Stress hormones and post-traumatic stress disorder in civilian trauma victims: a longitudinal study. Part II: the adrenergic response

Validity of mental and physical stress models

Different stress models are employed to enhance our understanding of the underlying mechanisms and explore potential interventions. However, the utility of these models remains a critical concern, as their validities may be limited by the complexity of stress processes. Literature review revealed that both mental and physical stress models possess reasonable construct and criterion validities, respectively reflected in psychometrically assessed stress ratings and in activation of the sympathoadrenal system and the hypothalamic-pituitary-adrenal axis. The findings are less robust, though, in the pharmacological perturbations' domain, including such agents as adenosine or dobutamine. Likewise, stress models' convergent- and discriminant validity vary depending on the stressors' nature. Stress models share similarities, but also have important differences regarding their validities. Specific traits defined by the nature of the stressor stimulus should be taken into consideration when selecting stress models. Doing so can personalize prevention and treatment of stress-related antecedents, its acute processing, and chronic sequelae. Further work is warranted to refine stress models' validity and customize them so they commensurate diverse populations and circumstances.

Diosgenin normalization of disrupted behavioral and central neurochemical activity after single prolonged stress

Introduction: Post-traumatic stress disorder (PTSD) is a chronic mental illness triggered by traumatic experiences such as wars, natural disasters, or catastrophes, and it is characterized by anxiety, depression and cognitive impairment. Diosgenin is a steroidal sapogenin with known neuroprotective and antioxidant properties. This study aimed to assess the pharmacological potential of diosgenin in a single prolonged stress (SPS) model of PTSD, plus other behavioral models along with any consequent alterations in brain neurochemistry in male mice. Methodology: SPS was induced by restraining animals for 2 h, followed by 20 min of forced swim, recuperation for 15 min, and finally, exposure to ether to induce anesthesia. The SPS-exposed animals were treated with diosgenin (20, 40, and 60 mg/kg) and compared with the positive controls, fluoxetine or donepezil, then they were observed for any changes in anxiety/depression-like behaviors, and cognitive impairment. After behavioral screening, postmortem serotonin, noradrenaline, dopamine, vitamin C, adenosine and its metabolites inosine and hypoxanthine were quantified in the frontal cortex, hippocampus, and striatum by high-performance liquid chromatography. Additionally, animal serum was screened for changes in corticosterone levels. Results: The results showed that diosgenin reversed anxiety- and depression-like behaviors, and ameliorated cognitive impairment in a dose-dependent manner. Additionally, diosgenin restored monoamine and vitamin C levels dose-dependently and modulated adenosine and its metabolites in the brain regions. Diosgenin also reinstated otherwise increased serum corticosterone levels in SPS mice. Conclusion: The findings suggest that diosgenin may be a potential candidate for improving symptoms of PTSD.

Potential peripheral biomarkers associated with the emergence and presence of posttraumatic stress disorder symptomatology: A systematic review

BACKGROUND

Evidence suggests posttraumatic stress disorder (PTSD) involves an interplay between psychological manifestations and biological systems. Biological markers of PTSD could assist in identifying individuals with underlying dysregulation and increased risk; however, accurate and reliable biomarkers are yet to be identified.

METHODS

A systematic review following the PRISMA guidelines was conducted. Databases included EMBASE, MEDLINE, and Cochrane Central. Studies from a comprehensive 2015 review (Schmidt et al., 2015) and English language papers published subsequently (between 2014 and May 2022) were included. Forty-eight studies were eligible.

RESULTS

Alterations in neuroendocrine and immune markers were most commonly associated with PTSD symptoms. Evidence indicates PTSD symptoms are associated with hypothalamic-pituitary-adrenal axis dysfunction as represented by low basal cortisol, a dysregulated immune system, characterized by an elevated pro-inflammatory state, and metabolic dysfunction. However, a considerable number of studies neglected to measure sex or prior trauma, which have the potential to affect the biological outcomes of posttraumatic stress symptoms. Mixed findings are indicative of the complexity and heterogeneity of PTSD and suggest the relationship between allostatic load, biological markers, and PTSD remain largely undefined.

CONCLUSIONS

In addition to prospective research design and long-term follow up, it is imperative future research includes covariates sex, prior trauma, and adverse childhood experiences. Future research should include exploration of biological correlates specific to PTSD symptom domains to determine whether underlying processes differ with symptom expression, in addition to subclinical presentation of posttraumatic stress symptoms, which would allow for greater understanding of biomarkers associated with disorder risk and assist in untangling directionality.

Risk Factors for Abdominal Pain-Related Disorders of Gut-Brain Interaction in Adults and Children: A Systematic Review

BACKGROUND & AIMS

Many studies have assessed risk factors of irritable bowel syndrome (IBS) and other abdominal pain-related disorders of gut-brain interaction (AP-DGBI); however, the role of these factors is unclear due to heterogeneous study designs. The aim of this systematic review was to extensively evaluate the literature and determine clinical risk and protective factors for the presence and persistence of AP-DGBI in children and adults.

METHODS

A PubMed search identified studies investigating potential risk and protective factors for AP-DGBI in adults and children. Inclusion criteria included fully published studies with a control group; exclusion criteria included poor-quality studies (using a validated scale). For each factor, the proportion of studies that found the factor to be a risk factor, protective factor, or neither was summarized. The number of studies, diagnostic criteria, number of subjects, and average study quality rating provided further context. Whenever possible, a meta-analysis generated pooled odds ratios or mean difference.

RESULTS

The systematic review included 348 studies. Female sex, gastroenteritis, abuse, stress, psychological disorders, somatic symptoms, and poor sleep were consistent risk factors for developing AP-DGBI in adults and children. In adults, additional risk factors included obesity, smoking, and increased use of medical resources. Protective AP-DGBI factors in adults included social support and optimism; no studies for protective factors were found for children.

