and neurotrophins can shape the immune defense against viral diseases. Based on this understanding, we describe how people with high psychosocial stress can be identified, which behaviors and psychosocial interventions may contribute to optimal stress management, and how psychoneuroimmune knowledge can be used to improve adequate care for COVID-19 and other patients with viral infections.

The pre-efficacy phase testing for PAfitME™-A behavioral physical activity intervention to manage moderate and severe symptoms among advanced stage cancer patients

Fatigue and pain are the most frequently reported symptoms among advanced-stage cancer patients. Although physical activity (PA) is known to improve the aforementioned symptoms, few patients demonstrate the physically active behavior that adheres to the clinical guidelines regarding PA. The current article presents an exemplar that used the National Institute of Health's Obesity-Related Behavioral Intervention Trial (ORBIT) model and developed a behavioral intervention known as the personalized Physical Activity intervention with fitness graded Motion Exergames (PAfitME™). There were two phases of testing in the ORBIT model presented in the current paper. In Phase I testing, a standardized exergame prescription was evaluated by an advisory board and a single-case study was used to evaluate the personalized exergame prescription with personalization of the fitness levels. In Phase IIa, a within-group pre- and posttest design was used to evaluate the personalized exergame prescriptions with personalization of the fitness levels, self-efficacy, and variation in fatigue/pain. Subsequently, a complete intervention package was developed in accordance with a logic model, driven from the result of the Phase IIa testing with clinically significant findings. Currently, PAfitME™ is under Phase IIb testing in a randomized clinical trial with a control group. PAfitME™ employs a personalized approach to initiate and promote physically active behavior, to facilitate the management of fatigue and pain in cancer patients. Positive results from an efficacy trial would support the use of PAfitME™ in the management of fatigue and pain in advanced-stage cancer patients.

Hair Cortisol as a Marker of Intergenerational Heritage of War? A Study of Veterans and Their Offspring

OBJECTIVE

Posttraumatic stress disorder (PTSD) has been associated with lower circulating cortisol levels in specific subgroups, which have also been found in the offspring of people with PTSD. The analysis of hair cortisol concentrations (HCC) is a recent methodology which is used to assess long-term systemic cortisol levels. We aimed to study veterans with war-related lifetime PTSD and their respective offspring with regards to HCC. We also studied the influence of lifetime major depressive disorder (MDD), war experiences, and childhood adversities on HCC in these groups.

METHODS

31 male veterans with PTSD and 28 without PTSD and 69 adult offspring were studied. HCC were quantified by liquid chromatography tandem-mass spectrometry.

RESULTS

No differences in HCC were found between veterans with and without PTSD, or between their respective offspring. Veterans without MDD showed a positive association between total war exposure and HCC. Veterans reporting more frequent childhood physical abuse had lower HCC. Veterans-with-PTSD's offspring with MDD had increased HCC compared to offspring without MDD. Offspring's exposure to more frequent childhood physical abuse was negatively associated with HCC in those without MDD.

CONCLUSION

HCC did not appear to constitute a marker of intergenerational heritage of war-related PTSD, except in the case of veteranswith-PTSD's offspring with MDD. Our data suggest that HCC is a marker of adult reported childhood physical abuse.

