No improvement of posttraumatic stress disorder symptoms with guanfacine treatment

Alpha-2 Agonists in Children and Adolescents With Post-traumatic Stress Disorder: A Systematic Review

Exposure to traumatic stress is common among children. Post-traumatic stress disorder (PTSD) is a debilitating chronic mental disorder that can develop following exposure to a traumatic event. Psychopharmacological research in pediatric PTSD is limited. There is some evidence supporting the use of alpha-2 (α2) agonists for symptoms associated with PTSD. This systematic review identified published studies evaluating the effectiveness of α2 agonists in treating PTSD symptoms in children and adolescents. We conducted an extensive literature search on PubMed, MEDLINE, EMBASE, Cochrane Collaboration, and PsycINFO databases for published articles that evaluated the use of α2 agonists (clonidine and guanfacine) for treating symptoms of PTSD in children and adolescents. The study protocol was registered in Prospero (ID: CRD42021273692) and followed the PRISMA guidelines. A total of 10 published articles about clonidine or guanfacine use in PTSD in children and adolescents were identified. Studies found clonidine effective in reducing PTSD symptoms; however, the effects were variable. Clonidine and guanfacine showed effectiveness in treating nightmares, hyperarousal, aggression, and sleep disturbances and reducing re-experiencing, avoidant, and hyperarousal symptom clusters. No randomized, double-blind, placebo-controlled trials were found during the literature search. α2 agonists' effectiveness in treating symptoms associated with PTSD in children and adolescents is preliminary. Future placebo-controlled trials are needed to assess the efficacy and safety of α2 agonists.

Pharmacotherapy for post traumatic stress disorder (PTSD)

BACKGROUND

Posttraumatic stress disorder (PTSD) is a prevalent and disabling disorder. Evidence that PTSD is characterised by specific psychobiological dysfunctions has contributed to a growing interest in the use of medication in its treatment.

OBJECTIVES

To assess the effects of medication for reducing PTSD symptoms in adults with PTSD.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; Issue 11, November 2020); MEDLINE (1946-), Embase (1974-), PsycINFO (1967-) and PTSDPubs (all available years) either directly or via the Cochrane Common Mental Disorders Controlled Trials Register (CCMDCTR). We also searched international trial registers. The date of the latest search was 13 November 2020.

SELECTION CRITERIA

All randomised controlled trials (RCTs) of pharmacotherapy for adults with PTSD.

DATA COLLECTION AND ANALYSIS

Three review authors (TW, JI, and NP) independently assessed RCTs for inclusion in the review, collated trial data, and assessed trial quality. We contacted investigators to obtain missing data. We stratified summary statistics by medication class, and by medication agent for all medications. We calculated dichotomous and continuous measures using a random-effects model, and assessed heterogeneity.

MAIN RESULTS

We include 66 RCTs in the review (range: 13 days to 28 weeks; 7442 participants; age range 18 to 85 years) and 54 in the meta-analysis.  For the primary outcome of treatment response, we found evidence of beneficial effect for selective serotonin reuptake inhibitors (SSRIs) compared with placebo (risk ratio (RR) 0.66, 95% confidence interval (CI) 0.59 to 0.74; 8 studies, 1078 participants), which improved PTSD symptoms in 58% of SSRI participants compared with 35% of placebo participants, based on moderate-certainty evidence.  For this outcome we also found evidence of beneficial effect for the noradrenergic and specific serotonergic antidepressant (NaSSA) mirtazapine: (RR 0.45, 95% CI 0.22 to 0.94; 1 study, 26 participants) in 65% of people on mirtazapine compared with 22% of placebo participants, and for the tricyclic antidepressant (TCA) amitriptyline (RR 0.60, 95% CI 0.38 to 0.96; 1 study, 40 participants) in 50% of amitriptyline participants compared with 17% of placebo participants, which improved PTSD symptoms. These outcomes are based on low-certainty evidence. There was however no evidence of beneficial effect for the number of participants who improved with the antipsychotics (RR 0.51, 95% CI 0.16 to 1.67; 2 studies, 43 participants) compared to placebo, based on very low-certainty evidence. For the outcome of treatment withdrawal, we found evidence of a harm for the individual SSRI agents compared with placebo (RR 1.41, 95% CI 1.07 to 1.87; 14 studies, 2399 participants). Withdrawals were also higher for the separate SSRI paroxetine group compared to the placebo group (RR 1.55, 95% CI 1.05 to 2.29; 5 studies, 1101 participants). Nonetheless, the absolute proportion of individuals dropping out from treatment due to adverse events in the SSRI groups was low (9%), based on moderate-certainty evidence. For the rest of the medications compared to placebo, we did not find evidence of harm for individuals dropping out from treatment due to adverse events.