CONCLUSIONS

There are multiple risk factors for AP-DGBI in adults and children. These include female sex, gastroenteritis, abuse, stress, poor sleep, obesity, psychological disorders, and somatic symptoms. Additional studies are needed in children, on protective factors, and on factors associated with persistence of AP-DGBI.

Contrasting Associations Between Heart Rate Variability and Brainstem-Limbic Connectivity in Posttraumatic Stress Disorder and Its Dissociative Subtype: A Pilot Study

Background

Increasing evidence points toward the need to extend the neurobiological conceptualization of posttraumatic stress disorder (PTSD) to include evolutionarily conserved neurocircuitries centered on the brainstem and the midbrain. The reticular activating system (RAS) helps to shape the arousal state of the brain, acting as a bridge between brain and body. To modulate arousal, the RAS is closely tied to the autonomic nervous system (ANS). Individuals with PTSD often reveal altered arousal patterns, ranging from hyper- to blunted arousal states, as well as altered functional connectivity profiles of key arousal-related brain structures that receive direct projections from the RAS. Accordingly, the present study aims to explore resting state functional connectivity of the RAS and its interaction with the ANS in participants with PTSD and its dissociative subtype.

Methods

Individuals with PTSD (n = 57), its dissociative subtype (PTSD + DS, n = 32) and healthy controls (n = 40) underwent a 6-min resting functional magnetic resonance imaging and pulse data recording. Resting state functional connectivity (rsFC) of a central node of the RAS – the pedunculopontine nuclei (PPN) – was investigated along with its relation to ANS functioning as indexed by heart rate variability (HRV). HRV is a prominent marker indexing the flexibility of an organism to react adaptively to environmental needs, with higher HRV representing greater effective adaptation.

Results

Both PTSD and PTSD + DS demonstrated reduced HRV as compared to controls. HRV measures were then correlated with rsFC of the PPN. Critically, participants with PTSD and participants with PTSD + DS displayed inverse correlations between HRV and rsFC between the PPN and key limbic structures, including the amygdala. Whereas participants with PTSD displayed a positive relationship between HRV and PPN rsFC with the amygdala, participants with PTSD + DS demonstrated a negative relationship between HRV and PPN rsFC with the amygdala.

Conclusion

The present exploratory investigation reveals contrasting patterns of arousal-related circuitry among participants with PTSD and PTSD + DS, providing a neurobiological lens to interpret hyper- and more blunted arousal states in PTSD and PTSD + DS, respectively.

Autonomic dysfunction and cardiovascular risk in post-traumatic stress disorder

BACKGROUND

Patients with post-traumatic stress disorder (PTSD) have an increased risk for cardiovascular disease. The underlying mechanisms are unclear but impaired autonomic function may contribute. However, research in this field has shown contradictory results and the causal links between PTSD, autonomic dysfunction, and cardiovascular risk remain unknown. This brief review summarizes the current knowledge on alterations in autonomic function and cardiovascular risk in patients with PTSD.

LITERATURE SEARCH STRATEGY

A PubMed search of the literature was performed using the following keywords: autonomic function, heart rate variability, blood pressure variability, sympathetic activity, baroreflex function, and cardiovascular risk in combination with PTSD. Evidence-based studies conducted between 2000 and 2021 were selected.

RESULTS

In total 1221 articles were identified and of these, 61 (48 original research papers, 13 review articles) were included in this review. Many, though not all, studies have reported increased activity of the sympathetic nervous system and decreased activity of the parasympathetic nervous system (namely, autonomic imbalance) in PTSD patients. There seems to be enough evidence to suggest impairments in baroreflex function in PTSD, leading to blood pressure dysregulation. It appears that the chronicity of PTSD diagnosis and symptom severity are independent risk factors for cardiovascular disease, which may be linked with impaired autonomic function.

CONCLUSIONS

Increased cardiovascular risk may be associated with autonomic dysfunction in PTSD. Whether autonomic dysfunction can serve as a biomarker for the onset and progression of PTSD remains to be determined. It also needs to determine if autonomic imbalance increases the risk of developing PTSD.

Stress response in dissociation and conversion disorders: A systematic review

Dissociative disorders (DD) and conversion disorders (CD) are frequent in general and psychiatric populations. Some evidence suggest that the hypothalamic-pituitary axis (HPA) and autonomic nervous system (ANS) are dysregulated in both disorders. We carried out a systematic review of the literature to summarize the existing knowledge on the stress response, via HPA and/or ANS, in patients with DD, CD, or dissociative symptoms. We systematically searched Medline and Web of Science using the Medical Subject Headings related to stress axis, CD, DD, and dissociative symptoms following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results suggest that in participants without psychiatric history, high cortisol secretion is related to high dissociation scores. Conversely the stress system might be blunted in patients with post-traumatic stress disorder who develop dissociative symptoms. Stress response changes seem to be associated with the emergence and persistence of dissociative and conversion disorders. Hence, monitoring the stress response and examining closely the history of stress exposure in DD and CD should be encouraged in future larger studies.

A critical review of mechanisms of adaptation to trauma: Implications for early interventions for posttraumatic stress disorder

Although many attempts have been made to limit development of posttraumatic stress disorder (PTSD) by early intervention after trauma exposure, these attempts have achieved only modest success. This review critiques the biological and cognitive strategies used for early intervention and outlines the extent to which they have prevented PTSD. The major predictors of PTSD are reviewed, with an emphasis on potential mechanisms that may underpin the transition from acute stress reaction to development of PTSD. This review highlights that there is a wide range of biological and cognitive factors that have been shown to predict PTSD. Despite this, the major attempts at early intervention have focused on strategies that attempt to augment extinction processes or alter appraisals in the acute period. The documented predictors of PTSD indicate that a broader range of potential strategies could be explored to limit PTSD. The evidence that people follow different trajectories of stress response following trauma and there is a wide array of acute predictors of PTSD indicates that a flexible and tailored approach needs to be investigated to evaluate more effective early intervention strategies.

