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Adolescent-onset depression is a prevalent and debilitating condition commonly associated with treatment refractory depression and non-response to first-line antidepressants. There are, however, no objective tests to determine who may or may not respond to antidepressants. As depressed adolescents are especially vulnerable to the lifelong consequences of ineffectively-treated depression, it is critical to identify neurobiological predictors of treatment non-response in this population. Here, we describe the scientific rationale and protocol for the Teen Inflammation Glutamate Emotion Research (TIGER) study, a prospective 18-month investigation of 160 depressed adolescents who will be assessed before and after treatment with selective serotonin reuptake inhibitors. TIGER will be using ultra-high field imaging to test the effects of acute stress and antidepressant treatment on inflammatory and glutamatergic processes hypothesized to underlie depression maintenance. Results from this work will motivate future studies testing alternative therapeutics for depressed adolescents at risk for treatment resistant depression. ClinicalTrials.gov Identifier: NCT05329441.

BackgroundAlthough social rejection is among the strongest proximal precipitants of major depressive disorder (MDD), little is known about the underlying neurobiological mechanisms and whether neural sensitivity to social rejection may help explain differences in MDD risk. To address this issue, we tested whether neural responses to social threat differed in female adolescents at high vs. low maternal risk for MDD.MethodFemale adolescents with (high-risk; n = 22, Mage = 14.68) and without (low-risk; n = 30, Mage = 15.07) a maternal history of depression were experimentally exposed to negative and neutral social evaluation while undergoing an fMRI scan. Neural responses were assessed by event-related activity and functional connectivity, as well as multivoxel pattern analysis. Activity and functional connectivity analyses focused on a priori-selected regions of interest implicated in self-referential processing and emotion regulation.ResultsCompared to low-risk female adolescents, high-risk female adolescents exhibited greater increases in self-reported depression and social disconnection following social evaluation. Moreover, compared to low-risk female adolescents, high-risk female adolescents exhibited greater amygdala responses to negative social evaluation and a differential pattern of functional connectivity in brain regions related to emotion regulation, self-referential processing, and negative affect. Additionally, these markers of neural threat reactivity were related to depressive symptoms.LimitationsA cross-sectional study design and relatively small, Western sample.ConclusionsThese results suggest that exaggerated neural reactivity to social threat-and an atypical pattern of related functional connectivity-is evident in individuals with a preclinical risk factor for depression. Targeting such responding may thus be a fruitful strategy for preventing depression in at-risk youth.

ABSTRACT Intensive longitudinal biomarker data are increasingly common in scientific studies that seek temporally granular understanding of the role of behavioral and physiological factors in relation to outcomes of interest. Intensive longitudinal biomarker data, such as those obtained from wearable devices, are often obtained at a high frequency typically resulting in several hundred to thousand observations per individual measured over minutes, hours, or days. Often in longitudinal studies, the primary focus is on relating the means of biomarker trajectories to an outcome, and the variances are treated as nuisance parameters, although they may also be informative for the outcomes. In this paper, we propose a Bayesian hierarchical model to jointly model a cross‐sectional outcome and the intensive longitudinal biomarkers. To model the variability of biomarkers and deal with the high intensity of data, we develop subject‐level cubic B‐splines and allow the sharing of information across individuals for both the residual variability and the random effects variability. Then different levels of variability are extracted and incorporated into an outcome submodel for inferential and predictive purposes. We demonstrate the utility of the proposed model via an application involving bio‐monitoring of hertz‐level heart rate information from a study on social stress. [ABSTRACT FROM AUTHOR]

Objectives: The impacts of stress on inflammation, although hypothesized, have not been thoroughly examined, especially in relation to social and environmental factors and particularly within Black populations. This study aims to explore the biological mechanisms of embodiment linking stress and health to understand physiological changes in the body's response to psychological stress in a Nigerian population. Through a multidisciplinary approach, this study queries the relationship between stress, cortisol, and salivary C‐reactive protein (sCRP), a biomarker of inflammation, while also validating the use of sCRP as a potential and accurate stress indicator in the field. Methods: In this cross‐sectional study, 138 passive drool saliva samples (nfemale = 89 nmale = 49) were collected and assessed for sCRP and cortisol levels in adults. Participants also completed a short demographic survey and, to measure psychological stress, the General Health Questionnaire 12 (GHQ‐12). Relationships between sCRP and stress‐related variables (i.e., cortisol, GHQ‐12, and demographic data) were assessed using Spearman's correlations, simple regression, multivariable linear regression, and exploratory factor analysis. Results: sCRP levels ranged from 20.57 to 6879.41 pg/mL across all samples, with significant differences between female and male participants. The GHQ‐12 was not a significant predictor of sCRP variability. However, socio‐demographic factors such as body mass index (BMI), age, self‐reported sex, ethnic identity, and cortisol were significant predictors, collectively explaining 24%–27% of the variation in sCRP. Conclusion: Socio‐demographic predictors like BMI, age, sex, and particularly ethnic group experience in Nigeria encapsulate aspects of embodied stress, that significantly affect sCRP variability. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusions Adolescents exposed to victimization are at an increased risk for a variety of adverse mental health outcomes, including depressive symptoms. Yet, the biological pathways underlying these associations remain poorly understood. Focusing on within‐person processes, we examined whether low‐grade systemic inflammation mediated the longitudinal associations between peer victimization and depressive symptoms in adolescence.207 adolescents (at baseline Mage = 12.69 years; SD = 0.49; 43.5% female) participated in a multi‐wave longitudinal study, with assessments repeated every 6 months over 1.5 years. At each assessment wave, participants self‐reported their peer victimization experiences and depressive symptoms. Dried blood spots were collected at each wave using a finger prick procedure to assay a key marker of low‐grade systemic inflammation, interkeukin‐6 (IL‐6). Data were analyzed using random‐intercept cross‐lagged panel models.The cross‐lagged paths from IL‐6 to depressive symptoms were significant across all models and waves (β12 = .13; β23 = .12; β34 = .08), indicating that when adolescents' levels of low‐grade systemic inflammation were above their person‐specific average, they reported increased levels of depressive symptoms in the subsequent months. However, no significant cross‐lagged within‐person associations emerged between peer victimization and either IL‐6 or depressive symptoms.The findings provide no evidence for the hypothesized mediating role of inflammation in the within‐person associations between peer victimization and depressive symptoms. Nevertheless, they extend prior research by indicating that elevated levels of low‐grade systemic inflammation predict the development of depressive symptoms in adolescence. [ABSTRACT FROM AUTHOR]

