Daytime prazosin reduces psychological distress to trauma specific cues in civilian trauma posttraumatic stress disorder

Psychotherapeutic and pharmacological agents for post-traumatic stress disorder with sleep disorder: network meta-analysis

OBJECTIVE

The current guidelines and canonical norms of diagnosis or treatment for Post-traumatic stress disorder (PTSD) with sleep disorder are still conflicting and have not yet reached a consensus. This study aimed to unravel the most effective countermeasures between two categories (psychotherapy and pharmacotherapy) put forward by the National Institute for Health and Clinical Excellence (NICE) and World Federation of Societies of Biological Psychiatry (WFSBP) respectively to treat PTSD individuals co-exist with sleep disorders.

METHODS

Four databases, including PubMed, EMBASE, Cochrane Library, and APA PsyNet, were searched from inception to February 02, 2023.

RESULTS

Twenty articles with 24 Randomized controlled trials (RCTs) and a total number of 1,647 participants were included. As demonstrated in the network meta-analysis comparison results, CBT-I (standardized mean differences (SMD) = -1.51,95% confidence interval (CI):-2.55 to -0.47), CBT-I plus IRT (SMD = -1.71, 95%CI:-3.39, -0.03), prazosin (SMD = -0.87,95%CI:-1.59 to -0.16) and hydroxyzine (SMD = -1.06, 95%CI: -1.94 to -0.19) significantly reduced PTSD symptoms compared with placebo. In contrast to placebo, CBT-I (SMD = -5.61,95%CI:-8.82 to -2.40) significantly improved sleep quality. For nightmare severity, IRT (SMD =-0.65, 95%CI:-1.00 to -0.31), prazosin (SMD = -1.20,95%CI:-1.72 to -0.67) and hydroxyzine (SMD = -0.98,95%CI:-1.58 to -0.37) significantly reduced nightmare severity in comparison with placebo.

CONCLUSIONS

This study suggested that under most circumstances, psychotherapy namely CBT-I had a favorable profile, but pharmacotherapy with prazosin was effective in managing nightmare severity. The sole avail of CBT-I was recommended to improving sleep quality while CBT-I and CBT-I plus IRT showed excellent management of PTSD symptom severity. Exposure to CBT-I isrecommended for depression. The relevant clinical guidelines for the management of individuals with PTSD and sleep disorders may regard this as a reference.

PROSPERO

CRD42023415240.

Stress and Inflammation Target Dorsolateral Prefrontal Cortex Function: Neural Mechanisms Underlying Weakened Cognitive Control

Most mental disorders involve dysfunction of the dorsolateral prefrontal cortex (dlPFC), a recently evolved brain region that subserves working memory, abstraction, and the thoughtful regulation of attention, action, and emotion. For example, schizophrenia, depression, long COVID, and Alzheimer's disease are all associated with dlPFC dysfunction, with neuropathology often being focused in layer III. The dlPFC has extensive top-down projections, e.g., to the posterior association cortices to regulate attention and to the subgenual cingulate cortex via the rostral and medial PFC to regulate emotional responses. However, the dlPFC is particularly dependent on arousal state and is very vulnerable to stress and inflammation, which are etiological and/or exacerbating factors for most mental disorders. The cellular mechanisms by which stress and inflammation impact the dlPFC are a topic of current research and are summarized in this review. For example, the layer III dlPFC circuits that generate working memory-related neuronal firing have unusual neurotransmission, depending on NMDA receptor and nicotinic α7 receptor actions that are blocked under inflammatory conditions by kynurenic acid. These circuits also have unusual neuromodulation, with the molecular machinery to magnify calcium signaling in spines needed to support persistent firing, which must be tightly regulated to prevent toxic calcium actions. Stress rapidly weakens layer III connectivity by driving feedforward calcium-cAMP (cyclic adenosine monophosphate) opening of potassium channels on spines. This is regulated by postsynaptic noradrenergic α2A adrenergic receptor and mGluR3 (metabotropic glutamate receptor 3) signaling but dysregulated by inflammation and/or chronic stress exposure, which contribute to spine loss. Treatments that strengthen the dlPFC via pharmacological (the α2A adrenergic receptor agonist, guanfacine) or repetitive transcranial magnetic stimulation manipulation provide a rational basis for therapy.

Therapeutic Effects of Tamsulosin in Nightmare Disorder: A Randomized, Double Blind, Placebo-Controlled, Cross-Over, Pilot Study

Nightmare disorder is associated with functional impairment, distress, and low quality of life; however, studies on pharmacotherapy of this debilitating disorder yielded mixed results. Prazosin, a non-selective α1 blocker is reported to be effective in treatment of post-traumatic stress disorder-related nightmares. We aimed at investigating therapeutic effects of tamsulosin which has higher affinity for blocking α1A and α1D adrenoceptors in treatment of nightmare disorder. A randomized, double blind, cross-over, placebo-controlled pilot study was conducted. Patients were randomly assigned to receive Tamsulosin 0.4 mg once daily or placebo for period of four weeks. Following a 2-week wash-out period, they were crossed over to the other group and received drug or placebo for duration of 4 additional weeks. Nightmare frequency and intensity measurements were carried out using Disturbing Dreams and Nightmares Severity Index (DDNSI). Blood pressure measurements were also performed. According to per protocol analysis, mean DDNSI scores decreased following administration of tamsulosin and a statistical trend towards significance was reported (p=0.065, d=0.236). Results of intention to treat analysis showed significant difference in DDNSI scores after drug use (p=0.030, d=0.651). Additionally, DDNSI scores dropped significantly following placebo use. However, intention to treat analysis showed no statistically significant difference pre and post placebo period (0.064, d=0.040). Tamsulosin may be effective in treatment of nightmare disorder. However, further larger clinical trials are recommended to clarify the effectiveness of tamsulosin and α1 subtypes in pharmacotherapy of nightmares.

