Salivary cortisol lower in posttraumatic stress disorder

Current and Cumulative Stress Experiences: A Model for Arab American Young Adults

BACKGROUND

The effect of multiple stressors on immigrant young adults' endocrine functioning and health outcomes has not been comprehensively investigated.

AIMS

This study tested a theoretical model of cumulative and current stressor effects on the hypothalamic-pituitary-adrenocortical (HPA) axis functioning and health-related quality of life (HRQL) among Arab American young adults.

METHODS

Using a cross-sectional design, we recruited 160 participants, ages 18 to 24 years, from an urban university in the Midwest. Cumulative stress was assessed by self-report measures of childhood adversity, bullying victimization, and perceived ethnic discrimination. Current perceived stress was measured using the Perceived Stress Scale (PSS) while cortisol levels were measured in participants' hair. Structural equation modeling tested the effects of cumulative and current stress on cortisol and HRQL.

RESULTS

Cumulative stress was negatively associated with HRQL (standardized path coefficient = -.51, p < .05). Interestingly, however, cumulative stress was inversely associated with hair cortisol level (standardized path coefficient = -.51, p < .05). Current stress was positively associated with cortisol level (standardized path coefficient = .43, p < .05) and negatively associated with the mental HRQL (standardized path coefficient < -.37, p < .05).

CONCLUSION

Cumulative stress exhibited a different effect on HPA functioning from current perceived stress. Mental health was significantly impaired by both cumulative and current perceived stress. Implications for mental health nursing practice and research among Arab Americans are discussed.

Study protocol and rationale for a pilot randomized clinical trial comparing processing of positive memories technique with supportive counseling for PTSD

BACKGROUND

Research indicates that positive memories have a role in posttraumatic stress disorder's (PTSD) symptomatology and treatment. Following treatment development guidelines, a novel PTSD intervention - Processing of Positive Memories Technique (PPMT) - was developed and subsequently examined for its effects and feasibility in pilot studies. Extending this research, the proposed pilot randomized clinical trial with PPMT and Supportive Counseling (SC) arms will examine PPMT's effects on PTSD severity and biomarkers of stress systems' dysregulation (awakening salivary alpha amylase [sAA] and cortisol concentrations); examine mechanistic targets (affect) underlying PPMT's effects; and refine PPMT. We hypothesize that the PPMT arm will report greater decreases in PTSD severity and greater decreases in awakening sAA/cortisol ratio compared to the SC arm; and that improved affect (more positive affect and less negative affect) will mediate associations between intervention arm and changes in PTSD severity.

METHODS

We will recruit 70 individuals aged 18-65 years with PTSD. They will be randomized to 5 weekly therapy sessions of PPMT or SC, and will be assessed at baseline, weekly during treatment, 1-week post-treatment, and 3-months post-treatment. Primary outcomes are past-week PTSD severity, past-week positive and negative affect levels, and feedback data on PPMT's feasibility, format, and content. The secondary outcome is the awakening sAA/cortisol ratio. Statistical analyses include mixed-effect models and within-subjects cross-lag longitudinal mediation analyses.

CONCLUSION

Study results will advance knowledge of trauma interventions by examining effects and feasibility of a novel PTSD intervention, and by elucidating potential mechanisms underlying PPMT's effects. Clinical Trials #: NCT05523453.

Exploring the interplay between posttraumatic stress disorder, gut microbiota, and inflammatory biomarkers: a comprehensive meta-analysis

Introduction

Posttraumatic stress disorder (PTSD) is the most common mental health disorder to develop following exposure to trauma. Studies have reported conflicting results regarding changes in immune biomarkers and alterations in the abundance of bacterial taxa and microbial diversity in patients with PTSD.

Aim

The purpose of this meta-analysis is to summarize existing studies examining gut microbiota characteristics and changes in immune biomarkers in patients with PTSD.

Methods

Relevant studies were systematically searched in PubMed, Scopus, and Embase, published in English between January 1, 1960, and December 1, 2023. The outcomes included changes in abundance and diversity in gut microbiota (gut microbiota part) and changes in immune biomarkers (immune part).

Results

The meta-analysis included a total of 15 studies, with 9 focusing on changes in inflammatory biomarkers and 6 focusing on changes in gut microbiota composition in patients with PTSD. No differences were observed between groups for all inflammatory biomarkers (P≥0.05). Two of the six studies found that people with PTSD had less alpha diversity. However, the overall Standardized Mean Difference (SMD) for the Shannon Diversity Index was not significant (SMD 0.27, 95% CI -0.62-0.609, p = 0.110). Regarding changes in abundance, in two of the studies, a significant decrease in Lachnospiraceae bacteria was observed.

Conclusion

This meta-analysis provides a comprehensive overview of gut microbiota characteristics in PTSD, suggesting potential associations with immune dysregulation. Future research should address study limitations, explore causal relationships, and consider additional factors influencing immune function in individuals with PTSD.

Systematic review registration

https://www.crd.york.ac.uk, identifier CRD42023476590.

Corticotropin-releasing factor signaling and its potential role in the prefrontal cortex-dependent regulation of anxiety

A large body of literature has highlighted the significance of the corticotropin-releasing factor (CRF) system in the regulation of neuropsychiatric diseases. Anxiety disorders are among the most common neuropsychiatric disorders. An increasing number of studies have demonstrated that the CRF family mediates and regulates the development and maintenance of anxiety. Thus, the CRF family is considered to be a potential target for the treatment of anxiety disorders. The prefrontal cortex (PFC) plays a role in the occurrence and development of anxiety, and both CRF and CRF-R1 are widely expressed in the PFC. This paper begins by reviewing CRF-related signaling pathways and their different roles in anxiety and related processes. Then, the role of the CRF system in other neuropsychiatric diseases is reviewed and the potential role of PFC CRF signaling in the regulation of anxiety disorders is discussed. Although other signaling pathways are potentially involved in the process of anxiety, CRF in the PFC primarily modulates anxiety disorders through the activation of corticotropin-releasing factor type1 receptors (CRF-R1) and the excitation of the cAMP/PKA signaling pathway. Moreover, the main signaling pathways of CRF involved in sex differentiation in the PFC appear to be different. In summary, this review suggests that the CRF system in the PFC plays a critical role in the occurrence of anxiety. Thus, CRF signaling is of great significance as a potential target for the treatment of stress-related disorders in the future.

Stress circuitry: mechanisms behind nervous and immune system communication that influence behavior

Inflammatory processes are increased by stress and contribute to the pathology of mood disorders. Stress is thought to primarily induce inflammation through peripheral and central noradrenergic neurotransmission. In healthy individuals, these pro-inflammatory effects are countered by glucocorticoid signaling, which is also activated by stress. In chronically stressed individuals, the anti-inflammatory effects of glucocorticoids are impaired, allowing pro-inflammatory effects to go unchecked. Mechanisms underlying this glucocorticoid resistance are well understood, but the precise circuits and molecular mechanisms by which stress increases inflammation are not as well known. In this narrative review, we summarize the mechanisms by which chronic stress increases inflammation and contributes to the onset and development of stress-related mood disorders. We focus on the neural substrates and molecular mechanisms, especially those regulated by noradrenergic signaling, that increase inflammatory processes in stressed individuals. We also discuss key knowledge gaps in our understanding of the communication between nervous and immune systems during stress and considerations for future therapeutic strategies. Here we highlight the mechanisms by which noradrenergic signaling contributes to inflammatory processes during stress and how this inflammation can contribute to the pathology of stress-related mood disorders. Understanding the mechanisms underlying crosstalk between the nervous and immune systems may lead to novel therapeutic strategies for mood disorders and/or provide important considerations for treating immune-related diseases in individuals suffering from stress-related disorders.

