Pharmacologic reduction of CNS noradrenergic activity in PTSD: the case for clonidine and prazosin

Attention deficits as a key player in the symptomatology of posttraumatic stress disorder: A review

Posttraumatic stress disorder (PTSD) is a debilitating psychiatric disorder characterized by symptoms such as re-experiencing of the psychotrauma and hyperarousal. Although current literature mainly discusses the emotionally related aspects of these symptoms, studies also highlight the relation between re-experiencing, hyperarousability, and attention deficits, which are associated with poorer daily function and reduced quality of life. This review provides a comprehensive analysis of the existing research on attention deficits among adults with PTSD. A systematic search through five databases resulted in the inclusion of 48 peer-reviewed, English-language articles, describing 49 distinct studies. Using a total of 47 different attentional assessment tools, the majority of studies investigated sustained (n = 40), divided (n = 16), or selective (n = 14) attention. A total of 30 studies (61.2%) found significant correlations between PTSD symptoms and attention deficits, and 10 studies (20.4%) found that higher levels of attention deficits were predictive of worse PTSD symptoms. Moreover, neuroimaging results of six (f)MRI and three EEG studies identified various potential neurobiological pathways involved, including (pre)frontal attention networks. Together, the body of research shows that attention deficits in individuals with PTSD are common and occur in surroundings with emotionally neutral stimuli. Nonetheless, current treatment strategies do not target these attentional difficulties. We propose a novel perspective to PTSD diagnosis and treatment strategies based on attention deficits and their relation with top-down regulation of re-experiencing and subsequent other PTSD symptoms.

The Effects of Pharmacological Treatment of Nightmares: A Systematic Literature Review and Meta-Analysis of Placebo-Controlled, Randomized Clinical Trials

Nightmares are highly prevalent and distressing for the sufferer, which underlines the need for well-documented treatments. A comprehensive literature review and meta-analysis of the effects of different pharmacological placebo-controlled randomized clinical trials, covering the period up to 1 December 2022, was performed. Searches were conducted in PubMed, Embase, Web of Science, PsychInfo, Cinahl, and Google Scholar, resulting in the identification of 1762 articles, of which 14 met the inclusion criteria: pharmacological intervention of nightmares, based on a placebo-controlled randomized trial published in a European language, reporting outcomes either/or in terms of nightmare frequency, nightmare distress, or nightmare intensity, and reporting sufficient information enabling calculation of effect sizes. Most studies involved the effect of the α1-adrenergic antagonist prazosin in samples of veterans or soldiers suffering from posttraumatic stress disorder. Other medications used were hydroxyzine, clonazepam, cyproheptadine, nabilone, and doxazosin. The vast majority of studies were conducted in the USA. The studies comprised a total of 830 participants. The Clinician-Administered PTSD Scale was the most frequently used outcome measure. The results showed an overall effect size of Hedges' g = 0.50 (0.42 after adjustment for publication bias). The synthetic cannabinoid nabilone (one study) showed the highest effect size (g = 1.86), followed by the histamine H1-antagonist hydroxyzine (one study), and prazosin (10 studies), with effect sizes of g = 1.17 and g = 0.54, respectively. Findings and limitations are discussed, and recommendations for future studies are provided.

Propranolol versus Other Selected Drugs in the Treatment of Various Types of Anxiety or Stress, with Particular Reference to Stage Fright and Post-Traumatic Stress Disorder

Propranolol, a non-cardioselective β1,2 blocker, is most commonly recognised for its application in the therapy of various cardiovascular conditions, such as hypertension, coronary artery disease, and tachyarrhythmias. However, due to its ability to cross the blood-brain barrier and affinity towards multiple macromolecules, not only adrenoreceptors, it has also found application in other fields. For example, it is one of the very few medications successfully applied in the treatment of stage fright. This review focuses on the application of propranolol in the treatment of various types of anxiety and stress, with particular reference to stage fright and post-traumatic stress disorder (PTSD). Both mechanisms of action as well as comparison with other therapies are presented. As those indications for propranolol are, in most countries, considered off-label, this review aims to gather information that can be useful while making a decision about the choice of propranolol as a drug in the treatment of those mental conditions.

Peri-Ictal Autonomic Control of Cardiac Function and Seizure-Induced Death

Sudden unexpected death in epilepsy (SUDEP) accounts for the deaths of 8–17% of patients with epilepsy. Although the mechanisms of SUDEP are unknown, one proposed mechanism is abnormal control of the heart by the autonomic nervous system (ANS). Our objective was to determine whether the broad changes in ictal heart rate experienced by mouse models of SUDEP are (1) due to the ANS and (2) contribute to seizure-induced death. Seizures were induced by electrical stimulation of the hippocampus of a mouse carrying the human SCN8A encephalopathy mutation p.Asn1768Asp (N1768D; “D/+ mice”). Using standard autonomic pharmacology, the relative roles of the parasympathetic and sympathetic nervous systems on heart rate changes associated with seizures were determined. All induced seizures had pronounced ictal bradycardia and postictal tachycardia. Seizure susceptibility or severity were unchanged by the pharmacological agents. Administration of Atropine, a muscarinic antagonist, eliminated ictal bradycardia, while carbachol, a muscarinic agonist, had no effect on ictal bradycardia, but reduced postictal tachycardia. Sotalol, an adrenergic β-receptor antagonist, had no effect on ictal bradycardia, but did suppress postictal tachycardia. Isoproterenol, a β-receptor agonist, had no effect on either ictal bradycardia or postictal tachycardia. Administration of the α1-receptor antagonist prazosin increases the incidence of seizure-induced death in D/+ mice. Although postictal heart rate was lower for these fatal seizures in the presence of prazosin, rates were not as low as that recorded for carbachol treated mice, which all survived. Both ictal bradycardia and postictal tachycardia are manifestations of the ANS. Bradycardia is mediated by a maximal activation of the parasympathetic arm of the ANS, and tachycardia is mediated by parasympathetic inactivation and sympathetic activation. While the changes in heart rate during seizures are profound, suppression of postictal heart rate did not increase seizure mortality.

Clonidine Use for the Treatment of Nightmares in Posttraumatic Stress Disorder

Introduction

While clonidine is used clinically for the treatment of nightmares in posttraumatic stress disorder (PTSD), few case reports demonstrating this indication exist, and there have been few studies investigating clonidine's mechanism of action for controlling nightmare symptoms. Case Report. In order to further characterize clonidine's role in treating nightmare symptoms in PTSD, we offer this case report describing one United States veteran who presented to an inpatient psychiatric unit after a suicide attempt. At that time, she described a remote history of PTSD symptoms, including nightmares, flashbacks, hyperarousal, and avoidance behaviors which had been well controlled on sertraline and clonidine. Upon her admission, her home sertraline and alprazolam were continued but her home clonidine was not continued. On day two of her hospital stay, she stated that her nightmares had returned. Her home clonidine was restarted on day two. On day three and thereafter, the patient no longer complained of nightmares.

Conclusion

Our patient's nightmare symptoms had been controlled for years after beginning clonidine as an outpatient, but off clonidine, she had a return of her nightmare symptoms. Her nightmares again resolved once clonidine was resumed. Given this pattern in the patient's response to clonidine, this case may serve as additional evidence in the literature that clonidine has a role in treating nightmares in PTSD. Current proposed mechanisms of action for clonidine's ability to control nightmare symptoms in PTSD include that clonidine may alter the proportions of REM and non-REM sleep in a dose-dependent manner or that clonidine may play a role in memory consolidation. Further formal medication trials are the ideal future direction for establishing this role for clonidine.