A Pilot Study on the Effectiveness of Prazosin as a Treatment of Post-Traumatic Stress Disorder-Related Nightmares in Women with Bulimia Nervosa

Objectives Post-traumatic stress disorder (PTSD) symptoms are reported in over 36% of individuals with bulimia nervosa. To date, none of the clinical trials have examined nightmare reduction in this population. We evaluated the effectiveness of prazosin in bulimic females experiencing PTSD-related nightmares. We hypothesized that prazosin will decrease nightmares, normalize cortisol levels and secretory patterns, and improve sleep. Methods Our seven-week prospective, randomized, double-blind, placebo-controlled crossover pilot trial recruited eight adult women. Each participant received three weeks of prazosin and a placebo, separated by a one-week washout period. The order of treatment was counterbalanced across participants. Self-reports, clinician-administered scales, and salivary cortisol was collected to measure outcomes. Results A significant treatment effect was seen in nightmare intensity on the Clinician-Administered PTSD Scale (CAPS-I) (p=0.026) and a marginally significant effect on nightmare frequency (p=0.069). The only significant main effect of treatment on self-reported sleep parameters was on nightmares. Cortisol secretory patterns did not change, but on average, study participants had significantly higher cortisol levels compared to normative values. ANOVA showed a significant main effect of time for cortisol (F(4, 28) = 6.15, p=.001) but no within or between groups significant effects (ps>.179). Follow-up tests showed the effect of time was linear (F(1, 7) = 10.77, p=.013). Conclusion Prazosin significantly reduced intensity and marginally reduced the frequency of PTSD-related nightmares in bulimia nervosa but did not affect subjective sleep efficiency, quality, cortisol levels, or diurnal cortisol secretory pattern. Larger trials using objective sleep measures are warranted to replicate these findings.

Pharmacological strategies for post-traumatic stress disorder (PTSD): From animal to clinical studies

Post-traumatic stress disorder (PTSD) is a disabling psychiatric condition with a critical familiar, personal, and social impact. Patients diagnosed with PTSD show various symptoms, including anxiety, depression, psychotic episodes, and sleep disturbances, complicating their therapeutic management. Only sertraline and paroxetine, two selective serotonin reuptake inhibitors, are approved by different international agencies to treat PTSD. In addition, these drugs are generally combined with psychotherapy to achieve positive results. However, these pharmacological strategies present limited efficacy. Nearly half of the PTSD patients do not experience remission of symptoms, possibly due to the high prevalence of psychiatric comorbidities. Therefore, in clinical practice, other off-label medications are common, even though the effectiveness of these drugs needs to be further investigated. In this line, antipsychotics, antiepileptics, adrenergic blockers, benzodiazepines, and other emerging pharmacological agents have aroused interest as potential therapeutic tools to improve some specific symptoms of PTSD. Thus, this review is focused on the most widely used drugs for the pharmacological treatment of PTSD with a translational approach, including clinical and preclinical studies, to emphasize the need to develop safer and more effective medications.

Twice Daily Prazosin and Valproic Acid in the Treatment of Flashbacks in PTSD

Posttraumatic stress disorder (PTSD) is a debilitating stress disorder occurring in the context of a traumatic event and is characterized by intrusive and avoidance symptoms, negative alterations in cognition and mood, and arousal and reactivity changes. Despite its representation throughout literature, the pathophysiology of PTSD remains incompletely understood, thus contributing to broad, variable, and at times, experimental treatment options. The authors present the first documented case of the rapid and successful management of PTSD using valproic acid and twice daily dosing of prazosin aimed at targeting symptoms of hyperarousal and both daily and nightly intrusive symptoms of flashbacks and nightmares, respectively. The authors also discuss postulations of the underlying mechanisms of action responsible for such symptom alleviation. Further investigation is needed to expand upon our knowledge of the use of such agents in the treatment of PTSD to improve upon existing clinical guidelines, especially in the acute setting, thus providing better overall prognosis.

Autonomic dysfunction and cardiovascular risk in post-traumatic stress disorder

BACKGROUND

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

LITERATURE SEARCH STRATEGY

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

RESULTS

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

CONCLUSIONS

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

Electroacupuncture Attenuates Anxiety-Like Behaviors in a Rat Model of Post-traumatic Stress Disorder: The Role of the Ventromedial Prefrontal Cortex

Electroacupuncture (EA) is a promising clinical approach to treating posttraumatic stress disorder (PTSD), yet the mechanisms whereby EA can alleviate anxiety and other PTSD symptoms have yet to be clarified. In the present report, rats underwent EA for 14 consecutive days following modified single prolonged stress (MSPS) exposure. These animals were then evaluated in open field and elevated plus maze tests (OFT and EPM), while Fos immunohistochemical staining was performed to assess ventromedial prefrontal cortex (vmPFC) functional activation. In addition, an extracellular recording and stimulation system was used to analyze vmPFC inputs into the ventral tegmental area (VTA) in these rats. Temporary vmPFC inactivation was further performed to assess whether this was sufficient to reverse the anxiolytic effects of EA. Overall, rats that underwent EA treatment spent more time in the central region (OFT) and the open arm (EPM) relative to MSPS model animals (P < 0.05). These MSPS model animals also exhibited significantly fewer activated Fos-positive nuclei in the vmPFC following behavioral testing, while EA was associated with a significant relative increase in c-Fos expression in this region. The transient inactivation of the vmPFC was sufficient to reverse the effects of EA treatment on anxiety-like behaviors in MSPS model rats. MSPS and SEA rats exhibiting no differences in bursting activity between baseline and vmPFC stimulation, whereas bursting activity rose relative to baseline upon ventral mPFC stimulation in EA treated and control rats. Together, these findings indicate that the vmPFC and its inputs into the VTA are functionally linked to the anxiolytic activity of EA, implicating this pathway in the EA-mediated treatment of PTSD.