On making (and turning adaptive to) maladaptive aversive memories in laboratory rodents

Fear conditioning and avoidance tasks usually elicit adaptive aversive memories. Traumatic memories are more intense, generalized, inflexible, and resistant to attenuation via extinction- and reconsolidation-based strategies. Inducing and assessing these dysfunctional, maladaptive features in the laboratory are crucial to interrogating posttraumatic stress disorder's neurobiology and exploring innovative treatments. Here we analyze over 350 studies addressing this question in adult rats and mice. There is a growing interest in modeling several qualitative and quantitative memory changes by exposing already stressed animals to freezing- and avoidance-related tests or using a relatively high aversive training magnitude. Other options combine aversive/fearful tasks with post-acquisition or post-retrieval administration of one or more drugs provoking neurochemical or epigenetic alterations reported in the trauma aftermath. It is potentially instructive to integrate these procedures and incorporate the measurement of autonomic and endocrine parameters. Factors to consider when defining the organismic and procedural variables, partially neglected aspects (sex-dependent differences and recent vs. remote data comparison) and suggestions for future research (identifying reliable individual risk and treatment-response predictors) are discussed.

A narrative review of the epigenetics of post-traumatic stress disorder and post-traumatic stress disorder treatment

Epigenetic research in post-traumatic stress disorder (PTSD) is essential, given that environmental stressors and fear play such a crucial role in its development. As such, it may provide a framework for understanding individual differences in the prevalence of the disorder and in treatment response. This paper reviews the epigenetic markers associated with PTSD and its treatment, including candidate genes and epigenome-wide studies. Because the etiopathogenesis of PTSD rests heavily on learning and memory, we also draw upon animal neuroepigenetic research on the acquisition, update and erasure of fear memory, focusing on the mechanisms associated with memory reconsolidation. Reconsolidation blockade (or impairment) treatment in PTSD has been studied in clinical trials and, from a neurological perspective, may hold promise for identifying epigenetic markers of successful therapy. We conclude this paper by discussing several key considerations and challenges in epigenetic research on PTSD in humans.

Post-traumatic stress disorder may set the neurobiological stage for eating disorders: A focus on glutamatergic dysfunction

Post-traumatic stress disorder (PTSD) is a trauma and stress-related disorder which has been shown to be highly comorbid with, and commonly a precedent of, the eating disorders anorexia nervosa, bulimia nervosa, and binge eating disorder. The objective of this review is to discuss a potential overlapping neurobiological mechanism for this comorbidity. Alterations in glutamatergic neurotransmission have been observed in all four of the aforementioned disorders. Excessive excitation via glutamate contributes to excitotoxicity, and over-activation of the hypothalamic-pituitary-adrenal axis, both of which have implications for the deterioration of various brain structures. Prominent structures impacted include the hippocampus, hypothalamus, and prefrontal cortex, all of which are integral to the regulation of stress and eating. The current review suggests that altered glutamate function by trauma or extreme stress may facilitate PTSD and subsequent eating disorder onset, and that glutamatergic modulation may be a key treatment for individuals suffering from these conditions. This overlapping mechanism may help inform future research on individuals with comorbid PTSD and eating disorders, and it could also help inform ways to potentially prevent the onset of these conditions.

Explorations of avoidance and approach coping and perceived stress with a computer-based avatar task: detrimental effects of resignation and withdrawal

Background

Individuals differ in how they react to stress or trauma through different coping styles in which they may deal directly with a stressor by adopting approach coping styles or disengage with a stressor by utilizing avoidant coping styles. Avoidant coping styles have been linked to adverse outcomes including psychological distress, anxiety disorders, and post-traumatic stress disorder (PTSD). Recently, avoidance coping styles as measured by a subset of items on the Brief COPE were found to have a weak positive relationship with performance on a computer-based avatar task which is related to avoidant personality temperaments. This avatar task was developed as an alternative for paper and pencil self-report inventories for measuring avoidant tendencies based on possible response biases of avoidant individuals. In the current study, avoidance and approach coping styles as measured by the Brief Approach/Avoidance Coping Questionnaire (BACQ) were compared to avoidant coping as measured by the Brief COPE and performance on the avatar task. In addition to approach and avoidance coping, the BACQ also measures active avoidance coping (i.e., diversion) and passive avoidance coping (i.e., resignation and withdrawal). The relationships between approach and avoidance coping and performance on the avatar task were also analyzed with the outcome of perceived stress as measured by the Perceived Stress Scale (PSS).

Methods

One hundred undergraduates voluntarily completed the BACQ, the Brief COPE, and the PSS. Participants also completed a computer-based task in which they guided an avatar through a series of social situations where they indicated how they would interact with or avoid interacting with strangers.

Results

Approach coping had a weak negative relationship to avoidance coping as measured by the BACQ and the Brief COPE. Performance on the avatar task had a moderate positive relationship with avoidance coping (diversion as well as resignation and withdrawal) as measured by the BACQ and a moderate negative relationship with approach coping as measured by the BACQ. A model including only approach, diversion, and resignation and withdrawal coping best predicted performance on the avatar task in a linear regression model. While resignation and withdrawal coping and diversion coping had moderate positive relationships to avatar task scores, only resignation and withdrawal had a strong positive relationship to perceived stress. A model than included only resignation and withdrawal coping best predicted perceived stress in a linear regression model. Overall, passive avoidant coping styles (i.e., resignation and withdrawal), but not active avoidant coping style (i.e., diversion), were related to perceived stress. These results support the continued study of multiple aspects of avoidant coping styles as well as the avatar task to increase our understanding of the maladaptive effects of excessive avoidance in the face of stress.

Neurobiological effects of perceived stress are different between adolescents and middle-aged adults

Stress is an inevitable element of everyday living. Developmental studies suggested that adolescents are more vulnerable and sensitive to the effect of stress due to their developing brains, especially in areas related to stress perception and processing. This voxel-based morphometry study examined the association between various neurobiological markers and the level of perceived stress experienced by adolescents (n = 26) and middle-aged adults (n = 26). Our findings indicated that differences existed in the relationships between perceived stress and the structural volume of the orbitofrontal cortex (OFC) extending to the insula and amygdala. Specifically, the levels of perceived stress and the grey matter volume of the orbitofrontal cortex, the insula, and the amygdala were positively related in adolescents but negatively related for adults. Furthermore, a significant negative correlation between perceived stress and cortisol levels was observed in adults, whereas the relationship between perceived stress and cortisol levels was not significant for adolescents. Perceived stress measurement may be better than cortisol levels in terms of reflecting the emotional states of adolescents. In sum, the relationships between perceived stress and neurobiological markers were different between adolescents and middle-aged adults and thus appeared to be age dependent.

Biopsychosocial correlates of psychological distress in Latina mothers

BACKGROUND

Few studies have explored the relationship between psychological, psychosocial and biological factors among Latinas. An integrated understanding of how these factors associate with psychological distress is necessary for the development of culturally relevant screening tools and interventions. The study aim was to examine the relationships among (a) psychological distress symptoms, (b) psychosocial factors (discrimination, acculturation, acculturative stress, economic hardship), and (c) biological (DNA methylation of stress-related genes) factors among Latinas during pregnancy and postpartum period.