Prazosin for treatment of post-traumatic stress disorder: a systematic review and meta-analysis

BACKGROUND

Prazosin has been an accepted treatment for patients with post-traumatic stress disorder (PTSD) who experience sleep disturbances, including nightmares. Results of a recent large randomized control trial did not find benefit of prazosin vs placebo in improving such outcomes. A meta-analysis that includes this most recent trial was conducted to examine the pooled effect of prazosin vs placebo on sleep disturbances and overall PTSD symptoms in patients with PTSD.

METHODS

A systematic review of the published literature on trials comparing prazosin vs placebo for improvement of overall PTSD scores, nightmares, and sleep quality was conducted. Hedges' g standardized mean differences (SMD) between prazosin and placebo were calculated for each outcome across studies.

RESULTS

Six randomized placebo-controlled studies representing 429 patients were included in the analysis, including two studies with a crossover design. Results showed prazosin significantly improved overall PTSD scores (SMD = -0.31; 95% confidence intervals [CI]: -0.62, -0.01), nightmares (SMD = -0.75; 95% CI: -1.24, -0.27), and sleep quality (SMD = -0.57; 95% CI: -1.02, -0.13). In the largest trial, prazosin showed a reduction in clinical outcome measures similar to past studies, but a relatively large placebo effect size, particularly for nightmares, contributed to no treatment differences.

CONCLUSIONS

Despite the results of a recent, large randomized study, pooled effect estimates show that prazosin has a statistically significant benefit on PTSD symptoms and sleep disturbances. Limitations that should be considered include heterogeneity of study design and study populations as well as the small number of studies conducted and included in this meta-analysis.

Distribution of the Noradrenaline Innervation and Adrenoceptors in the Macaque Monkey Thalamus

Noradrenaline (NA) in the thalamus has important roles in physiological, pharmacological, and pathological neuromodulation. In this work, a complete characterization of NA axons and Alpha adrenoceptors distributions is provided.

NA axons, revealed by immunohistochemistry against the synthesizing enzyme and the NA transporter, are present in all thalamic nuclei. The most densely innervated ones are the midline nuclei, intralaminar nuclei (paracentral and parafascicular), and the medial sector of the mediodorsal nucleus (MDm). The ventral motor nuclei and most somatosensory relay nuclei receive a moderate NA innervation. The pulvinar complex receives a heterogeneous innervation. The lateral geniculate nucleus (GL) has the lowest NA innervation.

Alpha adrenoceptors were analyzed by in vitro quantitative autoradiography. Alpha-1 receptor densities are higher than Alpha-2 densities. Overall, axonal densities and Alpha adrenoceptor densities coincide; although some mismatches were identified. The nuclei with the highest Alpha-1 values are MDm, the parvocellular part of the ventral posterior medial nucleus, medial pulvinar, and midline nuclei. The nucleus with the lowest Alpha-1 receptor density is GL. Alpha-2 receptor densities are highest in the lateral dorsal, centromedian, medial and inferior pulvinar, and midline nuclei.

These results suggest a role for NA in modulating thalamic involvement in consciousness, limbic, cognitive, and executive functions.

Doxazosin improved COVID-19 associated nightmare in a patient with major depressive disorder: a case report with a positive rechallenge

This article reports on the treatment of a patient with nightmares who was treated with doxazosin of an alpha 1-adrenergic antagonists. A 71-year-old Japanese major depressive disorder (MDD) woman experienced nightmares after the coronavirus disease 2019 pandemic. She had nightmares about being chased by a coronavirus and catching the corona virus. After adding doxazosin 1 mg daily in the morning, her nightmares led to remission without side effects. We also had a rechallenge regimen with doxazosin. The nightmares ceased on the second night of the rechallenge and did not return with continued treatment. This case report suggests that doxazosin may be a useful therapeutic option to target nightmares in individuals with MDD.

Low-dose clonidine in veterans with Posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) symptoms of hyperarousal are mediated through sympathetic nervous system hyperactivity. PTSD symptoms, including distressing thoughts and memories, flashbacks, hyperarousal, and sleep disturbances, have been linked with elevated norepinephrine levels in the cerebrospinal fluid. Clonidine, an alpha2-adrenergic agonist, reduces the release of norepinephrine and has been suggested as a treatment for PTSD. However, literature for use of clonidine in PTSD is limited. The objective of this study was to evaluate clinical records of patients with PTSD treated with clonidine to assess reported efficacy and safety. A cohort of veterans with PTSD treated with clonidine at a midwestern VA hospital between July 2015 and January 2018 were studied retrospectively. Medical records of 79 patients with moderate to severe PTSD symptoms were reviewed by three independent clinicians using the Clinical Global Impressions (CGI) scale to quantify symptom severity (CGI-S) before starting clonidine and subjects' change in symptoms (CGI-I) after starting clonidine. Data on adverse events were also collected. Subgroup analyses were conducted on the impact of comorbid diagnoses, concurrent medications, and substance use. Mean CGI-S score at baseline was 4.8 (5 = markedly ill). After treatment with low-dose clonidine, 72% of patients experienced improvement, and 49% scored "much improved" or "very much improved." Adverse effects were reported by 18 out of 79 subjects. In this retrospective analysis of veterans prescribed clonidine for PTSD, CGI-I scores suggested improvement in PTSD symptoms, and minimal side effects were reported. In addition, some comorbid diagnoses and concurrent medications were correlated with variations in outcomes.

Using Prazosin to Treat Posttraumatic Stress Disorder and Associations: A Systematic Review

OBJECTIVE

A central adrenergic hyperactivation is described in the neurobiology of posttraumatic stress disorder (PTSD) with probable variable symptomatic impact. Few studies have evaluated using the alpha-1 adrenergic antagonist prazosin for such symptoms; however, given the likely pathophysiology involved, this drug may play an important role in the pharmacological approach to PTSD.

METHODS

This study assessed articles already published on the use of prazosin through a systematic review along a timeline in view of the symptomatic target of difficult access by standardized treatments. The impact of using this medication for the general symptoms of PTSD is also discussed. Several databases were searched for articles in the literature on the use of prazosin to treat PTSD.

RESULTS

A total of 168 articles were found containing search terms in the title or abstract. Overall, 85 articles met the criteria described, and 48 studies were explored to conduct the present systematic review. Most articles showed some improvement after prazosin administration, especially in relation to sleep symptoms (nightmares and night waking). Only one article demonstrated no improvement after the use of this drug. More randomized studies are needed.

CONCLUSION

Several clinical studies demonstrated the relevant role of prazosin for treating PTSD symptoms. Prazosin is an affordable and cost-effective pharmacological option compared to other drugs used to treat PTSD.

Evaluation of low dose prazosin for PTSD-associated nightmares in children and adolescents

Introduction

Knowledge about fundamental sleep disorders and dysregulation that occurs in children with PTSD is limited. Prazosin is an alpha-1 receptor antagonist often used off label for the treatment of PTSD-associated nightmares in adults; however, evaluation of its use in pediatrics and adolescents is limited. The primary objective of this study was to assess the impact of prazosin on nightmares associated with PTSD in this population. Secondary objectives included assessing side effects, changes in blood pressure, and 30-day readmission rates.

Methods

This was a retrospective, single-center chart review of inpatients diagnosed with PTSD nightmares from January 1, 2017, to July 31, 2019. Patients 4 to 18 years old with a PTSD diagnosis, experiencing nightmares, and initiating any dose of prazosin were assessed to determine efficacy and tolerance.

