Investigating biological traces of traumatic stress in changing societies: challenges and directions from the ESTSS Task Force on Neurobiology

Real-world stress resilience is associated with the responsivity of the locus coeruleus

Individuals may show different responses to stressful events. Here, we investigate the neurobiological basis of stress resilience, by showing that neural responsitivity of the noradrenergic locus coeruleus (LC-NE) and associated pupil responses are related to the subsequent change in measures of anxiety and depression in response to prolonged real-life stress. We acquired fMRI and pupillometry data during an emotional-conflict task in medical residents before they underwent stressful emergency-room internships known to be a risk factor for anxiety and depression. The LC-NE conflict response and its functional coupling with the amygdala was associated with stress-related symptom changes in response to the internship. A similar relationship was found for pupil-dilation, a potential marker of LC-NE firing. Our results provide insights into the noradrenergic basis of conflict generation, adaptation and stress resilience.

Harnessing the Neurobiology of Resilience to Protect the Mental Well-Being of Healthcare Workers During the COVID-19 Pandemic

Healthcare workers are at a high risk of psychological morbidity in the face of the COVID-19 pandemic. However, there is significant variability in the impact of this crisis on individual healthcare workers, which can be best explained through an appreciation of the construct of resilience. Broadly speaking, resilience refers to the ability to successfully adapt to stressful or traumatic events, and thus plays a key role in determining mental health outcomes following exposure to such events. A proper understanding of resilience is vital in enabling a shift from a reactive to a proactive approach for protecting and promoting the mental well-being of healthcare workers. Research in the past decade has identified six areas that provide promising leads in understanding the biological basis of individual variations in resilience. These are: (1) the key role played by the monoamines noradrenaline and serotonin, (2) the centrality of the hypothalamic-pituitary-adrenal axis in influencing stress vulnerability and resilience, (3) the intimate links between the immune system and stress sensitivity, (4) the role of epigenetic modulation of gene expression in influencing the stress response, (5) the role played by certain neuropeptides as a natural “brake” mechanism in the face of stress, and (6) the neurobiological mechanisms by which environmental factors, such as exercise, diet, and social support, influence resilience to subsequent life events. Though much of this research is still in its early stages, it has already provided valuable information on which strategies – including dietary changes, lifestyle modification, environmental modification, psychosocial interventions, and even pharmacological treatments – may prove to be useful in fostering resilience in individuals and groups. This paper examines the above evidence more closely, with a specific focus on the challenges faced by healthcare workers during the COVID-19 pandemic, and provides suggestions regarding how it may be translated into real-world interventions, as well as how the more tentative hypotheses advanced in this field may be tested during this critical period.

Neurobiological Trajectories Involving Social Isolation in PTSD: A Systematic Review

Social isolation (SI) stress has been recognized as a major risk factor of morbidity in humans and animals, exerting damaging effects at the physical and mental health levels. Posttraumatic stress disorder (PTSD), on the other hand, occurs as a result of experiencing serious, life-threatening, traumatic events and involves involuntary re-experiencing trauma (intrusion), avoidance symptoms, and distortions of cognition and emotional arousal. The literature shows that PTSD is affected by genetic predisposition and triggers a large neurocircuitry involving the amygdala, insula, hippocampus, anterior cingulate- and prefrontal-cortex, and affects the function of the neuroendocrine and immune systems. Social isolation seems to influence the predisposition, onset and outcome of PTSD in humans, whereas it constitutes a valid model of the disorder in animals. According to the PRISMA (preferred reporting items for systematic reviews and meta-analyses) protocol, we systematically reviewed all original studies involving the neurobiological trajectories between SI and PTSD published till July 2019 (database: PubMed/Medline). Out of 274 studies, 10 met the inclusion criteria. We present the results of the retrieved studies in terms of hypothalamic-pituitary-adrenal (HPA)-axis and endocannabinoid system function, immune reactions, neuroplasticity, novel pharmacological targets, and shortening of telomere length, which confirm a synergistic effect on a neurobiological level between the two entities.