Hair cortisol levels in posttraumatic stress disorder and metabolic syndrome

Individuals with post-traumatic stress disorder (PTSD) evidence increased rates of metabolic syndrome (MetS), and both PTSD and MetS are associated with alterations in hypothalamic-pituitary-adrenal (HPA) axis function. Few investigations have examined the possible role of HPA-axis dysfunction in the co-occurrence of PTSD and MetS. In a case-control study, we aimed to determine whether hair cortisol concentrations (HCC) were associated with (i) PTSD caseness and severity and (ii) PTSD and MetS co-occurrence. We used the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) to determine PTSD diagnoses and severity scores in 216 females of mixed ancestry aged between 20 and 79 years (M = 43.8, SD =13.3). Hair samples, representing a three-month retrospective window of cortisol levels, were obtained and analyzed utilizing liquid chromatography-tandem mass spectrometry. We constructed multivariate linear regression models to evaluate whether PTSD diagnosis, PTSD severity, and MetS comorbidity were associated with HCC, controlling for potential confounders. HCC were significantly higher (adj β = 0.154, p = .033; Cohen's d = 0.44) in PTSD patients (n = 110) than trauma-exposed controls (n = 106) and CAPS severity scores (adj β = 0.207, p = .005) were significantly associated with HCC. MetS was not associated with HCC and there were no significant interactions between PTSD and MetS on HCC. This study provides evidence of a chronically dysregulated neuroendocrine mediated stress response in PTSD, with a clear dose-response relationship. HCC do not, however, appear to have specificity for the comorbidity of PTSD and MetS in this sample.LAY SUMMARYWe found that levels of the stress hormone, cortisol, measured in hair samples were significantly higher in South African women with post-traumatic stress disorder (PTSD) than in women who had also experienced trauma but did not have PTSD. Hair cortisol levels were, however, not associated with metabolic syndrome, a cluster of risk factors for heart disease, in the women studied. We thus show that South African women with PTSD have elevated long-term stress hormone levels and that this effect is related to PTSD and not solely due to trauma exposure.

Hair cortisol as a biomarker of stress and resilience in South African mixed ancestry females

BACKGROUND

Hair cortisol concentrations (HCC) are increasingly used as a biomarker of stress, however limited research exists regarding the relationship between HCC and protective factors, such as resilience. Additionally, studies measuring HCC need to account for possible confounders, and these factors have not been examined in sufficiently diverse settings.

OBJECTIVES

Our objectives were to identify determinants of HCC in a sample of mixed ancestry adults and investigate the association of HCC with measures of self-perceived stress and resilience.

METHODS

Our sample comprised 164 females (mean age 46.5 years, SD = 15.0), self-identifying as mixed ancestry, who were control participants in a case-control study (SHARED ROOTS), conducted in Cape Town, South Africa from May 2014 until June 2017. We examined which socio-demographic, hair related, clinical and behavioural factors were associated with HCC in both unadjusted and adjusted linear regression models. Furthermore, the relationship of HCC with self-perceived stress and resilience scores were also examined.

RESULTS

HCC (Mdn 4.4 pg/ml; IQR 2.8; 11.4) were significantly positively associated with hair product use and breastfeeding, and significantly negatively associated with age, level of education, duration of sun exposure, duration of storage, and demonstrated a trend towards significance with frequency of hair washing, in adjusted models. HCC were inversely associated with CD-RISC scores (adj β = -0.179, p =  0.012) but were not significantly associated with PSS scores (adj β = -0.001, p =  0.989).

CONCLUSIONS

We identified specific determinants of HCC in our sample, including the first indication that sun exposure has an effect on HCC under naturalistic conditions. These potential confounders need to be controlled for in the design and analysis of future studies. HCC may be a biomarker of resilience to stress, rather than perceived stress. Further research measuring HCC in more diverse settings and populations and including constructs related to resilience are needed.

Acute Physiological Responses Following a Bout of Vigorous Exercise in Military Soldiers and First Responders with PTSD: An Exploratory Pilot Study

Post-traumatic stress disorder (PTSD) is a prevalent and debilitating condition associated with psychological conditions and chronic diseases that may be underpinned by dysfunction in the autonomic nervous system (ANS), the hypothalamic-pituitary-adrenal (HPA) axis and chronic systemic low-grade inflammation. The objective of this pilot study was to determine psychological, ANS [heart rate variability (HRV)], HPA (salivary cortisol) and inflammatory (salivary C-Reactive Protein) responses to a bout of vigorous exercise in male first responders, military veterans and active duty personnel with (n = 4) and without (n = 4) PTSD. Participants (50.1 ± 14.8 years) performed a thirteen-minute, vigorous intensity (70%–80% of heart rate max), one-on-one boxing session with a certified coach. Physiological and psychological parameters were measured before, during, immediately after to 30 min post-exercise, and then at 24 h and 48 h post. The effect sizes demonstrated large to very large reductions in HRV that lasted up to 48 h post-exercise in the PTSD group compared with unclear effects in the trauma-exposed control (TEC) group. There were unclear effects for depression, anxiety and stress as well as salivary biomarkers for both groups at all time-points. Findings may reflect stress-induced changes to the ANS for PTSD sufferers.