Challenges of post-traumatic stress disorder (PTSD) in Iraq: biochemical network and methodologies. A brief review

Post-traumatic stress disorder (PTSD) is a multifaceted syndrome due to its complex pathophysiology. Signals of illness include alterations in genes, proteins, cells, tissues, and organism-level physiological modifications. Specificity of sensitivity to PTSD suggests that response to trauma depend on gender and type of adverse event being experienced. Individuals diagnosed with PTSD represent a heterogeneous group, as evidenced by differences in symptoms, course, and response to treatment. It is clear that the biochemical mechanisms involved in PTSD need to be elucidated to identify specific biomarkers. A brief review of the recent literature in Pubmed was made to explore the major biochemical mechanisms involved in PTSD and the methodologies applied in the assessment of the disease. PTSD shows pre-exposure vulnerability factors in addition to trauma-induced alterations. The disease was found to be associated with dysfunctions of the hypothalamic-pituitary-adrenal axis (HPA) and hypothalamus-pituitary-thyroid axis. Sympathetic nervous system (SNS) activity play a role in PTSD by releasing norepinephrine and epinephrine. Cortisol release from the adrenal cortex amplifies the SNS response. Cortisol levels in PTSD patients, especially women, are later reduced by a negative feedback mechanism which contributes to neuroendocrine alterations and promotes structural changes in the brain leading to PTSD. Gender differences in normal HPA responsiveness may be due to an increased vulnerability in women to PTSD. Serotonin and dopamine levels were found to be abnormal in the presence of PTSD. Mechanisms such as the induction of neuroinflammation and alterations of mitochondrial energy processing were also associated with PTSD.

The hypothalamic-pituitary-adrenal axis in PTSD: Pathophysiology and treatment interventions

Questions of how altered functioning of the hypothalamic pituitary adrenal (HPA) axis contribute to the development and maintenance of posttraumatic stress disorder (PTSD) have been the focus of extensive animal and human research. As a rule, results have been inconsistent across studies, likely due to a variety of confounding variables that have received inadequate attention. Important confounding factors include the effects of early life stress, biological sex, and the glucocorticoid used for interventions. In this manuscript we review: 1) the literature on identified abnormalities of HPA axis function in PTSD, both in terms of basal functioning and as part of challenge paradigms; 2) the role of HPA axis function pre- and immediately post-trauma as a risk factor for PTSD development; 3) the impact of HPA axis genes' allelic variants and epigenetic modifications on PTSD risk; 4) the contributions of HPA axis components to fear learning and extinction; and 5) therapeutic manipulations of the HPA axis to both prevent and treat PTSD, including the role of glucocorticoids as part of medication enhanced psychotherapy.

Catecholamines in Post-traumatic Stress Disorder: A Systematic Review and Meta-Analysis

Studies on the association between post-traumatic stress disorder (PTSD) and levels of catecholamines have yielded inconsistent results. The aim of this study was to conduct a systematic review and meta-analysis to assess whether concentrations of the catecholamines dopamine, norepinephrine, and epinephrine are associated with PTSD. This study searched relevant articles in the following databases: PubMed, Embase, Web of Science, and Psyc-ARTICLES. Each database was searched from its inception to September, 2018. Data related to catecholamine concentrations were extracted for patients with PTSD and the controls to calculate standardized mean differences and to evaluate effect sizes. A meta-analysis was then performed to compare the concentration of each catecholamine between the two groups in blood and/or urine samples. Heterogeneity was quantified using I² and its significance was tested using the Q statistics. Subgroup analyses of the types of controls, PTSD assessment tools, and assayed methods used in the studies were performed to explore sources of heterogeneity among studies. Random-effects models were used to combine results from selected studies. A total of 1,388 articles were identified, of which 27 were included in the final analysis. Heterogeneity was high; hence random-effects models were used to combine results of selected studies. Results revealed significantly higher norepinephrine levels in people with PTSD than in the controls [standardized mean difference (SMD) = 0.35, 95% confidence interval (CI): 0.13 to 0.57, p = 0.002]. No difference was found in dopamine and epinephrine concentrations between the two groups. Elevated norepinephrine levels may be an important indicator for PTSD.

Elevated allostatic load in individuals presenting at psychiatric emergency services

OBJECTIVE

Individuals requiring psychiatric emergency services are often highly distressed and intoxicated. To provide an objective and comprehensive measure of their stress-related physiological dysregulations, we indexed allostatic load with 14 biomarkers collected within 24 h of patients' admission to the largest psychiatric hospital in the Canadian province of Quebec.

METHODS

This study (N = 278) combines data for emergency patients (n = 76; 65.8% women; M age = 44.97, SE = 1.6) and hospital workers who served as sex- and age-matched controls (n = 202; 70.8% women; M age = 40.10, SE = 0.83). Sex-specific allostatic load indices summarized neuroendocrine (cortisol), immune (tumor necrosis factor-α, interleukin-6, c-reactive protein), metabolic (insulin, glycosylated hemoglobin, total cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides, body mass index), and cardiovascular (heart rate, systolic and diastolic blood pressure) functioning. Well-validated questionnaires assessed substance (ab)use.

RESULTS

Individuals presenting at psychiatric emergency showed elevated allostatic load, drug abuse, and tobacco use compared to controls. Elevated allostatic load in emergency patients was driven by elevated cortisol, interleukin-6, systolic blood pressure, and heart rate; however, allostatic load was not explained by substance (ab)use or demographic variables. Sub-group analyses revealed that emergency patients primarily diagnosed with bipolar, depressive, or anxiety disorders showed higher allostatic load than those diagnosed with personality disorder(s).

