Effects of trauma-related audiovisual stimulation on cerebrospinal fluid norepinephrine and corticotropin-releasing hormone concentrations in post-traumatic stress disorder

[Posttraumatic stress disorder clinical guidelines and treatment standards: focus on the symptoms of the psychophysiological arousal]

The article describes the main diagnostic criteria and principles of posttraumatic stress disorder (PTSD) diagnostic with the consideration of risk factors and specific clinical features. The main biomarkers search trends and existing limitations are considered. The role of the psychophysiological arousal symptoms claster is highlighted in the clinical picture of PTSD as well as in connection with the main cluster of re-experiencing symptoms activation and slowing of sanogenesis process. The necessity of PTSD detection in somatic medicine is thoroughly described. The article presents therapeutic algorithms of the latest international and Russian PTSD treatment clinical guidelines based on the individual combination of psychotherapy and psychopharmacotherapy treatment choice. Additionally the accumulated during the last decades national clinical experience of the anxiety disorders treatment, including the symptoms of psychophysiological arousal is highlighted that determined the list of the recommended drugs indicating the evidence level, in the PTSD treatment standards and guidelines. The treatment choices possibilities with the consideration of different PTSD symptoms cluster expression and comorbid states and individual case distress level specific are presented. Main evidence based psychotherapeutic methods are described.

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.

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.

Involvement of the GABAergic system in PTSD and its therapeutic significance

The neurobiological mechanism of post-traumatic stress disorder (PTSD) is poorly understood. The inhibition of GABA neurons, especially in the amygdala, is crucial for the precise regulation of the consolidation, expression, and extinction of fear conditioning. The GABAergic system is involved in the pathophysiological process of PTSD, with several studies demonstrating that the function of the GABAergic system decreases in PTSD patients. This paper reviews the preclinical and clinical studies, neuroimaging techniques, and pharmacological studies of the GABAergic system in PTSD and summarizes the role of the GABAergic system in PTSD. Understanding the role of the GABAergic system in PTSD and searching for new drug targets will be helpful in the treatment of PTSD.

Deriving psychiatric symptom-based biomarkers from multivariate relationships between psychophysiological and biochemical measures

Identification of biomarkers for psychiatric disorders remains very challenging due to substantial symptom heterogeneity and diagnostic comorbidity, limiting the ability to map symptoms to underlying neurobiology. Dimensional symptom clusters, such as anhedonia, hyperarousal, etc., are complex and arise due to interactions of a multitude of complex biological relationships. The primary aim of the current investigation was to use multi-set canonical correlation analysis (mCCA) to derive biomarkers (biochemical, physiological) linked to dimensional symptoms across the anxiety and depressive spectrum. Active-duty service members (N = 2,592) completed standardized depression, anxiety and posttraumatic stress questionnaires and several psychophysiological and biochemical assays. Using this approach, we identified two phenotype associations between distinct physiological and biological phenotypes. One was characterized by symptoms of dysphoric arousal (anhedonia, anxiety, hypervigilance) which was associated with low blood pressure and startle reactivity. This finding is in line with previous studies suggesting blunted physiological reactivity is associated with subpopulations endorsing anxiety with comorbid depressive features. A second phenotype of anxious fatigue (high anxiety and reexperiencing/avoidance symptoms coupled with fatigue) was associated with elevated blood levels of norepinephrine and the inflammatory marker C-reactive protein in conjunction with high blood pressure. This second phenotype may describe populations in which inflammation and high sympathetic outflow might contribute to anxious fatigue. Overall, these findings support the growing consensus that distinct neuropsychiatric symptom patterns are associated with differential physiological and blood-based biological profiles and highlight the potential of mCCA to reveal important psychiatric symptom biomarkers from several psychophysiological and biochemical measures.

The impact of COVID-19 on cardiovascular health behaviors in student veterans

BACKGROUND AND AIMS

Pandemics have previously resulted in increased cardiovascular morbidity and mortality. It is unclear if the effects of the COVID-19 pandemic will be amplified in individuals at high risk for cardiovascular disease, such as military populations, resulting in augmented cardiovascular events in Veterans. The purpose of this study was to determine if traditional behavioral risk factors for cardiovascular disease are amplified due to the COVID-19 pandemic and if risk factors are more prevalent in Veterans compared to non-Veterans.

METHODS AND RESULTS

Thirty-two student Veterans and 46 non-Veteran students between the ages of 18 and 35 completed a Qualtrics self-report questionnaire assessing health behaviors, physical activity, and mental health both before and during COVID-19. Veterans displayed worse pre-COVID cardiovascular health behaviors such as poor sleep habits, greater use of tobacco, alcohol, and energy drinks, and lower values of social engagement compared to non-Veterans. Many health behaviors remained unchanged in student Veterans during the pandemic. The non-Veteran group exhibited augmentation of cardiovascular health behaviors during COVID-19, shown through the worsening sleep habits, increased anxiety, and reduced physical activity.

CONCLUSION

Student Veterans demonstrate heightened risk for cardiovascular disease based on the pre-COVID elevation of behavioral risk factors. These behavioral factors continued to remain elevated during the COVID-19 pandemic. Non-Veteran students displayed amplification of behavioral risk factors for cardiovascular disease due to the COVID-19 pandemic. These results highlight the need for resources and interventions for our student veterans and suggest long-term cardiovascular consequences for all students who suffered through the COVID-19 pandemic.

CRF serum levels differentiate PTSD from healthy controls and TBI in military veterans

Background and Objective

Posttraumatic stress disorder (PTSD) is a serious and frequently debilitating psychiatric condition that can occur in people who have experienced traumatic stressors, such as war, violence, sexual assault and other life‐threatening events. Treatment of PTSD and traumatic brain injury (TBI) in veterans is challenged by diagnostic complexity, partially due to PTSD and TBI symptoms overlap and to the fact that subjective self‐report assessments may be influenced by a patient's willingness to share their traumatic experiences and resulting symptoms. Corticotropin‐releasing factor (CRF) is one of the main mediators of hypothalamic pituitary adrenal (HPA)‐axis responses in stress and anxiety.

Methods and Results

We analyzed serum CRF levels in 230 participants including heathy controls (64), and individuals with PTSD (53), TBI (70) or PTSD + TBI (43) by enzyme immunoassay (EIA). Significantly lower CRF levels were found in both the PTSD and PTSD + TBI groups compared to healthy control (PTSD vs. Controls: P = 0.0014, PTSD + TBI vs. Controls: P = 0.0011) and chronic TBI participants (PTSD vs. TBI: P < 0.0001, PTSD + TBI vs. TBI: P < 0.0001), suggesting a PTSD‐related mechanism independent from TBI and associated with CRF reduction. CRF levels negatively correlated with PTSD severity on the Clinically Administered PTSD Scale (CAPS‐5) scale in the whole study group.