Inflammation in Post-Traumatic Stress Disorder (PTSD): A Review of Potential Correlates of PTSD with a Neurological Perspective

Post-traumatic stress disorder (PTSD) is a chronic condition characterized by symptoms of physiological and psychosocial burden. While growing research demonstrated signs of inflammation in PTSD, specific biomarkers that may be representative of PTSD such as the detailed neural correlates underlying the inflammatory responses in relation to trauma exposure are seldom discussed. Here, we review recent studies that explored alterations in key inflammatory markers in PTSD, as well as neuroimaging-based studies that further investigated signs of inflammation within the brain in PTSD, as to provide a comprehensive summary of recent literature with a neurological perspective. A search was conducted on studies published from 2009 through 2019 in PubMed and Web of Science. Fifty original articles were selected. Major findings included elevated levels of serum proinflammatory cytokines in individuals with PTSD across various trauma types, as compared with those without PTSD. Furthermore, neuroimaging-based studies demonstrated that altered inflammatory markers are associated with structural and functional alterations in brain regions that are responsible for the regulation of stress and emotion, including the amygdala, hippocampus, and frontal cortex. Future studies that utilize both central and peripheral inflammatory markers are warranted to elucidate the underlying neurological pathway of the pathophysiology of PTSD.

Pharmacological rewriting of fear memories: A beacon for post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is a psychopathological response that develops after exposure to an extreme life-threatening traumatic event. Its prevalence ranges from 0.5% to 14.5% worldwide. Due to the complex pathophysiology of PTSD, currently available treatment approaches are associated with high chances of failure, thus further research to identify better pharmacotherapeutic approaches is needed. The traumatic event associated with fear memories plays an important role in the development of PTSD and could be considered as the main culprit. PTSD patient feels frightened in a safe environment as the memories of the traumatic event are revisited. Neurocircuit involving normal processing of fear memories get disturbed in PTSD hence making a fear memory to remain to dominate even after years of trauma. Persistence of fear memories could be explained by acquisition, re-(consolidation) and extinction triad as all of these processes have been widely explored in preclinical as well as clinical studies and set a therapeutic platform for fear memory associated disorders. This review focuses on neurocircuit and pathophysiology of PTSD in context to fear memories and pharmacological targeting of fear memory for the management of PTSD.

A clinical model for identifying an inflammatory phenotype in mood disorders

Increasingly, clinical research has found inflammatory correlates of psychiatric disorders, particularly mood symptomatology. Biological measures may provide greater precision in many cases and may capture clinically-relevant inflammatory signposts, such as central obesity risk, inflammation-associated co-morbid medical conditions, or proinflammatory lifestyle choices. In order to expand understanding of the role of inflammation in mood disorders, we propose a more inclusive clinical model for capturing an inflammatory phenotype of depression by identifying clinically-relevant inflammatory phenotypes grounded in biology. Our model includes chronic conditions and lifestyle behaviors associated with clinically elevated inflammation in mood disorders. Elements of this "inflamed depression" model include: obesity, low HDL concentrations, elevated triglyceride concentrations, chronically elevated blood pressure, clinical diagnosis of hypothyroidism, migraines, rheumatoid arthritis, adult onset diabetes, inflammatory bowel diseases, inflammatory skin conditions, and lifestyle factors including smoking cigarettes and chronic stress.

Early Social Stress Promotes Inflammation and Disease Risk in Rhesus Monkeys

Early social stress has potent lifelong health effects. We examined the association of early stress in the attachment relationship (low maternal sensitivity, low MS), lower maternal social hierarchy rank, and greater frequency of group-level social conflict, with biomarkers of inflammatory stress response in plasma (IL-8, MCP-1 and CRP collected two hours after temporary separation from mothers and social groups) and risk for developing a common macaques disease outcome (infectious colitis) in 170 socially-housed rhesus monkeys. We controlled for gene-environment correlations by comparing cross-fostered subjects with infants reared by their biological mothers. Low MS predicted higher levels of pro-inflammatory cytokines and proteins at 3-4 months of age (F(3, 162) = 3.508, p = 0.002, partial eta2 = 0.061) and higher lifetime risk for developing colitis for up to twelve years of age (chi square = 5.919, p = 0.026). Lower maternal social rank (F (3, 162) = 3.789, p = 0.012, partial eta2 = 0.06) and higher rates of social conflict (F (3, 162) = 4.264, p = 0.006, partial eta2 = 0.074) each also predicted greater inflammation in infancy, but not lifetime colitis risk (both p > 0.05). The effects of low MS, lower social rank, and higher social conflict were significant in infants reared by biological mothers and cross-fostered infants, suggesting that our results did not arise from gene-environment correlations, but environmental stressors alone. We conclude that several types of early social stress confer risk for inflammation in infancy, but that stress in the mother-infant relationship may confer the longest-term risk for adverse health outcomes.