Results

Forty-two patients were evaluated to determine symptom improvement after initiation of prazosin for PTSD nightmares in children and adolescents. Of the 42 patients, 24 (57.1%) reported improvement in nightmares (average dose 1.05 mg). For secondary results, 38 (90.5%) patients continued prazosin at discharge, and 2 (5%) were readmitted within 30 days for reasons other than PTSD-associated nightmares. Thirty-four (81%) reported having no adverse effects to prazosin. There was no significant difference in systolic (P = .1883) or diastolic (P = .2777) blood pressure preinitiation and postinitiation of prazosin.

Discussion

Despite the limitations of this retrospective study, the data suggests that prazosin may be associated with an improvement in nightmares in children and adolescents with PTSD. Adverse events were rarely reported, and there was no significant change in blood pressure with initiation of prazosin.

Noradrenergic circuits in the forebrain control affective responses to novelty

RATIONALE

In rodents, exposure to novel environments elicits initial anxiety-like behavior (neophobia) followed by intense exploration (neophilia) that gradually subsides as the environment becomes familiar. Thus, innate novelty-induced behaviors are useful indices of anxiety and motivation in animal models of psychiatric disease. Noradrenergic neurons are activated by novelty and implicated in exploratory and anxiety-like responses, but the role of norepinephrine (NE) in neophobia has not been clearly delineated.

OBJECTIVE

We sought to define the role of central NE transmission in neophilic and neophobic behaviors.

METHODS

We assessed dopamine β-hydroxylase knockout (Dbh -/-) mice lacking NE and their NE-competent (Dbh +/-) littermate controls in neophilic (novelty-induced locomotion; NIL) and neophobic (novelty-suppressed feeding; NSF) behavioral tests with subsequent quantification of brain-wide c-fos induction. We complimented the gene knockout approach with pharmacological interventions.

RESULTS

Dbh -/- mice exhibited blunted locomotor responses in the NIL task and completely lacked neophobia in the NSF test. Neophobia was rescued in Dbh -/- mice by acute pharmacological restoration of central NE with the synthetic precursor L-3,4-dihydroxyphenylserine (DOPS), and attenuated in control mice by the inhibitory α2-adrenergic autoreceptor agonist guanfacine. Following either NSF or NIL, Dbh -/- mice demonstrated reduced c-fos in the anterior cingulate cortex, medial septum, ventral hippocampus, bed nucleus of the stria terminalis, and basolateral amygdala.

CONCLUSION

These findings indicate that central NE signaling is required for the expression of both neophilic and neophobic behaviors. Further, we describe a putative noradrenergic novelty network as a potential therapeutic target for treating anxiety and substance abuse disorders.

α1-Adrenergic Receptors in Neurotransmission, Synaptic Plasticity, and Cognition

α₁-adrenergic receptors are G-Protein Coupled Receptors that are involved in neurotransmission and regulate the sympathetic nervous system through binding and activating the neurotransmitter, norepinephrine, and the neurohormone, epinephrine. There are three α₁-adrenergic receptor subtypes (α_1A, α_1B, α_1D) that are known to play various roles in neurotransmission and cognition. They are related to two other adrenergic receptor families that also bind norepinephrine and epinephrine, the β- and α₂-, each with three subtypes (β₁, β₂, β₃, α_2A, α_2B, α_2C). Previous studies assessing the roles of α₁-adrenergic receptors in neurotransmission and cognition have been inconsistent. This was due to the use of poorly-selective ligands and many of these studies were published before the characterization of the cloned receptor subtypes and the subsequent development of animal models. With the availability of more-selective ligands and the development of animal models, a clearer picture of their role in cognition and neurotransmission can be assessed. In this review, we highlight the significant role that the α₁-adrenergic receptor plays in regulating synaptic efficacy, both short and long-term synaptic plasticity, and its regulation of different types of memory. We will also present evidence that the α₁-adrenergic receptors, and particularly the α_1A-adrenergic receptor subtype, are a potentially good target to treat a wide variety of neurological conditions with diminished cognition.

Relative prevalence of 10 types of pharmacodynamic interactions in psychiatric treatment

OBJECTIVE

To assess the relative prevalence and factors affecting the prescription of medication combinations with a theoretical efficacy limiting pharmacodynamic interaction, defined as two medications with opposing indications and side effects or antagonistic action at the primary receptor of mechanism of action.

METHOD

One hundred sixteen combinations were identified for 10 types of pharmacodynamic interactions. PubMed was searched for each combination to assess the quality of evidence either supporting clinical use or verifying reduced efficacy. Micromedex was searched to determine the presence of warnings to prescribers of reduced efficacy. The prevalence in clinical practice was determined by computer review of the Genoa Healthcare database for all prescribers at 10 participating community mental health centers. The expected prevalence was calculated as the product of the probability of each medication prescribed alone and was compared with the actual prevalence of the combination using the test of proportions.

RESULTS

The frequency of prescription of eight combinations met the Bonferroni corrected level of significance of p < 0.001. Four were combinations of amphetamine and D2 antagonists and each were prescribed less often than chance, p = 0.0001 consistent with epidemiological studies and multiple animal studies verifying an efficacy limiting interaction. Despite epidemiological studies indicating increased risk of accidents, alprazolam and amphetamine were prescribed more often than chance, p = 0.0001. Micromedex generated warnings for efficacy limiting interactions for five other combinations, but with no subsequent change in prescription frequency.

CONCLUSIONS

Neither presence of medical evidence nor warnings from Micromedex consistently affect the prescription of combinations with pharmacodynamic efficacy limiting interactions.

Myocardial fibrosis, inflammation, and altered cardiac gene expression profiles in rats exposed to a predator-based model of posttraumatic stress disorder

People who are exposed to life-threatening trauma are at risk of developing posttraumatic stress disorder (PTSD). In addition to psychological manifestations, PTSD is associated with an increased risk of myocardial infarction, arrhythmias, hypertension, and other cardiovascular problems. We previously reported that rats exposed to a predator-based model of PTSD develop myocardial hypersensitivity to ischemic injury. This study characterized cardiac changes in histology and gene expression in rats exposed this model. Male rats were subjected to two cat exposures (separated by a period of 10 d) and daily cage-mate changes for 31 d. Control rats were not exposed to the cat or cage-mate changes. Ventricular tissue was analyzed by RNA sequencing, western blotting, histology, and immunohistochemistry. Multifocal lesions characterized by necrosis, mononuclear cell infiltration, and collagen deposition were observed in hearts from all stressed rats but none of the control rats. Gene expression analysis identified clusters of upregulated genes associated with endothelial to mesenchymal transition, endothelial migration, mesenchyme differentiation, and extracellular matrix remodeling in hearts from stressed rats. Consistent with endothelial to mesenchymal transition, rats from stressed hearts exhibited increased expression of α-smooth muscle actin (a myofibroblast marker) and a decrease in the number of CD31 positive endothelial cells. These data provide evidence that predator-based stress induces myocardial lesions and reprograming of cardiac gene expression. These changes may underlie the myocardial hypersensitivity to ischemia observed in these animals. This rat model may provide a useful tool for investigating the cardiac impact of PTSD and other forms of chronic psychological stress.Lay summaryChronic predator stress induces the formation of myocardial lesions characterized by necrosis, collagen deposition, and mononuclear cell infiltration. This is accompanied by changes in gene expression and histology that are indicative of cardiac remodeling. These changes may underlie the increased risk of arrhythmias, myocardial infarction, and other cardiac pathologies in people who have PTSD or other forms of chronic stress.