Conclusions

Hyperactivation of the HPA axis has been classically identified in acute stress. However, the recognized enhanced feedback inhibition of the HPA axis in chronic stress supports our findings of lower CRF in PTSD patients. This study suggests that reduced serum CRF in PTSD should be further investigated. Future validation studies will establish if CRF is a possible blood biomarker for PTSD and/or for differentiating PTSD and chronic TBI symptomatology.

The HPA axis is activated under acute stress conditions, but an enhanced feedback inhibition may be prevalent in chronic stress conditions such as PTSD.

We observed a reduction in serum CRF levels in veterans with PTSD and PTSD + TBI, but not in veterans with chronic TBI alone.

A serum CRF reduction may be indicative of CNS mechanisms specific to PTSD and should be further evaluated as a possible peripheral biomarker.

Symptom profiles and treatment status of older adults with chronic post-traumatic stress disorder

OBJECTIVE

Failure to diagnose and treat post-traumatic stress disorder (PTSD) may help explain the substantial disability, increased cognitive decline, and adverse health outcomes suffered by older adults with this disorder. To evaluate this possibility, we examined symptom differences among older and younger individuals with PTSD and measured the frequency with which older adults receive standard of care treatment.

METHODS

Clinician-Administered PTSD Scale for DSM (CAPS) scores were compared between younger and older adults with PTSD. Profiles were calculated for the most dominant CAPS symptom cluster reported by each participant, and the age cutoff best differentiating symptom clusters between individuals was determined. Clinical interview data (older adult sample only) were evaluated by trained raters to determine rates at which PTSD participants accessed treatment.

RESULTS

Among 108 individuals with PTSD, 69% of participants <67 years old had Criterion C (avoidance) symptoms as the most dominant cluster compared to 39% of participants ≥67 (p = 0.016). Eight percent of participants <67 years had Criterion E (hyperarousal) symptoms as the most dominant cluster compared to 30% of participants ≥67 (p = 0.016). Less than 25% of the older adults (N = 53 subsample) were receiving a first-line pharmacotherapy option for PTSD, and 0% of participants were currently participating in an evidence-based psychotherapy for PTSD.

CONCLUSIONS

Clinicians evaluating patients should be aware that different symptom profiles may be present between younger and older adults with PTSD. Despite their high risk for adverse neuropsychiatric and other health consequences, older adults with PTSD appear to infrequently receive first-line clinical treatment.

Blunted salivary cortisol response to psychosocial stress in women with posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is characterized by alterations in the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS). There is evidence for a blunted HPA axis reactivity to psychosocial stress. Less is known about how the SNS reacts to psychosocial stress. Here, we compared the HPA axis and SNS responses to psychosocial stress and a non-stressful condition in patients with PTSD and in healthy individuals. Twenty-one women with PTSD and 32 healthy women participated in the Trier social stress test (TSST) and placebo TSST (P-TSST). We measured salivary cortisol, alpha amylase activity and blood pressure before and after the tests. Subjective perceived stress response was also assessed. We found a blunted cortisol response to the TSST in patients with PTSD compared with healthy participants 10 min (t (51) = -2.58, p = .01) and 25 min (t (51) = -2.16, p = .04) after TSST. We found no evidence for an increased SNS reactivity after psychosocial stress in patients with PTSD (all p > .05). Patients with PTSD, but not healthy participants, reported more dissociative symptoms (t (20) = -2.31, p = .03) and being more tired (t (20) = 2.90, p = .01) directly after TSST compared with the placebo condition. Our results suggest a blunted HPA stress reactivity and an increased subjective perceived stress response in female patients with PTSD. Longitudinal studies could test if these altered stress responses constitute a predisposition to or a cause of PTSD. Future studies should investigate whether these results are transferable to men.

Sleep Changes Across the Female Hormonal Cycle Affecting Memory: Implications for Resilient Adaptation to Traumatic Experiences

We review findings and propose a model explaining why women's adaptation to traumatic stress might be different than men's, including the role of cycling hormones and sleep differences in the development of post-traumatic stress and other stress-related disorders. Women are diagnosed with stress-related mental health disorders at a higher frequency than men. Most mental health disorders involve sleep disturbances, which may contribute to these disorders. The mechanisms by which sleep contributes to the development of mental health disorders in women have not been addressed in basic research. Sleep features such as spindle density and rapid eye movement (REM) sleep theta power are important for the role of sleep in emotion and cognition. The effect of hormonal cycles on these and other critical sleep features is only beginning to be understood. We explore what sleep factors could confer resilience to mental health disorders and how they might be altered by hormonal cycles in women. We target a specific system at the nexus of arousal control, stress response, and memory consolidation processes that has not been explored at all in women or across the hormonal cycle in animal studies: the locus coeruleus noradrenergic (LC-NE) system.

Korean Red Ginseng prevents posttraumatic stress disorder-triggered depression-like behaviors in rats via activation of the serotonergic system

Background

Posttraumatic stress disorder (PTSD), a mental disorder induced by traumatic stress and often accompanied by depression and/or anxiety, may involve an imbalance in the neurotransmitters associated with the fear response. Korean Red Ginseng (KRG) has long been used as a traditional medicine and is known to be involved in a variety of pharmacological activities. We used the open field test and forced swimming test to examine the effects of KRG on the depression-like response of rats after exposure to single prolonged stress (SPS), leading to activation of the serotonergic system.

Methods

Male rats received KRG (30, 50, and 100 mg/kg, intraperitoneal injection) once daily for 14 days after exposure to SPS.

Results

Daily KRG administration significantly improved depression-like behaviors in the forced swimming test, increased the number of lines crossed and time spent in the central zone in the open field test, and decreased freezing behavior in contextual and cued fear conditioning. KRG treatment attenuated SPS-induced decreases in serotonin (5-HT) tissue concentrations in the hippocampus and medial prefrontal cortex. The increased 5-HT concentration during KRG treatment may be partially attributable to the 5-hydroxyindoleacetic acid/5-HT ratio in the hippocampus of rats with PTSD. These effects may be caused by the activation of hippocampal genes encoding tryptophan hydroxylase-1 and 2 mRNA levels.

Conclusion

Our findings suggest that KRG has an antidepressant effect in rats subjected to SPS and may represent an effective use of traditional medicine for the treatment of PTSD.

Antidepressant-Like Effects of Hesperidin in Animal Model of Post-Traumatic Stress Disorder

OBJECTIVE

Post-traumatic stress disorder (PTSD) is a psychiatric disorder characterized by depression and anxiety, that arises due to an imbalance of neurotransmitters in response to excessive stress. Hesperidin (HSD) is a naturally occurring flavonoid shown to exert a variety of biological activities, including antioxidant, anti-inflammatory, and neuroprotective effects.