The association between adversity and hair cortisol levels in humans: A meta-analysis

Adverse life events are associated with a constellation of negative health outcomes. Theory and research suggest that the hypothalamic-pituitary-adrenal (HPA) axis acts as one mechanism connecting adverse experiences with negative health outcomes. However, this relation is complicated by the potential for adversity to be associated with both hyperactivity and hypoactivity of the HPA axis, as assessed in both animal and human studies. Over the past decade, methodological advances have enabled the sampling of cortisol stored in hair, which provides a marker of HPA axis activity over a several-month period. The present meta-analysis included 28 studies to assess the strength and direction of the relation between adverse experiences and hair cortisol levels. Analyses were conducted using multilevel modeling (MLM) to quantify the magnitude of effects and mixture modeling to identify distinct subgroups of studies. Results of MLM analyses indicated that the overall effect size was small but significant d = 0.213, 95% CI [0.034, 0.397]. There was also significant between-study variance (τ = 0.155, 95% CI [0.065, 0.367]). Mixture modeling to identify distinct classes of studies based on effect size and direction resulted in a 2-class model: The first class included four studies with an overall negative and moderate effect size (d = -0.478, 95% CI [-0.639, -0.318]), and the second class included the remaining 24 studies with an overall positive and significant, albeit small, effect size (d = 0.141, 95% CI [0.084, 0.199]). Moderator analyses indicated that the strength and direction of the association between adversity and hair cortisol were moderated by features of the adversity exposure (e.g., type of adversity, timing of adversity), characteristics of the samples (e.g., clinical status, racial distribution), and features of the publication (e.g., publication type, geographic region of study). The findings refine our understanding of the long-term impact of adversity on dysregulation of the HPA axis, particularly as reflected in hair cortisol measures.

Novel method of measuring chronic stress for preterm infants: Skin cortisol

BACKGROUND AND OBJECTIVES

Infants who begin life in the medicalized environment of the neonatal intensive care unit (NICU) do so under stressful conditions. Environmental exposures are often abrasive to vulnerable infants, while invasive and noninvasive lifesaving interventions provide additional pain and/or stress. The most commonly selected biomarker to measure stress is cortisol. The skin is the barrier between the external environment and communicates with our neurological, endocrine and immune regulatory networks. To examine if skin cortisol may be a reliable biomarker of stress, NICU stress exposure and repeated measurements of skin cortisol in very preterm infants were examined retrospectively during the first 6 weeks of life. The temporal relationship between skin cortisol and NICU stress exposure was also analyzed.

MATERIALS AND METHODS

Participants included 82 preterm infants born weighing less than 1500 g, admitted to a level III NICU, with a mean gestational age of 28.5 weeks. Infants were studied from birth through 6 weeks of life. NICU stress data was collected using the Neonatal Infant Stressor Scale. Skin samples were collected using d-squame tape as soon after birth as possible and every two weeks thereafter.

RESULTS

On average, infants experienced approximately 43 stressful events per day during the first 6 weeks of life in the NICU. Stress level and cortisol reactivity varied by gestation age. Higher stress resulted in higher cortisol for infant >28 weeks; lower stress scores were associated with higher stress for infants <28 weeks. Stress exposure during 7 days prior to cortisol sampling yielded the highest AUC for the 2 groups. A statistically significant interaction was identified between gestational age and stress exposure during the previous 7 days (p < 0.01).

CONCLUSION

This is the first study to demonstrate skin cortisol as a preterm infant biomarker of chronic stress exposure. For infants with appropriate skin maturation, this non-invasive sampling method provides several benefits. Importantly, this method may be less intrusive and disruptive for preterm infants.

