Urinary catecholamine excretion and severity of PTSD symptoms in Vietnam combat veterans

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.

Revisiting propranolol and PTSD: Memory erasure or extinction enhancement?

Posttraumatic stress disorder (PTSD) has been described as the only neuropsychiatric disorder with a known cause, yet effective behavioral and pharmacotherapies remain elusive for many afflicted individuals. PTSD is characterized by heightened noradrenergic signaling, as well as a resistance to extinction learning. Research aimed at promoting more effective treatment of PTSD has focused on memory erasure (disrupting reconsolidation) and/or enhancing extinction retention through pharmacological manipulations. Propranolol, a β-adrenoceptor antagonist, has received considerable attention for its therapeutic potential in PTSD, although its impact on patients is not always effective. In this review, we briefly examine the consequences of β-noradrenergic manipulations on both reconsolidation and extinction learning in rodents and in humans. We suggest that propranolol is effective as a fear-reducing agent when paired with behavioral therapy soon after trauma when psychological stress is high, possibly preventing or dampening the later development of PTSD. In individuals who have already suffered from PTSD for a significant period of time, propranolol may be less effective at disrupting reconsolidation of strong fear memories. Also, when PTSD has already developed, chronic treatment with propranolol may be more effective than acute intervention, given that individuals with PTSD tend to experience long-term, elevated noradrenergic hyperarousal.

Sexual dysfunction and neuroendocrine correlates of posttraumatic stress disorder in combat veterans: Preliminary findings

Sexual dysfunction is not a symptom of PTSD but is a common clinical complaint in trauma survivors with this disorder. In that there are biological parallels in the neuroendocrine processes underlying both PTSD and sexual behavior, we conducted an exploratory investigation of the relationship of PTSD and related neuroendocrine indicators with sexual dysfunction in armed service veterans. Major Depressive Disorder, highly comorbid with PTSD and sexual dysfunction, was also assessed. In veterans with PTSD, sexual problems were associated with plasma DHEA and cortisol, urinary catecholamines, and glucocorticoid sensitivity, even when controlling for the effects of comorbid depression. In a subsample analysis, testosterone levels did not distinguish PTSD or sexual dysfunction, suggesting that sexual problems reported by veterans in this sample were not the result of organic disorder. PTSD did predict higher dihydrotestosterone (DHT) levels, which were associated with sexual problems. More detailed assessment of sexual dysfunction in biologically informed studies of PTSD is warranted to clarify the relationships of PTSD symptomatology and related neurobiology with sexual dysfunction.

Failed efficacy of ziprasidone in the treatment of post-traumatic stress disorder

Background

Post-traumatic stress disorder (PTSD) is a chronic anxiety disorder that is often difficult to treat. Patients suffering from PTSD often fail to respond to antidepressants and may have a high incidence of positive symptoms of psychosis, though antipsychotic medications have been minimally studied in this population. The aim of this study was to assess the impact of the atypical antipsychotic ziprasidone (Geodon) on PTSD symptom clusters, as well as comorbid major depressive disorder. To our knowledge, this is the first completed randomized controlled trial investigating the potential efficacy and tolerability of ziprasidone in patients with chronic PTSD.

Methods

We conducted a 9-week prospective, randomized, double-blind, placebo-controlled trial of ziprasidone in 30 patients diagnosed with PTSD and comorbid depression. After screening and randomization, patients completed nine weekly study visits at which treatment safety and efficacy were evaluated. Primary measures of efficacy included total and subscale scores from the Clinician-Administered PTSD Scale (CAPS), while the Hamilton Rating Scale for Depression (HAM-D), Hamilton Anxiety Scale (HAM-A), Clinical Global Impression (CGI), and Treatment Outcome PTSD Scale (TOP-8) were implemented as secondary efficacy measures.

Results

We observed no significant effect of treatment on reduction of PTSD or depression symptoms from pre- to post-treatment.

Conclusions

Our findings suggest that ziprasidone treatment may not significantly improve symptoms of PTSD or comorbid depression, though further study is needed.

Epigenetic Alterations Associated with War Trauma and Childhood Maltreatment

Survivors of war trauma or childhood maltreatment are at increased risk for trauma-spectrum disorders such as post-traumatic stress disorder (PTSD). In addition, traumatic stress has been associated with alterations in the neuroendocrine and the immune system, enhancing the risk for physical diseases. Traumatic experiences might even affect psychological as well as biological parameters in the next generation, i.e. traumatic stress might have transgenerational effects. This article outlines how epigenetic processes, which represent a pivotal biological mechanism for dynamic adaptation to environmental challenges, might contribute to the explanation of the long-lasting and transgenerational effects of trauma. In particular, epigenetic alterations in genes regulating the hypothalamus-pituitary-adrenal axis as well as the immune system have been observed in survivors of childhood and adult trauma. These changes could result in enduring alterations of the stress response as well as the physical health risk. Furthermore, the effects of parental trauma could be transmitted to the next generation by parental distress and the pre- and postnatal environment, as well as by epigenetic marks transmitted via the germline. While epigenetic research has a high potential of advancing our understanding of the consequences of trauma, the findings have to be interpreted with caution, as epigenetics only represent one piece of a complex puzzle of interacting biological and environmental factors. Copyright © 2015 John Wiley & Sons, Ltd.

An Overview of Translationally Informed Treatments for Posttraumatic Stress Disorder: Animal Models of Pavlovian Fear Conditioning to Human Clinical Trials

Posttraumatic stress disorder manifests after exposure to a traumatic event and is characterized by avoidance/numbing, intrusive symptoms and flashbacks, mood and cognitive disruptions, and hyperarousal/reactivity symptoms. These symptoms reflect dysregulation of the fear system likely caused by poor fear inhibition/extinction, increased generalization, and/or enhanced consolidation or acquisition of fear. These phenotypes can be modeled in animal subjects using Pavlovian fear conditioning, allowing investigation of the underlying neurobiology of normative and pathological fear. Preclinical studies reveal a number of neurotransmitter systems and circuits critical for aversive learning and memory that have informed the development of therapies used in human clinical trials. In this review, we discuss the evidence for a number of established and emerging pharmacotherapies and device-based treatments for posttraumatic stress disorder that have been developed via a bench to bedside translational model.