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.

A mechanistic model for individualised treatment of anxiety disorders based on predictive neural biomarkers

Increased amygdala responsiveness is the hallmark of fear and a characteristic across patients with anxiety disorders. The amygdala is embedded in a complex regulatory circuit. Multiple different mechanisms may elevate amygdala responsiveness and lead to the occurrence of an anxiety disorder. While top-down control by the prefrontal cortex (PFC) downregulates amygdala responses, the locus coeruleus (LC) drives up amygdala activation via noradrenergic projections. This indicates that the same fearful phenotype may result from different neural mechanisms. We propose a mechanistic model that defines three different neural biomarkers causing amygdala hyper-responsiveness in patients with anxiety disorders: (a) inherent amygdala hypersensitivity, (b) low prefrontal control and (c) high LC drive. First-line treatment for anxiety disorders is exposure-based cognitive behavioural therapy, which strengthens PFC recruitment during emotion regulation and thus targets low-prefrontal control. A treatment response rate around 50% (Loerinc et al., 2015, Clinical Psychological Reviews, 42, 72-82) might indicate heterogeneity of underlying neurobiological mechanisms among patients, presumably leading to high variation in treatment benefit. Transforming insights from cognitive neuroscience into applicable clinical heuristics to categorise patients based on their underlying biomarker may support individualised treatment selection in psychiatry. We review literature on the three anxiety-related mechanisms and present a mechanistic model that may serve as a rational for pathology-based diagnostic and biomarker-guided treatment selection in psychiatry.

Post-traumatic stress disorder: a state-of-the-art review of evidence and challenges

Post-traumatic stress disorder (PTSD) is arguably the most common psychiatric disorder to arise after exposure to a traumatic event. Since its formal introduction in the DSM-III in 1980, knowledge has grown significantly regarding its causes, maintaining mechanisms and treatments. Despite this increased understanding, however, the actual definition of the disorder remains controversial. The DSM-5 and ICD-11 define the disorder differently, reflecting disagreements in the field about whether the construct of PTSD should encompass a broad array of psychological manifestations that arise after trauma or should be focused more specifically on trauma memory phenomena. This controversy over clarifying the phenotype of PTSD has limited the capacity to identify biomarkers and specific mechanisms of traumatic stress. This review provides an up-to-date outline of the current definitions of PTSD, its known prevalence and risk factors, the main models to explain the disorder, and evidence-supported treatments. A major conclusion is that, although trauma-focused cognitive behavior therapy is the best-validated treatment for PTSD, it has stagnated over recent decades, and only two-thirds of PTSD patients respond adequately to this intervention. Moreover, most people with PTSD do not access evidence-based treatment, and this situation is much worse in low- and middle-income countries. Identifying processes that can overcome these major barriers to better management of people with PTSD remains an outstanding challenge.

Temporal effect of electroacupuncture on anxiety-like behaviors and c-Fos expression in the anterior cingulate cortex in a rat model of post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is a psychiatric disease which leads to a series of anxiety-like behaviors. In this study, we investigated the temporal effects of electroacupuncture (EA) at acupoint ST36 on anxiety-like behaviors and the expression of c-Fos in the anterior cingulate cortex (ACC) in a rat model of PTSD. PTSD was induced by a single prolonged stress procedure comprising three stages: restraint for 2 h, forced swim for 20 min, and pentobarbital sodium anesthesia. EA at acupoint ST36 was performed from 7:00-9:00 once a day for 7 consecutive days. Open field test (OFT) and elevated plus maze (EPM) test were used to assess the success of the model and evaluate anxiety-like behaviors. Immunohistochemistry was used to detect Fos-positive nuclei in the ACC. We observed that EA performed from 7:00-9:00 was associated with significantly more time spent in the center area during the OFT and in the open arm during the EPM, as well as lower corticosterone response compared with that of regular EA (P < 0.05). PTSD rats expressed significantly less c-Fos in the ACC. Timed EA significantly increased c-Fos expression in the ACC. The effect of timed EA acting on PTSD rats was linked to altered neuronal activation in the ACC. Compared to regular EA, timed EA exhibited superior therapeutic effects by attenuating anxiety-like behaviors in PTSD rats. These results emphasize the association between temporal parameters of EA manipulation and acupuncture effects. Timed acupuncture therapy may be a novel therapeutic application in the treatment of PTSD.

Loss of Prefrontal Cortical Higher Cognition with Uncontrollable Stress: Molecular Mechanisms, Changes with Age, and Relevance to Treatment

The newly evolved prefrontal cortex (PFC) generates goals for "top-down" control of behavior, thought, and emotion. However, these circuits are especially vulnerable to uncontrollable stress, with powerful, intracellular mechanisms that rapidly take the PFC "off-line." High levels of norepinephrine and dopamine released during stress engage α1-AR and D1R, which activate feedforward calcium-cAMP signaling pathways that open nearby potassium channels to weaken connectivity and reduce PFC cell firing. Sustained weakening with chronic stress leads to atrophy of dendrites and spines. Understanding these signaling events helps to explain the increased susceptibility of the PFC to stress pathology during adolescence, when dopamine expression is increased in the PFC, and with advanced age, when the molecular "brakes" on stress signaling are diminished by loss of phosphodiesterases. These mechanisms have also led to pharmacological treatments for stress-related disorders, including guanfacine treatment of childhood trauma, and prazosin treatment of veterans and civilians with post-traumatic stress disorder.