Understanding Resilience and Preventing and Treating PTSD

Resilience is defined as the dynamic ability to adapt successfully in the face of adversity, trauma, or significant threat. Some of the key early studies of resilience were observational studies in children. They were followed by research in adults, studies testing interventions to promote resilience in different populations, and a recent upsurge of studies on the underlying genomic and neurobiological mechanisms. Neural and molecular studies in preclinical models of resilience are also increasingly identifying active stress adaptations in resilient animals. Knowledge gained from animal and human studies of resilience can be harnessed to develop new preventive interventions to enhance resilience in at-risk populations. Further, treatment interventions focused on enhancing potentially modifiable protective factors that are consistently linked to psychological resilience can enrich currently available treatment interventions for individuals with posttraumatic stress disorder (PTSD). Translating our expanding knowledge of the neurobiology of resilience additionally promises to yield novel therapeutic strategies for treating this disabling condition. This review summarizes the vast field of resilience research spanning genomic, psychosocial, and neurobiological levels, and discusses how findings have led and can lead to new preventive and treatment interventions for PTSD.

Exercise Intervention in PTSD: A Narrative Review and Rationale for Implementation

Posttraumatic stress disorder (PTSD) is a prominent mental health problem in veteran and community populations. There is accumulating evidence to suggest that aerobic exercise may serve as an effective treatment option for individuals with PTSD. The purpose of this review is to summarize the existing literature exploring aerobic exercise and PTSD and briefly discuss potential mechanisms of PTSD symptom reduction. A search of electronic databases and reference sections of relevant articles published through October 1, 2018 revealed 19 relevant studies that examined aerobic exercise and PTSD symptomatology. A narrative review of extant studies provides encouraging evidence that aerobic exercise interventions alone or as an adjunct to standard treatment may positively impact PTSD symptoms. Potential mechanisms by which aerobic exercise could exert a positive impact in PTSD include exposure and desensitization to internal arousal cues, enhanced cognitive function, exercise-induced neuroplasticity, normalization of hypothalamic pituitary axis (HPA) function, and reductions in inflammatory markers. Randomized clinical trials and translational neuroscience approaches are required to clarify the efficacy of exercise intervention for PTSD and elucidate potential mechanisms of exercise-induced PTSD symptom reduction.

The clinical applications and practical relevance of human conditioning paradigms for posttraumatic stress disorder

The classical conditioning paradigm of fear learning has spawned a number of experimental variations for the explanation of posttraumatic stress disorder (PTSD) etiology. These paradigms include extinction learning and recall, fear inhibition, fear generalization, and conditioned avoidance. As such, each of these paradigms have significant applications for understanding the development, maintenance, treatment, and relapse of the fear-related features of PTSD. In the present review, we describe each of these conditioning-based paradigms with reference to the clinical applications, and supported by case examples from patients with severe PTSD symptoms. We also review the neurobiological models of conditioning and extinction in animals, psychiatrically healthy humans, and PTSD patients, and discuss the current balance of evidence suggesting a number of biological, behavioral, and cognitive mechanisms/moderators of the conditioning and extinction process in experimental and clinical contexts.

Posttraumatic Stress Disorder Symptom Network Analysis in U.S. Military Veterans: Examining the Impact of Combat Exposure

Recent work inspired by graph theory has begun to conceptualize mental disorders as networks of interacting symptoms. Posttraumatic stress disorder (PTSD) symptom networks have been investigated in clinical samples meeting full diagnostic criteria, including military veterans, natural disaster survivors, civilian survivors of war, and child sexual abuse survivors. Despite reliable associations across reported networks, more work is needed to compare central symptoms across trauma types. Additionally, individuals without a diagnosis who still experience symptoms, also referred to as subthreshold cases, have not been explored with network analysis in veterans. A sample of 1,050 Iraq/Afghanistan-era U.S. military veterans (851 males, mean age = 36.3, SD = 9.53) meeting current full-criteria PTSD (n = 912) and subthreshold PTSD (n = 138) were assessed with the Structured Clinical Interview for DSM-IV Disorders (SCID). Combat Exposure Scale (CES) scores were used to group the sample meeting full-criteria into high (n = 639) and low (n = 273) combat exposure subgroups. Networks were estimated using regularized partial correlation models in the R-package qgraph, and robustness tests were performed with bootnet. Frequently co-occurring symptom pairs (strong network connections) emerged between two avoidance symptoms, hypervigilance and startle response, loss of interest and detachment, as well as, detachment and restricted affect. These associations replicate findings reported across PTSD trauma types. A symptom network analysis of PTSD in a veteran population found significantly greater overall connectivity in the full-criteria PTSD group as compared to the subthreshold PTSD group. Additionally, novel findings indicate that the association between intrusive thoughts and irritability is a feature of the symptom network of veterans with high levels of combat exposure. Mean node predictability is high for PTSD symptom networks, averaging 51.5% shared variance. With the tools described here and by others, researchers can help refine diagnostic criteria for PTSD, develop more accurate measures for assessing PTSD, and eventually inform therapies that target symptoms with strong network connections to interrupt interconnected symptom complexes and promote functional recovery.