METHODS

A sample of 150 pregnant Latinas completed the Inventory of Depression and Anxiety Symptoms II (IDAS-II), psychosocial questionnaires (discrimination, acculturation, acculturative stress, economic hardship) before (24-32 weeks) and after gestation (4-6 weeks postpartum). Blood samples were collected between 24-32 weeks gestation. Correlations were determined between psychosocial and biological measures and psychological distress measures. Multivariable linear regression models were conducted to assess the relationships between IDAS and stressors.

RESULTS

Several correlations among psychosocial measures,DNA methylation factors and IDAS-II variables were identified. Among the psychosocial measures, everyday discrimination was the most strongly and consistently associated with IDAS-II. DNA methylation of NR3C1 affects the associations between psychological and psychosocial distress.

LIMITATIONS

We only assessed DNA methylation during pregnancy and focused on four HPA-related genes. Longitudinal assessment of DNA methylation and genome-wide analysis can provide a better picture of the role of methylation in psychological distress.

CONCLUSIONS

This work may assist clinicians and policy makers in effectively recognizing and preventing maternal mental health disparities based on discrimination and other psychosocial stressors in at-risk groups.

Cannabis use and posttraumatic stress disorder comorbidity: Epidemiology, biology and the potential for novel treatment approaches

Cannabis use is increasing among some demographics in the United States and is tightly linked to anxiety, trauma, and stress reactivity at the epidemiological and biological level. Stress-coping motives are highly cited reasons for cannabis use. However, with increased cannabis use comes the increased susceptibility for cannabis use disorder (CUD). Indeed, CUD is highly comorbid with posttraumatic stress disorder (PTSD). Importantly, endogenous cannabinoid signaling systems play a key role in the regulation of stress reactivity and anxiety regulation, and preclinical data suggest deficiencies in this signaling system could contribute to the development of stress-related psychopathology. Furthermore, endocannabinoid deficiency states, either pre-existing or induced by trauma exposure, could provide explanatory insights into the high rates of comorbid cannabis use in patients with PTSD. Here we review clinical and preclinical literature related to the cannabis use-PTSD comorbidity, the role of endocannabinoids in the regulation of stress reactivity, and potential therapeutic implications of recent work in this area.

Mathematical modeling of depressive disorders: Circadian driving, bistability and dynamical transitions

The hypothalamus-pituitary-adrenal (HPA) axis is a key neuroendocrine system implicated in stress response, major depression disorder, and post-traumatic stress disorder. We present a new, compact dynamical systems model for the response of the HPA axis to external stimuli, representing stressors or therapeutic intervention, in the presence of a circadian input. Our work builds upon previous HPA axis models where hormonal dynamics are separated into slow and fast components. Several simplifications allow us to derive an effective model of two equations, similar to a multiplicative-input FitzHugh-Nagumo system, where two stable states, a healthy and a diseased one, arise. We analyze the effective model in the context of state transitions driven by external shocks to the hypothalamus, but also modulated by circadian rhythms. Our analyses provide mechanistic insight into the effects of the circadian cycle on input driven transitions of the HPA axis and suggest a circadian influence on exposure or cognitive behavioral therapy in depression, or post-traumatic stress disorder treatment.

Yoga for veterans with PTSD: Cognitive functioning, mental health, and salivary cortisol

Objective: Research indicates that cognitive functioning is negatively impacted by exposure to chronic stress due to overactivation of the stress response. Yoga has demonstrated benefits when practiced by individuals diagnosed with posttraumatic stress disorder (PTSD). This quasi-experimental pilot study examined the impact of a yoga intervention on cognitive functioning, symptoms of PTSD, and the biological stress response in Veterans diagnosed with PTSD. Method: Cognitive functioning, self-report measures of mental health symptoms, and salivary cortisol were measured within two weeks prior to beginning and following completion of a 10-week yoga protocol. Veterans with PTSD participated in gender-specific groups of the yoga intervention. Paired t tests and correlational analyses were used to analyze quantitative data. Results: Statistically significant improvements were observed between baseline and postintervention scores on measures of response inhibition, PTSD, depression, sleep, quality of life, and subjective neurocognitive complaints. Positive correlations were found between baseline and postintervention changes in sleep and depression, and between change in cortisol output and a measure of life satisfaction. Statistically significant differences (baseline to postintervention) for other objective measures of cognitive performance and cortisol were not detected. Conclusions: Results provide preliminary support for the practice of yoga to improve cognitive functioning (response inhibition) related to symptoms of PTSD while also improving mental health symptoms, sleep, and quality of life. Positive correlations affirm the role of sleep in mood symptoms and indicate the need for further examination of the role of cortisol in life satisfaction. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Hypothalamic-pituitary-adrenal axis activity in post-traumatic stress disorder and cocaine use disorder

Post-traumatic stress disorder (PTSD) is often comorbid with cocaine use disorder (CUD), but little is known about hypothalamic-pituitary-adrenal (HPA) axis function in PTSD + CUD. Here we review the clinical and pre-clinical literature of PTSD and CUD with the goal of generating hypotheses about HPA axis activity in comorbid PTSD + CUD. Low glucocorticoid (CORT) levels immediately after trauma exposure are associated with PTSD. CORT administered within 12 h of trauma exposure reduces later PTSD symptoms. Weeks-years after trauma, meta-analyses find lower CORT levels in patients with PTSD relative to never-traumatized controls; the same is found in a pre-clinical model of PTSD. In rodents, reduced basal CORT levels are consistently found after chronic cocaine self-administration. Conversely, increased CORT levels are found in CUD patients during the first 2 weeks of cocaine abstinence. There is evidence for CORT hyper-suppression after dexamethasone, high glucocorticoid receptor (GR) number pre-trauma, and increased GR translocation to the nucleus in PTSD. Hyper-suppression of HPA axis activity after dexamethasone suggests that PTSD individuals may have increased anterior pituitary GR. Given evidence for decreased anterior pituitary GR in rats that self-administer cocaine, PTSD + CUD individuals may have normal GR density and low basal CORT levels during late abstinence. Future studies should aim to reconcile the differences in pre-clinical and clinical basal CORT levels during cocaine and assess HPA axis function in both rodent models of CUD that consider stress-susceptibility and in PTSD + CUD individuals. Although additional studies are necessary, individuals with PTSD + CUD may benefit from behavioral and psychopharmacological treatments to normalize HPA axis activity. LAY SUMMARY Post-traumatic stress disorder (PTSD) is often comorbid with cocaine use disorder (CUD), but little is known about the hypothalamic-pituitary-adrenal (HPA) axis function in PTSD + CUD. The current review provides a synthesis of available clinical and pre-clinical data on PTSD and CUD with the goal of generating hypotheses about HPA axis activity in comorbid PTSD + CUD. While this review finds ample evidence supporting aberrant HPA axis activity in both PTSD and CUD, it suggests that more research is needed to understand the unique changes HPA axis activity in PTSD + CUD, as well as the bidirectional relationship between stress-susceptibility and motivation to seek cocaine.