CONCLUSIONS

This study demonstrates that individuals presenting at psychiatric emergency services show physiological dysregulations associated with chronic stress. Future research should explore the clinical utility of allostatic load in predicting comorbidities among psychiatric patients.

The Current Evidence for Acute Stress Disorder

PURPOSE OF REVIEW

The aim of this review is to provide a summary of the current evidence pertaining to the course of acute and chronic posttraumatic stress, the diagnosis of acute stress disorder (ASD), and treatment of acute stress disorder and prevention of posttraumatic stress disorder (PTSD).

RECENT FINDINGS

Although acute stress disorder was introduced partly to predict subsequent PTSD, longitudinal studies indicate that ASD is not an accurate predictor of PTSD. Recent analytic approaches adopting latent growth mixture modeling have shown that trauma-exposed people tend to follow one of four trajectories: (a) resilient, (b) worsening, (c) recovery, and (d) chronically distressed. The complexity of the course of posttraumatic stress limits the capacity of the ASD diagnosis to predict subsequent PTSD. Current evidence indicates that the treatment of choice for ASD is trauma-focused cognitive behavior therapy, and this intervention results in reduced chronic PTSD severity. Recent attempts to limit subsequent PTSD by early provision of pharmacological interventions have been promising, especially administration of corticosterone to modulate glucocorticoid levels. Although the ASD diagnosis does not accurately predict chronic PTSD, it describes recently trauma-exposed people with severe distress. Provision of CBT in the acute phase is the best available strategy to limit subsequent PTSD.

Endogenous salivary α-amylase does not interact with skin conductance response during fear extinction in posttraumatic stress disorder

Posttraumatic Stress Disorder (PTSD) is associated with elevated noradrenergic signaling, which has an impact on emotional learning and memory. Fear extinction is thought to underlie the processes of exposure therapy, however the relationship between noradrenaline and extinction in PTSD is unclear. Participants with PTSD (n = 21), trauma-exposure without PTSD (TC; n = 36), and non-trauma-exposed controls (NTC; n = 27) completed a fear conditioning and extinction paradigm, and conditioned fear was indexed by skin conductance response (SCR). Salivary α-amylase (sAA) collected at baseline and immediately post-fear acquisition was used as an index of noradrenaline, and we examined whether sAA in response to fear acquisition was a moderator between fear extinction and PTSD symptoms. While there was a significant increase in sAA from baseline to post-fear acquisition, this was not modulated by group. Compared to TC and NTC, the PTSD group displayed a slower decline in SCRs during early extinction, which generalized across stimulus type, and was not moderated by sAA. These findings suggest that the relationship between fear extinction and PTSD symptoms does not change as a function of sAA levels; however previous research suggests other processes of fear learning may be associated with noradrenergic activity in PTSD.

Propranolol can induce PTSD-like memory impairments in rats

Introduction

One hallmark symptom of post-traumatic stress disorder (PTSD) is an inability to restrict fear responses to the appropriate predictor. An infusion of glucocorticoids (GCs) after a high-intensity shock has been shown to induce PTSD-like memory impairments. In addition to GCs, noradrenergic signalling is also recognized as a key biomarker underlying PTSD symptomatology.

Methods

To explore the role of the noradrenergic system in PTSD-like memory impairments, in this study, various doses of the β-adrenoceptor antagonist propranolol were systemically or bilaterally injected into the dorsal hippocampus immediately after unpaired cue-shock contextual fear conditioning, and then the rats were tested 24 h later.

Results

Interestingly, we found that only low-dose propranolol could induce PTSD-like memory impairments, as rats showed reduced freezing to the correct predictor and generalized fear responses to the safe cues, accompanied by increased NE levels in the hippocampus and altered neural activity within the frontal-subcortical circuit.

Conclusion

These findings demonstrate that the noradrenergic system is involved in regulating the consolidation of contextual fear memory and that propranolol can dose-dependently induce PTSD-like memory impairments.

Migraine and the risk of post-traumatic stress disorder among a cohort of pregnant women

Background

Individually both migraine and post-traumatic stress disorder (PTSD) prevalence estimates are higher among women. However, there is limited data on the association of migraine and PTSD in women during pregnancy.

Methods

We examined the association between migraine and PTSD among women attending prenatal clinics in Peru. Migraine was characterized using the International Classification of Headache Disorders (ICHD)-III beta criteria. PTSD was assessed using the PTSD Checklist-Civilian Version (PCL-C). Multivariable logistic regression analyses were performed to estimate odds ratios (OR) and 95% confidence intervals (CI) after adjusting for confounders.

Results

Of the 2922 pregnant women included, 33.5% fulfilled criteria for any migraine (migraine 12.5%; probable migraine 21.0%) and 37.4% fulfilled PTSD criteria. Even when controlling for depression, women with any migraine had almost a 2-fold increased odds of PTSD (OR: 1.97; 95% CI: 1.64–2.37) as compared to women without migraine. Specifically, women with migraine alone (i.e. excluding probable migraine) had a 2.85-fold increased odds of PTSD (95% CI: 2.18–3.74), and women with probable migraine alone had a 1.61-fold increased odds of PTSD (95% CI: 1.30–1.99) as compared to those without migraine, even after controlling for depression. In those women with both migraine and comorbid depression, the odds of PTSD in all migraine categories were even further increased as compared to those women without migraine.

Conclusion

In a cohort of pregnant women, irrespective of the presence or absence of depression, the odds of PTSD is increased in those with migraine. Our findings suggest the importance of screening for PTSD, specifically in pregnant women with migraine.

Electronic supplementary material

The online version of this article (doi:10.1186/s10194-017-0775-5) contains supplementary material, which is available to authorized users.

