Diet Prevents Social Stress-Induced Maladaptive Neurobehavioural and Gut Microbiota Changes in a Histamine-Dependent Manner

Exposure to repeated social stress may cause maladaptive emotional reactions that can be reduced by healthy nutritional supplementation. Histaminergic neurotransmission has a central role in orchestrating specific behavioural responses depending on the homeostatic state of a subject, but it remains to be established if it participates in the protective effects against the insults of chronic stress afforded by a healthy diet. By using C57BL/6J male mice that do not synthesize histamine (Hdc−/−) and their wild type (Hdc+/+) congeners we evaluated if the histaminergic system participates in the protective action of a diet enriched with polyunsaturated fatty acids and vitamin A on the deleterious effect of chronic stress. Behavioural tests across domains relevant to cognition and anxiety were performed. Hippocampal synaptic plasticity, cytokine expression, hippocampal fatty acids, oxylipins and microbiota composition were also assessed. Chronic stress induced social avoidance, poor recognition memory, affected hippocampal long-term potentiation, changed the microbiota profile, brain cytokines, fatty acid and oxylipins composition of both Hdc−/−and Hdc+/+ mice. Dietary enrichment counteracted stress-induced deficits only in Hdc+/+ mice as histamine deficiency prevented almost all of the diet-related beneficial effects. Interpretation: Our results reveal a previously unexplored and novel role for brain histamine as a mediator of many favorable effects of the enriched diet. These data present long-reaching perspectives in the field of nutritional neuropsychopharmacology.

Cue-induced cocaine craving enhances psychosocial stress and vice versa in chronic cocaine users

There is evidence that stress and craving contribute to the development, maintenance, and relapse in cocaine use disorder. Previous research has shown altered physiological responses to psychosocial stress as well as increased vegetative responding to substance-related cues in chronic cocaine users (CU). However, how psychosocial stress and cue-induced craving interact in relation to the physiological response of CU is largely unknown. Therefore, we investigated the interaction between acute psychosocial stress and cocaine-cue-related reactivity in 47 CU and 38 controls. Participants were randomly exposed first to a video-based cocaine-cue paradigm and second to the Trier Social Stress Test (TSST) or vice versa in a crossed and balanced design to investigate possible mutually augmenting effects of both stressors on the physiological stress response. Plasma cortisol, ACTH, and noradrenaline as well as subjective stress and craving were assessed repeatedly over the course of the experimental procedure. Growth models and discontinuous growth models were used to estimate the responses during the cocaine-cue paradigm and TSST. Overall, both groups did not differ in their endocrinological responses to the TSST but CU displayed lower ACTH levels at baseline. The TSST did not elevate craving in CU. However, if the cocaine-cue video was shown first, CU displayed an enhanced cortisol response to the subsequent TSST. Cocaine-cues robustly evoked craving in CU but no stress response, while cue-induced craving was intensified after the TSST. Taken together, CU did not show an altered acute stress response during the TSST but stress and craving together seem to have mutually augmenting effects on their stress response.

Magic and Witchcraft Implications for Democratization and Poverty-Alleviating Aid in Africa