Role of enhanced glucocorticoid receptor sensitivity in inflammation in PTSD: insights from computational model for circadian-neuroendocrine-immune interactions

Although glucocorticoid resistance contributes to increased inflammation, individuals with posttraumatic stress disorder (PTSD) exhibit increased glucocorticoid receptor (GR) sensitivity along with increased inflammation. It is not clear how inflammation coexists with a hyperresponsive hypothalamic-pituitary-adrenal (HPA) axis. To understand this better, we developed and analyzed an integrated mathematical model for the HPA axis and the immune system. We performed mathematical simulations for a dexamethasone (DEX) suppression test and IC₅₀-dexamethasone for cytokine suppression by varying model parameters. The model analysis suggests that increasing the steepness of the dose-response curve for GR activity may reduce anti-inflammatory effects of GRs at the ambient glucocorticoid levels, thereby increasing proinflammatory response. The adaptive response of proinflammatory cytokine-mediated stimulatory effects on the HPA axis is reduced due to dominance of the GR-mediated negative feedback on the HPA axis. To verify these hypotheses, we analyzed the clinical data on neuroendocrine variables and cytokines obtained from war-zone veterans with and without PTSD. We observed significant group differences for cortisol and ACTH suppression tests, proinflammatory cytokines TNFα and IL6, high-sensitivity C-reactive protein, promoter methylation of GR gene, and IC_50-DEX for lysozyme suppression. Causal inference modeling revealed significant associations between cortisol suppression and post-DEX cortisol decline, promoter methylation of human GR gene exon 1F (NR3C1-1F), IC_50-DEX, and proinflammatory cytokines. We noted significant mediation effects of NR3C1-1F promoter methylation on inflammatory cytokines through changes in GR sensitivity. Our findings suggest that increased GR sensitivity may contribute to increased inflammation; therefore, interventions to restore GR sensitivity may normalize inflammation in PTSD.

Cannabinoids as therapeutics for PTSD

Post-traumatic stress disorder (PTSD) is a complex disorder that involves dysregulation of multiple neurobiological systems. The traumatic stressor plays a causal role in producing psychological dysfunction and the pattern of findings suggests that the hypothalamic-pituitary-adrenal (HPA) axis, which is instrumental for stress adaptation, is critically dysfunctional in PTSD. Given the lack of understanding of the basic mechanisms and underlying pathways that cause the disorder and its heterogeneity, PTSD poses challenges for treatment. Targeting the endocannabinoid (ECB) system to treat mental disorders, and PTSD in particular, has been the focus of research and interest in recent years. The ECB system modulates multiple functions, and drugs enhancing ECB signaling have shown promise as potential therapeutic agents in stress effects and other psychiatric and medical conditions. In this review, we focus on the interaction between the ECB-HPA systems in animal models for PTSD and in patients with PTSD. We summarize evidence supporting the use of cannabinoids in preventing and treating PTSD in preclinical and clinical studies. As the HPA system plays a key role in the mediation of the stress response and the pathophysiology of PTSD, we describe preclinical studies suggesting that enhancing ECB signaling is consistent with decreasing PTSD symptoms and dysfunction of the HPA axis. Overall, we suggest that a pharmacological treatment targeted at one system (e.g., HPA) may not be very effective because of the heterogeneity of the disorder. There are abnormalities across different neurotransmitter systems in the pathophysiology of PTSD and none of these systems function uniformly among all patients with PTSD. Hence, conceptually, enhancing ECB signaling may be a more effective avenue for pharmacological treatment.

Early Life Stress and Pediatric Posttraumatic Stress Disorder

Traumatic stress exposure during critical periods of development may have essential and long-lasting effects on the physical and mental health of individuals. Two thirds of youth are exposed to potentially traumatic experiences by the age of 17, and approximately 5% of adolescents meet lifetime criteria for posttraumatic stress disorder (PTSD). The role of the stress system is the maintenance of homeostasis in the presence of real/perceived and acute/chronic stressors. Early-life stress (ELS) has an impact on neuronal brain networks involved in stress reactions, and could exert a programming effect on glucocorticoid signaling. Studies on pediatric PTSD reveal diverse neuroendocrine responses to adverse events and related long-term neuroendocrine and epigenetic alterations. Neuroendocrine, neuroimaging, and genetic studies in children with PTSD and ELS experiences are crucial in understanding risk and resilience factors, and also the natural history of PTSD.

The mediating impact of PTSD symptoms on cortisol awakening response in the context of intimate partner violence

Multi-level modeling examined the association between cortisol awakening responses (CAR) and different PTSD symptom clusters in a sample of 158 female participants presenting with intimate partner violence-related PTSD. Results revealed that arousal over the past week and month, respectively ([β = -0.124, z = -2.33, p = .028; β = -.147, z = -2.19, p = .028]) significantly moderated the trajectory of cortisol levels, and emotional numbing symptom severity (over the past week [β = -0.122, z = -2.07, p = .076]) was found to be trending toward significance. In each case higher symptom severity was associated with flatter CAR slopes compared to those with lower symptom severity. Assessing PTSD symptom clusters in relation to cortisol may better inform future interventions compared to studies that assess PTSD globally. Our findings suggest a subtype of PTSD patients displaying higher levels of arousal may be more likely to experience alterations in HPA axis functioning.

The 24-hour urinary cortisol in post-traumatic stress disorder: A meta-analysis

Objective

Previous studies found inconsistent results on the relationship between post-traumatic stress disorder (PTSD) and concentrations of 24-hour (24-h) urinary cortisol. This study performed a systematic review and meta-analysis to summarize previous findings on this relationship.

Methods

We searched in the databases of Web of Science, PubMed, Embase, and Psyc-ARTICLES for articles published before September 2018. We used the random-effects model with restricted maximum-likelihood estimator to synthesize the effect sizes by calculating the standardized mean difference (SMD) and assessing its significance.

Results

Six hundred and nineteen articles were identified from the preceding databases and 20 of them were included in the meta-analysis. Lower concentrations of 24-h urinary cortisol were observed in patients with PTSD when compared with the controls (SMD = -0.49, 95%CI [-0.91; -0.07], p = 0.02). Subgroup analysis revealed that the concentrations of 24-h urinary cortisol were lower in PTSD patients than in the controls for studies that included female participants or studies that included participants from the United States of America.

Conclusions

Overall, decreased levels of 24-h urinary cortisol were linked with the pathophysiology of PTSD. Nonetheless, more studies should be conducted to validate the molecular underpinnings of urine cortisol degeneration in PTSD.

HPA axis function and diurnal cortisol in post-traumatic stress disorder: A systematic review

BACKGROUND

There is inconsistency in the literature regarding the nature of hypothalamic-pituitary-adrenal (HPA) axis functionality in post-traumatic stress disorder (PTSD).

PURPOSE

The review aimed to investigate HPA axis functionality via the diurnal profile of cortisol as it relates to PTSD.

METHODS

The authors conducted a systematic review of the literature from June 2017 - March 2019 in accordance with The PRISMA Statement in the following four databases: PubMed, MEDLINE, ScienceDirect and PsycINFO with Full Text. The search strategy was limited to articles in English language, published in peer-reviewed journals within the last decade and human studies. Search terms included "post-traumatic stress disorder" OR "PTSD", AND "hypothalamic pituitary adrenal axis" OR "HPA axis" AND "diurnal cortisol" OR "cortisol". PTSD sufferers of all trauma types, genders and socioeconomic statuses were included provided there was a "healthy" control group and an inclusion of reporting on inter-group measurements of diurnal cortisol profiles as a portrayal of HPA axis functionality.

RESULTS

A total of 10 studies met the criteria for inclusion in this review. The association between HPA axis functionality and PTSD was evaluated by the measurement of salivary and/or plasma cortisol concentrations. Only two studies demonstrated an association between PTSD and diurnal cortisol when compared with respective control groups while three studies found no associations. The remaining five studies found partial, mostly negative associations between PTSD and diurnal cortisol.