Stress and Obesity: Are There More Susceptible Individuals?

PURPOSE OF REVIEW

Stress has long been suspected to be interrelated to (abdominal) obesity. However, interindividual differences in this complex relationship exist. We suggest that the extent of glucocorticoid action partly explains these interindividual differences. We provide latest insights with respect to multiple types of stressors.

RECENT FINDINGS

Increased long-term cortisol levels, as measured in scalp hair, are strongly related to abdominal obesity and to specific mental disorders. However, not all obese patients have elevated cortisol levels. Possibly, the interindividual variation in glucocorticoid sensitivity, which is partly genetically determined, may lead to higher vulnerability to mental or physical stressors. Other evidence for the important role for increased glucocorticoid action is provided by recent studies investigating associations between body composition and local and systemic corticosteroids. Stress may play a major role in the development and maintenance of obesity in individuals who have an increased glucocorticoid exposure or sensitivity. These insights may lead to more effective and individualized obesity treatment strategies.

Inflammation Relates to Chronic Behavioral and Neurological Symptoms in Military Personnel with Traumatic Brain Injuries

Studies have shown that the presence of acute inflammation during recovery is indicative of poor outcomes after a traumatic brain injury (TBI); however, the role of chronic inflammation in predicting post-TBI-related symptoms remains poorly understood. The purpose of this study was to compare inflammatory biomarkers (tumor necrosis factor [TNF]-α, interleukin [IL]-6, and IL-10) in active duty personnel who either sustained or did not sustain a TBI. Service members were also assessed for post-traumatic stress disorder (PTSD), depression, and quality of life through self-reported measures. IL-6 and TNF-α concentrations were greater in the TBI group than in the control group. Of those with a TBI, IL-6 and TNF-α concentrations were greater in the high-PTSD group than the low-PTSD group. No significant differences were found in IL-10 or the IL-6/IL-10 ratios between those with low and high PTSD. Exploratory factor analysis was conducted to describe the latent structure of variables relating to emotional and physical health (i.e., Short Form 36 subcomponents, etc.) and their relationships within the TBI group with inflammatory cytokines. Four symptom profiles were found, with the third component most relating to PTSD and depression symptoms and high inflammation. This study indicates that the comorbidity of TBI and PTSD is associated with inflammation in a military sample, emphasizing the necessity for intervention in order to mitigate the risks associated with inflammation.

Systemic low-grade inflammation in post-traumatic stress disorder: a systematic review

Studies examining post-traumatic stress disorder (PTSD) have either emphasized a relationship between PTSD and a systemically pro-inflammatory state or identified a link between PTSD and chronic disease. The aim of this study was to evaluate the evidence for a relationship between individuals with PTSD and systemic low-grade inflammation that has been proposed to underlie chronic disease development in this population. The authors conducted a systematic review of the literature (January 2006 to April 2017) in accordance with the PRISMA statement in the following four databases: PubMed, MEDLINE, PsycINFO, and SPORTDiscus with Full Text. The search strategy was limited to articles published in peer-reviewed journals and to human studies. Nine studies measuring systemic inflammation and discussing its role in chronic disease development were selected for inclusion in this review. The association between markers of systemic inflammation and PTSD was evaluated by the measurement of a variety of systemic inflammatory markers including acute-phase proteins, complement proteins, pro- and anti-inflammatory cytokines, natural killer cells, and white blood cells. In general, systemic inflammatory biomarkers were elevated across the studies in the PTSD groups. There is evidence that PTSD is underpinned by the presence of a systemic low-grade inflammatory state. This inflammation may be the mechanism associated with increased risk for chronic disease in the PTSD population. From this, future research should focus on interventions that help to reduce inflammation, such as exercise.