Bedtime doses of prazosin do not affect daytime salivary amylase markers in PTSD

Overactivity of the noradrenergic (NE) system within the central nervous system (CNS) has been postulated as a key pathophysiology of posttraumatic stress disorder (PTSD). The activity of the enzyme salivary α-amylase (sAA) has been proposed as an indirect measure of CNS NE activity, and sAA is elevated in PTSD. As an antagonist of the α-1 NE receptor, prazosin would be expected to alter sAA values in PTSD patients. However, given its short half-life, it is not clear whether bedtime doses would have an effect on daytime sAA. In the present study, we assayed daytime sAA in 20 suicidal PTSD patients who were randomized to prazosin versus placebo at bedtime-only, and found no effect in daytime sAA. These findings are consistent with studies showing an advantage for twice daily dosing of prazosin in PTSD.

Noradrenergic α1-Adrenoceptor Actions in the Primate Dorsolateral Prefrontal Cortex

Noradrenergic (NE) α1-adrenoceptors (α1-ARs) contribute to arousal mechanisms and play an important role in therapeutic medications such as those for the treatment of posttraumatic stress disorder (PTSD). However, little is known about how α1-AR stimulation influences neuronal firing in the dorsolateral prefrontal cortex (dlPFC), a newly evolved region that is dysfunctional in PTSD and other mental illnesses. The current study examined the effects of α1-AR manipulation on neuronal firing in dlPFC of rhesus monkeys performing a visuospatial working memory task, focusing on the "delay cells" that maintain spatially tuned information across the delay period. Iontophoresis of the α1-AR antagonist HEAT (2-{[β-(4-hydroxyphenyl)ethyl]aminomethyl}-1-tetralone) had mixed effects, reducing firing in a majority of neurons but having nonsignificant excitatory effects or no effect in remaining delay cells. These data suggest that endogenous NE has excitatory effects in some delay cells under basal conditions. In contrast, the α1-AR agonists phenylephrine and cirazoline suppressed delay cell firing and this was blocked by coadministration of HEAT. These results indicate an inverted-U dose response for α1-AR actions, with mixed excitatory actions under basal conditions and suppressed firing with high levels of α1-AR stimulation such as with stress exposure. Immunoelectron microscopy revealed α1-AR expression presynaptically in axons and axon terminals and postsynaptically in spines, dendrites, and astrocytes. It is possible that α1-AR excitatory effects arise from presynaptic excitation of glutamate release, whereas postsynaptic actions suppress firing through calcium-protein kinase C opening of potassium channels on spines. The latter may predominate under stressful conditions, leading to loss of dlPFC regulation during uncontrollable stress.SIGNIFICANCE STATEMENT Noradrenergic stimulation of α1-adrenoceptors (α1-ARs) is implicated in posttraumatic stress disorder (PTSD) and other mental disorders that involve dysfunction of the prefrontal cortex, a brain region that provides top-down control. However, the location and contribution of α1-ARs to prefrontal cortical physiology in primates has received little attention. This study found that α1-ARs are located near prefrontal synapses and that α1-AR stimulation has mixed effects under basal conditions. However, high levels of α1-AR stimulation, as occur with stress, suppress neuronal firing. These findings help to explain why we lose top-down control under conditions of uncontrollable stress when there are high levels of noradrenergic release in brain and why blocking α1-AR, such as with prazosin, may be helpful in the treatment of PTSD.

Post-traumatic stress disorder: new directions in pharmacotherapy

As many as 10% of the population experience post-traumatic stress disorder (PTSD) at some time in their lives. It often runs a severe, chronic and treatment-resistant course. This article reviews the evidence base for typically recommended treatments such as cognitive-behavioural therapy (CBT), eye movement desensitisation and reprocessing and selective serotonin reuptake inhibitors (SSRIs). It tabulates the major randomised controlled trials of SSRIs and trauma-focused CBT and reviews research on novel treatments such as ketamine, MDMA, quetiapine, propranolol and prazosin.

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.

Alpha1-adrenergic receptor blockade in the VTA modulates fear memories and stress responses

Activity of the ventral tegmental area (VTA) and its terminals has been implicated in the Pavlovian associative learning of both stressful and rewarding stimuli. However, the role of the VTA noradrenergic signaling in fear responses remains unclear. We aimed to examine how alpha₁-adrenergic receptor (α₁-AR) signaling in the VTA affects conditioned fear. The role of α₁-AR was assessed using the micro-infusions into the VTA of the selective antagonists (0.1-1µg/0.5µl prazosin and 1µg/0.5µl terazosin) in acquisition and expression of fear memory. In addition, we performed control experiments with α₁-AR blockade in the mammillary bodies (MB) - a brain region with α₁-AR expression adjacent to the VTA. Intra-VTA but not intra-MB α₁-AR blockade prevented formation and retrieval of fear memories. Importantly, local administration of α₁-AR antagonists did not influence footshock sensitivity, locomotion or anxiety-like behaviors. Similarly, α₁-AR blockade in the VTA had no effects on negative affect measured as number of 22kHz ultrasonic vocalizations during fear conditioning training. We propose that noradrenergic signaling in the VTA via α₁-AR regulates formation and retrieval of fear memories but not other behavioral responses to stressful environmental stimuli. It enhances the encoding of environmental stimuli by the VTA to form and retrieve conditioned fear memories and to predict future behavioral outcomes. Our results provide novel insight into the role of the VTA α₁-AR signaling in the regulation of stress responsiveness and fear memory.