β-Adrenergic receptor signaling and modulation of long-term potentiation in the mammalian hippocampus

Encoding new information in the brain requires changes in synaptic strength. Neuromodulatory transmitters can facilitate synaptic plasticity by modifying the actions and expression of specific signaling cascades, transmitter receptors and their associated signaling complexes, genes, and effector proteins. One critical neuromodulator in the mammalian brain is norepinephrine (NE), which regulates multiple brain functions such as attention, perception, arousal, sleep, learning, and memory. The mammalian hippocampus receives noradrenergic innervation and hippocampal neurons express β-adrenergic receptors, which are known to play important roles in gating the induction of long-lasting forms of synaptic potentiation. These forms of long-term potentiation (LTP) are believed to importantly contribute to long-term storage of spatial and contextual memories in the brain. In this review, we highlight the contributions of noradrenergic signaling in general and β-adrenergic receptors in particular, toward modulating hippocampal LTP. We focus on the roles of NE and β-adrenergic receptors in altering the efficacies of specific signaling molecules such as NMDA and AMPA receptors, protein phosphatases, and translation initiation factors. Also, the roles of β-adrenergic receptors in regulating synaptic "tagging" and "capture" of LTP within synaptic networks of the hippocampus are reviewed. Understanding the molecular and cellular bases of noradrenergic signaling will enrich our grasp of how the brain makes new, enduring memories, and may shed light on credible strategies for improving mental health through treatment of specific disorders linked to perturbed memory processing and dysfunctional noradrenergic synaptic transmission.

The dopaminergic response to acute stress in health and psychopathology: A systematic review

Previous work in animals has shown that dopamine (DA) in cortex and striatum plays an essential role in stress processing. For the first time, we systematically reviewed the in vivo evidence for DAergic stress processing in health and psychopathology in humans. All studies included (n studies=25, n observations=324) utilized DA D2/3 positron emission tomography and measured DAergic activity during an acute stress challenge. The evidence in healthy volunteers (HV) suggests that physiological, but not psychological, stress consistently increases striatal DA release. Instead, increased medial prefrontal cortex (mPFC) DAergic activity in HV was observed during psychological stress. Across brain regions, stress-related DAergic activity was correlated with the physiological and psychological intensity of the stressor. The magnitude of stress-induced DA release was dependent on rearing conditions, personality traits and genetic variations in several SNPs. In psychopathology, preliminary evidence was found for stress-related dorsal striatal DAergic hyperactivity in psychosis spectrum and a blunted response in chronic cannabis use and pain-related disorders, but results were inconsistent. Physiological stress-induced DAergic activity in striatum in HV may reflect somatosensory properties of the stressor and readiness for active fight-or-flight behavior. DAergic activity in HV in the ventral striatum and mPFC may be more related to expectations about the stressor and threat evaluation, respectively. Future studies with increased sample size in HV and psychopathology assessing the functional relevance of stress-induced DAergic activity, the association between cortical and subcortical DAergic activity and the direct comparison of different stressors are necessary to conclusively elucidate the role of the DA system in the stress response.

Risk of stroke among patients with post-traumatic stress disorder: nationwide longitudinal study

BACKGROUND

Previous evidence has shown positive associations between post-traumatic stress disorder (PTSD) and hypertension, dyslipidaemia and diabetes mellitus, which are all risk factors for stroke, but the role of PTSD in the subsequent development of stroke is still unknown.

AIMS

To investigate the temporal association between PTSD and the development of stroke.

METHOD

Identified from the Taiwan National Health Insurance Research Database, 5217 individuals aged ≥18 years, with PTSD but with no history of stroke, and 20 868 age- and gender-matched controls were enrolled between 2002 and 2009, and followed up until the end of 2011 to identify the development of stroke.

RESULTS

Individuals with PTSD had an increased risk of developing any stroke (hazard ratio (HR) 3.37, 95% CI 2.44-4.67) and ischaemic stroke (HR = 3.47, 95% CI 2.23-5.39) after adjusting for demographic data and medical comorbidities. Sensitivity tests showed consistent findings (any stroke HR = 3.02, 95% CI 2.13-4.28; ischaemic stroke HR = 2.89, 95% CI 1.79-4.66) after excluding the first year of observation.

CONCLUSIONS

Individuals with PTSD have an increased risk of developing any stroke and ischaemic stroke. Further studies are required to investigate the underlying mechanisms.

Effect of current and lifetime posttraumatic stress disorder on 24-h urinary catecholamines and cortisol: results from the Mind Your Heart Study

Posttraumatic stress disorder (PTSD) is associated with an increased risk of cardiovascular disease and several other chronic illnesses. Alterations in the sympathetic nervous system (SNS) and the hypothalamic-pituitary-adrenal (HPA) axis in PTSD might contribute to these associations but findings regarding SNS and HPA activity in PTSD are heterogeneous. We measured 24-h urinary catecholamines and cortisol in a large cohort of adult outpatients recruited from 2 Veterans Affairs medical centers. 24-h urinary norepinephrine, epinephrine, dopamine and cortisol were measured by tandem mass spectrometry. Lifetime and current PTSD were assessed with the Clinician Administered PTSD Scale using DSM-IV-TR criteria. Out of 613 participants, 199 (32.5%) had current PTSD, 100 (16.3%) had lifetime but not current PTSD, and 314 (51.2%) never had PTSD. Patients with current PTSD had significantly higher norepinephrine secretion compared to those without PTSD. Patients in the lifetime PTSD group exhibited lower cortisol values compared to those without PTSD. Participants who never had PTSD showed the lowest norepinephrine and the highest cortisol values. All results remained stable when controlling for potentially confounding variables. This study provides evidence for increased norepinephrine secretion and decreased cortisol in PTSD. Future longitudinal studies are needed to determine whether these changes contribute to adverse health outcomes in patients with PTSD.