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.

Corticosterone Preexposure Increases NF-κB Translocation and Sensitizes IL-1β Responses in BV2 Microglia-Like Cells

Corticosterone (CORT), a critical mediator of the hypothalamus pituitary adrenal axis in rodents, is a stress hormone that is classically viewed as possessing immune-suppressive properties. CORT is now appreciated to also mediate the neuroimmune-priming effect of stress to innate-immune stimulation, and hence serves as a mechanistic link to the neuroimmune involvement in stress-related disorders. However, these dichotomous actions of CORT remain poorly defined. This study investigated the conditions and concentration dependency of CORT’s actions required to prime the innate-immune system. Here, we measured the effect of CORT pretreatment on the downstream pro-inflammatory responses of BV2 mouse microglia-like cells stimulated by lipopolysaccharide (LPS). We quantified the concentration-dependent CORT-mediated attenuation and enhancement of LPS-stimulated inflammatory response. A high physiological concentration (500 nM) of CORT attenuated LPS-induced inflammatory IL-1β cytokine production in a glucocorticoid receptor-dependent manner. However, a low concentration (50 nM) of CORT increased expression and release of IL-1β in a mineralocorticoid receptor-dependent manner, with accompanied increases in NF-κB translocation and changes to related gene transcription. These results suggest that a mild elevation in CORT may cause selective adaptations in microglia-like cells to overrespond to a second immune challenge in a non-classical manner, thus partially explaining both pro- and anti-inflammatory effects of CORT reported in the literature.

Mast Cell Activation in Brain Injury, Stress, and Post-traumatic Stress Disorder and Alzheimer's Disease Pathogenesis

Mast cells are localized throughout the body and mediate allergic, immune, and inflammatory reactions. They are heterogeneous, tissue-resident, long-lived, and granulated cells. Mast cells increase their numbers in specific site in the body by proliferation, increased recruitment, increased survival, and increased rate of maturation from its progenitors. Mast cells are implicated in brain injuries, neuropsychiatric disorders, stress, neuroinflammation, and neurodegeneration. Brain mast cells are the first responders before microglia in the brain injuries since mast cells can release prestored mediators. Mast cells also can detect amyloid plaque formation during Alzheimer's disease (AD) pathogenesis. Stress conditions activate mast cells to release prestored and newly synthesized inflammatory mediators and induce increased blood-brain barrier permeability, recruitment of immune and inflammatory cells into the brain and neuroinflammation. Stress induces the release of corticotropin-releasing hormone (CRH) from paraventricular nucleus of hypothalamus and mast cells. CRH activates glial cells and mast cells through CRH receptors and releases neuroinflammatory mediators. Stress also increases proinflammatory mediator release in the peripheral systems that can induce and augment neuroinflammation. Post-traumatic stress disorder (PTSD) is a traumatic-chronic stress related mental dysfunction. Currently there is no specific therapy to treat PTSD since its disease mechanisms are not yet clearly understood. Moreover, recent reports indicate that PTSD could induce and augment neuroinflammation and neurodegeneration in the pathogenesis of neurodegenerative diseases. Mast cells play a crucial role in the peripheral inflammation as well as in neuroinflammation due to brain injuries, stress, depression, and PTSD. Therefore, mast cells activation in brain injury, stress, and PTSD may accelerate the pathogenesis of neuroinflammatory and neurodegenerative diseases including AD. This review focusses on how mast cells in brain injuries, stress, and PTSD may promote the pathogenesis of AD. We suggest that inhibition of mast cells activation and brain cells associated inflammatory pathways in the brain injuries, stress, and PTSD can be explored as a new therapeutic target to delay or prevent the pathogenesis and severity of AD.