METHODS

This study was used the open field test (OFT) and forced swimming test (FST) to examine the effects of HSD on the depression-like response of rats after exposure to a single prolonged stress (SPS) leading to the dysregulation of the serotonergic activation system. Male rats were given HSD (20, 50, and 100 mg/kg, intraperitoneal injection, n=6-7 per group) once daily for 14 days after exposure to SPS. The influence of administration of HSD on SPS-induced behavioral responses and concentrations of serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), and monoamine oxidase-A (MAO-A) in the rat brain were also investigated using enzyme-linked immunoassays (ELISAs).

RESULTS

Daily HSD administration signifificantly improved depression-like behaviors in the FST (P0.05), increased the number of lines crossed in the central zone of the OFT (P0.01), and reduced freezing behavior both in contextual and cued fear conditioning. HSD treatment also attenuated the reduction in SPS-induced 5-HT concentrations in the hippocampus and amygdala. This increase in 5-HT concentrations during HSD treatment was partially attributed to a decrease in the 5-HIAA/5-HT ratio in the hippocampus of rats with PTSD. Furthermore, HSD treatment inhibited activity of MAO-A and decreases of tryptophan hydroxylase-1 expression in the hippocampus.

CONCLUSION

HSD was shown to exert antidepressant effects in rats exposed to SPS, suggesting that this natural flflavonoid may be an effective medicine for PTSD.

Acclimatization to Middle Attitude Hypoxia Masks the Symptoms of Experimental Posttraumatic Stress Disorder, but Does Not Affect Its Pathogenetic Mechanisms

The effects of acclimatization to middle attitude hypoxia on the resistance to acute emotional stress were studied on the model of posttraumatic stress disorder in rats. Anxyolitic, but not anxiogenic effect was observed in acclimatized rats. However, acclimatized rats with posttraumatic stress disorder were characterized by hypofunction of the pituitary-adrenocortical axis, which is typical of this pathology, and reduction in corticosterone/dehydroepiandrosterone ratio. At the neuroendocrine level, up-regulation of glucocorticoid receptors and a decrease in the level of corticotropin-releasing hormone in the hippocampus were revealed. The observed modifications of regulatory mechanisms can underlie hypofunction of the pituitary-adrenocortical axis. It was concluded that acclimatization to middle attitude hypoxia masks behavioral symptoms of posttraumatic stress disorder, but does not alter its pathogenetic neuroendocrine mechanisms.

Autonomic and Redox Imbalance Correlates With T-Lymphocyte Inflammation in a Model of Chronic Social Defeat Stress

Patients diagnosed with post-traumatic stress disorder (PTSD) are at a significantly elevated risk of developing comorbid inflammatory conditions, but the mechanisms underlying this predilection remain unclear. Our previous work has shown that T-lymphocytes exposed to elevated levels of norepinephrine (NE) displayed a pro-inflammatory signature reminiscent of an autoreactive phenotype. With this, we hypothesized that the increased sympathetic tone observed during psychological trauma may be promoting pro-inflammatory T-lymphocytes, which causes a predisposition to comorbid inflammatory conditions. Here, we examined the consequences of psychological trauma on splenic T-lymphocytes using a mouse model of repeated social defeat stress. Social defeat led to anxiety-like and depression-like behavior as has been previously described. The spleens of socially-defeated mice showed significant elevations of NE, tyrosine hydroxylase (TH), and acetylcholinesterase (ACHE) levels, which appeared to be due in part to increased expression within T-lymphocytes. Additionally, T-lymphocytes from stressed animals showed higher levels of pro-inflammatory cytokines and mitochondrial superoxide. Interestingly, in this model system, close associations exist within splenic T-lymphocytes amid the autonomic, inflammatory, and redox environments, but these only weakly correlate with individual behavioral differences among animals suggesting the psychological and physiological manifestations of trauma may not be tightly coupled. Last, we describe, for the first time, elevations in calprotectin levels within T-lymphocytes and in circulation of psychologically stressed animals. Calprotectin correlated with both behavioral and physiological changes after social defeat, suggesting the potential for a new biological marker and/or therapeutic target for psychological trauma and its inflammatory comorbidities.

MicroRNAs in Post-traumatic Stress Disorder

Post-traumatic stress disorder (PTSD) is a psychiatric disorder that can develop following exposure to or witnessing of a (potentially) threatening event. A critical issue is to pinpoint the (neuro)biological mechanisms underlying the susceptibility to stress-related disorder such as PTSD, which develops in the minority of ~15% of individuals exposed to trauma. Over the last few years, a first wave of epigenetic studies has been performed in an attempt to identify the molecular underpinnings of the long-lasting behavioral and mental effects of trauma exposure. The potential roles of non-coding RNAs (ncRNAs) such as microRNAs (miRNAs) in moderating or mediating the impact of severe stress and trauma are increasingly gaining attention. To date, most studies focusing on the roles of miRNAs in PTSD have, however, been completed in animals, using cross-sectional study designs and focusing almost exclusively on subjects with susceptible phenotypes. Therefore, there is a strong need for new research comprising translational and cross-species approaches that use longitudinal designs for studying trajectories of change contrasting susceptible and resilient subjects. The present review offers a comprehensive overview of available studies of miRNAs in PTSD and discusses the current challenges, pitfalls, and future perspectives of this field.

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.

Twenty-Seven Tamoxifen-Inducible iCre-Driver Mouse Strains for Eye and Brain, Including Seventeen Carrying a New Inducible-First Constitutive-Ready Allele

To understand gene function, the cre/loxP conditional system is the most powerful available for temporal and spatial control of expression in mouse. However, the research community requires more cre recombinase expressing transgenic mouse strains (cre-drivers) that restrict expression to specific cell types. To address these problems, a high-throughput method for large-scale production that produces high-quality results is necessary. Further, endogenous promoters need to be chosen that drive cell type specific expression, or we need to further focus the expression by manipulating the promoter. Here we test the suitability of using knock-ins at the docking site 5′ of Hprt for rapid development of numerous cre-driver strains focused on expression in adulthood, using an improved cre tamoxifen inducible allele (icre/ERT2), and testing a novel inducible-first, constitutive-ready allele (icre/f3/ERT2/f3). In addition, we test two types of promoters either to capture an endogenous expression pattern (MaxiPromoters), or to restrict expression further using minimal promoter element(s) designed for expression in restricted cell types (MiniPromoters). We provide new cre-driver mouse strains with applicability for brain and eye research. In addition, we demonstrate the feasibility and applicability of using the locus 5′ of Hprt for the rapid generation of substantial numbers of cre-driver strains. We also provide a new inducible-first constitutive-ready allele to further speed cre-driver generation. Finally, all these strains are available to the research community through The Jackson Laboratory.