A novel theory on the predictive value of variation in the β-endorphin system on the risk and severity of PTSD

Despite growing interest in genetic and psychosocial indicators of heightened susceptibility to posttraumatic stress disorder (PTSD), a predictive model, which explains why some individuals develop PTSD in response to life-threatening traumatic events, while others, when faced with the same or similar experiences, do not, has thus far remained out of reach. In this paper, we review the literature on gene-environment interactions in β-endorphin system functioning with regard to PTSD and suggest that variation, both genetic and with regard to environmental stimuli, in systems which, like the β-endorphin system, distort human perception of life-threatening traumatic experiences may account for some of the variance in resilience to the disorder. Given the role of β-endorphin in both social connections and physical exercise, this becomes especially relevant with regard to military selection, training, and leadership processes.

Pharmacological screening of a new alpha-2 adrenergic receptor agonist, mafedine, in zebrafish

Pharmacological agents acting at alpha-2 adrenergic receptors are widely used in physiology and neuroscience research. Mounting evidence of their potential utility in clinical and experimental psychopharmacology, necessitates new models and novel model organisms for their screening. Here, we characterize behavioral effects of mafedine (6-oxo-1-phenyl-2- (phenylamino)-1,6-dihydropyrimidine-4-sodium olate), a novel drug with alpha-2 adrenergic receptor agonistic effects, in adult zebrafish (Danio rerio) in the novel tank test of anxiety and activity. Following an acute 20-min exposure, mafedine at 60 mg/L produced a mild psychostimulant action with some anxiogenic-like effects. Repeated acute 20-min/day administration of mafedine for 7 consecutive days at 1, 5 and 10 mg/L had a similar action on fish behavior as an acute exposure to 60 mg/L. Since mafedine demonstrated robust behavioral effects in zebrafish - a sensitive vertebrate aquatic model, it is likely that it may modulate rodent and human behavior as well. Thus, further studies are needed to explore this possibility in detail, and whether it may foster clinical application of mafedine and related alpha-2 adrenergic agents.

Myocardial hypersensitivity to ischemic injury is not reversed by clonidine or propranolol in a predator-based rat model of posttraumatic stress disorder

Individuals with posttraumatic stress disorder (PTSD) are at increased risk for cardiovascular disease. We previously reported that a predator-based model of PTSD increases myocardial sensitivity to ischemic injury. Heightened sympathetic signaling has a well-established role in the formation of anxiety associated with PTSD and may also contribute to worsening of myocardial injury in the ischemic heart. Thus, we examined whether suppression of sympathetic tone protects the ischemic heart in rats subjected to this model of PTSD. Rats were treated with saline or clonidine throughout the 31-day stress paradigm. Behavior on the elevated plus maze (EPM) was assessed on Day 32, and hearts were subjected to an ischemic insult on day 33. Stressed rats exhibited increased anxiety on the EPM and significantly larger myocardial infarcts following ischemia. Clonidine reversed the anxiety-like behavior but had no impact on infarct size. In a subsequent experiment, rats were treated with propranolol in their drinking water throughout the stress paradigm. Propranolol had no effect on either anxiety or myocardial sensitivity to ischemic injury. These findings suggest that the myocardial hypersensitivity to ischemic injury observed in this model is not caused by increased sympathetic tone or chronic β-adrenergic receptor signaling.

The management of post-traumatic stress disorder and associated pain and sleep disturbance in refugees

More than 68 million people worldwide have been forcibly displaced and one-third of these are refugees. This article offers an overview of the current literature and reviews the epidemiology and evidence-based psychological and pharmacological management of post-traumatic stress disorder (PTSD), sleep disturbance and pain in refugees and asylum seekers. It also considers the relationship between sleep disturbance and PTSD and explores concepts of pain in relation to physical and psychological trauma and distress. During diagnosis, clinicians must be aware of ethnic variation in the somatic expression of distress. Treatments for PTSD, pain and sleep disturbance among refugees and asylum seekers are essentially the same as those used in the general population, but treatment strategies must allow for cultural and contextual factors, including language barriers, loss of freedom and threat of repatriation.

LEARNING OBJECTIVES

After reading this article you will be able to: •

DECLARATION OF INTEREST

None.

Position Paper for the Treatment of Nightmare Disorder in Adults: An American Academy of Sleep Medicine Position Paper

INTRODUCTION

Nightmare disorder affects approximately 4% of adults, occurring in isolation or as part of other disorders such as posttraumatic stress disorder (PTSD), and can significantly impair quality of life. This paper provides the American Academy of Sleep Medicine (AASM) position regarding various treatments of nightmare disorder in adults.

METHODS

A literature search was performed based upon the keywords and MeSH terms from the Best Practice Guide for the Treatment of Nightmare Disorder in Adults that was published in 2010 by the AASM. The search used the date range March 2009 to August of 2017, and sought to find available evidence pertaining to the use of behavioral, psychological, and pharmacologic therapies for the treatment of nightmares. A task force developed position statements based on a thorough review of these studies and their clinical expertise. The AASM Board of Directors approved the final position statements.

DETERMINATION OF POSITION

Positions of "recommended" and "not recommended" indicate that a treatment option is determined to be clearly useful or ineffective/harmful for most patients, respectively, based on a qualitative assessment of the available evidence and clinical judgement of the task force. Positions of "may be used" indicate that the evidence or expert consensus is less clear, either in favor or against the use of a treatment option. The interventions listed below are in alphabetical order within the position statements rather than clinical preference: this is not meant to be instructive of the order in which interventions should be used.

POSITION STATEMENTS

The following therapy is recommended for the treatment of PTSD-associated nightmares and nightmare disorder: image rehearsal therapy. The following therapies may be used for the treatment of PTSD-associated nightmares: cognitive behavioral therapy; cognitive behavioral therapy for insomnia; eye movement desensitization and reprocessing; exposure, relaxation, and rescripting therapy; the atypical antipsychotics olanzapine, risperidone and aripiprazole; clonidine; cyproheptadine; fluvoxamine; gabapentin; nabilone; phenelzine; prazosin; topiramate; trazodone; and tricyclic antidepressants. The following therapies may be used for the treatment of nightmare disorder: cognitive behavioral therapy; exposure, relaxation, and rescripting therapy; hypnosis; lucid dreaming therapy; progressive deep muscle relaxation; sleep dynamic therapy; self-exposure therapy; systematic desensitization; testimony method; nitrazepam; prazosin; and triazolam. The following are not recommended for the treatment of nightmare disorder: clonazepam and venlafaxine. The ultimate judgment regarding propriety of any specific care must be made by the clinician, in light of the individual circumstances presented by the patient, accessible treatment options, and resources.

Mental Health of Refugees and Asylum Seekers: Assessment and Intervention

With unprecedented numbers of displaced persons worldwide, mental health clinicians in high-income countries will increasingly encounter refugee and asylum-seeking patients, many of whom have experienced significant adversity before and after their migration. This paper presents a summary of the recent evidence on the assessment and treatment of refugees across the lifespan to inform clinicians' approaches to care of refugee patients in mental health care settings. Assessment and interventions for refugees are grounded in an ecosystemic approach which considers not only pre-migratory trauma, but social, familial, and cultural determinants of mental health in the host country. Evidence for psychotherapy and pharmacological treatments are reviewed, highlighting promising interventions while acknowledging that further research is needed. Ultimately, serving refugees necessitates a biopsychosocial approach that engages clinicians as medical experts, therapists, and advocates.

Using ecological momentary assessment to examine the relationship between craving and affect with opioid use in a clinical trial of clonidine as an adjunct medication to buprenorphine treatment

BACKGROUND

In a recent clinical trial (NCT00295308), we demonstrated that clonidine decreased the association between opioid craving and moderate levels of stress and affect in patients receiving buprenorphine-based opioid agonist therapy.