ABSTRACT & RÉSUMÉ & ZUSAMMENFASSUNG: The belief in occult forces is still deeply rooted in many African societies, regardless of education, religion, and social class of the people concerned. According to many Africans its incidence is even increasing due to social stress and strain caused (among others) by the process of modernization. Most often magic and witchcraft accusations work to the disadvantage of the poor and deprived, but under particular circumstances they become a means of the poor in the struggle against oppression by establishing "cults of counterviolence." Magic and witchcraft beliefs have increasingly been instrumentalized for political purposes. Apparently they can be used to support any kind of political system, whether despotic or democratic. The belief in occult forces has serious implications for development cooperation. Development projects, which constitute arenas of strategic groups in their struggle for power and control over project resources, are likely to add further social stress to an already endangered precarious balance of power, causing witchcraft accusations to flourish. In addition, witchcraft accusations may serve as indicators of hidden social conflicts which are difficult to detect by other methods. ----------------------------------------------------------------------------------------------------------------------------------------------------------------- RÉSUMÉ : [ La magie et la sorcellerie : conséquences pour la démocratisation et l'aide à la réduction de la pauvreté en Afrique ] - La croyance en forces occultes est encore profondément enracinée dans des nombreuses sociétés africaines, indépendamment de l'éducation, de la religion et de la classe sociale des personnes concernées. Selon des nombreux Africains, son incidence augmente encore en raison du stress social et de la tension causée (entre autres) par le processus de modernisation. Le plus souvent, les accusations de magie et de sorcellerie font mal aux pauvres et aux personnes défavorisées, mais dans des circonstances particulières, elles deviennent un moyen pour les pauvres dans la lutte contre l'oppression en établissant des « cultes de contre-violence ». Les croyances magiques et sorcelleries ont de plus en plus été instrumentées à des fins politiques. Apparemment, ils peuvent être utilisés pour soutenir tout type de système politique, qu'il soit despotique ou démocratique. La croyance en forces occultes a de sérieuses implications pour la coopération au développement. Les projets de développement, qui constituent des arènes de groupes stratégiques dans leur lutte pour le pouvoir et le contrôle sur les ressources du projet, sont susceptibles d'ajouter un stress social supplémentaire à un équilibre de pouvoir précaire déjà menacé, ce qui entraînera des accusations de sorcellerie. En outre, les accusations de sorcellerie peuvent servir d'indicateur de conflits sociaux cachés qui sont difficiles à détecter par d'autres méthodes. ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ZUSAMMENFASSUNG: [Magie und Hexerei: Implikationen für Demokratisierung und armuts-lindernde Entwicklungshilfe in Afrika] - Der Glaube an okkulte Mächte ist immer noch fest verankert in vielen afrikanischen Gesellschaften, unabhängig von Ausbildung, Religion und sozialer Klasse der betroffenen Menschen. Viele Afrikaner glauben sogar, dass Hexerei weiter zunimmt durch die wachsenden gesellschaftlichen Gegensätze im Rahmen der Modernisierung. In der Regel wirken Hexenanschuldigungen zum Nachteil der Armen und Entrechteten. Aber unter bestimmten Umständen können sie durch die Etablierung von ‚Kulten der Gegengewalt‘ auch zum Mittel der Armen in ihrem Kampf gegen Unterdrückung werden. Der Glaube an Magie und Hexerei wird in Afrika zunehmend für politische Zwecke instrumentalisiert. Augenscheinlich kann er zur Unterstützung jeglicher politischer Systeme, ob despotisch oder demokratisch, genutzt werden. Aus dem Glauben an okkulte Mächte ergeben sich gravierende Implikationen für die Entwicklungszusammenarbeit. Entwicklungsprojekt, die auf lokaler Ebene Schauplatz strategischer Gruppen in ihrer Auseinandersetzung um Macht und Kontrolle über Projektmittel bilden, sind dazu angetan, weiteren sozialen Stress zum ohnehin schon prekären Machtgleichgewicht hinzuzufügen, und heizen Hexenanschuldigungen damit an. Davon abgesehen, können Hexenanschuldigungen als Indikator für versteckte soziale Konflikte dienen, die durch andere Methoden der Entwicklungszusammenarbeit kaum aufzudecken sind.

Vascular and blood-brain barrier-related changes underlie stress responses and resilience in female mice and depression in human tissue

Prevalence, symptoms, and treatment of depression suggest that major depressive disorders (MDD) present sex differences. Social stress-induced neurovascular pathology is associated with depressive symptoms in male mice; however, this association is unclear in females. Here, we report that chronic social and subchronic variable stress promotes blood-brain barrier (BBB) alterations in mood-related brain regions of female mice. Targeted disruption of the BBB in the female prefrontal cortex (PFC) induces anxiety- and depression-like behaviours. By comparing the endothelium cell-specific transcriptomic profiling of the mouse male and female PFC, we identify several pathways and genes involved in maladaptive stress responses and resilience to stress. Furthermore, we confirm that the BBB in the PFC of stressed female mice is leaky. Then, we identify circulating vascular biomarkers of chronic stress, such as soluble E-selectin. Similar changes in circulating soluble E-selectin, BBB gene expression and morphology can be found in blood serum and postmortem brain samples from women diagnosed with MDD. Altogether, we propose that BBB dysfunction plays an important role in modulating stress responses in female mice and possibly MDD.