Recent advances in the neurobiology of posttraumatic stress disorder: A review of possible mechanisms underlying an effective pharmacotherapy

Recent progress in the field of neurobiology supported by clinical evidence gradually reveals the mystery of human brain functioning. So far, many psychiatric disorders have been described in great detail, although there are still plenty of cases that are misunderstood. These include posttraumatic stress disorder (PTSD), which is a unique disease that combines a wide range of neurobiological changes, which involve disturbances of the hypothalamic-pituitary-adrenal gland axis, hyperactivation of the amygdala complex, and attenuation of some hippocampal and cortical functions. Such multiplicity results in differential symptomatology, including elevated anxiety, nightmares, fear retrieval episodes that may trigger delusions and hallucinations, sleep disturbances, and many others that strongly interfere with the quality of the patient's life. Because of widespread neurological changes and the disease manifestation, the pharmacotherapy of PTSD remains unclear and requires a multidimensional approach and involvement of polypharmacotherapy. Hopefully, more and more neuroscientists and clinicians will study PTSD, which will provide us with new information that would possibly accelerate establishment of well-tolerated and effective pharmacotherapy. In this review, we have focused on neurobiological changes regarding PTSD, addressing the most disturbed brain structures and neurotransmissions, as well as discussing in detail the recently taken and novel therapeutic paths.

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.

Neurotransmitter, Peptide, and Steroid Hormone Abnormalities in PTSD: Biological Endophenotypes Relevant to Treatment

PURPOSE OF REVIEW

This review summarizes neurotransmitter, peptide, and other neurohormone abnormalities associated with posttraumatic stress disorder (PTSD) and relevant to development of precision medicine therapeutics for PTSD.

RECENT FINDINGS

As the number of molecular abnormalities associated with PTSD across a variety of subpopulations continues to grow, it becomes clear that no single abnormality characterizes all individuals with PTSD. Instead, individually variable points of molecular dysfunction occur within several different stress-responsive systems that interact to produce the clinical PTSD phenotype. Future work should focus on critical interactions among the systems that influence PTSD risk, severity, chronicity, comorbidity, and response to treatment. Effort also should be directed toward development of clinical procedures by which points of molecular dysfunction within these systems can be identified in individual patients. Some molecular abnormalities are more common than others and may serve as subpopulation biological endophenotypes for targeting of currently available and novel treatments.

A Clinician's Guide to PTSD Biomarkers and Their Potential Future Use

No clinically validated biomarkers have yet been found to assist in the diagnosis and treatment of posttraumatic stress disorder (PTSD). Innovation in clinical trial design, however, has led to the study of biomarkers as part of testing new medications and psychotherapies. There may soon be viable biomarkers to assist in diagnosis of PTSD and prediction of illness trajectory, severity, and functional outcomes; subtyping; and treatment selection. Processes for the identification and validation of biomarker findings are complex, involving several stages of clinical testing before use. The authors provide an overview of issues regarding the clinical use of PTSD biomarkers and examine a set of genetic, epigenetic, and other blood-based markers along with physiological markers currently proposed as candidate tests for PTSD. Studies that have identified candidate biomarkers with relevance to treatment selection in PTSD are discussed as a promising area of research that may lead to changes in clinical practice.

Oleuropein reduces anxiety-like responses by activating of serotonergic and neuropeptide Y (NPY)-ergic systems in a rat model of post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is a stress-related mental disorder caused by traumatic experiences. This psychopathological response to traumatic stressors induces anxiety in rats. Oleuropein (OLE), a major compound in olive leaves, reportedly possesses several pharmacological properties, including anti-cancer, anti-diabetic, and anti-atherosclerotic and neuropsychiatric activities. However, the anxiolytic-like effects of OLE and its mechanism of action in PTSD are unclear. The present study used several behavioral tests to examine the effects of OLE on symptoms of anxiety in rats after a single prolonged stress (SPS) exposure by inhibiting the hypothalamic-pituitary-adrenal axis. Male Sprague Dawley rats received OLE (10, 50 and 70 mg/kg, i.p., once daily) for 14 days after SPS exposure. Daily OLE (70 mg/kg) administration significantly increased the number and duration of open arm visits in the elevated plus maze (EPM) test, reduced the anxiety index and grooming behavior in the EPM test, and increased the time spent and number of central zone crossings in the open field test. OLE also blocked the SPS-induced decrease in hippocampal serotonin and neuropeptide Y expression in hippocampus. These findings suggest that OLE has anxiolytic-like effects on behavioral and biochemical symptoms similar to those observed in patients with PTSD.

Post-Traumatic Stress Disorder Delineating the Progression and Underlying Mechanisms Following Blast Traumatic Brain Injury

Posttraumatic Stress Disorder (PTSD) is a devastating condition that can develop after blast Traumatic Brain Injury (TBI). Ongoing work has been performed to understand how PTSD develops after injury. In this review, we highlight how PTSD affects individuals, discuss what is known about the physiologic changes to the hypothalamic pituitary axis and neurotransmitter pathways, and present an overview of genetic components that may predispose individuals to developing PTSD. We then provide an overview of current treatment strategies to treat PTSD in veterans and present new strategies that may be useful going forward. The need for further clinical and pre-clinical studies is imperative to improve diagnosis, treatment, and management for patients that develop PTSD following blast TBI.

An Open-Label Study of Doxazosin Extended-Release for PTSD: Findings and Recommendations for Future Research on Doxazosin

Objective

This report presents findings from an eight-week, open-label study of doxazosin extended-release for nightmares, sleep disturbance, and overall clinical symptoms in posttraumatic stress disorder (PTSD). Recommendations for future studies of doxazosin are provided.

Method

Fifteen male and female adults were enrolled. The primary endpoints were change in Clinician-Administered PTSD Scale total, nightmare, and sleep disturbance scores from pretreatment to end of treatment. Self-report data on PTSD, sleep quality, depression, and quality of life collected at three time points and sleep diary data collected daily were analyzed secondarily.

Results

Eight participants completed eight weeks of study treatment. Among completers, significant changes in nightmares and overall PTSD symptoms were found. Secondary analyses using data from completers and noncompleters demonstrated improvements in all secondary outcomes. Of the participants who dropped out of the study, four participants discontinued because of side effects, and three participants discontinued because of other barriers to study participation.

Conclusions

These findings indicate that doxazosin may be of value for some individuals with PTSD but problematic for others. Alternative formulations of doxazosin, such as the immediate-release formulation, should be studied. Future research should examine moderators of treatment tolerability and treatment effects to best identify those who will or will not benefit from doxazosin.

Corticotropin-Releasing Factor Receptor 1 Antagonism Is Ineffective for Women With Posttraumatic Stress Disorder

BACKGROUND

Medication and psychotherapy treatments for posttraumatic stress disorder (PTSD) provide insufficient benefit for many patients. Substantial preclinical and clinical data indicate abnormalities in the hypothalamic-pituitary-adrenal axis, including signaling by corticotropin-releasing factor, in the pathophysiology of PTSD.

METHODS

We conducted a double-blind, placebo-controlled, randomized, fixed-dose clinical trial evaluating the efficacy of GSK561679, a corticotropin-releasing factor receptor 1 (CRF₁ receptor) antagonist in adult women with PTSD. The trial randomized 128 participants, of whom 96 completed the 6-week treatment period.