AUTHORS' CONCLUSIONS

The findings of this review support the conclusion that SSRIs improve PTSD symptoms; they are first-line agents for the pharmacotherapy of PTSD, based on moderate-certainty evidence. The NaSSA mirtazapine and the TCA amitriptyline may also improve PTSD symptoms, but this is based on low-certainty evidence. In addition, we found no evidence of benefit for the number of participants who improved following treatment with the antipsychotic group compared to placebo, based on very low-certainty evidence. There remain important gaps in the evidence base, and a continued need for more effective agents in the management of PTSD.

Effectiveness, Acceptability and Safety of Pharmaceutical Management for Combat-Related PTSD in Adults Based on Systematic Review of Twenty-Two Randomized Controlled Trials

Objective: This study assessed the efficacy, acceptability, and safety of pharmaceutical management for combat-related post-traumatic stress disorder (PTSD) to provide a clinical decision-making basis for clinicians.

Method: A comprehensive search was conducted using Ovid MEDLINE, Ovid EMBASE, Cochrane Library, Scopus, ScienceDirect, and Web of Science for randomized controlled trails (RCTs), which reported pharmaceutical management and placobo for adults with combat-related PTSD, that were published until April 21, 2021. The effectiveness, acceptability, and adverse events (AEs), were designed as interested outcomes. The change in total symptoms of combat-related PTSD according to the clinician rating scale was defined as primary outcome, and the others were defined as secondary outcomes.

Results: Twenty-two RCTs with 1,221 patients were involved. Compared with placebo, overall active comparators had statistical differences for all outcomes, including the change in total symptoms of combat-related PTSD [SMD = −0.36, 95%CI (−0.62,−0.09)], depression [SMD = −0.28, 95%CI (−0.45,−0.10)], anxiety [SMD = −0.44, 95%CI (−0.64,−0.23)], re-experience [SMD = −0.33, 95%CI (−0.52,−0.13)], avoidance [SMD = −0.24, 95%CI (−0.43,−0.05)], and hyper-arousal [SMD = −0.26, 95%CI (−0.48,−0.03)]. Compared with the placebo, in terms of acceptability, overall active comparators did not significantly decrease all-cause discontinuance rates [RR = 0.97, 95%CI (0.78,1.20)], and the significance decreased due to AEs [RR = 2.42, 95%CI (1.41,4.13)]. Nevertheless, overall there was no statistically significant difference for overall AEs, including somnolence, sedation, dizziness, paresthesia, anxiety, blurred vision, generalized anxiety disorder, and sleep disturbance. All funnel plots were symmetrical and no publication bias was found.

Conclusion: Active drugs, especially amitriptyline, imipramine, and quetiapine, had a positive effect on the improvement of combat-related PTSD symptoms. Despite there being no significant increase in the AEs of the active drugs, the fact that the discontinuation rates of these drugs, including risperidone, imipramine, and topiramate, were increased deserves attention. Furthermore, as active drugs were effective across ethnic groups and battlefields, active drug regimens were revealed to be more appropriate for treating people with symptoms of extreme severe PTSD (≥80) or PTSD that is at least 8 weeks old. In addition, current evidence was from adults under 60 years of age and male combat-related PTSD. Whether this evidence can be extended to other populations of combat-related PTSD needs to be confirmed by subsequent high-quality, large-sample studies.