Background: Perinatal psychological distress adversely impacts the well-being and social adjustment of parents and their children. Expectant parents who have migrated may be at higher risk for perinatal psychological distress due to various migration-specific stressors and healthcare service barriers. Limited studies have examined the perceived determinants of perinatal distress in immigrant parents, particularly men. This study explored first and second-generation immigrant parents' lived experiences of social stressors and facilitators of perinatal psychological well-being. Methods: Participants were recruited by convenience and purposive sampling as part of a larger study. Semi-structured interviews were conducted virtually with first and second-generation immigrant women and men in Quebec, Canada. An inductive thematic analysis was performed. Results: Sixteen women (age = 34.8 ± 3.7 years) and ten men (age = 35.1 ± 4.9 years) from various ethnic backgrounds participated in the study at 7.4 ± 0.73 and 7.5 ± 0.72 months postpartum, respectively. Three themes were identified: (1) cultural pressures (cultural differences in parenting, gender-related cultural pressures, health and baby-related practices), (2) health and social service access (social benefits and resources, and systemic barriers in health care), and (3) discrimination (physical appearance or parental-related discrimination, gender-related discrimination, ethnic-related discrimination). First-generation immigrant parents reported greater acculturative stress (i.e. mental health stigma, health care access) and ethnic discrimination concerns related to their distress. Among men, barriers include feeling as though the paternal role was devalued by society and not receiving consideration by health care. Conclusions: Our results highlight different social factors of perinatal well-being perceived by men and women from various ethnic and immigration backgrounds during the perinatal period. Perceived factors include macro-level factors, such as a country's social climate, health and social policies and services, and social aspects of acculturative stress. Our findings suggest the need for continued efforts to challenge and eliminate discriminatory practices. Interventions and resources directed at first-generation immigrant parents should be bolstered. Understanding what parents perceive to facilitate or hinder their psychological well-being can help inform the development of tailored evidence-based programs and policies to better meet the mental health needs of Canadians and reduce gender disparities in the treatment of perinatal distress. [ABSTRACT FROM AUTHOR]

Stress is a critical factor in the development of mental disorders such as addiction, underscoring the importance of stress resilience strategies. While the ketogenic diet (KD) has shown efficacy in reducing alcohol consumption in male mice without cognitive impairment, its impact on the stress response and addiction development, especially in females, remains unclear. This study examined the KD's effect on increasing ethanol intake due to vicarious social defeat (VSD) in female mice. Sixty-four female OF1 mice were divided into two dietary groups: standard diet (n = 32) and KD (n = 32). These were further split based on exposure to four VSD or exploration sessions, creating four groups: EXP-STD (n = 16), VSD-STD (n = 16), EXP-KD (n = 16), and VSD-KD (n = 16). KD-fed mice maintained ketosis from adolescence until the fourth VSD/EXP session, after which they switched to a standard diet. The Social Interaction Test was performed 24 h after the last VSD session. Three weeks post-VSD, the Drinking in the Dark test and Oral Ethanol Self-Administration assessed ethanol consumption. The results showed that the KD blocked the increase in ethanol consumption induced by VSD in females. Moreover, among other changes, the KD increased the expression of the ADORA1 and CNR1 genes, which are associated with mechanisms modulating neurotransmission. Our results point to the KD as a useful tool to increase resilience to social stress in female mice. [ABSTRACT FROM AUTHOR]

Abstract Background Perinatal psychological distress adversely impacts the well-being and social adjustment of parents and their children. Expectant parents who have migrated may be at higher risk for perinatal psychological distress due to various migration-specific stressors and healthcare service barriers. Limited studies have examined the perceived determinants of perinatal distress in immigrant parents, particularly men. This study explored first and second-generation immigrant parents’ lived experiences of social stressors and facilitators of perinatal psychological well-being. Methods Participants were recruited by convenience and purposive sampling as part of a larger study. Semi-structured interviews were conducted virtually with first and second-generation immigrant women and men in Quebec, Canada. An inductive thematic analysis was performed. Results Sixteen women (age = 34.8 ± 3.7 years) and ten men (age = 35.1 ± 4.9 years) from various ethnic backgrounds participated in the study at 7.4 ± 0.73 and 7.5 ± 0.72 months postpartum, respectively. Three themes were identified: (1) cultural pressures (cultural differences in parenting, gender-related cultural pressures, health and baby-related practices), (2) health and social service access (social benefits and resources, and systemic barriers in health care), and (3) discrimination (physical appearance or parental-related discrimination, gender-related discrimination, ethnic-related discrimination). First-generation immigrant parents reported greater acculturative stress (i.e. mental health stigma, health care access) and ethnic discrimination concerns related to their distress. Among men, barriers include feeling as though the paternal role was devalued by society and not receiving consideration by health care. Conclusions Our results highlight different social factors of perinatal well-being perceived by men and women from various ethnic and immigration backgrounds during the perinatal period. Perceived factors include macro-level factors, such as a country’s social climate, health and social policies and services, and social aspects of acculturative stress. Our findings suggest the need for continued efforts to challenge and eliminate discriminatory practices. Interventions and resources directed at first-generation immigrant parents should be bolstered. Understanding what parents perceive to facilitate or hinder their psychological well-being can help inform the development of tailored evidence-based programs and policies to better meet the mental health needs of Canadians and reduce gender disparities in the treatment of perinatal distress.

Traumatic stress increases the risk for mental health conditions and adversely impacts health, academic performance, and coping. Transgender and gender diverse (TGD) youth experience higher rates of abuse and maltreatment and interpersonal and community-embedded discrimination than their cisgender peers. Neurobiologic stress responses and social stress theory provide useful frameworks for understanding the effects of discrimination, stigma, and rejection. Despite facing higher rates of interpersonal trauma, TGD youth are quite resilient when able to access supports and affirming trauma-informed services. Clinicians play an important role in identifying and addressing traumatic stress impacting TGD youth and bolstering resilience.