RESULTS

In both the intent-to-treat and completer samples, GSK561679 failed to show superiority over placebo on the primary outcome of change in Clinician-Administered PTSD Scale total score. Adverse event frequencies did not significantly differ between GSK561679- and placebo-treated subjects. Exploration of the CRF₁ receptor single nucleotide polymorphism rs110402 found that response to GSK561679 and placebo did not significantly differ by genotype alone. However, subjects who had experienced a moderate or severe history of childhood abuse and who were also GG homozygotes for rs110402 showed significant improvement after treatment with GSK561679 (n = 6) but not with placebo (n = 7) on the PTSD Symptom Scale-Self-Report.

CONCLUSIONS

The results of this trial, the first evaluating a CRF₁ receptor antagonist for the treatment of PTSD, combined with other negative trials of CRF₁ receptor antagonists for major depressive disorder, generalized anxiety disorder, and social anxiety disorder, suggest that CRF₁ receptor antagonists lack efficacy as monotherapy agents for these conditions.

Genesis and Maintenance of Attentional Biases: The Role of the Locus Coeruleus-Noradrenaline System

Emotionally arousing events are typically better remembered than mundane ones, in part because emotionally relevant aspects of our environment are prioritized in attention. Such biased attentional tuning is itself the result of associative processes through which we learn affective and motivational relevance of cues. We propose that the locus coeruleus-noradrenaline (LC-NA) system plays an important role in the genesis of attentional biases through associative learning processes as well as their maintenance. We further propose that individual differences in and disruptions of the LC-NA system underlie the development of maladaptive biases linked to psychopathology. We provide support for the proposed role of the LC-NA system by first reviewing work on attentional biases in development and its link to psychopathology in relation to alterations and individual differences in NA availability. We focus on pharmacological manipulations to demonstrate the effect of a disrupted system as well as the ADRA2b polymorphism as a tool to investigate naturally occurring differences in NA availability. We next review associative learning processes that-modulated by the LC-NA system-result in such implicit attentional biases. Further, we demonstrate how NA may influence aversive and appetitive conditioning linked to anxiety disorders as well as addiction and depression.

Posttraumatic Stress Disorder and Alcohol Use Disorder: A Critical Review of Pharmacologic Treatments

Treatment of alcohol use disorder (AUD) is complicated by the presence of psychiatric comorbidity including posttraumatic stress disorder (PTSD). This is a critical review of the literature to date on pharmacotherapy treatments of AUD and PTSD. A systematic literature search using PubMed MESH terms for alcohol and substance use disorders, PTSD, and treatment was undertaken to identify relevant randomized controlled trials (RCTs). The studies were independently evaluated (ILP and TLS) and those that evaluated the efficacy of a pharmacotherapy for individuals diagnosed with AUD and PTSD and were RCTs were selected. Studies were grouped in 3 categories: (i) those that evaluated first-line treatments for PTSD, (ii) those that evaluated medications to target AUD, and (iii) those that evaluated medications hypothesized to be effective in targeting alcohol consumption as well as PTSD symptoms. Nine RCTs were identified; 3 focused on medications to treat PTSD, 4 focused on AUD, and 3 to target both. One study included both a medication to treat PTSD and 1 to treat AUD so was discussed twice. All but 1 of the studies found that PTSD symptoms and drinking outcomes improved significantly over time. There is not 1 agent with clear evidence of efficacy in this comorbid group. The results for medications to treat PTSD are inconclusive because of contradictory results. There was weak evidence to support the use of medications to treat AUD among those with comorbidity with PTSD. Findings for medications that were hypothesized to treat both disorders were also contradictory. Most studies provided a combination of interventions to treat both disorders. Despite the contradictory results, this review suggests that individuals with AUD and comorbid PTSD can safely be prescribed medications used in noncomorbid populations and patients improve with treatment.

Inflammation in Fear- and Anxiety-Based Disorders: PTSD, GAD, and Beyond

The study of inflammation in fear- and anxiety-based disorders has gained interest as growing literature indicates that pro-inflammatory markers can directly modulate affective behavior. Indeed, heightened concentrations of inflammatory signals, including cytokines and C-reactive protein, have been described in posttraumatic stress disorder (PTSD), generalized anxiety disorder (GAD), panic disorder (PD), and phobias (agoraphobia, social phobia, etc.). However, not all reports indicate a positive association between inflammation and fear- and anxiety-based symptoms, suggesting that other factors are important in future assessments of inflammation's role in the maintenance of these disorders (ie, sex, co-morbid conditions, types of trauma exposure, and behavioral sources of inflammation). The most parsimonious explanation of increased inflammation in PTSD, GAD, PD, and phobias is via the activation of the stress response and central and peripheral immune cells to release cytokines. Dysregulation of the stress axis in the face of increased sympathetic tone and decreased parasympathetic activity characteristic of anxiety disorders could further augment inflammation and contribute to increased symptoms by having direct effects on brain regions critical for the regulation of fear and anxiety (such as the prefrontal cortex, insula, amygdala, and hippocampus). Taken together, the available data suggest that targeting inflammation may serve as a potential therapeutic target for treating these fear- and anxiety-based disorders in the future. However, the field must continue to characterize the specific role pro-inflammatory signaling in the maintenance of these unique psychiatric conditions.

Post-Traumatic Stress Disorder: The Relationship Between the Fear Response and Chronic Stress

Post-traumatic stress disorder (PTSD) is a disabling psychiatric condition that can develop following a physical, psychological, or sexual trauma. Despite the growing body of literature examining the psychological and biological factors involved in PTSD psychopathology, specific biomarkers that may improve diagnosis and treatment of PTSD have yet to be identified and validated. This challenge may be attributed to the diverse array of symptoms that individuals with the disorder manifest. Examining the interrelated stress and fear systems allows for a more comprehensive study of these symptoms, and through this approach, which aligns with the research domain criteria (RDoC) framework, neural and psychophysiological measures of PTSD have emerged. In this review, we discuss PTSD neurobiology and treatment within the context of fear and stress network interactions and elucidate the advantages of using an RDoC approach to better understand PTSD with fear conditioning and extinction paradigms.

Prediction of Possible Biomarkers and Novel Pathways Conferring Risk to Post-Traumatic Stress Disorder

Post-traumatic stress disorder is one of the common mental ailments that is triggered by exposure to traumatic events. Till date, the molecular factors conferring risk to the development of PTSD is not well understood. In this study, we have conducted a meta-analysis followed by hierarchical clustering and functional enrichment, to uncover the potential molecular networks and critical genes which play an important role in PTSD. Two datasets of expression profiles from Peripheral Blood Mononuclear Cells from 62 control samples and 63 PTSD samples were included in our study. In PTSD samples of GSE860 dataset, we identified 26 genes informative when compared with Post-deploy PTSD condition and 58 genes informative when compared with Pre-deploy and Post-deploy PTSD of GSE63878 dataset. We conducted the meta-analysis using Fisher, roP, Stouffer, AW, SR, PR and RP methods in MetaDE package. Results from the rOP method of MetaDE package showed that among these genes, the following showed significant changes including, OR2B6, SOX21, MOBP, IL15, PTPRK, PPBPP2 and SEC14L5. Gene ontology analysis revealed enrichment of these significant PTSD-related genes for cell proliferation, DNA damage and repair (p-value ≤ 0.05). Furthermore, interaction network analysis was performed on these 7 significant genes. This analysis revealed highly connected functional interaction networks with two candidate genes, IL15 and SEC14L5 highly enriched in networks. Overall, from these results, we concluded that these genes can be recommended as some of the potential targets for PTSD.