Utilization of machine learning for prediction of post-traumatic stress: a re-examination of cortisol in the prediction and pathways to non-remitting PTSD

To date, studies of biological risk factors have revealed inconsistent relationships with subsequent post-traumatic stress disorder (PTSD). The inconsistent signal may reflect the use of data analytic tools that are ill equipped for modeling the complex interactions between biological and environmental factors that underlay post-traumatic psychopathology. Further, using symptom-based diagnostic status as the group outcome overlooks the inherent heterogeneity of PTSD, potentially contributing to failures to replicate. To examine the potential yield of novel analytic tools, we reanalyzed data from a large longitudinal study of individuals identified following trauma in the general emergency room (ER) that failed to find a linear association between cortisol response to traumatic events and subsequent PTSD. First, latent growth mixture modeling empirically identified trajectories of post-traumatic symptoms, which then were used as the study outcome. Next, support vector machines with feature selection identified sets of features with stable predictive accuracy and built robust classifiers of trajectory membership (area under the receiver operator characteristic curve (AUC)=0.82 (95% confidence interval (CI)=0.80-0.85)) that combined clinical, neuroendocrine, psychophysiological and demographic information. Finally, graph induction algorithms revealed a unique path from childhood trauma via lower cortisol during ER admission, to non-remitting PTSD. Traditional general linear modeling methods then confirmed the newly revealed association, thereby delineating a specific target population for early endocrine interventions. Advanced computational approaches offer innovative ways for uncovering clinically significant, non-shared biological signals in heterogeneous samples.

Cortisol, heart rate, and blood pressure as early markers of PTSD risk: A systematic review and meta-analysis

Individuals with posttraumatic stress disorder (PTSD) typically exhibit altered hypothalamic-pituitary-adrenal (HPA) function and sympathetic nervous system (SNS) activity. The goals of this study were to determine whether HPA and SNS alterations in the immediate aftermath of trauma predict subsequent PTSD symptom development and whether inconsistencies observed between studies can be explained by key demographic and methodological factors. This work informs secondary prevention of PTSD by identifying subgroups of trauma survivors at risk for PTSD. This meta-analysis (26 studies, N=5186 individuals) revealed that higher heart rate measured soon after trauma exposure was associated with higher PTSD symptoms subsequently (r=0.13). Neither cortisol (r=-0.07) nor blood pressure (diastolic: r=-0.01; systolic: r=0.02) were associated with PTSD symptoms which may be influenced by methodological limitations. Associations between risk markers (heart rate, cortisol, systolic blood pressure) and PTSD symptoms were in the positive direction for younger samples and negative direction for older samples. These findings extend developmental traumatology models of PTSD by revealing an age-related shift in the presentation of early risk markers. More work will be needed to identify risk markers and pathways to PTSD while addressing methodological limitations in order to shape and target preventive interventions.

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.

The evolution of the molecular response to stress and its relevance to trauma and stressor-related disorders

The experience of "stress", in its broadest meaning, is an inevitable part of life. All living creatures have evolved multiple mechanisms to deal with such threats and challenges and to avoid damage to the organism that may be incurred from these stress responses. Trauma and stressor-related disorders are psychiatric conditions that are caused specifically by the experience of stress, though depression, anxiety and some other disorders may also be unleashed by stress. Stress, however, is not a mandatory criterion of these diagnoses. This article focuses on the evolution of the neurochemicals involved in the response to stress and the systems in which they function. This includes the skin and gut, and the immune system. Evidence suggests that responses to stress are evolutionarily highly conserved, have wider involvement than the hypothalamic pituitary adrenal stress axis alone, and that excessive stress responses can produce stressor-related disorders in both humans and animals.

Biological and psychological predictors of posttraumatic stress disorder onset and chronicity. A one-year prospective study

BACKGROUND

Few studies have prospectively examined risk factors for posttraumatic stress disorder (PTSD) in the aftermath of a traumatic exposure. The aim of this study is to identify the concurrent influence of psychological and biological diatheses on PTSD onset and maintenance, taking into account socio-demographic factors and psychiatric antecedents.

METHODS

A total of 123 civilians (61.8% of women) recruited in emergency units, were assessed using validated instruments during the first week and then at 1, 4, and 12 months post-trauma. Baseline assessment included evaluation of the psychological diathesis (i.e. psychiatric history and peritraumatic distress and dissociation), and the biological diathesis [i.e. cortisol, norepinephrine, epinephrine, c-reactive protein, total cholesterol, HDL cholesterol, glycosylated haemoglobin, waist-to-hip ratio (WHR), body mass index, diastolic and systolic blood pressure (SBP), and heart rate].

RESULTS

Multivariate logistic regression analyses demonstrated both psychological and biological diatheses to be independent risk factors for PTSD. Peritraumatic distress and dissociation predicted onset (1-month) and mid-term PTSD (4-months), respectively. PTSD risk was associated positively with SBP and negatively with WHR, throughout the follow-up. In addition, a higher level of 12 h-overnight urinary norepinephrine independently predicted mid-term PTSD (4-months).

CONCLUSIONS

This prospective study shows that peritraumatic psychological and biological markers are independent predictors of PTSD onset with specificities according to the stage of PTSD development; the psychological diathesis, i.e. peritraumatic distress and dissociation, being a better predictor of short-term dysfunction whereas biological diathesis was also predictive of development and maintenance of PTSD.

Sympathoneural and adrenomedullary responses to mental stress

This concept-based review provides historical perspectives and updates about sympathetic noradrenergic and sympathetic adrenergic responses to mental stress. The topic of this review has incited perennial debate, because of disagreements over definitions, controversial inferences, and limited availability of relevant measurement tools. The discussion begins appropriately with Cannon's "homeostasis" and his pioneering work in the area. This is followed by mental stress as a scientific idea and the relatively new notions of allostasis and allostatic load. Experimental models of mental stress in rodents and humans are discussed, with particular attention to ethical constraints in humans. Sections follow on sympathoneural responses to mental stress, reactivity of catecholamine systems, clinical pathophysiologic states, and the cardiovascular reactivity hypothesis. Future advancement of the field will require integrative approaches and coordinated efforts between physiologists and psychologists on this interdisciplinary topic.