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

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

Posttraumatic Stress Disorder: an integrated overview and neurobiological rationale for pharmacology

Thirty years of research on the biology of posttraumatic stress disorder now provides a foundation for hypotheses related to the mechanisms underlying the pharmacotherapy of this disorder. Only two medications, sertraline and paroxetine, are approved by the U.S. Food and Drug Administration for the treatment of PTSD. While these medications are somewhat effective, other treatment mechanisms must be explored to address the unmet need for effective treatment. This article provides a concise summary of advances in our understanding of the neurobiology of PTSD that suggest novel approaches to pharmacotherapy.

Treatment of Post-Traumatic Stress Disorders with the Alpha-1 Adrenergic Antagonist Prazosin

OBJECTIVE

The present review aims to assess the clinical efficacy and safety of the α-1-adrenergic antagonist prazosin as primary pharmacologic treatment for post-traumatic stress disorder (PTSD).

METHOD

A systematic review was performed using keywords (i.e., prazosin, α-1-adrenergic antagonist, α-1-blocker, post-traumatic stress disorder) in the databases PubMed/Medline (1966-May 2016), Embase (1966-May 2016), ScienceDirect (1823-May 2016), OvidSP (1946-May 2016) and Nature (1845-May 2016). To be considered for inclusion, studies had to test the efficacy of prazosin either alone or added to ongoing treatment in adults with PTSD, use validated tools to assess and monitor the disorders, allow comparisons on the basis of univariate analyses (i.e., p-values of t-tests and effect sizes) and list the identified adverse reactions.

RESULTS

12 studies were included: 5 randomized controlled trials, 4 open-label prospective trials and 3 retrospective file reviews. The evaluation concerned 276 patients exposed to civilian trauma (19%) or war trauma (81%). Prazosin significantly decreases trauma nightmares, avoidance, hypervigilance and improves patient status in all studies. No significant difference of blood pressure was observed at the end of trials.

CONCLUSIONS

Beyond the methodological and clinical biases of these studies, the present review not only confirms the effectiveness and good tolerability of prazosin, but also suggests its possible use as primary pharmacologic treatment for PTSD. Uncertainties remain, however, regarding the prescription modalities and dosages.

Symptom Presentation and Prescription of Sleep Medications for Veterans With Posttraumatic Stress Disorder

This study tested whether sleep medications prescribed to veterans diagnosed with posttraumatic stress disorder (PTSD) are being targeted to patients who report more severe insomnia or nightmares. Secondary analysis of survey and pharmacy data was conducted in samples of veterans from two periods: from 2006 to 2008 and from 2009 to 2013. Logistic regression tested associations between self-reported insomnia and nightmare severity, and being prescribed trazodone, prazosin, zolpidem, and benzodiazepines, controlling for PTSD severity and other covariates. In both samples, insomnia severity independently predicted trazodone receipt, and nightmare severity independently predicted prazosin receipt. In the later study, insomnia severity predicted receipt of zolpidem. Veterans in the later sample were more likely to receive trazodone, prazosin, and non-benzodiazepine hypnotics, and less likely to receive benzodiazepines than those in the earlier sample. Further research is needed to evaluate and optimize pharmacological and psychosocial treatments for sleep problems among veterans with PTSD.

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

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

Targeting Prefrontal Cortical Systems for Drug Development: Potential Therapies for Cognitive Disorders

Medications to treat cognitive disorders are increasingly needed, yet researchers have had few successes in this challenging arena. Cognitive abilities in primates arise from highly evolved N-methyl-d-aspartate (NMDA) receptor circuits in layer III of the dorsolateral prefrontal cortex. These circuits have unique modulatory needs that can differ from the layer V neurons that predominate in rodents, but they offer multiple therapeutic targets. Cognitive improvement often requires low doses that enhance the pattern of information held in working memory, whereas higher doses can produce nonspecific changes that obscure information. Identifying appropriate doses for clinical trials may be helped by assessments in monkeys and by flexible, individualized dose designs. The use of guanfacine (Intuniv) for prefrontal cortical disorders was based on research in monkeys, supporting this approach. Coupling our knowledge of higher primate circuits with the powerful methods now available in drug design will help create effective treatments for cognitive disorders.

Influence of the noradrenergic system on the formation of intrusive memories in women: an experimental approach with a trauma film paradigm

BACKGROUND

Intrusive memories of traumatic events are a core feature of post-traumatic stress disorder but little is known about the neurobiological formation of intrusions. The aim of this study was to determine whether the activity of the noradrenergic system during an intrusion-inducing stressor would influence subsequent intrusive memories.

METHOD

We conducted an experimental, double-blind, placebo-controlled study in 118 healthy women. Participants received a single dose of either 10 mg yohimbine, stimulating noradrenergic activity, or 0.15 mg clonidine, inhibiting noradrenergic activity, or placebo. Subsequently, they watched an established trauma film which induced intrusions. The number of consecutive intrusions resulting from the trauma film, the vividness of the intrusions, and the degree of distress evoked by the intrusions were assessed during the following 4 days. Salivary cortisol and α-amylase were collected before and after the trauma film.