Pharmacological therapy for post-traumatic stress disorder: a systematic review and meta-analysis of monotherapy, augmentation and head-to-head approaches

Background: Pharmacological approaches are widely used for post-traumatic stress disorder (PTSD) despite uncertainty over efficacy. Objectives: To determine the efficacy of all pharmacological approaches, including monotherapy, augmentation and head-to-head approaches (drug versus drug, drug versus psychotherapy), in reducing PTSD symptom severity. Method: A systematic review and meta-analysis of randomised controlled trials were undertaken; 115 studies were included. Results: Selective serotonin reuptake inhibitors (SSRIs) were found to be statistically superior to placebo in reduction of PTSD symptoms but the effect size was small (standardised mean difference -0.28, 95% CI -0.39 to -0.17). For individual monotherapy agents compared to placebo in two or more studies, we found small statistically significant evidence for the antidepressants fluoxetine, paroxetine, sertraline, venlafaxine and the antipsychotic quetiapine. For pharmacological augmentation, we found small statistically significant evidence for prazosin and risperidone. Conclusions: Some medications have a small positive effect on reducing PTSD symptom severity and can be considered as potential monotherapy treatments; these include fluoxetine, paroxetine, sertraline, venlafaxine and quetiapine. Two medications, prazosin and risperidone, also have a small positive effect when used to augment pharmacological monotherapy. There was no evidence of superiority for one intervention over another in the small number of head-to-head comparison studies.

Key Clinical Interest Outcomes of Pharmaceutical Administration for Veterans With Post-Traumatic Stress Disorder Based on Pooled Evidences of 36 Randomised Controlled Trials With 2,331 Adults

Background: The effects of drug treatment on veterans, who have a high risk of post-traumatic stress disorder (PTSD), are not clear, and the guidelines are different from the recommendations of the recent meta-analysis. Our goal was to find the efficacy and frequencies of complications of drugs that can treat PTSD in veterans. Method: We searched Ovid MEDLINE, Ovid Embase, The Cochrane Library and Web of Science until January 1, 2020. The outcomes were designed as the change of PTSD total scale, subsymptom score, response rate, frequencies of complications outcomes, and acceptability. Results: We included a total of 36 randomised controlled trials with a total of 2,331 adults. In terms of overall effect, drug treatment is more effective than placebo in change in total PTSD symptoms scale (SMD = -0.24, 95% CI [-0.42, -0.06]) and response (RR = 1.66, 95% CI [1.01, 2.72]). However, in terms of frequencies of complications, drugs generally had a higher withdrawal rate (RR = 1.02, 95% CI [0.86, 1.20]) and a higher frequencies of complications (RR = 1.72, 95% CI [1.20, 2.47]) than placebo. Risperidone showed a good curative effect in change in total PTSD symptoms scale (SMD = -0.22, 95% CI [-0.43, 0.00]) and acceptability (RR = 1.31, 95% CI [0.82, 2.59]). The drugs acting on 5-HT receptors, our results showed that symptoms of hyper-arousal (SMD = -0.54, 95% CI [-0.86, -0.21]), symptoms of re-experiencing (SMD = -0.62, 95% CI [-0.86, -0.39]) and symptoms of avoidance (SMD = -0.53, 95% CI [- 0.77,-0.3]), The drugs acting on dopamine receptors, our results showed that symptoms of re-experiencing (SMD = -0.35, 95% CI [-0.55, -0.16]) and the drugs acting on α2 receptor has a significant effect on reducing total PTSD symptoms scale (SMD = -0.34, 95% CI [-0.62, -0.06]). Conclusion: Drug therapy can effectively treat PTSD, but its frequencies of complications should be considered. Different from the guidelines for adult PTSD, this study supports atypical antipsychotics, selective serotonin reuptake inhibitors and receptors that act on 5-HT and dopamine for the treatment of PTSD in veterans. Based on evidence among these drugs, the risperidone is the most effective for veterans, otherwise, sertraline is used as an alternative.