Amygdala response to negative stimuli predicts PTSD symptom onset following a terrorist attack

OBJECTIVE

Individuals with posttraumatic stress disorder (PTSD) exhibit heightened amygdala reactivity and atypical activation patterns in the medial prefrontal cortex (mPFC) in response to negative emotional information. It is unknown whether these aspects of neural function are risk factors for PTSD or consequences of either trauma exposure or onset of the disorder. We had a unique opportunity to investigate this issue following the terrorist attacks at the 2013 Boston Marathon and the ensuing manhunt and shelter in place order. We examined associations of neural function measured prior to the attack with PTSD symptom onset related to these events.

METHODS

A sample of 15 adolescents (mean age = 16.5 years) who previously participated in a neuroimaging study completed a survey assessing posttraumatic symptoms related to the terrorist attack. We examined blood oxygen level dependent (BOLD) response to viewing and actively down-regulating emotional responses to negative stimuli in regions previously associated with PTSD, including the amygdala, hippocampus, and mPFC, as prospective predictors of posttraumatic symptom onset.

RESULTS

Increased BOLD signal to negative emotional stimuli in the left amygdala was strongly associated with posttraumatic symptoms following the attack. Reduced bilateral hippocampal activation during effortful attempts to down-regulate emotional responses to negative stimuli was also associated with greater posttraumatic symptoms. Associations of amygdala reactivity with posttraumatic symptoms were robust to controls for pre-existing depression, anxiety, and PTSD symptoms and prior exposure to violence.

CONCLUSIONS

Amygdala reactivity to negative emotional information might represent a neurobiological marker of vulnerability to traumatic stress and, potentially, a risk factor for PTSD.

Prospects for the pharmacological prevention of post-traumatic stress in vulnerable individuals

Biological studies of posttraumatic stress disorder (PTSD) have found alterations of physiological stress pathways [sympathetic nervous system (SNS) and the hypothalamic-pituitary-adrenal (HPA) axis] soon after trauma in individuals who have subsequently developed PTSD, leading researchers to hypothesize that pharmacological manipulation of stress hormone levels may aid in preventing the development of post-traumatic distress. The present paper first reviews the current understanding of the neurobiology of PTSD development and then provides the rationale and evidence for early pharmacological strategies to prevent/reduce post-traumatic distress in at-risk trauma victims. Emphasis is placed on those interventions targeting the SNS and the HPA axis. Furthermore, in light of recent calls to move away from categorical diagnostic outcomes, we discuss how examining post-traumatic distress from a transdiagnostic viewpoint may inform novel chemoprophylactic approaches (intervening pharmacologically after trauma to prevent post-traumatic distress). Current evidence is suggestive for medications, such as propranolol, hydrocortisone, morphine, and oxytocin, impacting early stress hormone levels and subsequent risk for post-traumatic distress; however, future research is needed prior to adapting recommendations for widespread use of any chemoprophylactic treatments.

Pharmacological modulation of acute trauma memories to prevent PTSD: considerations from a developmental perspective

Estimates of the lifetime prevalence of posttraumatic stress disorder (PTSD) in American adults range from 6.4% to 6.8%. PTSD is associated with increased risk for comorbid major depression, substance use disorder, suicide, and a variety of other mental and physical health conditions. Given the negative sequelae of trauma/PTSD, research has focused on identifying efficacious interventions that could be administered soon after a traumatic event to prevent or reduce the subsequent incidence of PTSD. While early psychosocial interventions have been shown to be relatively ineffective, early (secondary) pharmacological interventions have shown promise. These pharmacological approaches are largely based on the hypothesis that disruption of altered stress hormone levels and the consequent formation of trauma memories could protect against the development of PTSD. The present manuscript reviews the literature regarding the role of peri-traumatic stress hormones as risk factors for the development of PTSD and reviews evidence for the efficacy of exogenously modulating stress hormone levels to prevent/buffer the development of PTSD symptoms. Whereas prior literature has focused primarily on either child or adult studies, the present review incorporates both child and adult studies in a developmental approach to understanding risk for PTSD and how pharmacological modulation of acute memories may buffer the development of PTSD symptoms.

Posttraumatic stress disorder: a theoretical model of the hyperarousal subtype

Posttraumatic stress disorder (PTSD) is a frequent and distressing mental disorder, about which much remains to be learned. It is a heterogeneous disorder; the hyperarousal subtype (about 70% of occurrences and simply termed PTSD in this paper) is the topic of this article, but the dissociative subtype (about 30% of occurrences and likely involving quite different brain mechanisms) is outside its scope. A theoretical model is presented that integrates neuroscience data on diverse brain regions known to be involved in PTSD, and extensive psychiatric findings on the disorder. Specifically, the amygdala is a multifunctional brain region that is crucial to PTSD, and processes peritraumatic hyperarousal on grounded cognition principles to produce hyperarousal symptoms. Amygdala activity also modulates hippocampal function, which is supported by a large body of evidence, and likewise amygdala activity modulates several brainstem regions, visual cortex, rostral anterior cingulate cortex (rACC), and medial orbitofrontal cortex (mOFC), to produce diverse startle, visual, memory, numbing, anger, and recklessness symptoms. Additional brain regions process other aspects of peritraumatic responses to produce further symptoms. These contentions are supported by neuroimaging, neuropsychological, neuroanatomical, physiological, cognitive, and behavioral evidence. Collectively, the model offers an account of how responses at the time of trauma are transformed into an extensive array of the 20 PTSD symptoms that are specified in the Diagnostic and Statistical Manual of Mental Disorders, Fifth edition. It elucidates the neural mechanisms of a specific form of psychopathology, and accords with the Research Domain Criteria framework.