RESULTS

A significant time × treatment interaction for the number of intrusions and the vividness of intrusions indicated a different time course of intrusions depending on treatment. Post-hoc tests revealed a delayed decrease of intrusions and a delayed decrease of intrusion vividness after the trauma film in the yohimbine group compared with the clonidine and placebo groups. Furthermore, after yohimbine administration, a significant increase in salivary cortisol levels was observed during the trauma film.

CONCLUSIONS

Our findings indicate that pharmacological activation of the noradrenergic system during an emotionally negative event makes an impact on consecutive intrusive memories and their vividness in healthy women. The noradrenergic system seems to be involved in the formation of intrusive memories.

Initiation of pharmacotherapy for post-traumatic stress disorder among veterans from Iraq and Afghanistan: a dimensional, symptom cluster approach

BACKGROUND

The pharmacological treatment of post-traumatic stress disorder (PTSD) is extremely challenging, as no specific agent has been developed exclusively to treat this disorder. Thus, there are growing concerns among the public, providers and consumers associated with its use as the efficacy of some agents is still in question.

AIMS

We applied a dimensional and symptom cluster-based approach to better understand how the heterogeneous phenotypic presentation of PTSD may relate to the initiation of pharmacotherapy for PTSD initial episode.

METHOD

US veterans who served in the conflicts in Iraq and Afghanistan and received an initial PTSD diagnosis at the US Veterans Health Administration between 2008 and 2011 were included in this study. Veterans were followed for 365 days from initial PTSD diagnosis to identify initiation for antidepressants, anxiolytics/sedatives/hypnotics, antipsychotics and prazosin. Multivariable analyses were used to assess the relationship between the severity of unique PTSD symptom clusters and receiving prescriptions from each medication class, as well as the time from diagnosis to first prescription.

RESULTS

Increased severity of emotional numbing symptoms was independently associated with the prescription of antidepressants, and they were prescribed after a substantially shorter period of time than other medications. Anxiolytics/sedatives/hypnotics prescription was associated with heightened re-experiencing symptoms and sleep difficulties. Antipsychotics were associated with elevated re-experiencing and numbing symptoms and prazosin with reported nightmares.

CONCLUSIONS

Prescribing practices for military-related PTSD appear to follow US VA/DoD clinical guidelines. Results of this study suggest that a novel dimensional and symptom cluster-based approach to classifying the phenotypic presentation of military-related PTSD symptoms may help inform prescribing patterns for PTSD.

DECLARATION OF INTEREST

None.

COPYRIGHT AND USAGE

© The Royal College of Psychiatrists 2016. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license.

Prazosin for Trauma Nightmares and Sleep Disturbances in Combat Veterans with Post-Traumatic Stress Disorder

Background

Prazosin is significantly effective to reduce sleep disturbance and trauma nightmare in patients with post-traumatic stress disorder (PTSD); however, results of different studies were evaluated.

Objectives

The current randomized clinical trial aimed to assess the effects of prazosin on sleep parameters and nightmares among veterans with chronic PTSD.

Materials and Methods

Thirty-two veterans with chronic war-induced PTSD and distressing nightmares were randomized into prazosin and placebo groups for eight weeks. The main symptoms were qualified using the recurrent distressing dreams item of the clinician administered PTSD scale (CAPS) and the daytime symptom severity was measured by PTSD checklist (PCL) and the objective sleep quality assessment by actigraphy.

Results

Compared with placebo, prazosin had no significant effects on reduction of daytime symptoms (P = 0.69) and frequency and intensity of trauma-related nightmares. Also, there were no significant differences between pre- and post-treatment actigraphy measurements (P > 0.05).

Conclusions

The study findings showed that prazosin had no significant effect on reduction of PTSD symptoms as well as nightmares among veterans with chronic PTSD. Further clinical trials are needed to define the effect of prazosin on sleep physiology and whether such effects regarding the therapeutic response.

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

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

Animal models for posttraumatic stress disorder: An overview of what is used in research

Posttraumatic stress disorder (PTSD) is a common anxiety disorder characterised by its persistence of symptoms after a traumatic experience. Although some patients can be cured, many do not benefit enough from the psychological therapies or medication strategies used. Many researchers use animal models to learn more about the disorder and several models are available. The most-used physical stressor models are single-prolonged stress, restraint stress, foot shock, stress-enhanced fear learning, and underwater trauma. Common social stressors are housing instability, social instability, early-life stress, and social defeat. Psychological models are not as diverse and rely on controlled exposure to the test animal’s natural predator. While validation of these models has been resolved with replicated symptoms using analogous stressors, translating new findings to human patients remains essential for their impact on the field. Choosing a model to experiment with can be challenging; this overview of what is possible with individual models may aid in making a decision.

Pharmacologic management of comorbid post-traumatic stress disorder and addictions

BACKGROUND AND OBJECTIVES

Post-traumatic Stress Disorder (PTSD) and substance use disorders (SUD) frequently co-occur, and their combination can increase poor health outcomes as well as mortality.

METHODS

Using PUBMED and the list of references from key publications, this review article covered the epidemiology, neurobiology and pharmacotherapy of PTSD with comorbid alcohol, opiate, and cannabis use disorders. These SUD represent two with and one without FDA approved pharmacotherapies.