Association of depressive and anxiety symptoms with 24-hour urinary catecholamines in individuals with untreated high blood pressure

OBJECTIVE

Depression and anxiety are considered risk factors for cardiovascular disease (CVD). The explanatory mechanisms, however, are still to be characterized. One proposed pathophysiological pathway is dysregulation of the autonomic nervous system, including heightened sympathetic nervous system activity. This study examined the relationship between symptoms of depression, anxiety, and sympathetic nervous system activity in individuals with untreated high blood pressure.

METHODS

A total of 140 participants with untreated high blood pressure (55% white, 38.5% female, mean [standard deviation] age = 45.5 [8.55] years) collected urine over a 24-hour period on 3 separate occasions. Urine samples were assayed for mean 24-hour epinephrine (EPI24) and norepinephrine excretion. Depressive symptoms were assessed using the Beck Depression Inventory, with anxiety symptoms assessed using the Spielberger State-Trait Anxiety Inventory.

RESULTS

Depression and anxiety scores were intercorrelated (r = 0.76, p < .001). EPI24 was positively correlated with anxiety (r = 0.20, p = .02) but not depression (r = 0.02, p = .77), whereas 24-hour urinary norepinephrine excretion was not correlated with anxiety (r = 0.10, p = .21) or with depression (r = 0.07, p = .39). Regression models, accounting for sex, age, body mass index, race, mean systolic ambulatory blood pressure, tobacco use, alcohol use, physical activity, and sleep efficiency confirmed that anxiety was associated with EPI24 excretion (p = .023) and that depressive symptoms were not (p = .54).

CONCLUSIONS

Anxiety was associated with heightened sympathoadrenal activity, suggesting a biological pathway through which anxiety could increase CVD risk. Anxiety and depression may confer increased CVD risk via different mechanisms.

Autonomic arousal during actigraphically estimated waking and sleep in male veterans with PTSD

Physiological hyperarousal is manifested acutely by increased heart rate, decreased respiratory sinus arrhythmia, and increased skin conductance level and variability. Yet it is uncertain to what extent such activation occurs with the symptomatic hyperarousal of posttraumatic stress disorder (PTSD). We compared 56 male veterans with current PTSD to 54 males who never had PTSD. Subjects wore ambulatory devices that recorded electrocardiograms, finger skin conductance, and wrist movement while in their normal environments. Wrist movement was monitored to estimate sleep and waking periods. Heart rate, but not the other variables, was elevated in subjects with PTSD equally during waking and during actigraphic sleep (effect sizes, Cohen's d, ranged from 0.63 to 0.89). The length of the sleep periods and estimated sleep fragmentation did not differ between groups. Group heart rate differences could not be explained by differences in body activity, PTSD hyperarousal symptom scores, depression, physical fitness, or antidepressant use.

Differential effects of sertraline in a predator exposure animal model of post-traumatic stress disorder

Serotonin (5-HT), norepinephrine (NE), and other neurotransmitters are modulated in post-traumatic stress disorder (PTSD). In addition, pro-inflammatory cytokines (PIC) are elevated during the progression of the disorder. Currently, the only approved pharmacologic treatments for PTSD are the selective-serotonin reuptake inhibitors (SSRI) sertraline and paroxetine, but their efficacy in treating PTSD is marginal at best. In combat-related PTSD, SSRIs are of limited effectiveness. Thus, this study sought to analyze the effects of the SSRI sertraline on inflammation and neurotransmitter modulation via a predator exposure/psychosocial stress animal model of PTSD. We hypothesized that sertraline would diminish inflammatory components and increase 5-HT but might also affect levels of other neurotransmitters, particularly NE. PTSD-like effects were induced in male Sprague-Dawley rats (n = 6/group × 4 groups). The rats were secured in Plexiglas cylinders and placed in a cage with a cat for 1 h on days 1 and 11 of a 31-day stress regimen. PTSD rats were also subjected to psychosocial stress via daily cage cohort changes. At the conclusion of the stress regimen, treatment group animals were injected intraperitoneally (i.p.) with sertraline HCl at 10 mg/kg for 7 consecutive days, while controls received i.p. vehicle. The animals were subsequently sacrificed on day 8. Sertraline attenuated inflammatory markers and normalized 5-HT levels in the central nervous system (CNS). In contrast, sertraline produced elevations in NE in the CNS and systemic circulation of SSRI treated PTSD and control groups. This increase in NE suggests SSRIs produce a heightened noradrenergic response, which might elevate anxiety in a clinical setting.

The Impact of Stress Hormones on Post-traumatic Stress Disorders Symptoms and Memory in Cardiac Surgery Patients

The relationship and interactions between stress hormones and post-traumatic stress disorder (PTSD) are well established from both animal and human research studies. This interaction is especially important in the post-operative phase of cardiac surgery where the development of PTSD symptoms will result in increased morbidity and mortality and prolong length of stay for critically ill cardiac surgery patients. Cardiopulmonary bypass itself will independently result in massive inflammation response and release of stress hormones in the perioperative period. Glucocorticoid may reduce this response and result in reduction of PTSD symptom clusters and therefore improve health outcome. In this review, we plan to conduct a systemic review and analysis of the literatures on this topic.

Post traumatic stress disorder and the adrenal gland

Low serum and urinary Cortisol has been a consistent finding in post traumatic stress disorder (PTSD). Glucocorticoid receptor numbers are increased. PTSD patients have a significantly lower adrenocorticotropic hormone (ACTH) in response to corticotrophin releasing hormone (CRH) when compared to a control group of normal volunteers. The dexamethasone suppression test exhibits an exaggerated suppression response of Cortisol to dexamethasone, when the dose utilised is lower than that utilised to test patients with depression. Increased urine levels of noradrenaline and dopamine has been noted in patients with PTSD. This is believed to be related to the hyperarousal state of 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.

Associations of socioeconomic and psychosocial factors with urinary measures of cortisol and catecholamines in the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Stress hormones have been hypothesized to contribute to the social patterning of cardiovascular disease but evidence of differences in hormone levels across social groups is scant.