The use of biomarkers in the military: from theory to practice

This paper provides a summary of relevant issues covered in the conference, "The Use of Biomarkers in the Military: Theory to Practice" held at the New York Academy of Science on September 14, 2012. The conference covered the state of the science in identification of PTSD biomarkers, including, the definition of different classes of biomarkers pertaining to PTSD. The aim of the satellite conference was to bring together researchers who have been supported by the Department of Defense, Veterans Administration, National Institutes of Health, and other agencies around the world, who are interested in the identification of biomarkers for PTSD risk, diagnosis, symptom severity and treatment response, for a discussion of salient issues regarding biomarker development for PTSD, as well as special considerations for the use of biomarkers in the military.

Central hyperadrenergic state after lightning strike

OBJECTIVE

To describe and review autonomic complications of lightning strike.

METHODS

Case report and laboratory data including autonomic function tests in a subject who was struck by lightning.

RESULTS

A 24-year-old man was struck by lightning. Following that, he developed dysautonomia, with persistent inappropriate sinus tachycardia and autonomic storms, as well as posttraumatic stress disorder (PTSD) and functional neurologic problems.

INTERPRETATION

The combination of persistent sinus tachycardia and episodic exacerbations associated with hypertension, diaphoresis, and agitation was highly suggestive of a central hyperadrenergic state with superimposed autonomic storms. Whether the additional PTSD and functional neurologic deficits were due to a direct effect of the lightning strike on the central nervous system or a secondary response is open to speculation.

Epigenetic Mechanisms Shape the Biological Response to Trauma and Risk for PTSD: A Critical Review

Posttraumatic stress disorder (PTSD) develops in approximately one-quarter of trauma-exposed individuals, leading us and others to question the mechanisms underlying this heterogeneous response to trauma. We suggest that the reasons for the heterogeneity relate to a complex interaction between genes and the environment, shaping each individual's recovery trajectory based on both historical and trauma-specific variables. Epigenetic modifications provide a unique opportunity to elucidate how preexisting risk factors may contribute to PTSD risk through changes in the methylation of DNA. Preexisting risks for PTSD, including depression, stress, and trauma, result in differential DNA methylation of endocrine genes, which may then result in a different biological responses to trauma and subsequently a greater risk for PTSD onset. Although these relationships are complex and currently inadequately described, we provide a critical review of recent studies to examine how differences in genetic and proteomic biomarkers shape an individual's vulnerability to PTSD development, thereby contributing to a heterogeneous response to trauma.

Psychobiology of PTSD in the acute aftermath of trauma: Integrating research on coping, HPA function and sympathetic nervous system activity

Research on the psychobiological sequelae of trauma has typically focused on long-term alterations in individuals with chronic posttraumatic stress disorder (PTSD). Far less is known about the nature and course of psychobiological risk factors for PTSD during the acute aftermath of trauma. In this review, we summarize data from prospective studies focusing on the relationships among sympathetic nervous system activity, hypothalamic-pituitary-adrenal function, coping strategies and PTSD symptoms during the early recovery (or non-recovery) phase. Findings from pertinent studies are integrated to inform psychobiological profiles of PTSD-risk in children and adults in the context of existing models of PTSD-onset and maintenance. Data regarding bidirectional relations between coping strategies and stress hormones is reviewed. Limitations of existing literature and recommendations for future research are discussed.

Interindividual Variability in Stress Susceptibility: A Role for Epigenetic Mechanisms in PTSD

Post-traumatic stress disorder (PTSD) is a psychiatric condition characterized by intrusive and persistent memories of a psychologically traumatic event that leads to significant functional and social impairment in affected individuals. The molecular bases underlying persistent outcomes of a transient traumatic event have remained elusive for many years, but recent studies in rodents have implicated epigenetic modifications of chromatin structure and DNA methylation as fundamental mechanisms for the induction and stabilization of fear memory. In addition to mediating adaptations to traumatic events that ultimately cause PTSD, epigenetic mechanisms are also involved in establishing individual differences in PTSD risk and resilience by mediating long-lasting effects of genes and early environment on adult function and behavior. In this review, we discuss the current evidence for epigenetic regulation of PTSD in human studies and in animal models and comment on ways in which these models can be expanded. In addition, we identify key outstanding questions in the study of epigenetic mechanisms of PTSD in the context of rapidly evolving technologies that are constantly updating and adjusting our understanding of epigenetic modifications and their functional roles. Finally, we discuss the potential application of epigenetic approaches in identifying markers of risk and resilience that can be utilized to promote early intervention and develop therapeutic strategies to combat PTSD after symptom onset.

Physiologic changes associated with violence and abuse exposure: an examination of related medical conditions

Although the extant evidence is replete with data supporting linkages between exposure to violence or abuse and the subsequent development of medical illnesses, the underlying mechanisms of these relationships are poorly defined and understood. Physiologic changes occurring in violence- or abuse-exposed individuals point to potentially common biological pathways connecting traumatic exposures with medical outcomes. Herein, the evidence describing the long-term physiologic changes in abuse- and violence-exposed populations and associated medical illnesses are reviewed. Current data support that (a) specific neurobiochemical changes are associated with exposure to violence and abuse; (b) several biological pathways have the potential to lead to the development of future illness; and (c) common physiologic mechanisms may moderate the severity, phenomenology, or clinical course of medical illnesses in individuals with histories of exposure to violence or abuse. Importantly, additional work is needed to advance our emerging understanding of the biological mechanisms connecting exposure to violence and abuse and negative health outcomes.