Comparative Efficacy and Acceptability of Pharmaceutical Management for Adults With Post-Traumatic Stress Disorder: A Systematic Review and Meta-Analysis

The current clinical guidelines on post-traumatic stress disorder (PTSD) recommend selective serotonin reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors (SNRIs) of drugs. However, there is uncertainty about the efficacy of other drugs and selecting which treatments work best for which patients. This meta-analysis evaluated efficacy and acceptability of pharmaceutical management for adults with PTSD. Randomized-controlled trials, which reported active comparators and placebo-controlled trials of pharmaceutical management for adults with PTSD, from the Ovid Medline, EMBase, CENTRAL, PsycINFO, Ovid Health and Psychosocial Instruments, and ISIWeb of Science, were searched until June 21, 2019. In terms of efficacy, all active drugs demonstrated superior effect than placebo (SMD = -0.33; 95% CI, -0.43 to -0.23). The medications were superior to placebo in reducing the symptom of re-experiencing, avoidance, hyperarousal, depression, and anxiety. For acceptability, medicine interventions for PTSD showed no increase in all-cause discontinuation compared with placebo. Nevertheless, in terms of safety, medicine interventions indicated a higher risk of adverse effect compared with placebo (RR = 1.47, 95% CI: 1.24 to 1.75). Compared with placebo, the SSRIs and atypical antipsychotics drugs had significant efficacy whether in patients with severe or extremely severe PTSD status. However, only atypical antipsychotics (SMD = -0.29, 95% CI: -0.48 to -0.10) showed superior efficacy than placebo in veterans. Medication management could be effective in intervention of PTSD, which demonstrated a sufficient improvement in the core symptoms. This meta-analysis supports the status of SSRIs and SNRIs as recommended pharmacotherapy. However, patients with different clinical characteristics of PTSD should consider individualized drug management.

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.

Translating Molecular and Neuroendocrine Findings in Posttraumatic Stress Disorder and Resilience to Novel Therapies

Many biological systems are altered in association with posttraumatic stress disorder (PTSD) and resilience. However, there are only few approved pharmacological treatments for PTSD, and no approved medications to enhance resilience. This article provides a critical review of select neurobiological findings in PTSD and resilience, and also of pharmacologic approaches that have emerged from this work. The medications summarized involve engagement with targets in the adrenergic, hypothalamic-pituitary-adrenal axis, and neuropeptide Y systems. Other highlighted approaches involve the use of ketamine and 3,4-methylenedioxymethamphetamine-assisted psychotherapy, which recently surfaced as promising strategies for PTSD, though the neurobiological mechanisms underlying their actions, including for promoting resilience, are not yet fully understood. The former approaches fall within the broad concept of "rational pharmacotherapy," in that they attempt to directly target dysregulated systems known to be associated with posttraumatic symptoms. To the extent that use of ketamine and 3,4-methylenedioxymethamphetamine promotes symptom improvement and resilience in PTSD, this provides an opportunity for reverse translation and identification of relevant targets and mechanisms of action through careful study of biological changes resulting from these interventions. Promoting resilience in trauma-exposed individuals may involve more than pharmacologically manipulating dysregulated molecules and pathways associated with developing and sustaining PTSD symptom severity, but also producing a substantial change in mental state that increases the ability to engage with traumatic material in psychotherapy. Neurobiological examination in the context of treatment studies may yield novel targets and promote a greater understanding of mechanisms of recovery from trauma.

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.

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.

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.

Biomarkers of post-deployment resilience among military service members

The development of PTSD after military deployment is influenced by a combination of biopsychosocial risk and resilience factors. In particular, physiological factors may mark risk for symptom progression or resiliency. Research in civilian populations suggests elevated catecholamines after trauma are associated with PTSD months following the trauma. However, less is known regarding physiological markers of PTSD resilience among post-deployment service members (SM). We therefore assessed whether catecholamines obtained shortly after deployment were associated with combat-related PTSD symptoms three months later. Eighty-seven SMs completed the Clinician-Administered PTSD Scale for DSM-IV and blood draws within two months after return from deployment to Iraq or Afghanistan ("Time 1" or "T1") and three months later ("Time 2" or "T2"). Linear regression analyses demonstrated that lower norepinephrine at T1 was associated with lower PTSD symptoms at T2. In particular, T1 norepinephrine was positively associated with T2 symptom intensity and avoidance symptoms. The present findings represent a biologically-informed method of assessing PTSD resilience after deployment, which may aid clinicians in providing tailored treatments for those in the greatest need. Further research is needed to validate these findings and incorporate physiological measures within an assessment battery.