COVID-19 patient accounts of illness severity, treatments and lasting symptoms

First-person accounts of COVID-19 illness and treatment can complement and enrich data derived from electronic medical or public health records. With patient-reported data, it is uniquely possible to ascertain in-depth contextual information as well as behavioral and emotional responses to illness. The Novel Coronavirus Illness Patient Report (NCIPR) dataset includes complete survey responses from 1,584 confirmed COVID-19 patients ages 18 to 98. NCIPR survey questions address symptoms, medical complications, home and hospital treatments, lasting effects, anxiety about illness, employment impacts, quarantine behaviors, vaccine-related behaviors and effects, and illness of other family/household members. Additional questions address financial security, perceived discrimination, pandemic impacts (relationship, social, stress, sleep), health history, and coping strategies. Detailed patient reports of illness, environment, and psychosocial impact, proximal to timing of infection and considerate of demographic variation, is meaningful for understanding pandemic-related public health from the perspective of those that contracted the disease.

The rosy future paradox: Positive future thinking without task relevance enhances negative biases and anxiety for aversive events

Expectations have an important role in guiding behavior and the interpretation of novel information, but can contain negative biases such as is the case in anxiety disorders. Positive future thinking may provide an accessible way to attenuate these negatively biases. However, much is still unclear about the optimal form of such positive interventions, and it is unknown if the effects go beyond subjective experience. Here, we used a positive future thinking intervention to adapt the way a stressful event is experienced. Participants imagined either task-relevant (N = 21) or irrelevant (N = 21) positive future events before being subjected to the Trier Social Stress Task, or did not receive the intervention (N= 20). We recorded resting state EEG during the anticipation and recovery phases of the TSST to assess intervention and trait anxiety related differences in the level of frontal delta-beta coupling, which is considered a neurobiological substrate of emotion regulation. Results show that the intervention reduces event-related stress and anxiety, and increases social fixation behavior and task performance, but only if future thinking is task relevant. Paradoxically, task-irrelevant positive future thoughts enhance negative perceptual biases and stress reactivity. This increase in stress reactivity in the task-irrelevant group was corroborated by the elevated levels frontal delta-beta coupling during event anticipation, especially for those with high trait anxiety. This suggests an increased demand for emotion regulation following the task-irrelevant intervention, possibly due to the contextual incongruence between positive imagery and the stressor. Together, these results show that positive future thinking can mitigate the negative emotional, behavioral and neurobiological consequences of a stressful event, but that it should not be applied indiscriminately. Task-relevant positive future thinking can be an accessible way to boost efficacy of exposure therapy for pathological anxiety, and can help people deal with negative anticipation in daily life.

Effects of an incremental theory of the personality intervention on psychophysiological responses to social stress during the transition to college

This randomized controlled trial (NCT04786496) examined the effects of a preventive intervention based on Incremental Theory of the Personality (ITP) on psychophysiological responses to social stress and evaluated whether levels of depression moderate the intervention effects. The participants, 107 first-year university students, were randomly assigned to one of three conditions: ITP intervention, ITP + a self-affirmation intervention (SA), and a control condition (CC). Indicators of the Hypothalamic–Pituitary–Adrenal axis, autonomic nervous system, and subjective mood were assessed with the Trier Social Stress Task. Participants in the ITP condition displayed a lower decline in respiratory sinus arrythmia (RSA) compared to those in the CC during the first phases of the task [Slopes: -0.08 (0.09) vs -0.21 (0.09), z = 2.86, p = .004] and a higher decrease in cortisol at recovery [β = -0.18 (0.08), z = -2.37, p = .018]. Depressive symptoms moderated the effect of ITP [β = -0.10 (0.05), z = -2.15, p =.032] and ITP+SA [β = -0.09 (0.04), z = -2.06, p =.039] in the decline during stress and recovery in RSA. In participants with low/medium levels of depressive symptoms, both interventions predicted a lower decline during stress [Slopes: -0.06 (0.09) for ITP, -0.17 (.09) for ITP+SA, and -0.26 (0.09) for CC] and higher recovery in RSA [Slopes: 0.18 (0.01) for ITP, 0.24 (0.01) for ITP+SA, and 0.30 (0.01) for CC]. The findings suggest that the ITP intervention has the potential to be an effective preventive intervention to reduce the stress response.