OBJECTIVES

To examine the relationship between illicit opioid use and craving and affect during the evaluation of clonidine as an adjunct medication in buprenorphine treatment for opioid use disorder. Secondarily, to examine whether those relationships are driven by within- or between-participant factors.

METHODS

This was a secondary data analysis from our original trial. Participants (N = 108, female: n = 23, male n = 85) receiving buprenorphine were randomized to receive adjunct clonidine or placebo. Participants used portable electronic devices to rate stress, mood, and craving via ecological momentary assessment (EMA) four times randomly each day. To associate the EMA data with illicit opioid use, each EMA report was linked to participants' next urine drug screen (thrice weekly). We used generalized linear mixed models to examine the interaction between treatment group and illicit opioid use, as well as to decompose the analysis into within- and between-participant effects.

RESULTS

Craving for opioids and cocaine was increased when participants were using illicit opioids; this effect was greater in the clonidine group. For affect, mood was poorer during periods preceding opioid-positive urines than opioid-negative urines for clonidine-treated participants, whereas there was no difference for placebo participants.

CONCLUSION

This secondary analysis provides evidence that for participants maintained on opioid agonist therapy, clonidine minimized the behavioral impact of moderate levels of negative affect and craving.

Noradrenergic Modulation of Fear Conditioning and Extinction

The locus coeruleus norepinephrine (LC-NE) system plays a broad role in learning and memory. Here we begin with an overview of the LC-NE system. We then consider how both direct and indirect manipulations of the LC-NE system affect cued and contextual aversive learning and memory. We propose that NE dynamically modulates Pavlovian conditioning and extinction, either promoting or impairing learning aversive processes under different levels of behavioral arousal. We suggest that under high levels of stress (e.g., during/soon after fear conditioning) the locus coeruleus (LC) promotes cued fear learning by enhancing amygdala function while simultaneously blunting prefrontal function. Under low levels of arousal, the LC promotes PFC function to promote downstream inhibition of the amygdala and foster the extinction of cued fear. Thus, LC-NE action on the medial prefrontal cortex (mPFC) might be described by an inverted-U function such that it can either enhance or hinder learning depending on arousal states. In addition, LC-NE seems to be particularly important for the acquisition, consolidation and extinction of contextual fear memories. This may be due to dense adrenoceptor expression in the hippocampus (HPC) which encodes contextual information, and the ability of NE to regulate long-term potentiation (LTP). Moreover, recent work reveals that the diversity of LC-NE functions in aversive learning and memory are mediated by functionally heterogeneous populations of LC neurons that are defined by their projection targets. Hence, LC-NE function in learning and memory is determined by projection-specific neuromodulation that accompanies various states of behavioral arousal.

Treatment of sleep disturbances in refugees suffering from post-traumatic stress disorder

Sleep disturbances are often referred to as the hallmark of Post-Traumatic Stress Disorder (PTSD). Although PTSD is prevalent in refugees, studies on sleep disturbances in trauma-affected refugees are scarce. This article presents the results of two studies: a systematic review of the literature on treatment of sleep disturbances in adult trauma-affected refugees and a study of the role of sleep disturbances in the PTSD symptom structure. Study 1, the literature review, identified five studies on treatment of sleep disturbances: four studies were on pharmacological treatment and one study on music therapy. The identified studies had small sample sizes and few carried out statistical analysis. It was not possible from the available literature to recommend any specific treatment of sleep disturbances. In Study 2, a clinical sample of 752 refugees, fulfilling criteria for PTSD and enrolled in treatment at the Competence Centre for Transcultural Psychiatry, Denmark, completed the Harvard Trauma Questionnaire (HTQ) before and after treatment. To determine item discrimination, the data was tested with a Rasch model. 99.1% reported trouble sleeping and 98.7% reported recurrent nightmares. The Rasch analysis displayed fit residuals of 0.05 for trouble sleeping and -1.16 for nightmares, indicating sufficient discrimination. Trouble sleeping and nightmares proved important parts of the HTQ response structure. This study indicates that sleep disturbances are a prominent part of the PTSD symptom structure in refugees but that research on treatment of sleep disturbances is limited. Further research on sleep disturbances in trauma-affected refugees is therefore needed.

Pharmacological treatment of refugees with trauma-related disorders: What do we know today?

There is a dearth of evidence on the effectiveness of pharmacological treatment for refugees with trauma-related disorders. The present paper provides an overview of available literature on the subject and discusses the transferability of results from studies on other groups of patients with post traumatic stress disorder (PTSD). We conducted a systematic review of published treatment outcome studies on PTSD and depression among refugees. Fifteen studies were identified and reviewed. Most studies focused on the use of antidepressants. Included studies differed widely in method and quality. The majority were observational studies and case studies. Small sample sizes limited the statistical power. Few studies reported effect sizes, confidence intervals, and statistical significance of findings. No specific pharmacological treatment for PTSD among refugees can be recommended on the basis of the available literature. There is a need for well-designed clinical trials, especially with newer antidepressants and antipsychotics. Until such studies are available, clinical practice and design of trials can be guided by results from studies of other groups of PTSD patients, although differences in pharmacogenetics, compliance, and trauma reactions may affect the direct transferability of results from studies on nonrefugee populations.

Effect of Rivastigmine Augmentation in Treatment of Male Patients With Combat-Related Chronic Posttraumatic Stress Disorder: A Randomized Controlled Trial

BACKGROUND

Posttraumatic stress disorder (PTSD) is one of the chronic and disabling psychiatric disorders, particularly in combat veterans. In a case series, rivastigmine was suggested to be an effective augmentation in treatment of PTSD. The aim of the present study was to evaluate this finding in a randomized controlled trial.

METHOD

A 12-week, double-blind, placebo-controlled clinical trial was performed on 36 male patients (aged 42-60 years) diagnosed with chronic, combat-related PTSD. Subjects were screened for apparent cognitive deficits by means of Mini-Mental State Examination. All patients received selective serotonin reuptake inhibitors plus sodium valproate for 4 weeks and then reevaluated. Subjects who did not show adequate response were randomly assigned into 3 groups receiving rivastigmine (up to 6 mg/d), placebo, or the prior treatment regimen. Efficacy of medication was measured by administering PTSD Check List-Military Version at baseline and weeks 2, 4, 8, and 12. Collected data were analyzed by analysis of variance and repeated measurement. Reported differences were considered significant at the level of 0.05 or less.

RESULTS

The 3 groups showed statistically significant reductions in the total PTSD Check List-Military Version, avoidance subscale, and the reexperience subscale but not in the hyperarousal subscale. No significant differences were found between the 3 groups.

CONCLUSIONS

In contrast to the previous case series, findings of the current study did not support the efficacy of adjunctive rivastigmine in treatment of PTSD. This hypothetically could be due to the fact that all the study's subjects scored higher than 25 on Mini-Mental State Examination.

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.

The timing of administration of intravenous dexmedetomidine during lower limb surgery: a randomized controlled trial

Background

Dexmedetomidine, a selective alpha-2 agonist, has sedative, analgesic, and anxiolytic effects without respiratory depression. Dexmedetomidine can cause a biphasic cardiovascular response, and induce transient hypertension. Hypotension is a common complication of spinal anesthesia. Decreasing anxiety of patients before procedure is important for high quality of procedure. This study aimed to compare the incidence of hypotension and patients’ anxiety and comfort levels when dexmedetomidine was intravenously administered before and after spinal anesthesia.