Molecular indicators of stress-induced neuroinflammation in a mouse model simulating features of post-traumatic stress disorder

A social-stress mouse model was used to simulate features of post-traumatic stress disorder (PTSD). The model involved exposure of an intruder (male C57BL/6) mouse to a resident aggressor (male SJL) mouse for 5 or 10 consecutive days. Transcriptome changes in brain regions (hippocampus, amygdala, medial prefrontal cortex and hemibrain), blood and spleen as well as epigenome changes in the hemibrain were assayed after 1- and 10-day intervals following the 5-day trauma or after 1- and 42-day intervals following the 10-day trauma. Analyses of differentially expressed genes (common among brain, blood and spleen) and differentially methylated promoter regions revealed that neurogenesis and synaptic plasticity pathways were activated during the early responses but were inhibited after the later post-trauma intervals. However, inflammatory pathways were activated throughout the observation periods, except in the amygdala in which they were inhibited only at the later post-trauma intervals. Phenotypically, inhibition of neurogenesis was corroborated by impaired Y-maze behavioral responses. Sustained neuroinflammation appears to drive the development and maintenance of behavioral manifestations of PTSD, potentially via its inhibitory effect on neurogenesis and synaptic plasticity. By contrast, peripheral inflammation seems to be directly responsible for tissue damage underpinning somatic comorbid pathologies. Identification of overlapping, differentially regulated genes and pathways between blood and brain suggests that blood could be a useful and accessible brain surrogate specimen for clinical translation.

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.

Intimate partner violence is associated with increased maternal hair cortisol in mother-child dyads

BACKGROUND

The chronic consequences of intimate partner violence (IPV) on HPA activation are a topic of debate. The current study investigated hair cortisol concentrations in female victims of IPV and their children.

METHODS

A total of 52 mother-child dyads were divided into two groups depending on exposure to IPV: IPV group (n=27 dyads) and control group (n=25 dyads). Hair cortisol concentration was measured in 1-cm-long hair strands, representing 30days of exposure before assessment. PTSD and depression symptoms were assessed in the mother and child.

RESULTS

Women reporting IPV presented with higher hair cortisol levels, depression and PTSD symptoms severity in comparison to control women. Children who witnessed IPV reported more severe PTSD symptoms, but depressive symptoms and hair cortisol were not statistically different than those in control children. Correlation analyses revealed a positive association between the number of injury events and the level of hair cortisol in children. No associations between the hair cortisol levels in mothers and those in their children were found.

CONCLUSION

Higher hair cortisol levels detected in women exposed to IPV reflected long-lasting changes in HPA axis functioning associated with chronic stress exposure. Children whose parents recurrently engage in violent conflicts with intimate partners may often feel threatened and consequently reporting more PTSD-related symptoms. Given that experiencing and witnessing violence during childhood and adolescence are predictive of intimate partner violence in adulthood, the need of early interventions is crucial.

Quality of life in patients with adrenal insufficiency correlates stronger with hydrocortisone dosage, than with long-term systemic cortisol levels

In patients with adrenal insufficiency (AI) a higher hydrocortisone intake has been associated with more impairment in quality of life (QoL). Irrespective of age, sex and severity of AI the dosage of hydrocortisone is titrated around 20mg/D in all patients with AI based on physical and mental signs and symptoms. However, until now it is unknown whether these QoL impairments are related to increased systemic cortisol exposure. Measurement of hair cortisol levels (CORThair) can be used to assess chronic systemic cortisol exposure. This study aimed to explore whether QoL in patients with AI is associated with CORThair and daily hydrocortisone intake. We performed a cross-sectional study in 120 patients with AI on stable hydrocortisone replacement, in whom hair samples and QoL data were collected. CORThair were measured with ELISA, and QoL was assessed with validated questionnaires (SF-36, EQ-5D, HADS, MFI-20). Patients reported impairments in 14 of 15 QoL subscales (p<0.001). More impairments in physical aspects of QoL correlated with higher CORThair and higher daily hydrocortisone intake (p<0.05), an effect that was more pronounced in female patients. Regression analyses including both CORThair and hydrocortisone intake revealed a significant negative contribution of higher hydrocortisone intake on physical aspects of QoL (p≤0.046), whereas no significant contribution was found for CORThair. The present study showed that patients with AI report several impairments in QoL which are associated with hydrocortisone intake, and to a lesser extent reflected by chronic systemic cortisol exposure as measured by hair cortisol. This suggests that QoL impairments in patients with AI are not per se the effect of prolonged exposure to elevated systemic cortisol levels.