Pretraumatic prolonged elevation of salivary MHPG predicts peritraumatic distress and symptoms of post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is associated with elevated catecholamines and increased sympathetic arousal. However, it is unknown whether this condition is a pre-existing vulnerability factor for PTSD or an acquired result of either trauma exposure or the development of PTSD symptoms. We sought to examine if salivary 3-methoxy-4-hydroxy-phenylglycol (MHPG) in response to a laboratory stressor prior to critical incident exposure predicts the development of PTSD symptoms and if early childhood trauma influences this relationship. In a prospective cohort study, 349 urban police officers were assessed during academy training (baseline) and 243 were reassessed 12 months after the start of active duty (follow-up). At baseline, participants observed a video consisting of police critical incidents. Salivary MHPG was measured before and immediately after the challenge, and after 20min recovery. At follow-up, peritraumatic distress and PTSD symptoms were assessed in relationship to the worst critical incident during the past year. Participants with childhood trauma showed a trend towards higher MHPG increase to the challenge. Higher MHPG levels after 20min recovery were associated with both higher levels of peritraumatic distress and PTSD symptoms at follow-up. In a path analysis, elevated MHPG levels predicted higher peritraumatic distress which in turn predicted higher levels of PTSD symptoms while the direct effect of elevated MHPG levels on PTSD symptoms was no longer significant. Prolonged elevation of salivary MHPG in response to a laboratory stressor marks a predisposition to experience higher levels of peritraumatic distress and subsequently more PTSD symptoms following critical incident exposure.

Post-traumatic stress disorder and migraine: epidemiology, sex differences, and potential mechanisms

Migraine is a common, often disabling disorder associated with a significant personal and societal burden. The presence of post-traumatic stress disorder (PTSD) may increase this disability substantially. Migraine and PTSD are both up to 3 times more common in women than in men. The divergence in prevalence rates of migraine and PTSD that occurs between the sexes after puberty suggests that gonadal hormones play an important role. In addition, the preponderance of PTSD in women may be related to their higher rates of interpersonal trauma, the most common cause of PTSD. However, recent data suggest that although the odds of PTSD are increased in both women and men with episodic migraine, this association is stronger in men than women. In this paper, we examine the epidemiology of PTSD and migraine, with an emphasis on the known sex differences. We then discuss the neurobiological changes associated with PTSD, the current hypotheses for the mechanisms relating PTSD and migraine, and the treatment implications of these findings.

Post-traumatic stress disorder, drug abuse and migraine: new findings from the National Comorbidity Survey Replication (NCS-R)

BACKGROUND

Post-traumatic stress disorder (PTSD) has been shown to be associated with migraine and drug abuse.

METHODS

This was an analysis of data from the National Comorbidity Survey Replication (NCS-R) to evaluate the association of PTSD in those with episodic migraine (EM) and chronic daily headache (CDH).

RESULTS

Our sample consisted of 5,692 participants. Lifetime and 12-month prevalence rates of PTSD were increased in those with EM and CDH. After adjustments, the lifetime odds ratio (OR) of PTSD was greater in those with EM (OR 3.07 confidence interval [CI]: 2.12, 4.46) compared to those without headache; was greater in men than women with EM (men: OR 6.86; CI: 3.11, 15.11; women: OR 2.77; CI: 1.83, 4.21); and was comparable or greater than the association between migraine with depression or anxiety. The lifetime OR of PTSD was also increased in CDH sufferers. The OR of illicit drug abuse was not increased in those with EM or CDH unless co-occurring with PTSD or depression.

CONCLUSION

The lifetime and 12-month OR of PTSD is increased in those with migraine or CDH, and is greater in men than women with migraine. The lifetime and 12-month OR of illicit drug abuse is not increased in those with migraine or CDH unless co-occurring with PTSD or depression.

Status of glucocorticoid alterations in post-traumatic stress disorder

The current status of glucocorticoid alterations in post-traumatic stress disorder (PTSD) will be described in this chapter. Emphasis will be placed on data that suggest that at least some glucocorticoid-related observations in PTSD reflect pretraumatic glucocorticoid status. Recent observations have provided some evidence that pretraumatic glucocorticoid alterations may arise from genetic, epigenetic, and possibly other environmental influences that serve to increase the likelihood of developing PTSD following trauma exposure, as well as modulate attendant biological alterations associated with its pathophysiology. Current studies in the field of PTSD employ glucocorticoid challenge strategies to delineate effects of exogenously administered glucocorticoids on neuroendocrine, cognitive, and brain function. Results of these studies have provided an important rationale for using glucocorticoid strategies in the treatment of PTSD.

Posttraumatic stress disorder in migraine

OBJECTIVE

To evaluate the relative frequency of posttraumatic stress disorder (PTSD) in episodic migraine (EM) and chronic daily headache (CDH) sufferers and the impact on headache-related disability.

BACKGROUND

Approximately 8% of the population is estimated to have PTSD. Recent studies suggest a higher frequency of PTSD in headache disorders. The association of PTSD and headache-related disability has not been examined.

METHODS

A prospective study was conducted at 6 headache centers. PTSD was assessed using the life events checklist and PTSD checklist, civilian version (PCL-C). We compared data from EM to CDH, and migraine with PTSD to migraine without PTSD. The PHQ-9 was used to assess depression, and headache impact test (HIT-6) to assess disability.

RESULTS

Of 767 participants, 593 fulfilled criteria for EM or CDH and were used in this analysis. The mean age was 42.2 years and 92% were women. The frequency of PTSD was greater in CDH than in EM (30.3% vs 22.4%, P = .043), but not after adjusting for demographics and depression (P = .87). However, participants with major depression and PTSD were more likely to have CDH than EM (24.6% vs 15.79%, P < .002). Disability was greater in migraineurs with PTSD, even after adjustments (65.2 vs 61.7, P = .002).

CONCLUSION

The frequency of PTSD in migraineurs, whether episodic or chronic, is higher than the historically reported prevalence of PTSD in the general population. In addition, in the subset of migraineurs with depression, PTSD frequency is greater in CDH sufferers than in episodic migraineurs. Finally, the presence of PTSD is independently associated with greater headache-related disability in migraineurs.