Methods

Seventy-four patients with American Society of Anesthesiologists physical status classification I or II were randomly allocated into two groups. Spinal anesthesia was performed using 12 mg of 0.5% heavy bupivacaine. In Group A, 1 μg/kg of dexmedetomidine was intravenously administered for 10 min, followed by the maintenance infusion of dexmedetomidine 0.2 μg/kg/hr after 5 min of intrathecal bupivacaine injection. Patients in Group B received same dose of dexmedetomidine by intravenous administration before 5 min of intrathecal bupivacaine injection. Perioperative vital signs, anxiety (using the Spielberger’s State-Trait Anxiety Inventory) and comfort (using the numerical rating scale) were evaluated.

Results

The incidence of hypotension was significantly lower in Group A (16.1%) than in Group B (48.4%) during infusion of dexmedetomidine (p = 0.01). The need for treatment of hypotension is higher in Group B than Group A (p = 0.02). The incidence of bradycardia and desaturation did not significantly differ between the two groups. There were no statistically significant differences regarding the patients’ anxiety and comfort.

Conclusions

Hypotension is more frequently occurred, and the treatment of hypotension is more needed in Group B. The intravenously administration of dexmedetomidine before spinal anesthesia has no advantages in hemodynamic status and patients’ comfort compared to that after spinal anesthesia during lower limb surgery.

Trial registration

ClinicalTrials.gov number, NCT02155010. Retrospectively registered on May 22, 2014.

Enhanced noradrenergic activity in the amygdala contributes to hyperarousal in an animal model of PTSD

Increased activity of the noradrenergic system in the amygdala has been suggested to contribute to the hyperarousal symptoms associated with post-traumatic stress disorder (PTSD). However, only two studies have examined the content of noradrenaline or its metabolites in the amygdala of rats previously exposed to traumatic stress showing inconsistent results. The aim of this study was to investigate the effects of an inescapable foot shock (IFS) procedure (1) on reactivity to novelty in an open-field (as an index of hyperarousal), and (2) on noradrenaline release in the amygdala during an acute stress. To test the role of noradrenaline in amygdala, we also investigated the effects of microinjections of propranolol, a β-adrenoreceptor antagonist, and clenbuterol, a β-adrenoreceptor agonist, into the amygdala of IFS and control animals. Finally, we evaluated the expression of mRNA levels of β-adrenoreceptors (β1 and β2) in the amygdala, the hippocampus and the prefrontal cortex. Male Wistar rats (3 months) were stereotaxically implanted with bilateral guide cannulae. After recovering from surgery, animals were exposed to IFS (10 shocks, 0.86mA, and 6s per shock) and seven days later either microdialysis or microinjections were performed in amygdala. Animals exposed to IFS showed a reduced locomotion compared to non-shocked animals during the first 5min in the open-field. In the amygdala, IFS animals showed an enhanced increase of noradrenaline induced by stress compared to control animals. Bilateral microinjections of propranolol (0.5μg) into the amygdala one hour before testing in the open-field normalized the decreased locomotion observed in IFS animals. On the other hand, bilateral microinjections of clenbuterol (30ng) into the amygdala of control animals did not change the exploratory activity induced by novelty in the open field. IFS modified the mRNA expression of β1 and β2 adrenoreceptors in the prefrontal cortex and the hippocampus. These results suggest that an increased noradrenergic activity in the amygdala contributes to the expression of hyperarousal in an animal model of PTSD.

Terazosin for the treatment of trauma-related nightmares: a report of 4 cases

The selective α1-adrenergic antagonist prazosin has been shown in multiple studies to be effective in targeting trauma-related nightmares in posttraumatic stress disorder. There are limited data regarding the effectiveness of another selective α1-adrenergic antagonist terazosin for the treatment of trauma-related nightmares. We present 4 cases in which terazosin was effectively used to treat nightmares as a second-line agent after prazosin failure. Further studies are needed to validate terazosin as an alternative to prazosin for the treatment of posttraumatic stress disorder-related nightmares.

The effect of flexible cognitive-behavioural therapy and medical treatment, including antidepressants on post-traumatic stress disorder and depression in traumatised refugees: pragmatic randomised controlled clinical trial

BACKGROUND

Little evidence exists on the treatment of traumatised refugees.

AIMS

To estimate treatment effects of flexible cognitive-behavioural therapy (CBT) and antidepressants (sertraline and mianserin) in traumatised refugees.

METHOD

Randomised controlled clinical trial with 2 × 2 factorial design (registered with Clinicaltrials.gov, NCT00917397, EUDRACT no. 2008-006714-15). Participants were refugees with war-related traumatic experiences, post-traumatic stress disorder (PTSD) and without psychotic disorder. Treatment was weekly sessions with a physician and/or psychologist over 6 months.

RESULTS

A total of 217 of 280 patients completed treatment (78%). There was no effect on PTSD symptoms, no effect of psychotherapy and no interaction between psychotherapy and medicine. A small but significant effect of treatment with antidepressants was found on depression.

CONCLUSIONS

In a pragmatic clinical setting, there was no effect of flexible CBT and antidepressants on PTSD, and there was a small-to-moderate effect of antidepressants and psychoeducation on depression in traumatised refugees.

Medical Approach to the Management of Traumatized Refugees

Refugees are a highly traumatized and culturally diverse group of patients who present many clinical challenges. Refugees have a high prevalence of traumas from torture, ethnic cleansing, and the effects of long civil wars. The most common diagnoses associated with the effects of such traumas are posttraumatic stress disorder (PTSD) or PTSD with comorbid depression; however, psychosis and neurocognitive disorders are also common. For those with PTSD, a suggested treatment approach is long-term supportive psychotherapy with drug treatment directed at reducing the most disruptive symptoms, such as insomnia, nightmares, and irritability or psychosis. The author recommends a sedative tricyclic antidepressant, clonidine or prazosin, and aripiprazole as a useful combination of medications to provide rapid relief. In addition to PTSD, long-term studies indicate a high prevalence of diabetes and hypertension in traumatized refugees. It is therefore important to perform a thorough evaluation for these disorders that includes the measurement of blood pressure and a blood test for diabetes. When managed with such a medical approach, refugees are generally accepting of psychiatric treatment and can obtain relief from the symptoms associated with the massive trauma and losses they have experienced.

Adolescent social isolation increases anxiety-like behavior and ethanol intake and impairs fear extinction in adulthood: Possible role of disrupted noradrenergic signaling

Alcohol use disorder, anxiety disorders, and post-traumatic stress disorder (PTSD) are highly comorbid, and exposure to chronic stress during adolescence may increase the incidence of these conditions in adulthood. Efforts to identify the common stress-related mechanisms driving these disorders have been hampered, in part, by a lack of reliable preclinical models that replicate their comorbid symptomatology. Prior work by us, and others, has shown that adolescent social isolation increases anxiety-like behaviors and voluntary ethanol consumption in adult male Long-Evans rats. Here we examined whether social isolation also produces deficiencies in extinction of conditioned fear, a hallmark symptom of PTSD. Additionally, as disrupted noradrenergic signaling may contribute to alcoholism, we examined the effect of anxiolytic medications that target noradrenergic signaling on ethanol intake following adolescent social isolation. Our results confirm and extend previous findings that adolescent social isolation increases anxiety-like behavior and enhances ethanol intake and preference in adulthood. Additionally, social isolation is associated with a significant deficit in the extinction of conditioned fear and a marked increase in the ability of noradrenergic therapeutics to decrease ethanol intake. These results suggest that adolescent social isolation not only leads to persistent increases in anxiety-like behaviors and ethanol consumption, but also disrupts fear extinction, and as such may be a useful preclinical model of stress-related psychopathology. Our data also suggest that disrupted noradrenergic signaling may contribute to escalated ethanol drinking following social isolation, thus further highlighting the potential utility of noradrenergic therapeutics in treating the deleterious behavioral sequelae associated with early life stress.