The behavioural response of mice lacking NK₁ receptors to guanfacine resembles its clinical profile in treatment of ADHD

Background and Purpose

Mice with functional ablation of substance P-preferring neurokinin-1 receptors (NK1R−/− mice) display behavioural abnormalities resembling those in attention deficit hyperactivity disorder (ADHD). Here, we investigated whether the ADHD treatment, guanfacine, alleviated the hyperactivity and impulsivity/inattention displayed by NK1R−/− mice in the light/dark exploration box (LDEB) and 5-choice serial reaction–time task (5-CSRTT), respectively. Following reports of co-morbid anxiety in ADHD, we also investigated effects of guanfacine on anxiety-like behaviour displayed by NK1R−/− and wild-type (WT) mice in the elevated plus maze (EPM).

Experimental Approach

Mice were treated with guanfacine (0.1, 0.3 or 1.0 mg·kg⁻¹, i.p.), vehicle or no injection and tested in the 5-CSRTT or the LDEB. Only the lowest dose of guanfacine was used in the EPM assays.

Key Results

In the 5-CSRTT, a low dose of guanfacine (0.1 mg·kg⁻¹) increased attention in NK1R−/− mice, but not in WT mice. This dose did not affect the total number of trials completed, latencies to respond or locomotor activity in the LDEB. Impulsivity was decreased by the high dose (1.0 mg·kg⁻¹) of guanfacine, but this was evident in both genotypes and is likely to be secondary to a generalized blunting of behaviour. Although the NK1R−/− mice displayed marked anxiety-like behaviour, guanfacine did not affect the behaviour of either genotype in the EPM.

Conclusions and Implications

This evidence that guanfacine improves attention at a dose that did not affect arousal or emotionality supports our proposal that NK1R−/− mice express an attention deficit resembling that of ADHD patients.

Linked Articles

This article is part of a themed section on Animal Models in Psychiatry Research. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-20

Emerging drugs for the treatment of anxiety

INTRODUCTION

Anxiety disorders are among the most prevalent and disabling psychiatric disorders in the United States and worldwide. Basic research has provided critical insights into the mechanism regulating fear behavior in animals and a host of animal models have been developed in order to screen compounds for anxiolytic properties. Despite this progress, no mechanistically novel agents for the treatment of anxiety have come to market in more than two decades.

AREAS COVERED

The current review will provide a critical summary of current pharmacological approaches to the treatment of anxiety and will examine the pharmacotherapeutic pipeline for treatments in development. Anxiety and related disorders considered herein include panic disorder, social anxiety disorder, generalized anxiety disorder and post-traumatic stress disorder. The glutamate, neuropeptide and endocannabinoid systems show particular promise as future targets for novel drug development.

EXPERT OPINION

In the face of an ever-growing understanding of fear-related behavior, the field awaits the translation of this research into mechanistically novel treatments. Obstacles will be overcome through close collaboration between basic and clinical researchers with the goal of aligning valid endophenotypes of human anxiety disorders with improved animal models. Novel approaches are needed to move basic discoveries into new, more effective treatments for our patients.

Chronic Stimulation of Alpha-2A-Adrenoceptors With Guanfacine Protects Rodent Prefrontal Cortex Dendritic Spines and Cognition From the Effects of Chronic Stress

The prefrontal cortex (PFC) provides top-down regulation of behavior, cognition, and emotion, including spatial working memory. However, these PFC abilities are greatly impaired by exposure to acute or chronic stress. Chronic stress exposure in rats induces atrophy of PFC dendrites and spines that correlates with working memory impairment. As similar PFC grey matter loss appears to occur in mental illness, the mechanisms underlying these changes need to be better understood. Acute stress exposure impairs PFC cognition by activating feedforward cAMP-calcium-K+ channel signaling, which weakens synaptic inputs and reduces PFC neuronal firing. Spine loss with chronic stress has been shown to involve calcium-protein kinase C signaling, but it is not known if inhibiting cAMP signaling would similarly prevent the atrophy induced by repeated stress. The current study examined whether inhibiting cAMP signaling through alpha-2A-adrenoceptor stimulation with chronic guanfacine treatment would protect PFC spines and working memory performance during chronic stress exposure. Guanfacine was selected due to 1) its established effects on cAMP signaling at post-synaptic alpha-2A receptors on spines in PFC, and 2) its increasing clinical use for the treatment of pediatric stress disorders. Daily guanfacine treatment compared to vehicle control was found to prevent dendritic spine loss in layer II/III pyramidal neurons of prelimbic PFC in rats exposed to chronic restraint stress. Guanfacine also protected working memory performance; cognitive performance correlated with dendritic spine density. These findings suggest that chronic guanfacine use may have clinical utility by protecting PFC gray matter from the detrimental effects of stress.