CONCLUSION

Despite some indications of an association between PTSD and dysregulated HPA axis functionality as demonstrated by diurnal cortisol output, the current review has revealed mixed findings. As such, a complete understanding of HPA axis dysregulation as it relates to PTSD remains unestablished. Given the findings, further investigation into the relationship between PTSD trauma-exposed and non-PTSD trauma-exposed individuals and diurnal cortisol is warranted.

Late glucocorticoid receptor antagonism changes the outcome of adult life stress

BACKGROUND

Stressors activate a wide spectrum of interacting hormonal and neuronal systems resulting in behavioral and physiological responses, with consequences for the development of psychopathology. Several recent studies demonstrated that treatment with the glucocorticoid receptor (GR) antagonist RU486 during adulthood normalized effects of early life stress. We aimed to evaluate the potential of RU486 to reverse stress-induced changes in an animal model of adult stress.

METHOD

We employed the single-prolonged stress (SPS) model as a multimodal stress exposure protocol in male rats. SPS rats and unstressed controls were treated with RU486 on days 8, 9, 10 after stress exposure and the effects of treatment were evaluated after another 4 days. We determined body weight gain, corticosterone levels, behavioral reactivity in anxiety tests, and brain gene expression of c-fos, corticosteroid receptors, drivers of the stress response and genes (epi-)genitally linked to PTSD.

RESULTS

RU486 affected body weight gain, corticosterone levels and open field behavior only in SPS rats. RU486 had history-independent effects in reducing fear in the elevated plus maze and fear conditioning behavior. Gene expression analysis showed a diversity of in- and interdependent effects of stress and RU486.

CONCLUSION

The effects of RU486 applied 1 week after stress and measured 4 days after treatment demonstrate that in the state of post-SPS the GR-dependence of homeostatic processes has changed. This suggests that GR-mediated processes are part of allostatic regulation after adult stress. The normalization of a number of SPS-effects after RU486 treatment reinforces the potential of targeting GR for treatment of stress-related psychopathologies.

Novel Treatment Targets Based on Insights in the Etiology of Depression: Role of IL-6 Trans-Signaling and Stress-Induced Elevation of Glutamate and ATP

Inflammation and psychological stress are risk factors for major depression and suicide. Both increase central glutamate levels and activate the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system. Both factors also affect the function of the chloride transporters, Na-K-Cl-cotransporter-1 (NKCC1) and K-Cl-cotransporter-2 (KCC2), and provoke interleukin-6 (IL-6) trans-signaling. This leads to measurable increases in circulating corticosteroids, catecholamines, anxiety, somatic and psychological symptoms, and a decline in cognitive functions. Recognition of the sequence of pathological events allows the prediction of novel targets for therapeutic intervention. Amongst others, these include blockade of the big-K potassium channel, blockade of the P2X4 channel, TYK2-kinase inhibition, noradrenaline α2B-receptor antagonism, nicotinic α7-receptor stimulation, and the Sgp130Fc antibody. A better understanding of downstream processes evoked by inflammation and stress also allows suggestions for tentatively better biomarkers (e.g., SERPINA3N, MARCKS, or ¹³C-tryptophan metabolism).

Ethnic differences in diurnal cortisol profiles in healthy adults: A meta-analysis

PURPOSE

Cortisol is a well-known biomarker of the physiological stress system; atypical cortisol patterns have been linked to many psychological and physiological illnesses. Previous studies have found vast health disparities among ethnic groups; however, studies examining the relationship between cortisol and ethnicity have found mixed results. This meta-analysis investigated whether there are differences in diurnal cortisol outcomes among ethnic groups, while considering the moderating roles of various individual factors and methodological approaches.

METHODS

Search phrases were entered into MEDLINE, PsycINFO, EMBASE, Cochrane Library, CINAHL, Scopus, and Web of Science. Effect sizes were extracted for ten diurnal cortisol outcomes, including waking, 30 min after waking, cortisol awakening response, slope, area under the curve, urinary twenty-four-hour secretion, total cortisol output, and midday, evening, and bedtime concentrations, for eight ethnic group comparisons, including Asians, Blacks, Hispanics, Indigenous people, Whites, Minority and Majority groups, and Multiethnic groups. Moderator analyses, including variables such as gender, age, and number of cortisol collection time points, were conducted.

RESULTS

There were significant ethnic differences in diurnal cortisol profiles, including cortisol awakening responses, with more robust differences in ethnic comparisons that included White participants. Differences in diurnal cortisol profiles were also moderated by gender, mean age, and sample size.

CONCLUSIONS

This meta-analysis supports the notion that ethnic groups exhibit distinct diurnal cortisol profiles, which, according to the biopsychosocial model of health, may be a result of unique sociocultural experiences. The limitations of this meta-analysis and future directions for stress research with various ethnic groups are discussed. Statement of contribution What is already known on this subject? Studies have found vast health disparities among ethnic groups. Psychological and physiological illnesses and atypical diurnal cortisol profiles are strongly correlated. Studies have examined the relationship between diurnal cortisol rhythms and ethnicity, but findings are mixed. What does this study add? This study is a systematic examination of the relationship between diurnal cortisol rhythm and ethnicity. Psychosocial and methodological factors moderate the relationship between diurnal cortisol output and ethnicity. This study provides insight on factors that contribute to health disparities among ethnic groups.

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.

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.

Multilevel Interactions of Stress and Circadian System: Implications for Traumatic Stress

The dramatic fluctuations in energy demands by the rhythmic succession of night and day on our planet has prompted a geophysical evolutionary need for biological temporal organization across phylogeny. The intrinsic circadian timing system (CS) represents a highly conserved and sophisticated internal "clock," adjusted to the 24-h rotation period of the earth, enabling a nyctohemeral coordination of numerous physiologic processes, from gene expression to behavior. The human CS is tightly and bidirectionally interconnected to the stress system (SS). Both systems are fundamental for survival and regulate each other's activity in order to prepare the organism for the anticipated cyclic challenges. Thereby, the understanding of the temporal relationship between stressors and stress responses is critical for the comprehension of the molecular basis of physiology and pathogenesis of disease. A critical loss of the harmonious timed order at different organizational levels may affect the fundamental properties of neuroendocrine, immune, and autonomic systems, leading to a breakdown of biobehavioral adaptative mechanisms with increased stress sensitivity and vulnerability. In this review, following an overview of the functional components of the SS and CS, we present their multilevel interactions and discuss how traumatic stress can alter the interplay between the two systems. Circadian dysregulation after traumatic stress exposure may represent a core feature of trauma-related disorders mediating enduring neurobiological correlates of trauma through maladaptive stress regulation. Understanding the mechanisms susceptible to circadian dysregulation and their role in stress-related disorders could provide new insights into disease mechanisms, advancing psychochronobiological treatment possibilities and preventive strategies in stress-exposed populations.

Efficacy of equine-assisted psychotherapy in veterans with posttraumatic stress disorder

BACKGROUND

Posttraumatic stress disorder (PTSD) is a common and debilitating disorder among war veterans. Although complementary and alternative therapies are gaining acceptance in the treatment of PTSD, the efficacy of animal-based therapies in this disorder is unknown. The goal of equine-assisted psychotherapy (EAP) is to improve the social, emotional, and/or cognitive functions of individuals with PTSD.