Both social support and social stress can impact adolescent physiology including hormonal responses during the sensitive transition to adolescence. Social support from parents continues to play an important role in socioemotional development during adolescence. Sources of social support and stress may be particularly impactful for adolescents with social anxiety symptoms. The goal of the current study was to examine whether adolescent social anxiety symptoms and maternal comfort moderated adolescents' hormonal response to social stress and support. We evaluated 47 emotionally healthy 11- to 14-year-old adolescents' cortisol and oxytocin reactivity to social stress and support using a modified version of the Trier Social Stress Test for Adolescents that included a maternal comfort paradigm. Findings demonstrated that adolescents showed significant increases in cortisol and significant decreases in oxytocin following the social stress task. Subsequently, we found that adolescents showed significant decreases in cortisol and increases in oxytocin following the maternal comfort paradigm. Adolescents with greater social anxiety symptoms showed higher levels of cortisol at baseline but greater declines in cortisol response following maternal social support. Social anxiety symptoms were unrelated to oxytocin response to social stress or support. Our findings provide further evidence that mothers play a key role in adolescent regulation of physiological response, particularly if the stressor is consistent with adolescents' anxiety. More specifically, our findings suggest that adolescents with higher social anxiety symptoms show greater sensitivity to maternal social support following social stressors. Encouraging parents to continue to serve as a supportive presence during adolescent distress may be helpful for promoting stress recovery during the vulnerable transition to adolescence. [ABSTRACT FROM AUTHOR]

Phenotypic differences often stem from genetic/maternal differences and/or early-life adaptations to local environmental conditions. In colonial animals, little is known on how variation in the social environment is embedded into individual phenotypes, nor what the consequences are on individual fitness. We conducted an experimental cross-fostering study on king penguins (Aptenodytes patagonicus), exchanging eggs among 134 pairs breeding in high-density (67 pairs) or low-density (67 pairs) areas of the same breeding colony. We investigated differences in parent and chick phenotypes and survival in relation to the density of their origin and foster environment. Adults breeding in colony areas of high density exhibited decreased resting behaviour and increased aggression and vigilance, increased hypometabolism during incubation fasts, and more moderate corticosterone responses shaped by exposure to chronic stressors (e.g. constant aggression by neighbours). Chick phenotypes were more influenced by the environment in which they were raised than their genetic/maternal origin. Chicks raised in high-density colonial environments showed enhanced weight gain and survival rates regardless of the density of their genetic parents' breeding areas. Our study experimentally shows advantages to breeding in colonial areas of higher breeder densities in king penguins, and highlights the importance of social settings in shaping phenotype expression in colonial seabirds. [ABSTRACT FROM AUTHOR]

Numerous studies have evidenced that neuropsychiatric disorders (mental illness and emotional disturbances) with aggression (or violence) pose a significant challenge to public health and contribute to a substantial economic burden worldwide. Especially, social disorganization (or social inequality) associated with childhood adversity has long-lasting effects on mental health, increasing the risk of developing neuropsychiatric disorders. Intestinal bacteria, functionally as an endocrine organ and a second brain, release various immunomodulators and bioactive compounds directly or indirectly regulating a host's physiological and behavioral homeostasis. Under various social challenges, stress-induced dysbiosis increases gut permeability causes serial reactions: releasing neurotoxic compounds, leading to neuroinflammation and neuronal injury, and eventually neuropsychiatric disorders associated with aggressive, violent, or impulsive behavior in humans and various animals via a complex bidirectional communication of the microbiota–gut–brain (MGB) axis. The dysregulation of the MGB axis has also been recognized as one of the reasons for the prevalence of social stress-induced injurious behaviors (feather pecking, aggression, and cannibalistic pecking) in chickens. However, existing knowledge of preventing and treating these disorders in both humans and chickens is not well understood. In previous studies, we developed a non-mammal model in an abnormal behavioral investigation by rationalizing the effects of gut microbiota on injurious behaviors in chickens. Based on our earlier success, the perspective article outlines the possibility of reducing stress-induced injurious behaviors in chickens through modifying gut microbiota via cecal microbiota transplantation, with the potential for providing a biotherapeutic rationale for preventing injurious behaviors among individuals with mental disorders via restoring gut microbiota diversity and function. [ABSTRACT FROM AUTHOR]

Adolescents' suicidal behavior frequently is preceded by interpersonal stress, but not all who experience distress attempt to end their lives. Recent theories have posited individual differences in stress-related inflammatory reactivity may be associated with psychopathology risk; this study examined inflammatory reactivity as a moderator of the prospective association between interpersonal stress and adolescents' suicidal behavior. Participants included 157 at-risk adolescent females (ages 12 to 16 years) and assessed individual differences in proinflammatory cytokine responses to a brief laboratory-based social stressor, both interpersonal and non-interpersonal life events, and suicidal behavior over an 18-month follow-up period. Measuring levels of the key proinflammatory cytokines interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) before and after an experimentally-induced social stressor, results revealed that blunted cytokine reactivity heightened the effect of high interpersonal stress exposure on risk for suicidal behaviors over the subsequent 9 months. Significant effects were not revealed for non-interpersonally themed stress. Finding highlight the urgent need for more research examining inflammation reactivity among adolescents.

Cognitive deficit is a debilitating complication of sickle cell disease (SCD), with a multifactorial etiopathogenesis. Here we show that neuroinflammation and dysregulation in lipidomics and transcriptomics profiles are major underlying mechanisms of social stress-induced cognitive deficit in SCD. Male Townes sickle cell (SS) mice and controls (AA) were exposed to social stress using the repeat social defeat (RSD) paradigm concurrently with or without treatment with minocycline. Mice were tested for cognitive deficit using novel object recognition and fear conditioning tests. SS mice exposed to RSD without treatment had worse performance on cognitive tests compared to SS mice exposed to RSD with treatment or to AA controls, irrespective of their RSD or treatment disposition. Additionally, compared to SS mice exposed to RSD with treatment, SS mice exposed to RSD without treatment had significantly more cellular evidence of neuroinflammation coupled with a significant shift in the differentiation of neural progenitor cells towards astrogliogenesis. Additionally, brain tissue from SS mice exposed to RSD was significantly enriched for genes associated with blood-brain barrier dysfunction, neuron excitotoxicity, inflammation, and significant dysregulation in sphingolipids important to neuronal cell processes. We demonstrate in this study that social stress induces cognitive deficit in SS mice, concurrently with neuroinflammation and lipid dysregulation.

Social stress is the most significant source of chronic stress in humans and is commonly associated with health impairment. Individual differences in the behavioral coping responses to stress have been proposed to mediate the negative effects of stress on physical, behavioral and mental health. Animal models, particularly mice, offer valuable insights into the physiological and neurobiological correlates of behavioral coping strategies in response to chronic social stress. Here we aim to identify differences and similarities among stress protocols in mice, with particular attention to how neuroendocrine and/or behavioral responses vary according to different coping strategies, while highlighting the need for standardized approaches in future research. A systematic review was undertaken following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA statement). A total of 213 references were identified by electronic search, and after the screening, 18 articles were found to meet all the established criteria. We analyzed differences in the stress protocol, the characterization and classification of coping strategies and the physiological and behavioral differences according to coping. The results show that differences in behavioural expression under chronic social stress (coping) may also be associated with physiological differences and differential susceptibility to disease. However, this review also underlines the importance of a cautious interpretation of the results obtained. The lack of consistency in the nomenclature and procedures associated with the study of coping strategies for social stress, as well as the absence of a uniform classification, highlight the importance of using a common language when approaching the study of coping strategies. Thereby, this review encourages the development of a more defined method and criteria for assessing coping strategies, based on both behavioral and biological indicators.