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.

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.

Targeting memory processes with drugs to prevent or cure PTSD

INTRODUCTION

Post-traumatic stress disorder (PTSD) is a chronic debilitating psychiatric disorder resulting from exposure to a severe traumatic stressor and an area of great unmet medical need. Advances in pharmacological treatments beyond the currently approved SSRIs are needed.

AREAS COVERED

Background on PTSD, as well as the neurobiology of stress responding and fear conditioning, is provided. Clinical and preclinical data for investigational agents with diverse pharmacological mechanisms are summarized.

EXPERT OPINION

Advances in the understanding of stress biology and mechanisms of fear conditioning plasticity provide a rationale for treatment approaches that may reduce hyperarousal and dysfunctional aversive memories in PTSD. One challenge is to determine if these components are independent or reflect a common underlying neurobiological alteration. Numerous agents reviewed have potential for reducing PTSD core symptoms or targeted symptoms in chronic PTSD. Promising early data support drug approaches that seek to disrupt dysfunctional aversive memories by interfering with consolidation soon after trauma exposure, or in chronic PTSD, by blocking reconsolidation and/or enhancing extinction. Challenges remain for achieving selectivity when attempting to alter aversive memories. Targeting the underlying traumatic memory with a combination of pharmacological therapies applied with appropriate chronicity, and in combination with psychotherapy, is expected to substantially improve PTSD treatment.

Sleep disturbances and PTSD: a perpetual circle?

BACKGROUND

Sleep facilitates the consolidation of fear extinction memory. Nightmares and insomnia are hallmark symptoms of posttraumatic stress disorder (PTSD), possibly interfering with fear extinction and compromising recovery. A perpetual circle may develop when sleep disturbances increase the risk for PTSD and vice versa. To date, therapeutic options for alleviating sleep disturbances in PTSD are limited.

METHODS

WE CONDUCTED THREE STUDIES TO EXAMINE THE RELATIONSHIP BETWEEN SLEEP AND POSTTRAUMATIC SYMPTOMS: (1) a prospective longitudinal cohort study examining the impact of pre-deployment insomnia symptoms and nightmares on the development of PTSD; (2) a cross-sectional study examining subjective sleep measures, polysomnography, endocrinological parameters, and memory in veterans with PTSD, veterans without PTSD, and healthy controls (HCs); (3) a randomized controlled trial (RCT) (n=14) comparing the effect of prazosin and placebo on sleep disturbances in veterans with PTSD. In addition to these studies, we systematically reviewed the literature on treatment options for sleep disturbances in PTSD.

RESULTS

Pre-deployment nightmares predicted PTSD symptoms at 6 months post-deployment; however, insomnia symptoms did not. Furthermore, in patients with PTSD, a correlation between the apnea index and PTSD severity was observed, while obstructive sleep apnea syndrome was not more prevalent. We observed a significant increase in awakenings during sleep in patients with PTSD, which were positively correlated with adrenocorticotropic hormone (ACTH) levels, negatively correlated with growth hormone (GH) secretion, and the subjective perception of sleep depth. Also, heart rate was significantly increased in PTSD patients. Interestingly, plasma levels of GH during the night were decreased in PTSD. Furthermore, GH secretion and awakenings were independent predictors for delayed recall, which was lower in PTSD. In our RCT, prazosin was not associated with improvement of any subjective and objective sleep parameters. Only a few RCTs have been published. They show promising results for atypical antipsychotics and prazosin, the latter especially on nightmare reduction.

CONCLUSIONS

Disturbed sleep due to nightmares increases the risk for PTSD. PTSD in turn leads to increased sleep fragmentation, decreased GH secretion, and frequent nightmares, which may again compromise fear extinction, synaptic plasticity, and recovery. This suggests that disturbed sleep is a precipitating and perpetuating factor in PTSD symptomatology, creating a perpetual circle. This dissertation suggests that activity of the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system (SNS) is involved in disturbed sleep in patients with PTSD.