PURPOSE

To examine the associations of socioeconomic and psychosocial factors with urinary levels of cortisol and catecholamines and determine whether these associations are modified by race/ethnicity.

METHODS

Measures of cortisol, epinephrine, norepinephrine and dopamine were obtained on 12-h overnight urine specimens from 942 White, African American and Hispanic participants in the Multi-Ethnic Study of Atherosclerosis (MESA). Linear regression was used to examine associations of income-wealth index, education, depression, anger, anxiety and chronic stress with the four hormones after adjustment for covariates.

RESULTS

Higher income-wealth index was associated with lower levels of urinary cortisol, epinephrine, norepinephrine and dopamine, after adjustment for age, sex, race/ethnicity, medication use, body mass index, smoking, and alcohol use. Education and psychosocial factors were not associated with urinary stress hormone levels in the full sample. However, there was some evidence of effect modification by race: SES factors were more strongly inversely associated with cortisol in African Americans than in other groups and anger was inversely associated with catecholamines in African Americans but not in the other groups.

CONCLUSIONS

Lower SES as measured by income-wealth index in a multi-ethnic sample is associated with higher levels of urinary cortisol and catecholamines. Heterogeneity in these associations by race/ethnicity warrants further exploration.

Predator exposure/psychosocial stress animal model of post-traumatic stress disorder modulates neurotransmitters in the rat hippocampus and prefrontal cortex

Post-Traumatic Stress Disorder (PTSD) can develop in response to a traumatic event involving a threat to life. To date, no diagnostic biomarkers have been identified for PTSD. Recent research points toward physiological abnormalities in the hypothalamic-pituitary-adrenal (HPA) axis, sympathoadrenal medullary and immune system that may be implicated in the disorder. The modulation of neurotransmitters is another possible mechanism, but their role in the progression of PTSD is poorly understood. Low serotonin (5-HT) may be a factor, but it may not be the only neurotransmitter affected as modulation affects levels of other neurotransmitters. In this study, we hypothesized the predator exposure/psychosocial stress rodent model of PTSD may alter levels of 5-HT and other neurotransmitters in the rat hippocampus and prefrontal cortex (PFC). Male Sprague-Dawley rats were used in this experiment. We induced PTSD via a predator exposure/psychosocial stress model, whereby rats were placed in a cage with a cat for 1 hour on days 1 and 11 of the 31-day experiment. Rats also received psychosocial stress via daily cage cohort changes. On day 32, the rats were sacrificed and the brains dissected to remove the hippocampus and PFC. Norepinephrine (NE), 5-Hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA), dopamine (DA), and 3,4-Dihydroxyphenylacetic acid (DOPAC), and 5-HT levels in the hippocampus and PFC were measured with high-performance liquid chromatography (HPLC). In the hippocampus, 5-HT and HVA were lower, while NE and DOPAC were higher, in the PTSD group vs. controls. In the PFC, only 5-HT was lower, while NE, DA, and DOPAC were higher, in the PTSD group vs. controls. The rate limiting enzymes tyrosine hydroxylase and tryptophan hydroxylase were also examined and confirmed our findings. These results demonstrate that the predator exposure/psychosocial stress model of PTSD produces neurotransmitter changes similar to those seen in human patients and may cause a heightened noradrenergic response.

A rare symptom in posttraumatic stress disorder: Spontaneous ejaculation

Patient: Male, 25

Final Diagnosis: Post Traumatic Stress Disorder

Symptoms: Insomnia • nightmares • spontaneous ejaculation

Medication: Paroxentine

Clinical Procedure: —

Specialty: Psychiatry

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.

Genetic approaches to understanding post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is increasingly recognized as both a disorder of enormous mental health and societal burden, but also as an anxiety disorder that may be particularly understandable from a scientific perspective. Specifically, PTSD can be conceptualized as a disorder of fear and stress dysregulation, and the neural circuitry underlying these pathways in both animals and humans are becoming increasingly well understood. Furthermore, PTSD is the only disorder in psychiatry in which the initiating factor, the trauma exposure, can be identified. Thus, the pathophysiology of the fear and stress response underlying PTSD can be examined and potentially interrupted. Twin studies have shown that the development of PTSD following a trauma is heritable, and that genetic risk factors may account for up to 30-40% of this heritability. A current goal is to understand the gene pathways that are associated with PTSD, and how those genes act on the fear/stress circuitry to mediate risk vs. resilience for PTSD. This review will examine gene pathways that have recently been analysed, primarily through candidate gene studies (including neuroimaging studies of candidate genes), in addition to genome-wide associations and the epigenetic regulation of PTSD. Future and on-going studies are utilizing larger and collaborative cohorts to identify novel gene candidates through genome-wide association and other powerful genomic approaches. Identification of PTSD biological pathways strengthens the hope of progress in the mechanistic understanding of a model psychiatric disorder and allows for the development of targeted treatments and interventions.

Post-traumatic stress disorder as a comorbidity: impact on disease outcomes

Post-traumatic stress disorder (PTSD) is associated with many psychiatric and nonpsychiatric comorbidities. Growing evidence suggests that PTSD as a comorbidity may impair drug adherence, quality of life and sleep quality, as well as increase rehospitalization rates, disease relapses, intensity of symptoms, morbidity and mortality. The aim of this article is to examine the literature regarding the effects of PTSD comorbidity on physical and mental health.

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.

BDNF Val66Met and DRD2 Taq1A polymorphisms interact to influence PTSD symptom severity: a preliminary investigation in a South African population

BACKGROUND

We evaluated the role that selected variants in serotonin transporter (5-HTT), dopamine receptor 2 (DRD2) and brain-derived neurotrophic factor (BDNF) genes play in PTSD symptom severity in an at-risk population. We also investigated the interaction between the genetic variants to determine whether these variables and the interactions between the variables influenced the severity of PTSD symptoms.