Chronic stress has been connected to a reduced effort and motivational deficits. To study effort-based motivation in rodents, operant conditioning is often employed. However, caloric restriction is typically imposed simultaneously. Since caloric restriction is a stressor in its own right, this procedure interferes with data interpretation. Here, we investigate whether chronic social defeat stress (CSD), lasting 10 consecutive days, would alter effort-based reward motivation in mice trained under ad libitum food conditions. Utilizing operant FED3 boxes in home cages, mice were trained within eight days to nose poke for palatable food. After training completion, operant memory was retained for at least 16 days, and mice demonstrated sustained effort, as assessed with a progressive ratio schedule, to obtain reward pellets. Directly after CSD exposure (10th day), mice exhibited reduced effort for palatable food rewards, but also displayed reduced nose poking in general. The effects of CSD on effort were short-lived, with no lasting impact on effort-based reward motivation one week post-stress. As corticosterone (CORT) levels were increased at day 10 of CSD, but not at day 17, we hypothesized that CORT might mediate the acute effects of CSD on effort-based reward motivation. Indeed, CORT administration [100 μg/ml], supplied via the drinking water, mirrored the CSD-induced CORT spike and temporarily reduced reward motivation. Our findings emphasize that CSD does not result in long-term deficits in reward motivation, suggesting a resilient adaptive response in mice under unrestricted feeding conditions. This study underscores the necessity of considering temporal dynamics of stress impacts and highlights the modulating effects of CORT. These insights contribute to a deeper understanding of the resilience mechanisms in motivational impairments and pave the way for further research into factors facilitating this resilience.

Regrouping practices are frequent in pig production, altering hierarchy and triggering aggressive behaviors. The present study aimed to investigate the physiological responses of piglets to an experimental model designed to induce stress through systematic social mixing in two trials. In Trial A, a total of 144 crossbred piglets (25 days postweaning) housed in one room within 36 pens (four piglets/pen) were used and randomly assigned to either a control group (piglets maintained in their pen, Ctrl-A) or a social challenge group (piglets mixed, SC-A). In Trial B, the same number of animals (33 days postweaning) and crossbreed line was used, and each piglet was assigned either to a control group (Ctrl-B) or a social challenge group (SC-B) in two independent rooms (rooms Ctrl and SC, 12 pens/ room, six piglets/pen). The social challenge consisted of daily moves of three out of four pen mates and five out of six pen mates, for Trials A and B, respectively. In the Ctrl groups, all piglets stayed in their original pen. Before the 1st mixing day and at the end of the 3rd mixing day, saliva (cortisol concentration) and blood (cortisol concentration changes, hemogram, and immunologic activation) samples were collected from two random piglets per pen. Skin lesion scores of all piglets were also recorded on the front, middle, and rear body regions. In Trial A, the total skin lesions score was higher in the SC-A group compared to the Ctrl-A group after the social challenge (0.53 vs. 0.17; p

BackgroundEarly-life adversity (ELA) has been linked to higher depression risk across the life span and chronic inflammatory conditions that contribute to earlier mortality. In this study, we characterized innate immune responses to acute social stress in a community sample of adolescents (mean age = 13.9 ± 1.6 years; 46.4% female) as a potential pathway linking ELA and depression pathogenesis.MethodsParents reported their child's exposure to 9 ELAs, and adolescents participated in the Trier Social Stress Test for Children, with blood collected immediately before and then at 60 and 90 minutes thereafter. Overall, 65 adolescents had complete data for analysis of stress-induced changes in gene expression and 84 adolescents had complete data for circulating inflammatory markers.ResultsRelative to adolescents exposed to no ELA (11.9%) or low ELA (ELA = 1-3; 67.9%), those exposed to high ELA (ELA = 4+; 20.2%) showed larger stress-associated increases in expression of both proinflammatory and innate antiviral gene transcripts in circulating blood. Consistent with a potential mediating role of sympathetic nervous system activity, promoter-based bioinformatics analyses implicated CREB transcription factor activity in structuring observed gene expression differences. These effects were accompanied by a smaller initial but protracted increase in circulating interleukin 6 in adolescents with high ELA.ConclusionsResults are consistent with the hypothesis that ELA may enhance cellular and gene regulatory reactivity to stress, which may, in turn, increase vulnerability to depression and other inflammation-related disease processes.

BACKGROUND: Women are at increased risk for psychosocial stress-related anxiety disorders, yet mechanisms regulating this risk are unknown. Psychosocial stressors activate microglia, and the resulting neuroimmune responses that females exhibit heightened sensitivity to may serve as an etiological factor in their elevated risk. However, studies examining the role of microglia during stress in females are lacking. METHODS: Microglia were manipulated in the stress-sensitive locus coeruleus (LC) of female rats in the context of social stress in two ways. First, intra-LC lipopolysaccharide (LPS; 0 or 3 μg/side, n = 5-6/group), a potent TLR4 agonist and microglial activator, was administered. One hour later, rats were exposed to control or an aggressive social defeat encounter between two males (WS, 15-min). In a separate study, females were treated with intra-LC or intra-central amygdala mannosylated liposomes containing clodronate (m-CLD; 0 or 25 μg/side, n = 13-14/group), a compound toxic to microglia. WS-evoked burying, cardiovascular responses, and sucrose preference were measured. Brain and plasma cytokines were quantified, and cardiovascular telemetry assessed autonomic balance. RESULTS: Intra-LC LPS augmented the WS-induced burying response and increased plasma corticosterone and interleukin-1β (IL-1β). Further, the efficacy and selectivity of microinjected m-CLD was fully characterized. In the context of WS, intra-LC m-CLD attenuated the hypervigilant burying response during WS as well as the accumulation of intra-LC IL-1β. Intra-central amygdala m-CLD had no effect on WS-evoked behavior. CONCLUSIONS: These studies highlight an innovative method for depleting microglia in a brain region specific manner and indicate that microglia in the LC differentially regulate hypervigilant WS-evoked behavioral and autonomic responses.