OBJECTIVE

This study aims to explore the effects of EAP on PTSD symptoms. We hypothesized that veterans with PTSD who participate in a standardized EAP program for 1 h per week for 6 weeks would experience decreased PTSD symptoms and would demonstrate increased resilience as compared with individuals who do not receive EAP intervention.

DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS

We conducted a sequentially assigned, two-arm parallel group trial comparing 6 weeks of EAP with standard, previously established, ongoing PTSD therapy. Therapy was conducted at a community EAP facility in conjunction with an academic University Hospital. Twenty adult veterans with symptomatic PTSD completed the study. Ten adult veterans with previously diagnosed PTSD were assigned to EAP and received directed interaction with trained horses for one hour a week in groups of 3 or 4 individuals, while also continuing their previously established therapies. A certified therapist supervised the sessions, and a professional horse handler was also present. Results were compared with those from 10 adult veterans who only received their standard previously established PTSD care as prescribed by their provider.

MAIN OUTCOME MEASURES

Changes in salivary cortisol, scores for the PTSD Check List-Military Version (PCL-M) and the Connor-Davidson Resilience Scale (CD-RISC) after 6 weeks of study were measured.

RESULTS

Of the 20 enrolled patients, 10 served in Afghanistan, 5 served in Iraq, and 3 served in Vietnam. Subjects were (47 ± 14) years old, were predominantly male, and had a body mass index of (29 ± 7) kg/m². They had (9.2 ± 6.1) years of military service and carried 66% ± 37% service-connected disability. PCL-M scores declined significantly in both groups and CD-RISC scores increased significantly in the EAP group. There was no difference between the groups with respect to the magnitude of change.

CONCLUSION

As compared to the control group, a 6-week EAP program did not produce a statistically significant difference with respect to PCL-M and CD-RISC scores, or salivary cortisol. However, our results suggest that EAP may work as well as standard therapy with respect to these parameters. This study supports further inquiry into EAP as a potentially efficacious alternative for veterans suffering from PTSD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT #03039361.

Salivary cortisol reveals overt and hidden anxiety in survivors of childhood cancer attending clinic

BACKGROUND

Symptoms of anxiety may arise from fear of cancer recurrence and memories of traumatic experiences during treatment. This study aimed to identify changes in mental health and cortisol, a biological marker of stress, associated with oncology surveillance clinic attendance.

METHODS

Adolescent and young adult (AYA) survivors of childhood cancer (aged 12-30 years, N = 46) attending a survivorship clinic were recruited. The State-Trait Anxiety Inventory, an anxiety self-rating and open answer question, and salivary cortisol collections were completed two weeks before and one day before clinic, on clinic day and two weeks after.

RESULTS

Trait anxiety scores were consistent with the normal population. State anxiety scores two weeks after clinic were significantly lower than baseline (p = 0.02). Cortisol diurnal slopes were flatter than baseline after clinic (p = 0.02). Evening cortisol levels were significantly higher than baseline two weeks post clinic (p = 0.02).

LIMITATIONS

Combined results from biological and psychometric assessments can be difficult to interpret. Larger cohorts will further delineate cortisol pathway activity and distress in AYA cancer survivors.

CONCLUSIONS

Psychometric evidence indicates that AYA survivors of childhood cancer perceive themselves to be less anxious after a survivorship clinic visit. Biological evidence, however, indicates a dysregulation of the hypothalamic-pituitary-adrenal axis which may be linked to clinic attendance. Weak correlations suggest that cortisol may not be a reliable indicator of self-perceived anxiety. This may be due to confounding lifestyle factors influencing the stress response or potential 'coping strategies' developed during past treatment experience which may, hypothetically, have masked self-perceived anxiety.

Salivary cortisol in post-traumatic stress disorder: a systematic review and meta-analysis

BACKGROUND

Studies investigating salivary cortisol level as susceptibility marker for post-traumatic stress disorder (PTSD) produced inconsistent results. The aim of this study was to compare salivary cortisol concentration levels in PTSD patients with those in controls by synthesizing published data.

METHODS

We did a systematic review, meta-analysis and meta-regression of studies comparing concentrations of salivary cortisol between patients with PTSD and controls. The electronic databases of PubMed, Embase, Web of Science and Psyc-ARTICLES were searched for relevant articles. A random-effects model with restricted maximum-likelihood estimator is used to synthesize the effect size (assessed by standardized mean difference).

RESULTS

A total of 784 articles were identified of which 22 were included in the final analysis. A trend of lower salivary cortisol levels was found in PTSD patients when compared with the controls (SMD = - 0.28, 95% CI-0.53;-0.04, p = 0.022). Subgroup analysis showed that the salivary cortisol levels were lower in patients with PTSD than in controls in studies conducted after 2007 or in studies using saliva samples collected in the morning.

CONCLUSIONS

The evidence from this meta-analysis supports that salivary samples collected in the morning consistently showed a lower salivary cortisol level in patients with PTSD than in controls, although whether salivary cortisol could be used as a diagnostic tool requires further research.

Cortisol Modulation by Ayahuasca in Patients With Treatment Resistant Depression and Healthy Controls

Major depression is a highly prevalent mood disorder, affecting about 350 million people, and around 30% of the patients are resistant to currently available antidepressant medications. Recent evidence from a randomized controlled trial (RCT) supports the rapid antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression. The aim of this study was to explore the effect of ayahuasca on plasma cortisol and awakening salivary cortisol response, in the same group of treatment-resistant patients (MD) and in healthy volunteers (C). Subjects received a single dose of ayahuasca or placebo (dosing session), and both plasma and awakening salivary cortisol response were measured at baseline (before dosing session) and 48 h after the dosing session. Baseline assessment (D0) showed blunted awakening salivary cortisol response and hypocortisolemia in patients, with respect to healthy controls. Salivary cortisol was also measured during dosing session, and we observed higher increases for both C and MD that ingested ayahuasca than placebo. After 48 h from the dosing session with ayahuasca, patients' awakening salivary cortisol response is similar to the ones detected in controls. No significant changes in plasma cortisol levels were observed 48 h after the sessions. Therefore, these findings point to new evidence on the modulation of salivary cortisol levels as a result of an ayahuasca session, both in healthy and depressive volunteers. Considering that cortisol acts in regulation of distinct physiological pathways, emotional and cognitive processes, it is assumed to be critically involved to the etiology of depression and its regulation seems to be important for the treatment and remission of major depression, ayahuasca use as antidepressant should be further investigated. Moreover, this study highlights the importance of psychedelics in the treatment of human mental disorders.

Psychosocial functioning and the cortisol awakening response: Meta-analysis, P-curve analysis, and evaluation of the evidential value in existing studies

Cortisol levels rise immediately after awakening and peak approximately 30-45min thereafter. Psychosocial functioning influences this cortisol awakening response (CAR), but there is considerable heterogeneity in the literature. The current study used p-curve and meta-analysis on 709 findings from 212 studies to test the evidential value and estimate effect sizes of four sets of findings: those associating worse psychosocial functioning with higher or lower cortisol increase relative to the waking period (CARi) and to the output of the waking period (AUCw). All four sets of findings demonstrated evidential value. Psychosocial predictors explained 1%-3.6% of variance in CARi and AUCw responses. Based on these effect sizes, cross-sectional studies assessing CAR would need a minimum sample size of 617-783 to detect true effects with 80% power. Depression was linked to higher AUCw and posttraumatic stress to lower AUCw, whereas inconclusive results were obtained for predictor-specific effects on CARi. Suggestions for future CAR research are discussed.