Alpha-2 receptor agonists for the treatment of posttraumatic stress disorder

Clonidine and guanfacine are alpha-2 receptor agonists that decrease sympathetic outflow from the central nervous system. Posttraumatic stress disorder (PTSD) is an anxiety disorder that is theorized to be related to a hyperactive sympathetic nervous system. Currently, the only US Food and Drug Administration (FDA)-approved medications for PTSD are the selective serotonin reuptake inhibitors (SSRIs) sertraline and paroxetine. Sometimes use of the SSRIs may not lead to full remission and symptoms of hyperarousal often persist. This article specifically reviews the literature on alpha-2 receptor agonist use for the treatment of PTSD and concludes that while the evidence base is limited, these agents might be considered useful when SSRIs fail to treat symptoms of agitation and hyperarousal in patients with PTSD.

Comparing the effect of prazosin and hydroxyzine on sleep quality in patients suffering from posttraumatic stress disorder

OBJECTIVES

In light of the high prevalence of sleep disorders in patients suffering from posttraumatic stress disorder (PTSD), this study sought to compare the effect of prazosin and hydroxyzine on sleep quality in this patient group.

METHODS

A total of 100 patients suffering from PTSD were assessed (mean age = 35.51 years, SD = 6.41; 28% females). Next, they were randomly assigned to one of three treatment groups: prazosin (33 patients), hydroxyzine (34 patients) or placebo (33 patients). The trial lasted for 8 weeks. The patients' sleep quality was assessed using the Pittsburgh Sleep Quality Index. Items taken from the Mini International Neuropsychiatric Interview were used to operationalize PTSD.

RESULTS

Compared to controls, patients treated with prazosin and hydroxyzine reported improved sleep and less nightmares. Improvement was greatest in patients treated with prazosin compared to hydroxyzine and placebo. Improvement in sleep was associated with an amelioration of their PTSD symptoms.

CONCLUSION

Both prazosin and hydroxyzine can be used to treat psychopharmacological sleep disorders and nightmares in patients suffering from PTSD, also leading to reductions in PTSD symptoms.

Preclinical perspectives on posttraumatic stress disorder criteria in DSM-5

Posttraumatic stress disorder (PTSD) now sits within the newly created "Trauma- and Stressor-Related Disorders" section of the Diagnostic and Statistical Manual of Mental Disorders (fifth edition; DSM-5). Through the refinement and expansion of diagnostic criteria, the DSM-5 version better clarifies the broad and pervasive effects of trauma on functioning, as well as the impact of development on trauma reactions. Aggressive and dissociative symptoms are more thoroughly characterized, reflecting increasing evidence that reactions to trauma often reach beyond the domains of fear and anxiety (these latter domains were emphasized in DSM-IV). These revised criteria are supported by decades of preclinical and clinical research quantifying traumatic stress-induced changes in neurobiological and behavioral function. Several features of the DSM-5 PTSD criteria are similarly and consistently represented in preclinical animal models and humans following exposure to extreme stress. In rodent models, for example, increases in anxiety-like, helplessness, or aggressive behavior, along with disruptions in circadian/neurovegetative function, are typically induced by severe, inescapable, and uncontrollable stress. These abnormalities are prominent features of PTSD and can help us in understanding the pathophysiology of this and other stress-associated psychiatric disorders. In this article we examine some of the changes to the diagnostic criteria of PTSD in the context of trauma-related neurobiological dysfunction, and discuss implications for how preclinical data can be useful in current and future clinical conceptualizations of trauma and trauma-related psychiatric disorders.

Dexmedetomidine alleviates anxiety-like behaviors and cognitive impairments in a rat model of post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is a psychiatric disease that has substantial health implications, including high rates of health morbidity and mortality, as well as increased health-related costs. Although many pharmacological agents have proven the effects on the development of PTSD, current pharmacotherapies typically only produce partial improvement of PTSD symptoms. Dexmedetomidine is a selective, short-acting α2-adrenoceptor agonist, which has anxiolytic, sedative, and analgesic effects. We therefore hypothesized that dexmedetomidine possesses the ability to prevent the development of PTSD and alleviate its symptoms. By using the rat model of PTSD induced by five electric foot shocks followed by three weekly exposures to situational reminders, we showed that the stressed rats displayed pronounced anxiety-like behaviors and cognitive impairments compared to the controls. Notably, repeated administration of 20μg/kg dexmedetomidine showed impaired fear conditioning memory, decreased anxiety-like behaviors, and improved spatial cognitive impairments compared to the vehicle-treated stressed rats. These data suggest that dexmedetomidine may exert preventive and protective effects against anxiety-like behaviors and cognitive impairments in the rats with PTSD after repeated administration.

Pharmacotherapy in the aftermath of trauma; opportunities in the 'golden hours'

Several lines of research have demonstrated that memories for fearful events become transiently labile upon re-exposure. Activation of molecular mechanisms is required in order to maintain retrieved information. This process is called reconsolidation. Targeting reconsolidation - as in exposure-based psychotherapy - offers therefore a potentially interesting tool to manipulate fear memories, and subsequently to treat disorders such as post-traumatic stress disorder (PTSD). In this paper we discuss the evidence for reconsolidation in rodents and humans and highlight recent studies in which clinical research on normal and abnormal fear extinction reduction of the expression of fear was obtained by targeting the process of reconsolidation. We conclude that reconsolidation presents an interesting opportunity to modify or alter fear and fear-related memories. More clinical research on normal and abnormal fear extinction is required.

Pharmacotherapy for post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is a serious mental illness of considerable importance from a public health perspective. Management of PTSD may involve the use of various treatment modalities, involving both nondrug treatments and pharmacotherapy. Nondrug treatment is regarded as the first-line option for PTSD and should be routinely incorporated into management plans for patients with PTSD. However, some patients do not achieve a sufficient response to nondrug therapy or are left with disabling residual symptoms in one or more areas. Antidepressants are currently the preferred medication for PTSD, with the most substantial evidence available to support the use of the selective serotonin reuptake inhibitors. Many patients with PTSD have symptoms that are resistant to initial drug treatment, meaning that it is often necessary to explore additional pharmacotherapy options to achieve optimal symptom control: antipsychotics, anti-adrenergic drugs, anxiolytics and anticonvulsants have all been advocated as treatments for PTSD. In addition to the management of core PTSD symptoms, it is also necessary for clinicians to address important associated comorbidities, most notably, substance-use disorders and mood disturbances. Interpretation of research studies of the efficacy and safety of PTSD pharmacotherapy is often difficult owing to methodological limitations and factors such as inclusion bias. Further research in fundamental neurosciences and pharmacogenomics may help to elucidate optimal pharmacotherapy options for PTSD in the future.