METHODS

PTSD symptoms were quantitatively assessed using the Davidson Trauma Scale (DTS) in 150 participants from an at-risk South African population. All participants were genotyped for the 5-HTTLPR, DRD2 Taq1A and BDNF Val66Met polymorphisms. Gene-gene interactions were investigated using various linear models. All analyses were adjusted for age, gender, major depressive disorder diagnosis, level of resilience, level of social support and alcohol dependence.

RESULTS

A significant interaction effect between DRD2 Taq1A and BDNF Val66Met variants on DTS score was observed. On the background of the BDNF Val66Val genotype, DTS score increased significantly with the addition of a DRD2 Taq1A A1 allele. However, on the BDNF Met66 allele background, the addition of an A1 allele was found to reduce total DTS score.

CONCLUSIONS

This study provides preliminary evidence for an epistatic interaction between BDNF Val66Met and DRD2 Taq1A polymorphisms on the severity of PTSD symptoms, where both too little and too much dopamine can result in increased PTSD symptom severity.

Higher striatal dopamine transporter density in PTSD: an in vivo SPECT study with [(99m)Tc]TRODAT-1

RATIONALE

Some evidence suggests a hyperdopaminergic state in posttraumatic stress disorder (PTSD). The 9-repetition allele (9R) located in the 3' untranslated region of the dopamine transporter (DAT) gene (SLC6A3) is more frequent among PTSD patients. In vivo molecular imaging studies have shown that healthy 9R carriers have increased striatal DAT binding. However, no prior study evaluated in vivo striatal DAT density in PTSD.

OBJECTIVES

The objective of this study was to evaluate in vivo striatal DAT density in PTSD.

METHODS

Twenty-one PTSD subjects and 21 control subjects, who were traumatized but asymptomatic, closely matched comparison subjects evaluated with the Clinician-Administered PTSD Scale underwent a single-photon emission computed tomography scan with [(99m)TC]-TRODAT-1. DAT binding potential (DAT-BP) was calculated using the striatum as the region of the interest and the occipital cortex as a reference region.

RESULTS

PTSD patients had greater bilateral striatal DAT-BP (mean ± SD; left, 1.80 ± 0.42; right, 1.78 ± 0.40) than traumatized control subjects (left, 1.62 ± 0.32; right, 1.61 ± 0.31; p = 0.039 for the left striatum and p = 0.032 for the right striatum).

CONCLUSIONS

These results provide the first in vivo evidence for increased DAT density in PTSD. Increases in DAT density may reflect higher dopamine turnover in PTSD, which could contribute to the perpetuation and potentiation of exaggerated fear responses to a given event associated with the traumatic experience. Situations that resemble the traumatic event turn to be interpreted as highly salient (driving attention, arousal, and motivation) in detriment of other daily situations.

Posttraumatic stress disorder in children and adolescents: neuroendocrine perspectives

Posttraumatic stress disorder (PTSD) is a syndrome of distress that develops after exposure to traumatic life experiences. Dysregulation of both the hypothalamic-pituitary-adrenal (HPA) axis and the locus caeruleus/norepinephrine-sympathetic nervous system (LC/NE-SNS) is associated with the pathophysiology of the disorder. Studies have demonstrated a neuroendocrine profile unique to adults with PTSD, with centrally elevated corticotropin-releasing hormone (CRH), low cortisol in the periphery, and elevated catecholamines. Traumatic stress experiences in early life are strong predisposing factors for later PTSD development. In addition, early life stress programs the developing brain to overreact to future stressors. In children and adolescents involved in motor vehicle accidents, we found that high evening salivary cortisol and morning serum interleukin 6 concentrations were predictive of PTSD development 6 months later. We demonstrated a progressive divergence of the HPA and LC/NE-SNS axes of the stress system, which may be part of the pathophysiologic mechanism responsible for PTSD maintenance. An initial elevation of cortisol in the aftermath of the trauma, followed by a gradual normalization and finally low cortisol secretion, together with a gradual elevation of catecholamines over time, may represent the natural history of neuroendocrine changes in pediatric PTSD. Thus, the low cortisol concentrations found in adults with PTSD may reflect prior trauma and might represent a biologic vulnerability factor for later PTSD development.

Etiopathogenic perspectives on chronic psycho traumatic and chronic psychotic symptoms: the hypothesis of a hyperdopaminergic endophenotype of PTSD

Post traumatic stress disorder (PTSD) is a complex and heterogeneous disorder, which specific symptoms are re-experiencing, increased arousal and avoidance of stimuli associated with the trauma. PTSD has much comorbidity like depression, substance abuse, somatic complaints, repeated dissociative phenomena and transitory or chronic psychotic reactions. PTSD can manifest itself in different clinical forms: some patients present higher symptoms in one domain as compared to another, probably because of abnormalities in different neurobiological systems. Hyposerotonergic and hypernoradrenergic PTSD endophenotypes have been previously identified and the purpose of this paper is to focus on the hypothesis of a hyperdopaminergic endophenotype. The current review discusses several entities: PTSD with psychotic features with or without depression, the comorbide use of psychoactive substances that increase psychotic symptoms and traumatic brain injuries as agents of psycho traumatic and psychotic features. For all of these nosographic entities, the dopaminergic neuromodulation may play a central role. The hypothesis of a hyperdopaminergic endophenotype of PTSD opens up new research and therapeutic perspectives. Although antipsychotics are frequently used for people with PTSD further studies are needed to develop a consensus on the guidelines for treating the psychotic forms of PTSD.