Pre-treatment cortisol awakening response predicts symptom reduction in posttraumatic stress disorder after treatment

Dysfunction of the HPA-axis has frequently been found in the aftermath of trauma exposure with or without PTSD. Decreasing HPA-axis reactivity to different stress cues has been reported during PTSD treatment. The cortisol awakening response (CAR_i) is a well-validated, standardized measure of HPA-axis reactivity which can be easily acquired in the clinical setting. Whether CAR_i changes over time in traumatized individuals are specific to PTSD treatment is unknown. Furthermore, a possible role for the baseline CAR_i in predicting symptom reduction after treatment in PTSD has not been examined before. To answer these questions, a cohort study was conducted in which the awakening cortisol was measured in both PTSD (N=41) and non-PTSD (N=25) combat-exposed male subjects. Measurements took place at inclusion and 6-8 months after inclusion for both the PTSD and the non-PTSD group. During the 6-8 months interval, PTSD patients received trauma-focused focused psychotherapy, whereas non-PTSD patients received no treatment. We found a decrease in the CAR_i over time in both groups, suggesting it was not specific to PTSD or the effect of treatment. Therefore, caution is warranted when attributing diminished HPA-axis reactivity over time to effects of PTSD treatment. Second, CAR_i prior to treatment predicted PTSD symptom reduction (CAPS score change) after treatment, and accounted for 10% of the variance, even when adjusted for changes in depressive symptoms and medication use during the study period. A putative role emerges for CAR_i as a predictive biomarker of symptom reduction in male individuals with combat-related PTSD.

Systematic Review on Post-Traumatic Stress Disorder Among Survivors of the Wenchuan Earthquake

Post-traumatic stress disorder (PTSD) widely occurs among victims or witness of disasters. With flashbacks, hyperarousal, and avoidance being the typical symptoms, PTSD became a focus of psychological research. The earthquake in Wenchuan, China, on May 12, 2008, was without precedent in magnitude and aftermath and caused huge damage, which drew scientists' attention to mental health of the survivors. We conducted a systematic overview by collecting published articles from the PubMed database and classifying them into five points: epidemiology, neuropathology, biochemistry, genetics and epigenetics, and treatment. The large body of research during the past 6 years showed that adolescents and adults were among the most studied populations with high prevalence rates for PTSD. Genomic and transcriptomic studies focusing on gene × environment studies as well as epigenetics are still rare, although a few available data showed great potential to better understand the pathophysiology of PTSD as multifactorial disease. Phytotherapy with Chinese herbs and acupuncture are rarely reported as of yet, although the first published data indicated promising therapy effects. Future studies should focus on the following points: (1) The affected populations under observation should be better defined concerning individual risk factor, time of observation, spatial movement, and individual disease courses of patients. (2) The role of social support for prevalence rates of PTSD should be observed in more detail. (3) Efficacy and safety of Chinese medicine should be studied to find potential interventions and effective treatments of PTSD.

Meditation in Stressed Older Adults: Improvements in self-rated mental health not paralleled by improvements in cognitive function or physiological measures

To determine if mindfulness meditation (MM) in older adults improves cognition and, secondarily, if MM improves mental health and physiology, 134 at least mildly stressed 50-85 year olds were randomized to a six-week MM intervention or a waitlist control. Outcome measures were assessed at baseline and two months later at Visit 2. The primary outcome measure was an executive function/attentional measure (flanker task). Other outcome measures included additional cognitive assessments, salivary cortisol, respiratory rate, heart rate variability, Positive and Negative Affect Schedule (PANAS), Center for Epidemiologic Studies Depression (CESD), Perceived Stress Scale (PSS), Neuroticism-Extraversion-Openness (NEO) personality traits, and SF-36 health-related quality of life. 128 participants completed the study though Visit 2 assessments. There was no significant change in the primary or other cognitive outcome measures. Even after statistical adjustment for multiple outcomes, self-rated measures related to negative affect and stress were all significantly improved in the MM intervention compared to wait-list group (PANAS-negative, CESD, PSS, and SF-36 health-related quality of life Vitality and Mental Health Component). The SF-36 Mental Health Component score improved more than the minimum clinically important difference. There were also significant changes in personality traits such as Neuroticism. Changes in positive affect were not observed. There were no group differences in salivary cortisol, or heart rate variability. These moderate sized improvements in self-rated measures were not paralleled by improvements in cognitive function or physiological measures. Potential explanations for this discrepancy in stress-related outcomes are discussed to help improve future studies.

Neurobiology of comorbid post-traumatic stress disorder and alcohol-use disorder

Post-traumatic stress disorder (PTSD) and alcohol-use disorder (AUD) are highly comorbid in humans. Although we have some understanding of the structural and functional brain changes that define each of these disorders, and how those changes contribute to the behavioral symptoms that define them, little is known about the neurobiology of comorbid PTSD and AUD, which may be due in part to a scarcity of adequate animal models for examining this research question. The goal of this review is to summarize the current state-of-the-science on comorbid PTSD and AUD. We summarize epidemiological data documenting the prevalence of this comorbidity, review what is known about the potential neurobiological basis for the frequent co-occurrence of PTSD and AUD and discuss successes and failures of past and current treatment strategies. We also review animal models that aim to examine comorbid PTSD and AUD, highlighting where the models parallel the human condition, and we discuss the strengths and weaknesses of each model. We conclude by discussing key gaps in our knowledge and strategies for addressing them: in particular, we (1) highlight the need for better animal models of the comorbid condition and better clinical trial design, (2) emphasize the need for examination of subpopulation effects and individual differences and (3) urge cross-talk between basic and clinical researchers that is reflected in collaborative work with forward and reverse translational impact.

The centrality of fear extinction in linking risk factors to PTSD: A narrative review

Recent prospective studies in emergency services have identified impaired fear extinction learning and memory to be a significant predictor of Posttraumatic Stress Disorder (PTSD), complementing a wealth of cross-sectional evidence of extinction deficits associated with the disorder. Additional fields of research show specific risk factors and biomarkers of the disorder, including candidate genotypes, stress and sex hormones, cognitive factors, and sleep disturbances. Studies in mostly nonclinical populations also reveal that the aforementioned factors are involved in fear extinction learning and memory. Here, we provide a comprehensive narrative review of the literature linking PTSD to these risk factors, and linking these risk factors to impaired fear extinction. On balance, the evidence suggests that fear extinction may play a role in the relationship between risk factors and PTSD. Should this notion hold true, this review carries important implications for the improvement of exposure-based treatments, as well as strategies for the implementation of treatment.

Posttraumatic Stress Disorder, Overweight, and Obesity: A Systematic Review and Meta-analysis

Previous reports have suggested a high prevalence of overweight and obesity among individuals with posttraumatic stress disorder (PTSD). Few studies, however, systematically analyze the relationship between PTSD and body mass index (BMI). We conducted a systematic review and meta-analysis aimed at estimating the association between PTSD and BMI. Fifty-four articles were reviewed, 30 of which (with 191,948 individuals with PTSD and 418,690 trauma-exposed individuals or healthy controls) were eligible for inclusion in the meta-analysis. The pooled standard mean difference, based on a random-effects model, was 0.41 (95% confidence interval, 0.28-0.54; z = 6.26; p < .001). Statistical heterogeneity between the included studies was high (p < .001; I = 99%). Despite limitations, the findings of this systematic review and meta-analysis suggest an association between PTSD and BMI. Furthermore, longitudinal studies tentatively indicate that PTSD may lead to an increase in BMI and, as such, to the development of overweight/obesity, particularly in women. Further prospective studies and research elaborating the nature and etiology of the association are required.