Psychiatric symptoms of noradrenergic dysfunction: a pathophysiological view

What psychiatric symptoms are caused by central noradrenergic dysfunction? The hypothesis considered in this review is that noradrenergic dysfunction causes the abnormalities in arousal level observed in functional psychoses. In this review, the psychiatric symptoms of noradrenergic dysfunction were inferred pathophysiologically from the neuroscience literature. This inference was examined based on the literature on the biology of psychiatric disorders and psychotropics. Additionally, hypotheses were generated as to the cause of the noradrenergic dysfunction. The central noradrenaline system, like the peripheral system, mediates the alarm reaction during stress. Overactivity of the system increases the arousal level and amplifies the emotional reaction to stress, which could manifest as a cluster of symptoms, such as insomnia, anxiety, irritability, emotional instability and exaggerated fear or aggressiveness (hyperarousal symptoms). Underactivity of the system lowers the arousal level and attenuates the alarm reaction, which could result in hypersomnia and insensitivity to stress (hypoarousal symptoms). Clinical data support the hypothesis that, in functional psychoses, the noradrenergic dysfunction is in fact associated with the arousal symptoms described above. The anti-noradrenergic action of anxiolytics and antipsychotics can explain their sedative effects on the hyperarousal symptoms of these disorders. The results of animal experiments suggest that excessive stress can be a cause of long-term noradrenergic dysfunction.

Animal models in translational studies of PTSD

Understanding the neurobiological mechanisms of post-traumatic stress disorder (PTSD) is of vital importance for developing biomarkers and more effective pharmacotherapy for this disorder. The design of bidirectional translational studies addressing all facets of PTSD is needed. Animal models of PTSD are needed not only to capture the complexity of PTSD behavioral characteristics, but also to address experimentally the influence of variety of factors which might determine an individual's vulnerability or resilience to trauma, e.g., genetic predisposition, early-life experience and social support. The current review covers recent translational approaches to bridge the gap between human and animal PTSD research and to create a framework for discovery of biomarkers and novel therapeutics.

Differential effectiveness of tianeptine, clonidine and amitriptyline in blocking traumatic memory expression, anxiety and hypertension in an animal model of PTSD

Individuals exposed to life-threatening trauma are at risk for developing post-traumatic stress disorder (PTSD), a debilitating condition that involves persistent anxiety, intrusive memories and several physiological disturbances. Current pharmacotherapies for PTSD manage only a subset of these symptoms and typically have adverse side effects which limit their overall effectiveness. We evaluated the effectiveness of three different pharmacological agents to ameliorate a broad range of PTSD-like symptoms in our established predator-based animal model of PTSD. Adult male Sprague-Dawley rats were given 1-h cat exposures on two occasions that were separated by 10 days, in conjunction with chronic social instability. Beginning 24 h after the first cat exposure, rats received daily injections of amitriptyline, clonidine, tianeptine or vehicle. Three weeks after the second cat exposure, all rats underwent a battery of behavioral and physiological tests. The vehicle-treated, psychosocially stressed rats demonstrated a robust fear memory for the two cat exposures, as well as increased anxiety expressed on the elevated plus maze, an exaggerated startle response, elevated heart rate and blood pressure, reduced growth rate and increased adrenal gland weight, relative to the vehicle-treated, non-stressed (control) rats. Neither amitriptyline nor clonidine was effective at blocking the entire cluster of stress-induced sequelae, and each agent produced adverse side effects in control subjects. Only the antidepressant tianeptine completely blocked the effects of psychosocial stress on all of the physiological and behavioral measures that were examined. These findings illustrate the differential effectiveness of these three treatments to block components of PTSD-like symptoms in rats, and in particular, reveal the profile of tianeptine as the most effective of all three agents.

Central hyperadrenergic state after lightning strike

OBJECTIVE

To describe and review autonomic complications of lightning strike.

METHODS

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

RESULTS

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

INTERPRETATION

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

Diminished vagal activity and blunted diurnal variation of heart rate dynamics in posttraumatic stress disorder

Affected autonomic heart regulation is implicated in the pathophysiology of cardiovascular diseases and is associated with posttraumatic stress disorder (PTSD). However, although sympathetic hyperactivation has been repeatedly shown in PTSD, research has neglected parasympathetic function. The objective of this study is the long-term assessment of heart rate (HR) dynamics and its diurnal changes as an index of autonomic imbalance in PTSD. Since tonic parasympathetic activity underlies long-range correlation of heartbeat interval fluctuations in the healthy state, we included nonlinear (unifractal) analysis as an important and sensitive readout to assess functional alterations. We conducted electrocardiogram recordings over a 24-h period in 15 deployed male subjects with moderate to high levels of combat exposure (PTSD: n = 7; combat controls: n = 8) in the supine position. HR dynamics were assessed in two 5-h sub-epochs in the time and frequency domains, and by nonlinear analysis based on detrended fluctuation analysis. Psychiatric symptoms were assessed using structured interviews, including the Clinician Administered PTSD Scale. Subjects with PTSD showed significantly higher baseline HR, higher LF/HF ratio in the frequency domain, blunted differences between day and night-time measures, as well as a higher scaling coefficient αfast during the day, indicating diminished tonic parasympathetic activity. Diminished diurnal differences and blunted tonic parasympathetic activity altering HR dynamics suggest central neuroautonomic dysregulation that could represent a possible link to increased cardiovascular disease in PTSD.

Current status on behavioral and biological markers of PTSD: a search for clarity in a conflicting literature

Extensive research has identified stereotypic behavioral and biological abnormalities in post-traumatic stress disorder (PTSD), such as heightened autonomic activity, an exaggerated startle response, reduced basal cortisol levels and cognitive impairments. We have reviewed primary research in this area, noting that factors involved in the susceptibility and expression of PTSD symptoms are more complex and heterogeneous than is commonly stated, with extensive findings which are inconsistent with the stereotypic behavioral and biological profile of the PTSD patient. A thorough assessment of the literature indicates that interactions among myriad susceptibility factors, including social support, early life stress, sex, age, peri- and post-traumatic dissociation, cognitive appraisal of trauma, neuroendocrine abnormalities and gene polymorphisms, in conjunction with the inconsistent expression of the disorder across studies, confounds attempts to characterize PTSD as a monolithic disorder. Overall, our assessment of the literature addresses the great challenge in developing a behavioral and biomarker-based diagnosis of PTSD.

Prazosin treatment of nightmares related to post-traumatic stress disorder

This case demonstrates the efficacy of prazosin in treating civilian post traumatic stress disorder (PTSD)-related nightmares. Although its mechanism is not fully elucidated, it is clear that prazosin decreases nightmares. Tolerability may limit one's ability to titrate to an effective dose.

Preclinical evaluation of reconsolidation blockade by clonidine as a potential novel treatment for posttraumatic stress disorder

Exposure to traumatic events can lead to posttraumatic stress disorder (PTSD). Current PTSD treatments typically only produce partial improvement. Hence, there is a need for preclinical research to identify new candidate drugs and to develop novel therapeutic approaches. Animal studies have indicated that fear memories can be weakened by blocking restabilization after retrieval, a process known as reconsolidation. Furthermore, evidence suggests that there are important alterations of the noradrenergic system in PTSD, and hence it may be of interest to study drugs that target this pathway. Here, we investigated the efficacy of clonidine, an α₂-adrenoreceptor agonist, to block reconsolidation in an animal model of persistent traumatic memories. Using an auditory fear conditioning paradigm in rats, we tested the efficacy of clonidine to weaken fear memory retention when administered systemically after retrieval. We evaluated dosage, number of treatments, and specificity in reconsolidation blockade. We found that postretrieval administration of clonidine disrupts fear-related memories in a dose-dependent manner and that two treatments are sufficient for maximal memory impairment. Furthermore, we determined that this effect is long lasting and specific to reconsolidation processes as shown by the selectivity to affect reactivated memories and the absence of spontaneous recovery and of postreactivation short-term memory impairment. Our results demonstrate the efficacy of systemic administration of clonidine following retrieval to persistently disrupt fear memory retention through reconsolidation blockade. This study provides important preclinical parameters for future therapeutic strategies involving clonidine to block reconsolidation as a novel treatment for PTSD symptoms.