Abstract Repeated stress can predispose to substance abuse. However, behavioral and neurobiological adaptations that link stress to substance abuse remain unclear. This study investigates whether intermittent social defeat (ISD), a stress protocol that promotes drug-seeking behavior, alters intertemporal decision-making and cortical inhibitory function in the medial prefrontal cortex (mPFC). Male long evans rats were trained in a delay discounting task (DDT) where rats make a choice between a fast (1 s) small reward (1 sugar pellet) and a large reward (3 sugar pellets) that comes with a time delay (10 s or 20 s). A decreased preference for delayed rewards was used as an index of choice impulsivity. Rats were exposed to ISD and tested in the DDT 24 h after each stress episode, and one- and two-weeks after the last stress episode. Immunohistochemistry was performed in rat’s brains to evaluate perineuronal nets (PNNs) and parvalbumin GABA interneurons (PV) labeling as markers of inhibitory function in mPFC. ISD significantly decreased the preference for delayed large rewards in low impulsive, but not high impulsive, animals. ISD also increased the density of PNNs in the mPFC. These results suggest that increased choice impulsivity and cortical inhibition predispose animals to seek out rewards after stress.

BackgroundDuring adolescence, microglia are actively involved in neocortical maturation while concomitantly undergoing profound phenotypic changes. Because the teenage years are also a time of experimentation with cannabis, we evaluated whether adolescent exposure to the drug's psychotropic constituent, Δ9-tetrahydrocannabinol (THC), might persistently alter microglia function.MethodsWe administered THC (5 mg/kg, intraperitoneal) once daily to male and female mice from postnatal day (PND) 30 to PND44 and examined the transcriptome of purified microglia in adult animals (PND70 and PND120) under baseline conditions or following either of two interventions known to recruit microglia: lipopolysaccharide injection and repeated social defeat. We used high-dimensional mass cytometry by time-of-flight to map brain immune cell populations after lipopolysaccharide challenge.ResultsAdolescent THC exposure produced in mice of both sexes a state of microglial dyshomeostasis that persisted until young adulthood (PND70) but receded with further aging (PND120). Key features of this state included broad alterations in genes involved in microglia homeostasis and innate immunity along with marked impairments in the responses to lipopolysaccharide- and repeated social defeat-induced psychosocial stress. The endocannabinoid system was also dysfunctional. The effects of THC were prevented by coadministration of either a global CB1 receptor inverse agonist or a peripheral CB1 neutral antagonist and were not replicated when THC was administered in young adulthood (PND70-84).ConclusionsDaily low-intensity CB1 receptor activation by THC during adolescence may disable critical functions served by microglia until young adulthood with potentially wide-ranging consequences for brain and mental health.

• Chronic social defeat stress increases ghsr mRNA expression in the VTA in male mice. • GHSR signaling in the VTA is required for stress-induced changes in caloric intake in male mice. • Inhibition of GHSR signaling in the VTA of male mice exacerbates anxiogenic effects of chronic stress. Ghrelin, a hormone secreted by the stomach, binds to the growth hormone secretagogue receptor (GHSR) in various brain regions to produce a number of behavioral effects that include increased feeding motivation. During social defeat stress, ghrelin levels rise in correlation with increased feeding and potentially play a role in attenuating the anxiogenic effects of social defeat. One region implicated in the feeding effects of ghrelin is the ventral tegmental area (VTA), a region implicated in reward seeking behaviors, and linked to social defeat in mice. Here we examined the role of GHSR signaling in the VTA in feeding behavior in mice exposed to social defeat stress. Male C57BL/J6 mice that were socially defeated once daily for 3 weeks ate more, had higher plasma ghrelin level and increased GHSR expression in the VTA compared to non-stressed mice. Socially defeated GHSR KO mice failed to increase their caloric intake in response to this stressor but rescue of GHSR expression in the VTA restored feeding responses. Finally, we pharmacologically blocked VTA GHSR signalling with JMV2959 infused via an indwelling VTA cannula connected to a minipump. Vehicle-treated mice increased their caloric intake during social defeat, but JMV2959-infusions attenuated feeding responses and increased anxiety-like behaviors. The data suggest that GHSR signalling in the VTA is critical for the increases in appetite observed during chronic social defeat stress. Furthermore, these data support the idea that GHSR signaling in the VTA may also have anxiolytic effects, and blocking GHSR in this region may result in an anxiety-like phenotype. [ABSTRACT FROM AUTHOR]

Social support is vital for mental and physical health and is linked to lower rates of disease and early mortality. Conversely, anti-social behavior can increase mortality risks, both for the initiator and target of the behavior. Chronic stress, which also can increase mortality, may serve as an important link between social behavior and healthy lifespan. There is a growing body of literature in both humans, and model organisms, that chronic social stress can result in more rapid telomere shortening, a measure of biological aging. Here we examine the role of anti-social behavior and social support on physiological markers of stress and aging in the social Japanese quail, Coturnix Japonica. Birds were maintained in groups for their entire lifespan, and longitudinal measures of antisocial behavior (aggressive agonistic behavior), social support (affiliative behavior), baseline corticosterone, change in telomere length, and lifespan were measured. We found quail in affiliative relationships both committed less and were the targets of less aggression compared to birds who were not in these relationships. In addition, birds displaying affiliative behavior had longer telomeres, and longer lifespans. Our work suggests a novel pathway by which social support may buffer against damage at the cellular level resulting in telomere protection and subsequent longer lifespans. [ABSTRACT FROM AUTHOR]

An alarming number of early adolescents between the ages of 11 and 14 report experiencing cyber-victimization (i.e., bullying that occurs online or via technology). Although research has demonstrated that spending more time on social media can increase the likelihood of cyber-victimization, less research has examined how adolescents are using social media. For example, the conflicts and problems that can arise from social media use may also increase vulnerability to cyber-victimization. The current study examined this association between problematic social media use and conflict (PSMUC) and cyber-victimization among a sample of early adolescents. Also, guided by the Social Information Processing model, the current study examined the indirect effect of social stress (i.e., feelings of isolation and social exclusion) in the association between PSMUC and cyber-victimization. Adolescents (N = 316) participated during the spring of sixth grade from a large public middle school in the Midwestern United States. Assessments included measures of PSMUC, cyber-victimization, and social stress. Using structural equation modeling, results indicated that PSMUC was associated with higher levels of cyber-victimization via higher levels of social stress. These findings indicate that social stress is an important mechanism to consider in the relationship between PSMUC and cyber-victimization experiences among early adolescents. Implications for prevention and intervention programs, as well as future research directions, are discussed. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to identify the factors that influence the social media behavior of Generation Z in the post-COVID era. A conceptual framework has now been constructed. Methodology: The purpose of the standardized questionnaire was to collect primary data from Generation Z university students employing a non-probability, purposive sampling method. 841 people completed the questionnaire. The SmartPLS-SEM4.0.9.9 program was used to analyze the study model. Results: It seems from the data that social stress, self-regulation, addictive smartphone use, and conduct related to social media use were important predictors of social media usage behavior. Furthermore, it was shown that the subjective well-being construct's moderation component lacked statistical significance. Research limitations: The study lacks more generalizability, as it only includes data from a limited sample of Generation Z individuals from Bangladesh, specifically those residing in the Dhaka region. Practical implications: By adding social stress and self-regulation, this study has advanced the body of current literature in addition to offering fresh perspectives and interpretations on how members of Generation Z use social media. In addition, this study aims to advance current understanding by categorizing key components that may promote the emergence of addictive behaviors associated with social media and smartphone use. Besides, by designing targeted lesson plans and interventions, the study's findings may help students become more self-reliant. Institutions that support social stress management and responsible technology use can assist students in striking a balance between their personal and academic life. Originality: This method will help to better understand how Gen Z uses social media and how addictive smartphone use and social media usage habits affect subjective well-being. [ABSTRACT FROM AUTHOR]

