A randomized, double-blind, placebo-controlled trial of hydrocortisone augmentation of Prolonged Exposure for PTSD in U.S. combat veterans

Understanding sex differences in extinction retention: Pre-extinction stress and sex hormone status

Difficulties in fear regulation can sometimes result in maladaptive fear responses. To better understand how to improve fear regulation, it is important to determine how known factors, such as sex hormone status and stress, might interact to influence fear memory. Research has shown that women with high estradiol levels (mid-cycle) and men exhibit better extinction retention compared to women with low estradiol levels (women in the early follicular cycle or using oral contraceptives). Stress has also been demonstrated to affect both the learning and retention of extinction. Despite documented interactions between stress and sex hormones, their combined effects have not been thoroughly studied. This study aims to examine the impact of stress as a function of sex hormone status on extinction learning and retention. A total of 168 non-clinical participants were studied, including men (n = 46), women using oral contraceptives (n = 38), women in the early follicular phase (n = 40), and women in mid-cycle (n = 44). On Day 1, fear acquisition training was performed. On day 2, prior to extinction training, half of the participants were exposed to a psychosocial stressor, while the other half performed a non-stressful control task. On day 3, extinction retention was tested. Fear was quantified using skin conductance responses, while stress hormones were quantified through saliva samples. Exposure to stress prior to extinction training did not affect extinction learning, regardless of sex hormone status. In contrast, pre-extinction stress exposure had different effects on extinction retention depending on hormone status. Stressed men showed impairment in extinction retention compared to controls, while the experimental condition had no effect on naturally cycling women. Regardless of stress exposure, early follicular women exhibited a deficit in fear regulation, while mid-cycle women showed effective fear regulation. Among women using oral contraceptives, the stress group demonstrated better extinction retention compared to the control group. These results demonstrate the importance of considering sex hormone status and stress exposure during extinction learning, as both components may modulate extinction retention. These results could help identifying hormonal conditions that may enhance the effectiveness of extinction-based psychological therapies used in the treatment of fear-related disorders.

State of the Science: Prolonged exposure therapy for the treatment of posttraumatic stress disorder

Prolonged exposure therapy (PE) is a well-established first-line treatment for posttraumatic stress disorder (PTSD) that is based on emotional processing theory. PE has been rigorously evaluated and tested in a large number of clinical trials in many countries covering a wide range of trauma populations. In this review, we summarize the evidence base supporting the efficacy of PE across populations, including adults with sexual assault-related PTSD and mixed trauma-related PTSD, military populations, and adolescents. We highlight important strengths and gaps in the research on PE with individuals from marginalized communities. We discuss the efficacy of PE on associated psychopathology and in the presence of the most commonly comorbid conditions, either alone or integrated with other treatments. In addition, we provide an overview of research examining strategies to augment PE. Much of this work remains preliminary, but numerous trials have tested PE in combination with other psychological or pharmacological approaches, interventions to facilitate extinction learning, and behavioral approaches, in the hopes of further increasing the efficiency and efficacy of PE. There are now several trials testing PE in novel formats that may have advantages over standard in-person PE, such as lower dropout and increased scalability. We examine this recent work on new models of delivering PE, including massed treatment, telehealth, and brief adaptations for primary care, all of which have the potential to increase access to PE. Finally, we highlight several promising areas for future research.

Brain FADE syndrome: the final common pathway of chronic inflammation in neurological disease

Importance

While the understanding of inflammation in the pathogenesis of many neurological diseases is now accepted, this special commentary addresses the need to study chronic inflammation in the propagation of cognitive Fog, Asthenia, and Depression Related to Inflammation which we name Brain FADE syndrome. Patients with Brain FADE syndrome fall in the void between neurology and psychiatry because the depression, fatigue, and fog seen in these patients are not idiopathic, but instead due to organic, inflammation involved in neurological disease initiation.