Audiovisual Stimulation Modulates Physical Performance and Biochemical and Hormonal Status of Athletes

We studied the effect of audiovisual stimulation training course on physical development, functional state of the cardiovascular system, blood biochemical parameters, and hormonal status of athletes. The training course led to improvement of physical performance and adaptive capacities of the circulatory system, increase in plasma levels of total protein, albumin, and glucose and total antioxidant activity, and decrease in triglyceride, lipase, total bilirubin, calcium, and phosphorus. The concentration of hormones (cortisol, thyrotropin, triiodothyronine, and thyroxine) also decreased under these conditions. In the control group, an increase in the concentration of creatinine and uric acid and a tendency toward elevation of lowdensity lipoproteins and total antioxidant activity were observed in the absence of changes in cardiac function and physical performance; calcium and phosphorus concentrations reduced. The improvement in functional state in athletes was mainly associated with intensification of anabolic processes and suppression of catabolic reactions after audiovisual stimulation (in comparison with the control). Stimulation was followed by an increase in the number of correlations between biochemical and hormonal changes and physical performance of athletes, which attested to better integration of processes at the intersystem level.

Posttraumatic stress disorder: A metabolic disorder in disguise?

Posttraumatic stress disorder (PTSD) is a heterogeneous psychiatric disorder that affects individuals exposed to trauma and is highly co-morbid with other adverse health outcomes, including cardiovascular disease and obesity. The unique pathophysiological feature of PTSD is the inability to inhibit fear responses, such that individuals suffering from PTSD re-experience traumatic memories and are unable to control psychophysiological responses to trauma-associated stimuli. However, underlying alterations in sympathetic nervous system activity, neuroendocrine systems, and metabolism associated with PTSD are similar to those present in traditional metabolic disorders, such as obesity and diabetes. The current review highlights existing clinical, translational, and preclinical data that support the notion that underneath the primary indication of impaired fear inhibition, PTSD is itself also a metabolic disorder and proposes altered function of inflammatory responses as a common underlying mechanism. The therapeutic implications of treating PTSD as a whole-body condition are significant, as targeting any underlying biological system whose activity is altered in both PTSD and metabolic disorders, (i.e. HPA axis, sympathetic nervous systems, inflammation) may elicit symptomatic relief in individuals suffering from these whole-body adverse outcomes.

Gastrodin reversed the traumatic stress-induced depressed-like symptoms in rats

Exposure to severe stress can lead to the development of neuropsychiatric disorders such as depression and post-traumatic stress disorder (PTSD) in at-risk individuals. Gastrodin (GAS), a primary constituent of an Oriental herbal medicine, has been shown to effectively treat various mood disorders. Thus, the present study aimed to determine whether GAS would ameliorate stress-associated depression-like behaviors in a rat model of single prolonged stress (SPS)-induced PTSD. Following the SPS procedure, rats received intraperitoneal administration of GAS (20, 50, or 100 mg/kg) once daily for 2 weeks. Subsequently, the rats performed the forced swimming test, and norepinephrine (NE) levels in the hippocampus were measured. Daily GAS (100 mg/kg) significantly reversed depression-like behaviors and restored SPS-induced increases in hippocampal NE concentrations as well as tyrosine hydroxylase expression in the locus coeruleus. Furthermore, the administration of GAS attenuated SPS-induced decreases in the hypothalamic expression of neuropeptide Y and the hippocampal mRNA expression of brain-derived neurotrophic factor. These findings indicate that GAS possesses antidepressant effects in the PTSD and may be an effective herbal preparation for the treatment of PTSD.

Priming locus coeruleus noradrenergic modulation of medial perforant path-dentate gyrus synaptic plasticity

Priming phenomenon, in which an earlier exposure to a stimulus or condition alters synaptic plasticity in response to a subsequent stimulus or condition, known as a challenge, is an example of metaplasticity. In this review, we make the case that the locus coeruleus noradrenergic system-medial perforant path-dentate gyrus pathway is a neural ensemble amenable to studying priming-challenge effects on synaptic plasticity. Accumulating evidence points to a tyrosine hydroxylase-dependent priming effect achieved by pharmacological (nicotine and antipsychotics) or physiological (septal theta driving) manipulations of the locus coeruleus noradrenergic system that can facilitate noradrenaline-induced synaptic plasticity in the dentate gyrus of the hippocampus. The evidence suggests the hypothesis that behavioural experiences inducing tyrosine hydroxylase expression in the locus coeruleus may be sufficient to prime this form of metaplasticity. We propose exploring this phenomenon of priming and challenge physiologically, to determine whether behavioural experiences are sufficient to prime the locus coeruleus, enabling subsequent pharmacological or behavioural challenge conditions that increase locus coeruleus firing to release sufficient noradrenaline to induce long-lasting potentiation in the dentate gyrus. Such an approach may contribute to unravelling mechanisms underlying this form of metaplasticity and its importance in stress-related mnemonic processes.

Noradrenergic dysregulation in the pathophysiology of PTSD

A central role for noradrenergic dysregulation in the pathophysiology of post-traumatic stress disorder (PTSD) is increasingly suggested by both clinical and basic neuroscience research. Here, we integrate recent findings from clinical and animal research with the earlier literature. We first review the evidence for net upregulation of the noradrenergic system and its responsivity to stress in individuals with PTSD. Next, we trace the evidence that the α₁ noradrenergic receptor antagonist prazosin decreases many of the symptoms of PTSD from initial clinical observations, to case series, to randomized controlled trials. Finally, we review the basic science work that has begun to explain the mechanism for this efficacy, as well as to explore its possible limitations and areas for further advancement. We suggest a view of the noradrenergic system as a central, modifiable link in a network of interconnected stress-response systems, which also includes the amygdala and its modulation by medial prefrontal cortex. Particular attention is paid to the evidence for bidirectional signaling between noradrenaline and corticotropin-releasing factor (CRF) in coordinating these interconnected systems. The multiple different ways in which the sensitivity and reactivity of the noradrenergic system may be altered in PTSD are highlighted, as is the evidence for possible heterogeneity in the pathophysiology of PTSD between different individuals who appear clinically similar. We conclude by noting the importance moving forward of improved measures of noradrenergic functioning in clinical populations, which will allow better recognition of clinical heterogeneity and further assessment of the functional implications of different aspects of noradrenergic dysregulation.