Simple Summary: A plethora of studies have evidenced that the gut microbiota profoundly influences host brain function and behavioral characteristics in humans and various animals. In laying hens, it has been reported that injurious behaviors (such as aggressive pecking, feather pecking, and cannibalism) are associated with dysregulation of the microbiota–gut–brain axis. This study further investigated the effects of the early-life transplantation of different cecal contents on aggressiveness and related behaviors in chickens. Cecal bacterial profiles of two divergently selected inbred genetic lines (donors) were analyzed and then orally transferred separately into newly hatched male chicks of a commercial layer strain (recipients). Effects of cecal microbiota transplantation on growth, physiology, and behavior were examined in the recipient chicks. This study first evidenced that social stress and stress-related injurious behaviors in chickens can be reduced by modification of the gut microbiota composition and brain serotonergic activities via the gut–brain axis. The results provide new insights into understanding the cellular mechanisms of the gut microbiota in regulating stress-induced abnormal behaviors and offer a novel strategy for improving health and welfare in laying hens. Injurious behaviors (i.e., aggressive pecking, feather pecking, and cannibalism) in laying hens are a critical issue facing the egg industry due to increased social stress and related health and welfare issues as well as economic losses. In humans, stress-induced dysbiosis increases gut permeability, releasing various neuroactive factors, causing neuroinflammation and related neuropsychiatric disorders via the microbiota–gut–brain axis, and consequently increasing the frequency and intensity of aggression and violent behaviors. Restoration of the imbalanced gut microbial composition has become a novel treatment strategy for mental illnesses, such as depression, anxiety, bipolar disorder, schizophrenia, impulsivity, and compulsivity. A similar function of modulating gut microbial composition following stress challenge may be present in egg-laying chickens. The avian cecum, as a multi-purpose organ, has the greatest bacterial biodiversity (bacterial diversity, richness, and species composition) along the gastrointestinal tract, with vitally important functions in maintaining physiological and behavioral homeostasis, especially during the periods of stress. To identify the effects of the gut microbiome on injurious behaviors in egg-laying chickens, we have designed and tested the effects of transferring cecal contents from two divergently selected inbred chicken lines on social stress and stress-related injurious behaviors in recipient chicks of a commercial layer strain. This article reports the outcomes from a multi-year study on the modification of gut microbiota composition to reduce injurious behaviors in egg-laying chickens. An important discovery of this corpus of experiments is that injurious behaviors in chickens can be reduced or inhibited through modifying the gut microbiota composition and brain serotonergic activities via the gut–brain axis, without donor-recipient genetic effects. [ABSTRACT FROM AUTHOR]

Stress is a major influence on mental health status; the ways that individuals respond to or copes with stressors determine whether they are negatively affected in the future. Stress responses are established by an interplay between genetics, environment, and life experiences. Psychosocial stress is particularly impactful during adolescence, a critical period for the development of mood disorders. In this study we compared two established, selectively-bred Sprague Dawley rat lines, the “internalizing” bred Low Responder (bLR) line versus the “externalizing” bred High Responder (bHR) line, to investigate how genetic temperament and adolescent environment impact future responses to social interactions and psychosocial stress, and how these determinants of stress response interact. Male bLR and bHR rats were exposed to social and environmental enrichment in adolescence prior to experiencing social defeat and were then assessed for social interaction and anxiety-like behavior. Adolescent enrichment caused rats to display more social interaction, as well as nominally less social avoidance, less submission during defeat, and resilience to the effects of social stress on corticosterone, in a manner that seemed more notable in bLRs. For bHRs, enrichment also caused greater aggression during a neutral social encounter and nominally during defeat, and decreased anxiety-like behavior. To explore the neurobiology underlying the development of social resilience in the anxious phenotype bLRs, RNA-seq was conducted on the hippocampus and nucleus accumbens, two brain regions that mediate stress regulation and social behavior. Gene sets previously associated with stress, social behavior, aggression and exploratory activity were enriched with differential expression in both regions, with a particularly large effect on gene sets that regulate social behaviors. Our findings provide further evidence that adolescent enrichment can serve as an inoculating experience against future stressors. The ability to induce social resilience in a usually anxious line of animals by manipulating their environment has translational implications, as it underscores the feasibility of intervention strategies targeted at genetically vulnerable adolescent populations.

The current concerns regarding the ever-increasing global burden of non-communicable diseases where mental disorders and related somatic diseases make a significant contribution triggered my interest in the review of social determinants of mental health. Sufficient evidence led to the link of political systems to mental ill-health of citizens and taking into account the drawbacks of the biopsychosocial model based interventions led me to the formulation of the biopsychopolitical model that may guide the curative and preventive interventions for mental and related somatic diseases that I collectively call Social Distress Coping Disorders (SDCDs). The present paper aimed to find the predictor that may guide epidemiological studies. While ironically the Human Development Index (HDI) and Social Development Index (SDI) positively correlate with the global prevalence of disorders like depression and anxiety; an attempt was made to find a predictor that may negatively correlate with the prevalence of SDCDs on a global scale with no success due to reasons elucidated. On a local scale, the income inequality measures weakly negatively correlated with hypertension at 95% CI (R= -0.307, β = -0.449, p= 0.030) while no correlation was found for depression (R= -0.106, β = -0.014, p= 0.47) in 50 African countries with available data, and possible reasons for this were mentioned. The link between political systems and social determinants of mental health is certain, while waiting for a suitable model and predictor due to biased data as shown, the validity of the biopsychopolitical model is assured.