Molecular variation at the SLC6A3 locus predicts lifetime risk of PTSD in the Detroit Neighborhood Health Study

Recent work suggests that the 9-repeat (9R) allele located in the 3'UTR VNTR of the SLC6A3 gene increases risk of posttraumatic stress disorder (PTSD). However, no study reporting this association to date has been based on population-based samples. Furthermore, no study of which we are aware has assessed the joint action of genetic and DNA methylation variation at SLC6A3 on risk of PTSD. In this study, we assessed whether molecular variation at SLC6A3 locus influences risk of PTSD. Participants (n = 320; 62 cases/258 controls) were drawn from an urban, community-based sample of predominantly African American Detroit adult residents, and included those who had completed a baseline telephone survey, had provided blood specimens, and had a homozygous genotype for either the 9R or 10R allele or a heterozygous 9R/10R genotype. The influence of DNA methylation variation in the SLC6A3 promoter locus was also assessed in a subset of participants with available methylation data (n = 83; 16 cases/67 controls). In the full analytic sample, 9R allele carriers had almost double the risk of lifetime PTSD compared to 10R/10R genotype carriers (OR = 1.98, 95% CI = 1.02-3.86), controlling for age, sex, race, socioeconomic status, number of traumas, smoking, and lifetime depression. In the subsample of participants with available methylation data, a significant (p = 0.008) interaction was observed whereby 9R allele carriers showed an increased risk of lifetime PTSD only in conjunction with high methylation in the SLC6A3 promoter locus, controlling for the same covariates. Our results confirm previous reports supporting a role for the 9R allele in increasing susceptibility to PTSD. They further extend these findings by providing preliminary evidence that a "double hit" model, including both a putatively reduced-function allele and high methylation in the promoter region, may more accurately capture molecular risk of PTSD at the SLC6A3 locus.

Altered salivary alpha-amylase awakening response in Bosnian War refugees with posttraumatic stress disorder

In posttraumatic stress disorder (PTSD), chronic activation of the sympathetic nervous system (SNS) has been suggested. No study so far has investigated diurnal secretion patterns of salivary alpha-amylase (sAA) in PTSD, a promising candidate for non-invasive assessment of SNS activity. We compared sAA diurnal profiles between a group of Bosnian War refugees with PTSD and a healthy control group, and further analyzed for associations with psychiatric symptoms and glucocorticoid (GC) sensitivity of inflammatory regulation. PTSD patients showed a sAA awakening response profile that was opposite to those seen in healthy controls, i.e. an increase instead of a sharp decrease. Patterns of sAA secretion were further positively associated with psychiatric symptoms of PTSD. Finally, higher sAA awakening responses were associated with higher GC sensitivity of inflammatory cytokine production. These findings are in line with altered SNS function in PTSD, and lend further support for employing assessment of diurnal sAA profiles as non-invasive biomarkers in stress-related disease.

The role of norepinephrine in differential response to stress in an animal model of posttraumatic stress disorder

BACKGROUND

Posttraumatic stress disorder (PTSD) is a prevalent psychiatric disorder precipitated by exposure to extreme traumatic stress. Yet, most individuals exposed to traumatic stress do not develop PTSD and may be considered psychologically resilient. The neural circuits involved in susceptibility or resiliency to PTSD remain unclear, but clinical evidence implicates changes in the noradrenergic system.

METHODS

An animal model of PTSD called Traumatic Experience with Reminders of Stress (TERS) was developed by exposing C57BL/6 mice to a single shock (2 mA, 10 sec) followed by exposure to six contextual 1-minute reminders of the shock over a 25-day period. Acoustic startle response (ASR) testing before the shock and after the last reminder allowed experimenters to separate the shocked mice into two cohorts: mice that developed a greatly increased ASR (TERS-susceptible mice) and mice that did not (TERS-resilient mice).

RESULTS

Aggressive and social behavioral correlates of PTSD increased in TERS-susceptible mice but not in TERS-resilient mice or control mice. Characterization of c-Fos expression in stress-related brain regions revealed that TERS-susceptible and TERS-resilient mice displayed divergent brain activation following swim stress compared with control mice. Pharmacological activation of noradrenergic inhibitory autoreceptors or blockade of postsynaptic α(1)-adrenoreceptors normalized ASR, aggression, and social interaction in TERS-susceptible mice. The TERS-resilient, but not TERS-susceptible, mice showed a trend toward decreased behavioral responsiveness to noradrenergic autoreceptor blockade compared with control mice.

CONCLUSIONS

These data implicate the noradrenergic system as a possible site of pathological and perhaps also adaptive plasticity in response to traumatic stress.

Prenatal stress induces long term stress vulnerability, compromising stress response systems in the brain and impairing extinction of conditioned fear after adult stress

Stress is a risk factor for the development of affective disorders, including depression, post-traumatic stress disorder, and other anxiety disorders. However, not all individuals who experience either chronic stress or traumatic acute stress develop such disorders. Thus, other factors must confer a vulnerability to stress, and exposure to early-life stress may be one such factor. In this study we examined prenatal stress (PNS) as a potential vulnerability factor that may produce stable changes in central stress response systems and susceptibility to develop fear- and anxiety-like behaviors after adult stress exposure. Pregnant Sprague-Dawley rats were immobilized for 1 h daily during the last week of pregnancy. Controls were unstressed. The male offspring were then studied as adults. As adults, PNS or control rats were first tested for shock-probe defensive burying behavior, then half from each group were exposed to a combined chronic plus acute prolonged stress (CAPS) treatment, consisting of chronic intermittent cold stress (4 °C, 6 h/d, 14 days) followed on day 15 by a single session of sequential acute stressors (social defeat, immobilization, cold swim). After CAPS or control treatment, different groups were tested for open field exploration, social interaction, or cued fear conditioning and extinction. Rats were sacrificed at least 5 days after behavioral testing for measurement of tyrosine hydroxylase (TH) and glucocorticoid receptor (GR) expression in specific brain regions, and plasma adrenocorticotropic hormone (ACTH) and corticosterone. Shock-probe burying, open field exploration and social interaction were unaffected by any treatment. However, PNS elevated basal corticosterone, decreased GR protein levels in hippocampus and prefrontal cortex, and decreased TH mRNA expression in noradrenergic neurons in the dorsal pons. Further, rats exposed to PNS plus CAPS showed attenuated extinction of cue-conditioned fear. These results suggest that PNS induces vulnerability to subsequent adult stress, resulting in an enhanced fear-like behavioral profile, and dysregulation of brain noradrenergic and hypothalamic-pituitary-adrenal axis (HPA) activity.