Emotional traits predict individual differences in amphetamine-induced positive mood in healthy volunteers

BACKGROUND

Previous research on emotional correlates of individual differences in subjective responses to D-amphetamine has focused on relatively broad personality traits. Yet, emotional functioning is best characterized by several narrow subcomponents, each of which may contribute uniquely to amphetamine response. Here, we examine several specific subdomains of emotional functioning in relation to acute amphetamine response.

METHOD

At a baseline session, healthy stimulant-naive volunteers (N = 97) completed measures of several subdomains of baseline trait emotional functioning and then completed two counterbalanced experimental sessions during which they received a single oral dose of 20 mg D-amphetamine or placebo. Acute subjective drug response measures were completed at repeated intervals before and after drug administration. Data from subjective measures that were significantly modulated by amphetamine were reduced using principal component analysis (amphetamine or placebo) into three higher-order factors of "positive mood," "arousal," and "drug high." Amphetamine did not significantly alter any "negative" subjective states. Separate multiple regression analyses were conducted regressing these three drug factors on baseline trait emotional functioning scales.

RESULTS

The combined set of trait emotional functioning indicators accounted for approximately 22 % of the variance in acute amphetamine-induced positive mood changes. Greater anticipatory pleasure and greater anxious distress each uniquely predicted greater amphetamine-induced positive mood. Trait emotional functioning did not significantly predict amphetamine-induced changes in arousal or drug high.

DISCUSSION

Emotional traits appear to moderate drug-induced positive mood but not other dimensions of amphetamine effects. Different facets of emotional functioning may differentially modulate amphetamine's subjective effect profile.

Locus coeruleus response to single-prolonged stress and early intervention with intranasal neuropeptide Y

Dysregulation of the central noradrenergic system is a core feature of post-traumatic stress disorder (PTSD). Here, we examined molecular changes in locus coeruleus (LC) triggered by single-prolonged stress (SPS) PTSD model at a time when behavioral symptoms are manifested, and the effect of early intervention with intranasal neuropeptide Y (NPY). Immediately following SPS stressors, male SD rats were administered intranasal NPY (SPS/NPY) or vehicle (SPS/V). Seven days later, TH protein, but not mRNA, was elevated in LC only of the SPS/V group. Although 90% of TH positive cells expressed GR, its levels were unaltered. Compared to unstressed controls, LC of SPS/V, but not SPS/NPY, expressed less Y2 receptor mRNA with more CRHR1 mRNA in subset of animals, and elevated corticotropin-releasing hormone (CRH) in central nucleus of amygdala. Following testing for anxiety on elevated plus maze (EPM), there were significantly increased TH, DBH and NPY mRNAs in LC of SPS-treated, but not previously unstressed animals. Their levels highly correlated with each other but not with behavioral features on EPM. Thus, SPS triggers long-term noradrenergic activation and higher sensitivity to mild stressors, perhaps mediated by the up-regulation influence of amygdalar CRH input and down-regulation of Y2R presynaptic inhibition in LC. Results also demonstrate the therapeutic potential of early intervention with intranasal NPY for traumatic stress-elicited noradrenergic impairments. Single-prolonged stress (SPS)-triggered long-term changes in the locus coeruleus/norepinephrine (LC/NE) system with increased tyrosine hydroxylase (TH) protein and CRH receptor 1(CRHR1) mRNA and lower neuropeptide Y receptor 2 (Y2R) mRNA levels as well as elevated corticotropin-releasing hormone (CRH) in the central nucleus of amygdala (CeA) that were prevented by early intervention with intranasal neuropeptide Y (NPY). SPS treatment led to increased sensitivity of LC to mild stress of elevated plus maze (EPM), with elevated mRNA for NE biosynthetic enzymes in subset of animals.

Diagnostic Biomarkers for Posttraumatic Stress Disorder: Promising Horizons from Translational Neuroscience Research

Posttraumatic stress disorder (PTSD) is a heterogeneous disorder that affects individuals exposed to trauma (e.g., combat, interpersonal violence, and natural disasters). Although its diagnostic features have been recently reclassified with the emergence of the Diagnostic and Statistical Manual for Mental Disorders, Fifth Edition, the disorder remains characterized by hyperarousal, intrusive reminders of the trauma, avoidance of trauma-related cues, and negative cognition and mood. This heterogeneity indicates the presence of multiple neurobiological mechanisms underlying the etiology and maintenance of PTSD. Translational research spanning the past few decades has revealed several potential avenues for the identification of diagnostic biomarkers for PTSD. These include, but are not limited to, monoaminergic transmitter systems, the hypothalamic-pituitary-adrenal axis, metabolic hormonal pathways, inflammatory mechanisms, psychophysiological reactivity, and neural circuits. The current review provides an update to the literature with regard to the most promising putative PTSD biomarkers, with specific emphasis on the interaction between neurobiological influences on disease risk and symptom progression. Such biomarkers will most likely be identified by multi-dimensional models derived from comprehensive descriptions of molecular, neurobiological, behavioral, and clinical phenotypes.

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.

Elevated salivary alpha amylase in adolescent sexual abuse survivors with posttraumatic stress disorder symptoms

OBJECTIVE

Little is known regarding neuroendocrine responses in adolescent girls with posttraumatic stress disorder (PTSD) who have experienced sexual abuse. Therefore, we collected saliva samples three times daily for 3 days to assess concentrations of salivary alpha amylase (sAA) - a surrogate marker for autonomic nervous system (ANS) activity and, in particular, sympathetic activity - in sexually abused adolescent girls.

METHODS

Twenty-four girls (mean age: 15±1.4 years) who had experienced recent sexual abuse (i.e., sexual abuse occurred 1-6 months prior to study enrollment) and 12 healthy comparison subjects (mean age: 14.8±1.3 years) completed a structured interview and assessments to ascertain symptoms of posttraumatic stress, then collected saliva at home upon awakening, 30 minutes after waking, and at 5 p.m. on three consecutive school days.

RESULTS

For sexually abused girls, total PTSD symptoms were associated with higher overall morning levels of sAA (r[20]=0.51, p=0.02), a finding driven by intrusive symptoms (r[20]=0.43, p<0.05) and hyperarousal symptoms (r[20]=0.58, p=0.01). There were no significant differences in diurnal sAA secretion between the sexually abused girls and healthy comparison adolescents.

CONCLUSIONS

Overall morning concentrations of sAA in sexually abused girls are associated with overall PTSD severity as well as symptoms of hyperarousal and intrusive symptoms, possibly reflecting symptom-linked increases in ANS tone. These data raise the possibility that alterations in ANS activity are related to the pathophysiology of sexual abuse-related PTSD in adolescent girls, and may inform therapeutic interventions (e.g., antiadrenergic medications).