Introduction: Revealing factors and mechanisms in determining species coexistence are crucial to community ecology, but studies using gut microbiota data are still lacking. Methods: Using gut microbiota data of 556 Brandt's voles from 37 treatments in eight experiments, we examined the relationship of species co-occurrence of gut microbiota in Brandt's voles (Lasiopodomys brandtii) with genetic distance (or genetic relatedness), community diversity, and several environmental variables. Results: We found that the species co-occurrence index (a larger index indicates a higher co-occurrence probability) of gut microbiota in Brandt's voles was negatively associated with the genetic distance between paired ASVs and the number of cohabitating voles in the experimental space (a larger number represents more crowding social stress), but positively with Shannon diversity index, grass diets (representing natural foods), and non-physical contact within an experimental space (representing less stress). Discussion: Our study demonstrated that high diversity, close genetic relatedness, and favorable living conditions would benefit species cooccurrence of gut microbiota in hosts. Our results provide novel insights into factors and mechanisms that shape the community structure and function of gut microbiota and highlight the significance of preserving the biodiversity of gut microbiota. [ABSTRACT FROM AUTHOR]

Because experiential avoidance is considered by some to be the root of most forms of psychopathology, it is often a primary intervention and research target. Yet, the current literature is limited by its assessment and conceptualization of experiential avoidance as a trait variable. Little attention is paid to how it operates as a context-dependent state-based factor. Further, more information is needed to determine how experiential avoidance relates to affective states in specific contexts. Links have been established between experiential avoidance and negative affect intensity in the contextual behavior science (CBS) literature. Studying more specific elements of state-based experiential avoidance as potential mediators of negative affect is an important next step. Thus, the overarching goal of the present study was to measure the indirect effect of state experiential avoidance on the relationship between trait experiential avoidance and dimensions of negative affect following exposure to several challenging tasks. Participants (N = 160) in the current study completed both the cold pressor test and Trier Social Stress Test (TSST) in a counterbalanced order. Non-parametric bootstrapping analyses revealed a significant indirect effect of state experiential avoidance on negative affect for the TSST condition. As predicted, these effects were strongest under interpersonal contexts rather than when physiological discomfort was evoked. Implications for conceptualizing experiential avoidance as state and trait and how these relate to CBS interventions are proposed. [ABSTRACT FROM AUTHOR]

Stress-inducing virtual reality (VR) systems have various applications in research, ranging from training to therapy to the observation of biological stress responses. Stress in VR can be evoked through environmental, cognitive, and social stimuli. Although various VR tasks can induce an autonomic nervous system (ANS) stress response, hypothalamic-pituitary-adrenal (HPA) axis stress responses have only been confirmed in VR for the virtual Trier social stress test (V-TSST). Understanding the impact of a wider variety of tasks on HPA-axis stress response could lead to the development of more effective stress relief measures and treatments. This study aims to clarify whether a virtual communication simulation, using a static procedure with a predetermined dialog, can evoke an HPA-axis stress response. Employing a virtual customer service system, we varied the intensity of the presented stress by changing the tone and gestures of the virtual customer. The findings confirm that HPA-axis stress responses can be elicited by such static virtual customer service training systems, and the stress responses can be adjusted by altering the avatar's attitude. These findings suggest potential applications in research for observing human physiological responses to stress and development of stress reduction strategies, thereby affirming the effectiveness of VR in communication training. [ABSTRACT FROM AUTHOR]

Although social rejection is among the strongest proximal precipitants of major depressive disorder (MDD), little is known about the underlying neurobiological mechanisms and whether neural sensitivity to social rejection may help explain differences in MDD risk. To address this issue, we tested whether neural responses to social threat differed in female adolescents at high vs. low maternal risk for MDD. Female adolescents with (high-risk; n = 22, M age = 14.68) and without (low-risk; n = 30, M age = 15.07) a maternal history of depression were experimentally exposed to negative and neutral social evaluation while undergoing an fMRI scan. Neural responses were assessed by event-related activity and functional connectivity, as well as multivoxel pattern analysis. Activity and functional connectivity analyses focused on a priori-selected regions of interest implicated in self-referential processing and emotion regulation. Compared to low-risk female adolescents, high-risk female adolescents exhibited greater increases in self-reported depression and social disconnection following social evaluation. Moreover, compared to low-risk female adolescents, high-risk female adolescents exhibited greater amygdala responses to negative social evaluation and a differential pattern of functional connectivity in brain regions related to emotion regulation, self-referential processing, and negative affect. Additionally, these markers of neural threat reactivity were related to depressive symptoms. A cross-sectional study design and relatively small, Western sample. These results suggest that exaggerated neural reactivity to social threat—and an atypical pattern of related functional connectivity—is evident in individuals with a preclinical risk factor for depression. Targeting such responding may thus be a fruitful strategy for preventing depression in at-risk youth. • We examined neural sensitivity to social rejection in adolescent females at high vs. low risk for MDD • High-risk females exhibited greater self-reported depression and social disconnection to social rejection • They also exhibited greater amygdala responses and different functional connectivity patterns during social rejection • Relevant brain regions included those implicated in emotion regulation, self-referential processing, and negative affect • Finally, these neural response patterns related to depression symptoms in both the daughters and their mothers [ABSTRACT FROM AUTHOR]

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Objectives: Inducing self-compassion has been shown to be helpful, particularly for individuals with high levels of social anxiety. However, few studies have compared a brief self-compassion intervention to another adaptive strategy. The primary aim of the present study was to examine the impact of a brief (5-min) self-compassion induction for social stress compared to another beneficial strategy. Method: Two studies were conducted to compare self-compassion and cognitive reappraisal as strategies for coping with past stressful social situations. In Study 1, participants (n = 276) were asked to recall and describe a situation during the COVID-19 pandemic where they felt judged and then were randomly assigned to either a self-compassion, cognitive reappraisal, or a control writing condition. In Study 2 (n = 277), participants were asked to recall any past stressful social situation where they felt judged by others. Results: For Study 1, those who completed either the self-compassion or cognitive reappraisal exercise reported significantly lower distress immediately after the induction, and higher levels of self-compassion and reappraisal compared to the control condition. For Study 2, only those who completed the self-compassion induction reported significantly higher levels of self-compassion and reappraisal and significantly lower levels of distress and state anxiety compared to those in the control condition, but the self-compassion and reappraisal conditions did not differ significantly from one another. Conclusion: These studies build support for the benefits of responding to social stressors with self-compassion. Preregistration: This study is not preregistered. [ABSTRACT FROM AUTHOR]