RESULTS

SUD is two to three times more likely among individuals with lifetime PTSD, and suicide, which is made more likely by both of these disorders, appears to be additively increased by having this comorbidity of SUD and PTSD. The shared neurobiological features of these two illnesses include amygdalar hyperactivity with hippocampal, medial prefrontal and anterior cingulate cortex dysfunction. Medications for comorbid PTSD and SUD include the PTSD treatment sertraline, often used in combination with anticonvulsants, antipsychotics, and adrenergic blockers. When PTSD is comorbid with alcohol use disorder (AUD), naltrexone, acamprosate or disulfiram may be combined with PTSD treatments. Disulfiram alone may treat both PTSD and AUD. For PTSD combined with opiate use disorder methadone or buprenorphine are most commonly used with sertraline. Marijuana use has been considered by some to be a treatment for PTSD, but no FDA treatment for this addiction is approved. Pregabalin and D-cycloserine are two innovations in pharmacotherapy for PTSD and SUD.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

Comorbid PTSD and SUD amplifies their lethality and treatment complexity. Although they share important neurobiology, these patients uncommonly respond to a single pharmacotherapy such as sertraline or disulfiram and more typically require medication combinations and consideration of the specific type of SUD.

A review of the use of stellate ganglion block in the treatment of PTSD

Current treatments for PTSD are often not effective or acceptable to the patient. There are a number of emerging new treatments. One promising new one is stellate ganglion block, an anesthetic treatment for pain which relieves symptoms of severe and chronic PTSD in some patients. The focus of this chapter is to summarize clinical evidence available for the effectiveness of cervical sympathetic ganglion injection called stellate ganglion block (SGB), as well as demonstrate possible clinical applications of its use. Cervical sympathetic blockade involves injecting a local anesthetic next to a group of nerves (ganglion) in the neck. The technique has been used clinically since 1925 with very few side effects. Finally, the neurobiology of SGB is discussed. Challenges to the use of SGB include the lack of randomized clinical trials and practitioners familiar with the use of SGB for PTSD.

The Effects of Stress Exposure on Prefrontal Cortex: Translating Basic Research into Successful Treatments for Post-Traumatic Stress Disorder

Research on the neurobiology of the stress response in animals has led to successful new treatments for Post-Traumatic Stress Disorder (PTSD) in humans. Basic research has found that high levels of catecholamine release during stress rapidly impair the top-down cognitive functions of the prefrontal cortex (PFC), while strengthening the emotional and habitual responses of the amygdala and basal ganglia. Chronic stress exposure leads to dendritic atrophy in PFC, dendritic extension in the amygdala, and strengthening of the noradrenergic (NE) system. High levels of NE release during stress engage low affinity alpha-1 adrenoceptors, (and likely beta-1 adrenoceptors), which rapidly reduce the firing of PFC neurons, but strengthen amygdala function. In contrast, moderate levels of NE release during nonstress conditions engage higher affinity alpha-2A receptors, which strengthen PFC, weaken amygdala, and regulate NE cell firing. Thus, either alpha-1 receptor blockade or alpha-2A receptor stimulation can protect PFC function during stress. Patients with PTSD have signs of PFC dysfunction. Clinical studies have found that blocking alpha-1 receptors with prazosin, or stimulating alpha-2A receptors with guanfacine or clonidine can be useful in reducing the symptoms of PTSD. Placebo-controlled trials have shown that prazosin is helpful in veterans, active duty soldiers and civilians with PTSD, including improvement of PFC symptoms such as impaired concentration and impulse control. Open label studies suggest that guanfacine may be especially helpful in treating children and adolescents who have experienced trauma. Thus, understanding the neurobiology of the stress response has begun to help patients with stress disorders.

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Research in animals has revealed how prefrontal cortex goes “off-line” during stress.

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Prefrontal cortical function is protected by α2A-, but impaired by α1-adrenoceptors.

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Based on this research, α1 blockers and α2A agonists are now in use to treat PTSD.

Developing zebrafish models relevant to PTSD and other trauma- and stressor-related disorders

While post-traumatic stress disorder (PTSD) and other trauma- and stress-related disorders (TSRDs) represent a serious societal and public health concern, their pathogenesis is largely unknown. Given the clinical complexity of TSRD development and susceptibility, greater investigation into candidate biomarkers and specific genetic pathways implicated in both risk and resilience to trauma becomes critical. In line with this, numerous animal models have been extensively used to better understand the pathogenic mechanisms of PTSD and related TSRD. Here, we discuss the rapidly increasing potential of zebrafish as models of these disorders, and how their use may aid researchers in uncovering novel treatments and therapies in this field.

Hypotensive and antihypertensive potential of 4-[(1-phenyl-1H-pyrazol-4-yl) methyl]1-piperazine carboxylic acid ethyl ester: a piperazine derivative

AIMS

Clinical complaints on the first-line of cardiovascular medications make continuous search for new drugs a necessity. This study evaluated the cardiovascular effects and mechanism of 4-[(1-phenyl-1H-pyrazol-4-yl)methyl]1-piperazine carboxylic acid ethyl ester (LQFM008).

MAIN METHODS

Normotensive male Wistar or spontaneously hypertensive rats (anesthetized or conscious) were used to evaluate the effect of LQFM008 on the mean arterial pressure (MAP), heart rate (HR), arterial blood flow (ABF), arterial vascular conductance (AVC), baroreflex effectiveness index (BI), systolic blood pressure (SBP), diastolic blood pressure (DBP) and vascular function.

KEY FINDINGS

In anesthetized normotensive rats, LQFM008 (7.3, 14.3 or 28.6 μmol/kg, i.v.) reduced MAP (-21.1±2.7; -23.9±4.7 or -32.4±8.3 mmHg, respectively) and AVC (22%, 32% or 38%) in a dose-dependent manner. LQFM008 elicited a temporal reduction in the SBP and DBP without changes to the BI of conscious normotensive rats. In hypertensive rats, LQFM008 (7.3, 14.3 or 28.6 μmol/kg, i.v.) reduced MAP (-2.3±2.6; -29.3±2.7 or -38.4±2.8 mmHg, respectively) and increased HR (1.6±3.7; 15.4±4.9 or 25.5±6.2 bmp, respectively) in a dose-dependent manner. A week of oral administration of LQFM008 47.7 μmol/kg elicited a temporal reduction in SBP of hypertensive rats. Pretreatments with atropine, WAY-100635 or L-NAME blocked the effect of LQFM008. In addition, LQFM008-induced endothelium-dependent vascular relaxation was inhibited by L-NAME.