Concepts of scientific integrative medicine applied to the physiology and pathophysiology of catecholamine systems

This review presents concepts of scientific integrative medicine and relates them to the physiology of catecholamine systems and to the pathophysiology of catecholamine-related disorders. The applications to catecholamine systems exemplify how scientific integrative medicine links systems biology with integrative physiology. Concepts of scientific integrative medicine include (i) negative feedback regulation, maintaining stability of the body's monitored variables; (ii) homeostats, which compare information about monitored variables with algorithms for responding; (iii) multiple effectors, enabling compensatory activation of alternative effectors and primitive specificity of stress response patterns; (iv) effector sharing, accounting for interactions among homeostats and phenomena such as hyperglycemia attending gastrointestinal bleeding and hyponatremia attending congestive heart failure; (v) stress, applying a definition as a state rather than as an environmental stimulus or stereotyped response; (vi) distress, using a noncircular definition that does not presume pathology; (vii) allostasis, corresponding to adaptive plasticity of feedback-regulated systems; and (viii) allostatic load, explaining chronic degenerative diseases in terms of effects of cumulative wear and tear. From computer models one can predict mathematically the effects of stress and allostatic load on the transition from wellness to symptomatic disease. The review describes acute and chronic clinical disorders involving catecholamine systems-especially Parkinson disease-and how these concepts relate to pathophysiology, early detection, and treatment and prevention strategies in the post-genome era.

Traumatic stress, oxidative stress and post-traumatic stress disorder: neurodegeneration and the accelerated-aging hypothesis

Post-traumatic stress disorder (PTSD) is associated with elevated risk for a variety of age-related diseases and neurodegeneration. In this paper, we review evidence relevant to the hypothesis that chronic PTSD constitutes a form of persistent life stress that potentiates oxidative stress (OXS) and accelerates cellular aging. We provide an overview of empirical studies that have examined the effects of psychological stress on OXS, discuss the stress-perpetuating characteristics of PTSD, and then identify mechanisms by which PTSD might promote OXS and accelerated aging. We review studies on OXS-related genes and the role that they may have in moderating the effects of PTSD on neural integrity and conclude with a discussion of directions for future research on antioxidant treatments and biomarkers of accelerated aging in PTSD.

Effects of intracerebroventricular corticotropin releasing factor on sensory-evoked responses in the rat visual thalamus

Corticotropin releasing factor (CRF) coordinates the brain׳s responses to stress. Recent evidence suggests that CRF-mediated activation of the locus coeruleus-norepinephrine (LC-NE) system contributes to alterations in sensory signal processing during stress. However, it remains unclear whether these actions are dependent upon the degree of CRF release. Using intracerebroventricular (ICV) infusions, we examine the dose-dependent actions of CRF on sensory-evoked discharges of neurons in the dorsal lateral geniculate nucleus of the thalamus (dLGN). The LGN is the primary relay for visual signals from retina to cortex, receiving noradrenergic modulation from the LC. In vivo extracellular recording in anesthetized rats was used to monitor single dLGN neuron responses to light flashes at three different stimulus intensities before and after administration of CRF (0.1, 0.3, 1.0, 3.0 or 10.0 μg). CRF produced three main effects on dLGN stimulus evoked activity: (1) increased magnitude of sensory evoked discharges at moderate doses, (2) decreased response latency, and (3) dose-dependent increases in the number of cells responding to a previously sub-threshold (low intensity) stimulus. These modulatory actions were blocked or attenuated by intra-LC infusion of a CRF antagonist prior to ICV CRF administration. Moreover, intra-LC administration of CRF (10 ng) mimicked the facilitating effects of moderate doses of ICV CRF on dLGN neuron responsiveness to light stimuli. These findings suggest that stressor-induced changes in sensory signal processing cannot be defined in terms of a singular modulatory effect, but rather are multi-dimensional and dictated by variable degrees of activation of the CRF-LC-NE system.

Pharmacological treatment of comorbid PTSD and substance use disorder: recent progress

Previous research has identified a strong association between posttraumatic stress disorder (PTSD) and substance use disorder (SUD), necessitating the development of treatments that address both conditions. Some pharmacotherapies are effective for the treatment of PTSD and SUD alone, however; no medications have been proven to be effective for the combination of these conditions. We review the recent advances in pharmacological treatment of comorbid PTSD and SUD. A randomized clinical trial of sertraline, a serotonin reuptake inhibitor (SSRI), did not show overall efficacy for comorbid PTSD and alcohol dependence (AD), although it may have efficacy among light drinkers. Another clinical trial demonstrated the efficacy of both disulfiram and naltrexone for the treatment of AD in individuals with PTSD. A more recent clinical trial suggested that norepinephrine uptake inhibitors may also have efficacy for the treatment of comorbid PTSD and AD. In animal and preliminary human studies, brain norepinephrine and glutamate/GABA have emerged as potential treatment targets for comorbid PTSD and SUD. Noradrenergic medications that are promising for comorbid PTSD and SUD include prazosin, guanfacine, and atomoxetine. Promising glutamate/GABA medications include topiramate, memantine, acamprosate, N-acetylcysteine (NAC), and ketamine. The safety and efficacy of these medications for the treatment of PTSD and SUD need to be tested in controlled clinical trials.

Cerebrospinal fluid neuropeptide Y in combat veterans with and without posttraumatic stress disorder

Accruing evidence indicates that neuropeptide Y (NPY), a peptide neurotransmitter, is a resilience-to-stress factor in humans. We previously reported reduced cerebrospinal fluid (CSF) NPY concentrations in combat-related posttraumatic stress disorder (PTSD) subjects as compared with healthy, non-combat-exposed volunteers. Here we report CSF NPY in combat-exposed veterans with and without PTSD. We quantified NPY concentrations in morning CSF from 11 male subjects with PTSD from combat in Iraq and/or Afghanistan and from 14 combat-exposed subjects without PTSD. NPY-like immunoreactivity (NPY-LI) was measured by EIA. The relationship between CSF NPY and clinical symptoms, as measured by the Clinician-Administered PTSD Scale (CAPS) and Beck Depression Inventory (BDI), was assessed, as was the relationship between combat exposure scale (CES) scores and CSF NPY. As compared with the combat-exposed comparison subjects without PTSD, individuals with PTSD had significantly lower concentrations of CSF NPY [mean CSF NPY was 258. 6 ± 21.64 pg/mL in the combat trauma-no PTSD group but only 180.5 ± 12.62 pg/mL in PTSD patients (p=0.008)]. After adjusting for CES and BDI scores the two groups were still significantly different with respect to NPY. Importantly, CSF NPY was negatively correlated with composite CAPS score and intrusive (re-experiencing) subscale scores, but did not significantly correlate with CES or BDI scores. Our current findings further suggest that NPY may regulate the manifestation of PTSD symptomatology, and extend previous observations of low CSF NPY concentrations in the disorder. Central nervous system NPY may be a clinically important pharmacotherapeutic target, and/or diagnostic measure, for PTSD.