Neonatal pain and reduced maternal care: Early-life stressors interacting to impact brain and behavioral development

Advances in neonatal intensive care units (NICUs) have drastically increased the survival chances of preterm infants. However, preterm infants are still exposed to a wide range of stressors during their stay in the NICU, which include painful procedures and reduced maternal contact. The activation of the hypothalamic-pituitary-adrenal (HPA) axis, in response to these stressors during this critical period of brain development, has been associated with many acute and long-term adverse biobehavioral outcomes. Recent research has shown that Kangaroo care, a non-pharmacological analgesic based on increased skin-to-skin contact between the neonate and the mother, negates the adverse outcomes associated with neonatal pain and reduced maternal care, however the biological mechanism remains widely unknown. This review summarizes findings from both human and rodent literature investigating neonatal pain and reduced maternal care independently, primarily focusing on the role of the HPA axis and biobehavioral outcomes. The physiological and positive outcomes of Kangaroo care will also be discussed in terms of how dampening of the HPA axis response to neonatal pain and increased maternal care may account for positive outcomes associated with Kangaroo care.

Mechanistic Pathways of Mindfulness Meditation in Combat Veterans With Posttraumatic Stress Disorder

OBJECTIVE

This study's objective was to evaluate the effect of two common components of meditation (mindfulness and slow breathing) on potential mechanistic pathways.

METHODS

A total of 102 combat veterans with posttraumatic stress disorder (PTSD) were randomized to (a) the body scan mindfulness meditation (MM), (b) slow breathing (SB) with a biofeedback device, (c) mindful awareness of the breath with an intention to slow the breath (MM+SB), or (d) sitting quietly (SQ). Participants had 6 weekly one-on-one sessions with 20 minutes of daily home practice. The mechanistic pathways and measures were as follows: (a) autonomic nervous system (hyperarousal symptoms, heart rate [HR], and heart rate variability [HRV]); (b) frontal cortex activity (attentional network task [ANT] conflict effect and event-related negativity and intrusive thoughts); and (c) hypothalamic-pituitary-adrenal axis (awakening cortisol). PTSD measures were also evaluated.

RESULTS

Meditation participants had significant but modest within-group improvement in PTSD and related symptoms, although there were no effects between groups. Perceived impression of PTSD symptom improvement was greater in the meditation arms compared with controls. Resting respiration decreased in the meditation arms compared with SQ. For the mechanistic pathways, (a) subjective hyperarousal symptoms improved within-group (but not between groups) for MM, MM+SB, and SQ, while HR and HRV did not; (b) intrusive thoughts decreased in MM compared with MM+SB and SB, while the ANT measures did not change; and (c) MM had lower awakening cortisol within-group (but not between groups).

CONCLUSION

Treatment effects were mostly specific to self-report rather than physiological measures. Continued research is needed to further evaluate mindfulness meditation's mechanism in people with PTSD.

The role of the hippocampus in the pathogenesis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a severe acquired illness characterized by a profound sensation of fatigue, not ameliorated by rest and resulting in a substantial decrease in the amount and quality of occupational, social and recreational activities. Despite intense research, the aetiology and pathogenesis of ME/CFS is still unknown and no conclusive biological markers have been found. As a consequence, an accepted curative treatment is still lacking and rehabilitation programmes are not very effective, as few patients recover. Increased knowledge of the mechanisms leading to the emergence and maintenance of the illness is called for. In this study, I will put forth an alternative hypothesis to explain some of the pathologies associated with ME/CFS, by concentrating on one of the major strategic organs of the brain, the hippocampus. I will show that the ME/CFS triggering factors also impact the hippocampus, leading to neurocognitive deficits and disturbances in the regulation of the stress system and pain perception. These deficits lead to a substantial decrease in activity and to sleep disorders, which, in turn, impact the hippocampus and initiate a vicious circle of increased disability.

Neuroinflammatory pathways in anxiety, posttraumatic stress, and obsessive compulsive disorders

As prevalence of anxiety, posttraumatic stress, and obsessive compulsive disorders continue to rise worldwide, increasing focus has been placed on immune mediated theories in understanding the underlying mechanisms of these disorders. Associations between the dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and these disorders have been recognized in the scientific literature, specifically in regard to cortisol levels, as well as changes in pro- and anti-inflammatory cytokines. The present commentary will systematically assess the scientific literature within the past decade in regard to the psychoneuroimmunology of anxiety, posttraumatic stress, and obsessive compulsive disorders. Understanding the mechanisms of these disorders is essential in order to determine efficacious and targeted treatment strategies, which may lead to substantial improvements in overall functioning, as well as significant decreases in societal and economic burden.

ApoE2 Exaggerates PTSD-Related Behavioral, Cognitive, and Neuroendocrine Alterations

Apolipoprotein E (apoE) is an essential component of lipoprotein particles in both the brain and periphery, and exists in three isoforms in the human population: E2, E3, and E4. ApoE has numerous, well-established roles in neurobiology. Most notably, E4 is associated with earlier onset and increased risk of Alzheimer's disease (AD). Although possession of E2 is protective in the context of AD, E2 appears to confer an increased incidence and severity of posttraumatic stress disorder (PTSD). However, the biological processes underlying this link remain unclear. In this study, we began to elucidate these associations by examining the effects of apoE on PTSD severity in combat veterans, and on PTSD-like behavior in mice with human apoE. In a group of 92 veterans with PTSD, we observed significantly higher Clinician-Administered PTSD Scale and PTSD Checklist scores in E2+ individuals, as well as alterations in salivary cortisol levels. Furthermore, we measured behavioral and biological outcomes in mice expressing human apoE after a single stressful event as well as following a period of chronic variable stress, a model of combat-related trauma. Mice with E2 showed impairments in fear extinction, and behavioral, cognitive, and neuroendocrine alterations following trauma. To the best of our knowledge, these data constitute the first translational demonstration of PTSD severity in men and PTSD-like symptoms in mice with E2, and point to apoE as a novel biomarker of susceptibility, and potential therapeutic target, for PTSD.

Sleep disturbances, TBI and PTSD: Implications for treatment and recovery

Post-Traumatic Stress Disorder (PTSD), traumatic brain injury (TBI), and sleep problems significantly affect recovery and functional status in military personnel and Veterans returning from combat. Despite recent attention, sleep is understudied in the Veteran population. Few treatments and rehabilitation protocols target sleep, although poor sleep remains at clinical levels and continues to adversely impact functioning even after the resolution of PTSD or mild TBI symptoms. Recent developments in non-pharmacologic sleep treatments have proven efficacious as stand-alone interventions and have potential to improve treatment outcomes by augmenting traditional behavioral and cognitive therapies. This review discusses the extensive scope of work in the area of sleep as it relates to TBI and PTSD, including pathophysiology and neurobiology of sleep; existing and emerging treatment options; as well as methodological issues in sleep measurements for TBI and PTSD. Understanding sleep problems and their role in the development and maintenance of PTSD and TBI symptoms may lead to improvement in overall treatment outcomes while offering a non-stigmatizing entry in mental health services and make current treatments more comprehensive by helping to address a broader spectrum of difficulties.