Top-down and bottom-up control of stress-coping

In this 30th anniversary issue review, we focus on the glucocorticoid modulation of limbic-prefrontocortical circuitry during stress-coping. This action of the stress hormone is mediated by mineralocorticoid receptors (MRs) and glucocorticoid receptors (GRs) that are co-expressed abundantly in these higher brain regions. Via both receptor types, the glucocorticoids demonstrate, in various contexts, rapid nongenomic and slower genomic actions that coordinate consecutive stages of information processing. MR-mediated action optimises stress-coping, whereas, in a complementary fashion, the memory storage of the selected coping strategy is promoted via GR. We highlight the involvement of adipose tissue in the allocation of energy resources to central regulation of stress reactions, point to still poorly understood neuronal ensembles in the prefrontal cortex that underlie cognitive flexibility critical for effective coping, and evaluate the role of cortisol as a pleiotropic regulator in vulnerability to, and treatment of, trauma-related psychiatric disorders.

Trauma and trauma care in Europe

The European countries have a long history of exposure to large-scale trauma. In the early 1990s the increasing awareness of the consequences of trauma within the mental health community led to the foundation of local societies for psychotraumatology across Europe and the European Society of Traumatic Stress Studies (ESTSS), which celebrated its 25th anniversary in 2018. The focus of this article is to describe the current state of care for survivors of trauma in the 15 European countries where ESTSS member societies have been established. Brief descriptions on the historical burden of trauma in each country are followed by an overview of the care system for trauma survivors in the countries, the state-of-the-art of interventions, current challenges in caring for survivors and the topics that need to be most urgently addressed in the future. The reports from the different countries demonstrate how important steps towards a better provision of care for survivors of trauma have been made in Europe. Given the cultural and economic diversity of the continent, there are also differences between the European countries, for instance with regard to the use of evidence-based treatments. Strategies to overcome these differences, like the new ESTSS training curricula for care-providers across Europe, are briefly discussed.

DHEA and DHEA-S levels in posttraumatic stress disorder: A meta-analytic review

Differences in hypothalamic-pituitary-adrenocortical (HPA) functioning between patients with posttraumatic stress disorder (PTSD) and controls are among the most consistent neurobiological findings in PTSD. HPA-axis activation results in the output of various steroid hormones including dehydroepiandrosterone (DHEA), which is then converted into dehydroepiandrosterone sulfate (DHEA-S), with anti-glucocorticoid actions among its pleiotropic effects. To investigate whether there is evidence for consistent differences in basal DHEA and DHEA-s levels between individuals with and without PTSD, we performed random-effect meta-analyses aggregating findings of previously published studies. Nine studies reporting on DHEA levels (486 participants) and 8 studies reporting on DHEA-S levels (501 participants) were included. No significant differences in DHEA or DHEA-S levels between PTSD and control groups were found. Exploratory subgroup analyses were performed to distinguish between effects of PTSD and trauma exposure. A trend for higher DHEA levels was found in PTSD patients compared to non-trauma-exposed controls (NTC) (k=3, SMD=1.12 95% CI -0.03-2.52, Z=1.91, p=0.06). Significantly higher DHEA-S levels were observed in PTSD patients compared to NTC (k=2, SMD=0.76, 95% CI 0.38-1.13, Z=3.94, p<0.001). Additionally, significantly higher DHEA levels were observed in trauma-exposed controls (TC) compared to NTC (k=3, SMD=0.66, 95% CI 0.33-0.99, Z=3.88, p<0.001, I²=86%) this suggests that trauma exposure, irrespective of further PTSD development, might increase basal DHEA and DHEA-S levels.

Novel pharmacological treatment strategies for posttraumatic stress disorder

INTRODUCTION

A wide range of medications have been studied for posttraumatic stress disorder (PTSD) and a number are registered for this indication. Nevertheless, current pharmacotherapies are only partially effective in some patients, and are minimally effective in others. Thus novel treatment avenues need to be explored. Areas covered: In considering novel pharmacological agents for the treatment of PTSD, this paper takes a translational approach. We outline how advances in our understanding of the underlying neurobiology of PTSD may inform the identification of potential new treatment targets, including glutamatergic, noradrenergic and opioid pathways. Expert commentary: Continued investigation of the neural substrates and signalling pathways involved in responses to trauma may inform the development of novel treatment targets for future drug development for PTSD. However, the translation of preclinical findings to clinical practice is likely to be complex and gradual.