Exaggerated platelet reactivity to physiological agonists in war veterans with posttraumatic stress disorder

An association between traumatic stress and cardiovascular disease (CVD) is supported by various epidemiological studies. Platelet activation and binding of activated platelets to leukocytes contributes to the pathophysiology of CVD. Evidence of hyperactive sympathetic nervous system, altered expression of platelet α(2)-adrenoreceptors (α(2)AR), and altered platelet adenylate cyclase activity in patients with posttraumatic stress disorder (PTSD) suggest that platelet reactivity in PTSD may be altered as well. We tested whether platelet reactivity to increasing doses of adenosine-diphosphate (ADP), epinephrine (EPI), or their combination differs between war veterans with PTSD (n=15) and healthy controls (n=12). For this purpose, citrated whole blood was incubated with increasing concentrations of ADP (0.1, 1, 10 μM), EPI alone (10 nM, 100 nM, 1000 nM), or EPI (10 nM, 100 nM, 1000 nM) in combination with 0.1 μM ADP. A subset of samples was also incubated with 10 μM yohimbine (YOH), α(2)AR antagonist, to distinguish receptor-specific effects. Platelet CD62P expression and formation of platelet-leukocyte aggregates (PLA) [platelet-monocyte (P-Mo), -lymphocyte (P-Ly), and -neutrophil (P-Ne) aggregates] were measured using three-color flow cytometry. Platelet reactivity was higher in war veterans with PTSD when compared to controls, as determined by greater CD62P expression and formation of PLA in response to ADP alone or in combination with EPI. Platelet reactivity also correlated with the severity of PTSD symptoms. Preliminary experiments with YOH indicate that stress-associated EPI elevations may contribute to platelet activation through a α(2)AR-dependent mechanism. The enhanced platelet reactivity observed in our study may be the underlying mechanism contributing to the development of CVD in PTSD patients.

Genotype-controlled analysis of serum dopamine β-hydroxylase activity in civilian post-traumatic stress disorder

BACKGROUND

Norepinephrine (NE) plays a central role in post-traumatic stress disorder (PTSD). Dopamine β-hydroxylase (DβH) converts dopamine (DA) to NE and its activity varies widely across individuals. Mustapic et al. (2007) reported a PTSD-associated deficit in serum DβH activity in a genotype-controlled analysis of combat veterans. We tested whether such a deficit would occur in a sample of civilians.

METHODS

The severity of current adult PTSD symptoms and current DSM-IV diagnosis of PTSD were determined by the PTSD Symptom Scale (PSS). Adulthood trauma exposure was assessed using the Traumatic Experience Inventory (TEI). Serum DβH activity (sDβH) was assayed by HPLC with electrochemical detection and genotypes were determined using the Taqman® platform.

RESULTS

Two hundred and twenty seven African American (AA) subjects were enrolled in this study, with a mean age (±SD) of 42.9 (±12.9) years. We found a strong association between rs1611115 genotype and sDβH (p<0.0001). After controlling for adulthood trauma exposure, there were no significant differences of sDβH between subjects who met a PTSD diagnosis and those who did not (p>0.05) in any genotype group. No significant correlations were found between sDβH and PTSD severity, but sDβH significantly associated with the status of comorbid depression based on the cutoff of HAMD (p=0.014) in subjects with PTSD.

CONCLUSIONS

We have replicated in this sample the prior finding that DBH rs1611115 genotype strongly associates with sDβH. No associations between sDβH and PTSD diagnosis or symptom severity were found in this civilian sample.

Mechanisms of change in negative thinking and urinary monoamines in depressed patients during acute treatment with group cognitive behavior therapy and antidepressant medication

This naturalistic study investigated the mechanisms of change in measures of negative thinking and in 24-h urinary metabolites of noradrenaline (norepinephrine), dopamine and serotonin in a sample of 43 depressed hospital patients attending an eight-session group cognitive behavior therapy program. Most participants (91%) were taking antidepressant medication throughout the therapy period according to their treating Psychiatrists' prescriptions. The sample was divided into outcome categories (19 Responders and 24 Non-responders) on the basis of a clinically reliable change index [Jacobson, N.S., & Truax, P., 1991.

CLINICAL SIGNIFICANCE

a statistical approach to defining meaningful change in psychotherapy research. Journal of Consulting and Clinical Psychology, 59, 12-19.] applied to the Beck Depression Inventory scores at the end of the therapy. Results of repeated measures analysis of variance [ANOVA] analyses of variance indicated that all measures of negative thinking improved significantly during therapy, and significantly more so in the Responders as expected. The treatment had a significant impact on urinary adrenaline and metadrenaline excretion however, these changes occurred in both Responders and Non-responders. Acute treatment did not significantly influence the six other monoamine metabolites. In summary, changes in urinary monoamine levels during combined treatment for depression were not associated with self-reported changes in mood symptoms.

Neuroendocrinology of post-traumatic stress disorder

Dysregulation of the stress system, including the hypothalamic-pituitary-adrenal (HPA) axis and the locus caeruleus/norepinephrine-sympathetic nervous system (SNS), is involved in the pathophysiology of post-traumatic stress disorder (PTSD), an anxiety disorder that develops after exposure to traumatic life events. Neuroendocrine studies in individuals with PTSD have demonstrated elevated basal cerebrospinal fluid corticotropin-releasing hormone concentrations and contradictory results from peripheral measurements, exhibiting low 24 hours excretion of urinary free cortisol, low or normal circulating cortisol levels or even high plasma cortisol levels. The direction of HPA axis activity (hyper-/or hypo-activation), as evidenced by peripheral cortisol measures, may depend on variables such as genetic vulnerability and epigenetic changes, age and developmental stage of the individual, type and chronicity of trauma, co-morbid depression or other psychopathology, alcohol or other drug abuse and time since the traumatic experience. On the other hand, peripheral biomarkers of the SNS activity are more consistent, showing increased 24h urinary or plasma catecholamines in PTSD patients compared to control individuals. Chronically disturbed hormones in PTSD may contribute to brain changes and further emotional and behavior symptoms and disorders, as well as to an increased cardiometabolic risk.