Observations

A review of randomized clinical trials in stroke, multiple sclerosis, Parkinson's disease, COVID, traumatic brain injury, and Alzheimer's disease reveal a paucity of studies with any component of Brain FADE syndrome as a primary endpoint. Furthermore, despite the relatively well-accepted notion that inflammation is a critical driving factor in these disease pathologies, none have connected chronic inflammation to depression, fatigue, or fog despite over half of the patients suffering from them.

Conclusions and relevance

Brain FADE Syndrome is important and prevalent in the neurological diseases we examined. Classical "psychiatric medications" are insufficient to address Brain FADE Syndrome and a novel approach that utilizes sequential targeting of innate and adaptive immune responses should be studied.

A transdiagnostic meta-analysis of acute augmentations to psychological therapy

At least half of all patients with mental health disorders do not respond adequately to psychological therapy. Acutely enhancing particular biological or psychological processes during psychological therapy may improve treatment outcomes. However, previous studies are confined to specific augmentation approaches, typically assessed within single diagnostic categories. Our objective was to assess to what degree acute augmentations of psychological therapy reduce psychiatric symptoms and estimate effect sizes of augmentation types (for example, brain stimulation or psychedelics). We searched Medline, PsycINFO and Embase for controlled studies published between database inception and 25 May 2022. We conducted a preregistered random-effects meta-analysis (PROSPERO CRD42021236403). We identified 108 studies (N = 5,889). Acute augmentation significantly reduced the severity of mental health problems (Hedges' g = -0.27, 95% CI: [-0.36, -0.18]; P < 0.0001), particularly for the transdiagnostic dimensions 'Fear' and 'Distress'. This result survived a trim-and-fill analysis to account for publication bias. Subgroup analyses revealed that pharmacological, psychological and somatic augmentations were effective, but to varying degrees. Acute augmentation approaches are a promising route to improve outcomes from psychological therapy.

Alleviating anxiety and taming trauma: Novel pharmacotherapeutics for anxiety disorders and posttraumatic stress disorder

Psychiatric disorders associated with psychological trauma, stress and anxiety are a highly prevalent and increasing cause of morbidity worldwide. Current therapeutic approaches, including medication, are effective in alleviating symptoms of anxiety disorders and posttraumatic stress disorder (PTSD), at least in some individuals, but have unwanted side-effects and do not resolve underlying pathophysiology. After a period of stagnation, there is renewed enthusiasm from public, academic and commercial parties in designing and developing drug treatments for these disorders. Here, we aim to provide a snapshot of the current state of this field that is written for neuropharmacologists, but also practicing clinicians and the interested lay-reader. After introducing currently available drug treatments, we summarize recent/ongoing clinical assessment of novel medicines for anxiety and PTSD, grouped according to primary neurochemical targets and their potential to produce acute and/or enduring therapeutic effects. The evaluation of putative treatments targeting monoamine (including psychedelics), GABA, glutamate, cannabinoid, cholinergic and neuropeptide systems, amongst others, are discussed. We emphasize the importance of designing and clinically assessing new medications based on a firm understanding of the underlying neurobiology stemming from the rapid advances being made in neuroscience. This includes harnessing neuroplasticity to bring about lasting beneficial changes in the brain rather than - as many current medications do - produce a transient attenuation of symptoms, as exemplified by combining psychotropic/cognitive enhancing drugs with psychotherapeutic approaches. We conclude by noting some of the other emerging trends in this promising new phase of drug development.

Glucocorticoid-based pharmacotherapies preventing PTSD

Posttraumatic stress disorder (PTSD) is a highly disabling psychiatric condition that may arise after exposure to acute and severe trauma. It is a highly prevalent mental disorder worldwide, and the current treatment options for these patients remain limited due to low effectiveness. The time window right after traumatic events provides clinicians with a unique opportunity for preventive interventions against potential deleterious alterations in brain function that lead to PTSD. Some studies pointed out that PTSD patients present an abnormal function of the hypothalamic-pituitary-adrenal axis that may contribute to a vulnerability toward PTSD. Moreover, glucocorticoids have arisen as a promising option for preventing the disorder's development when administered in the aftermath of trauma. The present work compiles the recent findings of glucocorticoid administration for the prevention of a PTSD phenotype, from human studies to animal models of PTSD. Overall, glucocorticoid-based therapies for preventing PTSD demonstrated moderate evidence in terms of efficacy in both clinical and preclinical studies. Although clinical studies point out that glucocorticoids may not be effective for all patients' subpopulations, those with adequate traits might greatly benefit from them. Preclinical studies provide precise insight into the mechanisms mediating this preventive effect, showing glucocorticoid-based prevention to reduce long-lasting behavioral and neurobiological abnormalities caused by traumatic stress. However, further research is needed to delineate the precise mechanisms and the extent to which these interventions can translate into lower PTSD rates and morbidity. This article is part of the Special Issue on 'Fear, Anxiety and PTSD'.