Pharmacological treatment of PTSD - established and new approaches

A large proportion of humans will experience a traumatic event at least once in their lifetime, with up to 10% then going on to developing posttraumatic stress disorder (PTSD). In this review we will discuss established pharmacological interventions for PTSD as well as highlight novel therapeutic strategies undergoing extensive pre-clinical research as well as ongoing clinical research. Such strategies include prophylactic treatments and use of pharmacotherapy as adjunctive treatment with established trauma-focused psychological therapies. These potential treatment approaches include modulation of stress effects on memory consolidation after trauma (e.g., glucocorticoid, corticotropin-releasing factor and norepinephrine signalling modulators), as well as putative cognitive enhancers that target mechanisms of conditioned fear extinction and reconsolidation (e.g., glucocorticoid receptor modulators and modulators of glutamate signalling such as positive allosteric modulators of glutamate receptors, glycine transporter inhibitors, or glycine agonists). We will discuss evidence for and against these potential novel treatment strategies and their limitations. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.

Prevention of posttraumatic stress disorder

Traumatic events are common, but the psychological distress that may follow usually subsides naturally. For some individuals, distress develops into posttraumatic stress disorder (PTSD). PTSD lends itself to the application of prevention strategies for at-risk individuals. The identification of a causal event may make prevention efforts for PTSD more feasible and effective than for other psychological disorders. For PTSD, these efforts target those traumatized persons who are beginning to exhibit symptoms of PTSD. These interventions could also target individuals meeting criteria for acute stress disorder with the goal of preventing chronic PTSD.

Pharmacotherapy of post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is a prevalent psychiatric disorder that may result in significant social and occupational debilitation unless symptoms are recognized and treated appropriately. Considerable research effort has been devoted over the last 20 years to developing effective pharmacological treatments for this illness. At this time, the bulk of the agents investigated include antidepressants, anticonvulsants, atypical antipsychotics, benzodiazepines, and antiadrenergic agents. Herein, we review the existing evidence base for these different classes of psychotropics in PTSD. Emphasis is placed on discussion of evidence stemming from randomized placebo-controlled clinical trials wherever possible. A brief description of novel agents that have shown initial promise for PTSD treatment is also provided.

Correlates and Treatments of Nightmares in Adults

Nightmares, distressing dreams that primarily arise from REM sleep, are prevalent among the general population and even more so among clinical populations. The frequency of nightmares and related nightmare distress are linked to both sleep disturbance and waking psychopathology. Based on the extant evidence, nightmares appear to be particularly relevant to posttraumatic stress disorder, and may even be implicated in its pathophysiology. Significant advances in treatment have occurred in recent years, with effective pharmacological and psychosocial interventions now available. Despite the progress that has been made, however, more consistent assessment methods and more rigorous study designs are needed to fully understand the causes and consequences of nightmares.

Safe enough to sleep: sleep disruptions associated with trauma, posttraumatic stress, and anxiety in children and adolescents

Sleep disturbance is an essential symptom of posttraumatic stress disorder, and recent evidence suggests that disrupted sleep may play an important role in the development of posttraumatic stress disorder following traumatic stress. The authors review several aspects of sleep as it relates to posttraumatic stress disorder. First, there is an association between traumatic stress and different components of disrupted sleep in children and adolescents. Second, sleep disruption appears to be a core feature of other pediatric anxiety disorders, and the authors consider if this preexisting sleep vulnerability may explain in part why preexisting anxiety disorders are a risk factor for developing posttraumatic stress disorder following a traumatic event. Third, the authors consider attachment theory and the social context of trauma and sleep disruption. This article concludes with a consideration of the therapeutic implications of these findings.