SIGNIFICANCE

Our findings showed hypotensive, antihypertensive and vasorelaxant effects of LQFM008 and suggest the participation of nitric oxide, 5-HT1A and muscarinic receptors.

Trauma exposure and sleep: using a rodent model to understand sleep function in PTSD

Post-traumatic stress disorder (PTSD) is characterized by intrusive memories of a traumatic event, avoidance behavior related to cues of the trauma, emotional numbing, and hyper-arousal. Sleep abnormalities and nightmares are core symptoms of this disorder. In this review, we propose a model which implicates abnormal activity in the locus coeruleus (LC), an important modifier of sleep-wake regulation, as the source of sleep abnormalities and memory abnormalities seen in PTSD. Abnormal LC activity may be playing a key role in symptom formation in PTSD via sleep dysregulation and suppression of hippocampal bidirectional plasticity.

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.

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

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

Molecular influences on working memory circuits in dorsolateral prefrontal cortex

The working memory circuits of the primate dorsolateral prefrontal cortex (dlPFC) are modulated in a unique manner, often opposite to the molecular mechanisms needed for long-term memory consolidation. Working memory, our "mental sketch pad" is an ephemeral process, whereby transient, mental representations form the foundation for abstract thought. The microcircuits that generate mental representations are found in deep layer III of the dlPFC, where pyramidal cells excite each other to keep information "in mind" through NMDA receptor synapses on spines. The catecholaminergic and cholinergic arousal systems have rapid and flexible influences on the strength of these connections, thus allowing coordination between arousal and cognitive states. These modulators can rapidly weaken connectivity, for example, as occurs during uncontrollable stress, via feedforward calcium-cAMP signaling opening potassium (K(+)) channels near synapses on spines. Lower levels of calcium-cAMP-K(+) channel signaling provide negative feedback within recurrent excitatory circuits, and help to gate inputs to shape the contents of working memory. There are also explicit mechanisms to inhibit calcium-cAMP signaling and strengthen connectivity, for example, postsynaptic α2A-adrenoceptors on spines. This work has led to the development of the α2A agonist, guanfacine, for the treatment of a variety of dlPFC disorders. In mental illness, there are a variety of genetic insults to the molecules that normally serve to inhibit calcium-cAMP signaling in spines, thus explaining why so many genetic insults can lead to the same phenotype of impaired dlPFC cognitive function. Thus, the molecular mechanisms that provide mental flexibility may also confer vulnerability when dysregulated in cognitive disorders.

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.

Prognostic and symptomatic aspects of rapid eye movement sleep in a mouse model of posttraumatic stress disorder

Not every individual develops Posttraumatic Stress Disorder (PTSD) after the exposure to a potentially traumatic event. Therefore, the identification of pre-existing risk factors and early diagnostic biomarkers is of high medical relevance. However, no objective biomarker has yet progressed into clinical practice. Sleep disturbances represent commonly reported complaints in PTSD patients. In particular, changes in rapid eye movement sleep (REMS) properties are frequently observed in PTSD patients. Here, we examined in a mouse model of PTSD whether (1) mice developed REMS alterations after trauma and (2) whether REMS architecture before and/or shortly after trauma predicted the development of PTSD-like symptoms. We monitored sleep-wake behavior via combined electroencephalogram/electromyogram recordings immediately before (24 h pre), immediately after (0-48 h post) and 2 months after exposure to an electric foot shock in male C57BL/6N mice (n = 15). PTSD-like symptoms, including hyperarousal, contextual, and generalized fear, were assessed 1 month post-trauma. Shocked mice showed early onset and sustained elevation of REMS compared to non-shocked controls. In addition, REMS architecture before trauma was correlated with the intensity of acoustic startle responses, but not contextual fear, 1 month after trauma. Our data suggest REMS as prognostic (pre-trauma) and symptomatic (post-trauma) marker of PTSD-like symptoms in mice. Translated to the situation in humans, REMS may constitute a viable, objective, and non-invasive biomarker in PTSD and other trauma-related psychiatric disorders, which could guide pharmacological interventions in humans at high risk.

Psychiatric disorders and sleep

There is growing experimental evidence that the relationship between psychiatric disorders and sleep is complex and includes bidirectional causation. This article provides the evidence that supports this point of view, reviewing data on sleep disturbances seen in patients with psychiatric disorders as well as data on the impact of sleep disturbances on psychiatric conditions. Although much has been learned about the psychiatric disorders-sleep relationship, additional research is needed to better understand the relationship. Such work promises to improve comprehension of these phenomena and lead to better treatment for the many patients with sleep disorders and psychiatric disorders.

Sympathetic system modulation to treat post-traumatic stress disorder (PTSD): a review of clinical evidence and neurobiology

A review of clinical evidence and neurobiology on the effects of modulation of sympathetic system modulation to treat post-traumatic stress disorder (PTSD) is being presented . The review provides an overview of currently available treatments followed by efficacy of orally effective sympathetic blocking agents. The main focus of the review is the application of stellate ganglion blocks (SGBs) or a local anesthetic blockade of the sympathetic ganglion in the neck.