Causally mapping human threat extinction relevant circuits with depolarizing brain stimulation methods

Laboratory threat extinction paradigms and exposure-based therapy both involve repeated, safe confrontation with stimuli previously experienced as threatening. This fundamental procedural overlap supports laboratory threat extinction as a compelling analogue of exposure-based therapy. Threat extinction impairments have been detected in clinical anxiety and may contribute to exposure-based therapy non-response and relapse. However, efforts to improve exposure outcomes using techniques that boost extinction - primarily rodent extinction - have largely failed to date, potentially due to fundamental differences between rodent and human neurobiology. In this review, we articulate a comprehensive pre-clinical human research agenda designed to overcome these failures. We describe how connectivity guided depolarizing brain stimulation methods (i.e., TMS and DBS) can be applied concurrently with threat extinction and dual threat reconsolidation-extinction paradigms to causally map human extinction relevant circuits and inform the optimal integration of these methods with exposure-based therapy. We highlight candidate targets including the amygdala, hippocampus, ventromedial prefrontal cortex, dorsal anterior cingulate cortex, and mesolimbic structures, and propose hypotheses about how stimulation delivered at specific learning phases could strengthen threat extinction.

Modeling gene × environment interactions in PTSD using human neurons reveals diagnosis-specific glucocorticoid-induced gene expression

Post-traumatic stress disorder (PTSD) can develop following severe trauma, but the extent to which genetic and environmental risk factors contribute to individual clinical outcomes is unknown. Here, we compared transcriptional responses to hydrocortisone exposure in human induced pluripotent stem cell (hiPSC)-derived glutamatergic neurons and peripheral blood mononuclear cells (PBMCs) from combat veterans with PTSD (n = 19 hiPSC and n = 20 PBMC donors) and controls (n = 20 hiPSC and n = 20 PBMC donors). In neurons only, we observed diagnosis-specific glucocorticoid-induced changes in gene expression corresponding with PTSD-specific transcriptomic patterns found in human postmortem brains. We observed glucocorticoid hypersensitivity in PTSD neurons, and identified genes that contribute to this PTSD-dependent glucocorticoid response. We find evidence of a coregulated network of transcription factors that mediates glucocorticoid hyper-responsivity in PTSD. These findings suggest that induced neurons represent a platform for examining the molecular mechanisms underlying PTSD, identifying biomarkers of stress response, and conducting drug screening to identify new therapeutics.

Neuromodulation as an Augmenting Strategy for Behavioral Therapies for Anxiety and PTSD: a Narrative Review

PURPOSE OF REVIEW

Post-traumatic stress disorder (PTSD) is a prevalent problem. Despite current treatments, symptoms may persist, and neuromodulation therapies show great potential. A growing body of research suggests that transcranial magnetic stimulation (TMS) is effective as a standalone treatment for PTSD, with recent research demonstrating promising use when combined synergistically with behavioral treatments. In this review, we survey this literature including data suggesting mechanisms involved in anxiety and PTSD that may be targeted by neurostimulation.

RECENT FINDINGS

Evidence suggests the mechanism of action for TMS that contributes to behavioral change may be enhanced neural plasticity via increased functionality of prefrontal and subcortical/limbic structures and associated networks. Some research has demonstrated a behavioral change in PTSD and anxiety due to enhanced extinction learning or improved ability to think flexibly and reduce ruminative tendencies. Growing evidence suggests TMS may be best used as a therapeutic adjunct, at least acutely, for extinction-based exposure therapies in patients by accelerating therapy response.