Post-traumatic stress disorder: emerging concepts of pharmacotherapy

Post-traumatic stress disorder (PTSD) can result from a traumatic experience that elicits emotions of fear, helpless or horror. Most individuals remain asymptomatic or symptoms quickly resolve, but in a minority intrusive imagery and nightmares, emotional numbing and avoidance, and hyperarousal persist for decades. PTSD is associated with psychiatric and medical co-morbidities, increased risk for suicide, and with poor social and occupational functioning. Psychotherapy and pharmacotherapy are common treatments. Whereas, research supports the efficacy of the cognitive behavioral psychotherapies, there is insufficient evidence to unequivocally support the efficacy of any specific pharmacotherapy. Proven effective pharmacologic agents are sorely needed to treat core and targeted PTSD symptoms, and for prevention. This review describes current and emerging pharmacotherapies that advance these goals.

Pharmacotherapy of PTSD: premises, principles, and priorities

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

Noradrenergic and serotonergic mechanisms in the neurobiology of posttraumatic stress disorder and resilience

Posttraumatic stress disorder (PTSD) is characterized mainly by symptoms of re-experiencing, avoidance and hyperarousal as a consequence of catastrophic and traumatic events that are distinguished from ordinary stressful life events. Although extensive research has already been done, the etiology of PTSD remains unclear. Research on the impact of trauma on neurobiological systems can be expected to inform the development of treatments that are directed specifically to symptoms of PTSD. During the past 25 years there has been a dramatic increase in the knowledge about noradrenergic and serotonergic mechanisms in stress response, PTSD and more recently in resilience and this knowledge has justified the use of antidepressants with monoaminergic mechanisms of action for patients with PTSD. Nevertheless, available treatments of PTSD are only to some extent effective and enhanced understanding of the neurobiology of PTSD may lead to the development of improved treatments for these patients. In the present review, we aim to close existing gaps between basic research in psychopathology, neurobiology and treatment development with the ultimate goal to translate basic research into clinically relevant findings which may directly benefit patients with PTSD.

Pharmacologic alternatives to antidepressants in posttraumatic stress disorder: a systematic review

The selective serotonin reuptake inhibitors (SSRIs) are considered the first-line pharmacological treatment for PTSD. However, even when treated with this class of drugs, response rates rarely exceed 60% and less than 20-30% of the patients achieve full remission. The aim of this study was to address this limitation by systematically reviewing the options left for the treatment of PTSD when patients do not respond satisfactorily to or tolerate SSRIs. A systematic review covering all original articles, letters and brief reports published in any language until October 2008 was conducted through searches in the ISI/Web of Science, PubMed and PILOTS databases. The search terms included the pharmacological class of each agent or its generic name plus "PTSD" or "stress disorder" in the title, in the abstract or as a keyword. Sixty-three articles were selected, covering the following categories: antipsychotics, anticonvulsants, adrenergic-inhibiting agents, opioid antagonists, benzodiazepines and other agents. None of the identified agents reached the level A of scientific evidence, 5 reached level B, 7 level C and 13 level D. The non-antidepressant agent with the strongest scientific evidence supporting its use in PTSD is risperidone, which can be envisaged as an effective add-on therapy when patients did not fully benefit from previous treatment with SSRIs. Prazosin, an adrenergic-inhibiting agent, is a promising alternative for cases of PTSD where nightmares and insomnia are prominent symptoms. So far, there is no consistent empirical support for using benzodiazepines in the prevention or in the treatment of PTSD, although these drugs could alleviate some associated non-specific symptoms, such as insomnia or anxiety. Further controlled clinical trials and meta-analysis are needed to guide clinicians in their search of effective pharmacological alternatives to antidepressants in PTSD.

Post-traumatic stress disorder: an evaluation of existing pharmacotherapies and new strategies

Post-traumatic stress disorder (PTSD) is often a chronic and disabling anxiety disorder that develops after exposure to a traumatic event. Researchers have demonstrated efficacy for both pharmacologic and psychosocial interventions in the treatment of PTSD. First-line pharmacotherapeutic options are the selective serotonin re-uptake inhibitors and serotonin noradrenaline re-uptake inhibitors. Older antidepressant agents, such as the tricyclic antidepressants and the monoamine oxidase inhibitor, phenelzine, have also proven efficacy in PTSD among more established agents. However, concerns for side effects have limited frequent use of these. Existing pharmacologic agents produce meaningful results and bear the advantage of treating depression and other co-morbid disorders, yet still fall short of being ideal due to limited response and remission rates and tolerability issues. The need for improving pharmacotherapy of PTSD remains compelling and directions for further research are discussed.