The role of the dopamine transporter (DAT) in the development of PTSD in preschool children

Population-based association studies have supported the heritability of posttraumatic stress disorder (PTSD). This study explored the influence of genetic variation in the dopamine transporter (DAT) 3' untranslated region variable number tandem repeat on the development of PTSD in preschool children exposed to Hurricane Katrina, diagnosed using a developmentally appropriate semistructured interview. A diagnosis according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition , (DSM-IV; American Psychiatric Association, 1994), total symptoms, and specifically Criterion D symptoms were significantly more likely to be found in children with the 9 allele. This study replicates a previous finding in adults with PTSD. The specificity of this finding to the increased arousal symptoms of Criterion D suggests that dopamine and the DAT allele may contribute to one heritable path in a multifinality model of the development of PTSD.

Effects of yohimbine and hydrocortisone on panic symptoms, autonomic responses, and attention to threat in healthy adults

RATIONALE

Research in rodents and non-human primates implicates the noradrenergic system and hypothalamic-pituitary-adrenal axis in stress, anxiety, and attention to threat. Few studies examine how these two neurochemical systems interact to influence anxiety and attention in humans.

OBJECTIVE

The objective of this paper is to examine the effects of exogenous yohimbine and hydrocortisone, as well as their combination (Y + H), on panic symptoms and attention to social threat cues.

METHODS

Thirty-two healthy adults underwent a pharmacological challenge in which they were blindly randomized to either yohimbine, hydrocortisone, Y + H, or placebo. Thirty minutes after drug infusion, attention to threat was measured using the dot probe task, a visual attention task that presents angry, happy, and neutral faces and measures the degree of attention allocated towards or away from the emotional faces. Panic and autonomic measures were assessed before and 30 min after drug infusion.

RESULTS

There was a significant increase in panic symptoms in the yohimbine and Y + H groups, but not in the hydrocortisone or placebo groups. Yohimbine resulted in a greater increase in panic symptoms than Y + H. On the dot probe task, the placebo group exhibited an attention bias to angry faces, whereas this bias was absent after yohimbine. When collapsing across groups, increased panic symptoms was associated with less attention to angry faces.

CONCLUSIONS

Exogenous hydrocortisone may attenuate noradrenergic-induced panic symptoms. The inverse relationship between panic symptoms and attention to angry faces extends prior research demonstrating attention modulation by stressful conditions.

Pharmacotherapy of PTSD: premises, principles, and priorities

Post-traumatic stress disorder (PTSD) is a prevalent anxiety disorder that results in multiple disabling symptoms. Research into the underlying neurobiology has implicated dysregulation in multiple neurotransmitter systems including norepinephrine, serotonin, and glutamate as well as the hypothalamic-pituitary axis. Understanding how these biological systems interact with each other and how they may affect key neural structures, such as the amygdala, hippocampus, and prefrontal cortex, to produce post-traumatic symptoms is critical for the development of effective pharmacological treatments. We briefly discuss the proposed biological dysfunctions underlying PTSD and how agents that target these dysfunctions may be utilized in PTSD. We then provide a review of the different pharmacological agents that have been investigated in PTSD. These drugs include: antidepressants, anti-adrenergic agents, anticonvulsants, benzodiazepines, atypical antipsychotics, and novel agents.

Symptom severity predicts degree of T cell activation in adult women following childhood maltreatment

Although depression is often associated with a reduction in cellular immune responses, other types of emotional disturbance and psychopathology can activate certain aspects of immunity. Activation markers on T cells, in particular, have been found to be elevated in post-traumatic stress states. However, little is known about the relationship between the severity of PTSD symptoms and the degree of change in T cell phenotypes, or about the potential role of neuroendocrine factors in mediating the association. Twenty-four women with a history of sexual trauma during childhood, including 11 who met diagnostic criteria for PTSD, were compared to 12 age-matched, healthy women without a history of maltreatment. The women provided fasted blood samples for enumeration of cell subsets by immunofluorescence and 24-h urine samples for analysis of catecholamine and cortisol levels. The percent of T cells expressing CD45RA, an early activation marker, was higher in the PTSD diagnosed women, and the levels correlated positively with intrusive symptoms and negatively with avoidant symptoms. These alterations in cell surface markers did not appear to be mediated by norepinephrine (NE) or cortisol, making them a distinctive and independent biomarker of arousal and disturbance in PTSD.

Noradrenergic dysfunction and the psychopharmacology of posttraumatic stress disorder

The catecholamine norepinephrine is a critical effector of the mammalian stress response and has been implicated in the pathophysiology of posttraumatic stress disorder (PTSD)-a syndrome intrinsically related to the experience of extraordinary stress. Symptom-linked hypernoradrenergic derangements have been observed in PTSD and several studies have examined the potential therapeutic effects of agents that dampen the centrally hyperactive noradrenergic state. These agents include compounds that decrease norepinephrine release (e.g. centrally acting alpha(2) agonists such as clonidine) and those which block post-synaptic norepinephrine receptors (e.g. centrally acting alpha(1) or beta receptor antagonists such as prazosin or propranolol). In this article, we review studies of central noreadrenergic hyperactivity under both basal and challenge conditions and explore the evidence for these derangements as potential psychopharmacologic targets in patients with PTSD. Given the significant involvement of CNS norepinephrine hyperactivity in PTSD, and its link to intrusive and hyperarousal symptoms, it is not surprising that interventions directed at this system have therapeutic potential in PTSD. The utility of these anti-adrenergics in the clinical treatment of PTSD remains to be determined, though it is possible that they may prove to have primary roles in a disorder that is only modestly responsive to antidepressant treatment.

Genetics of post-traumatic stress disorder: informing clinical conceptualizations and promoting future research

The purpose of this article is to provide an overview of genetic research involving post-traumatic stress disorder (PTSD). First, we summarize evidence for genetic influences on PTSD from family investigations. Second, we discuss the distinct contributions to our understanding of the genetics of PTSD permitted by twin studies. Finally, we summarize findings from molecular genetic studies, which have the potential to inform our understanding of underlying biological mechanisms for the development of PTSD.