SUMMARY

While TMS has shown promise as a standalone intervention, augmentation with psychotherapy is one avenue of interest. Non-responders to current EBPs might particularly benefit from this sort of targeted approach, and it may shorten treatment length, which would help the successful completion of a course of therapy.

The role of the immune system in posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) develops in a subset of individuals upon exposure to traumatic stress. In addition to well-defined psychological and behavioral symptoms, some individuals with PTSD also exhibit elevated concentrations of inflammatory markers, including C-reactive protein, interleukin-6, and tumor necrosis factor-α. Moreover, PTSD is often co-morbid with immune-related conditions, such as cardiometabolic and autoimmune disorders. Numerous factors, including lifetime trauma burden, biological sex, genetic background, metabolic conditions, and gut microbiota, may contribute to inflammation in PTSD. Importantly, inflammation can influence neural circuits and neurotransmitter signaling in regions of the brain relevant to fear, anxiety, and emotion regulation. Given the link between PTSD and the immune system, current studies are underway to evaluate the efficacy of anti-inflammatory treatments in those with PTSD. Understanding the complex interactions between PTSD and the immune system is essential for future discovery of diagnostic and therapeutic tools.

Association between perceived distress and salivary cortisol in veterans with mTBI

Mild traumatic brain injury (mTBI) is one of the most common injuries experienced by Veterans and can frequently result in a variety of post-concussive symptoms. Post-concussive headaches (PCH), one of the most common symptoms, can persist for years after the injury occurred. The long-lasting impacts of PCH can be extremely distressing for Veterans, thus necessitating the need to find reliable biomarkers that directly relate to subjective feelings of distress. Yoga-based interventions have been shown to improve both subjective and objective markers of stress. Techniques used in yoga, such as the focus on releasing muscular tension, are also recommended as strategies for treating PCH. Thus, yoga-based interventions provide a unique context for the comparison of subjective and objective measures of distress in Veterans with PCH. In this secondary, exploratory analysis, we examined the relationship between perceived distress and cortisol in sixteen Veterans with mTBI and long-term PCH within the context of a yoga intervention feasibility study. The Visual Analogue Scale (VAS), a validated tool for measuring subjective distress, was administered to participants immediately before and after 75-min yoga classes, which occurred twice weekly over eight weeks. Participants also provided salivary cortisol (pre- and post-yoga) at in-person sessions (eight) to compare to changes in VAS scores. We found that VAS scores were significantly reduced within five of the eight assessed yoga classes, but there were no significant changes in cortisol levels. No significant correlations were found between VAS scores and salivary cortisol levels. When looking at how cortisol levels changed over time (i.e., over the series of eight yoga sessions), there was a significant downward trajectory in post-yoga cortisol, but not after taking pre-class cortisol into account (i.e., within yoga session cortisol change over time). Taken together, we found that subjective distress, but not cortisol was reduced by yoga classes. These data suggest that salivary cortisol did not match changes in perceived distress, thus emphasizing the ongoing challenges of relating subjective and objective measures.

•

Perceived distress can negatively impact post-concussive symptoms.

•

Efforts are needed to relate objective and subjective measures of distress.

•

Subjective distress and salivary cortisol were examined within yoga sessions.

•

Subjective distress, but not cortisol was reduced within 5 of 8 yoga classes.

•

These data highlight the challenges of relating subjective and objective measures.

Translation of animal endocannabinoid models of PTSD mechanisms to humans: Where to next?

The endocannabinoid system is known to be involved in mechanisms relevant to PTSD aetiology and maintenance, though this understanding is mostly based on animal models of the disorder. Here we review how human paradigms can successfully translate animal findings to human subjects, with the view that substantially increased insight into the effect of endocannabinoid signalling on stress responding, emotional and intrusive memories, and fear extinction can be gained using modern paradigms and methods for assessing the state of the endocannabinoid system in PTSD.