Stress impacts prefrontal cortex (PFC) activity and modulates working memory performance. In a recent study, stimulating the dorsolateral PFC (dlPFC) using transcranial direct current stimulation (tDCS) interacted with social stress in modulating participants' working memory. More specifically, stress disrupted the enhancing effects of dlPFC tDCS on working memory performance. The current study aimed to further explore these initial findings by randomizing healthy females to four experimental conditions (N = 130); stimulation (right dlPFC tDCS vs. sham) and stress manipulation (social stress vs. control). Participants performed cognitive tasks (i.e., visual working memory task and a visual declarative memory task) at baseline and post-stimulation. They also completed self-report measures of stress and anxiety. A significant stimulation × stress interaction was evident in the declarative memory (One-Card Learning, OCL) task, while working memory performance was unaffected. Though tDCS stimulation and stress did not interact to affect working memory, further research is warranted as these initial findings suggest that immediate visual-memory learning may be affected by these factors. The limited number of earlier studies, as well as the variability in their designs, provides additional impetus for studying the interactive effects of stress and tDCS on human visual learning. [ABSTRACT FROM AUTHOR]

Previous studies showed that the dorsal premammillary nucleus of the hypothalamus (PMD) is involved in social passive defensive behaviors likely to be meditated by descending projections to the periaqueductal gray (PAG). We focused on the rostral dorsomedial PAG (rPAGdm) to reveal its putative neural mechanisms involved in mediating social defensive responses. By combining retrograde tracing and FOS expression analysis, we showed that in addition to the PMD, the rPAGdm is influenced by several brain sites active during social defeat. Next, we found that cytotoxic lesions of the rPAGdm drastically reduced passive defense and did not affect active defensive responses. We then examined the rPAGdm's projection pattern and found that the PAGdm projections are mostly restricted to midbrain sites, including the precommissural nucleus, different columns of the PAG, and the cuneiform nucleus (CUN). Also, we found decreased FOS expression in the caudal PAGdm, CUN, and PMD after the rPAGdm was lesioned. The results support that the rPAGdm mediates passive social defensive responses through ascending paths to prosencephalic circuits likely mediated by the CUN. This study provides further support for the role of the PAG in the modulation of behavioral responses by working as a unique hub for influencing prosencephalic sites during the mediation of aversive responses. [ABSTRACT FROM AUTHOR]

Despite increasing research, the links between racial discrimination and Black Americans' romantic relationship dynamics remain unclear. Guided by models of mundane extreme environmental stress (Peters & Massey, 1983), sociocultural family stress (McNeil Smith & Landor, 2018), and Black marital outcomes (Bryant et al., 2010), we conducted a systematic review of the literature examining racial discrimination and relationship dynamics among Black Americans in same‐race and interracial romantic relationships. Synthesizing findings from 32 published empirical articles, we find support for manifestations of each component of MEES in Black intimate life. We uncover evidence that racial discrimination is associated with compromised relationship functioning for Black Americans. Several psychosocial resources were also identified as either buffering these associations or posing drawbacks/limitations for Black Americans. We discuss notable gaps in the literature and directions for future research including intersectional investigations, broader examination of the MEES context, and de‐centering whiteness among studies of interracial relationship dynamics. [ABSTRACT FROM AUTHOR]

This study offers a counterpoint to the generalization of positive and linear effects resulting from challenge stressors in the workplace. The guiding objective was to verify whether social challenge stress impacts individuals' work engagement positively or negatively, according to the political skill degree available by professionals. We used moderation analysis and hierarchical regression to assess these relationships. The sample comes from civil servants of a Brazilian federal institution (N = 606). The results indicate that political skill moderates the relationship between social stress and engagement positively, except in cases where such skill is low, a situation in which the interaction becomes negative. The evidence also reveals that a positive curvilinear association better explains the association between social stress and work engagement. The findings suggest that the Challenge-Hindrance Stress Framework (CHF) has an application conditioned by the possible abilities that a given stressor demands to be evaluated as an obstacle or a challenge. We intended to extend the theory on stressors and contribute to the human resource management practice by elucidating conditions or portions of professionals in which the CHF does not apply or lacks contextualization.

Social support is vital for mental and physical health and is linked to lower rates of disease and early mortality. Conversely, anti-social behavior can increase mortality risks, both for the initiator and target of the behavior. Chronic stress, which also can increase mortality, may serve as an important link between social behavior and healthy lifespan. There is a growing body of literature in both humans, and model organisms, that chronic social stress can result in more rapid telomere shortening, a measure of biological aging. Here we examine the role of anti-social behavior and social support on physiological markers of stress and aging in the social Japanese quail, Coturnix Japonica. Birds were maintained in groups for their entire lifespan, and longitudinal measures of antisocial behavior (aggressive agonistic behavior), social support (affiliative behavior), baseline corticosterone, change in telomere length, and lifespan were measured. We found quail in affiliative relationships both committed less and were the targets of less aggression compared to birds who were not in these relationships. In addition, birds displaying affiliative behavior had longer telomeres, and longer lifespans. Our work suggests a novel pathway by which social support may buffer against damage at the cellular level resulting in telomere protection and subsequent longer lifespans.

Declining cognition, physical health, and mental health are common yet major publichealth challenges. However, research connecting declining cognition and health to common social stressors is limited. This paper aims to replicate Lindert et al. (2021), who used the MIDUS data set, a national sample of non-institutionalized, English-speaking respondents aged 25-74 living throughout the United States, to investigate the decline in episodic memory and executive function with social stress variables. The subsequent extension of the original study seeks to predict various physical and mental health outcomes from different community trust variables. In both the replication and extension, multivariate linear regression models were used to analyze the effect of social stressors and trust on cognition and health. We replicated the results reported in the original study, which suggested greater levels of perceived inequality in the family, marital stress, lifetime discrimination, and daily discrimination were significantly associated with more cognitive decline. Additionally, we found that lower levels of trust in neighbors and friends, as well as having few trusting relationships, were significantly associated with worse physical and mental health in both men and women.

Stress is a critical factor in the development of mental disorders such as addiction, underscoring the importance of stress resilience strategies. While the ketogenic diet (KD) has shown efficacy in reducing alcohol consumption in male mice without cognitive impairment, its impact on the stress response and addiction development, especially in females, remains unclear. This study examined the KD’s effect on increasing ethanol intake due to vicarious social defeat (VSD) in female mice. Sixty-four female OF1 mice were divided into two dietary groups: standard diet (n = 32) and KD (n = 32). These were further split based on exposure to four VSD or exploration sessions, creating four groups: EXP-STD (n = 16), VSD-STD (n = 16), EXP-KD (n = 16), and VSD-KD (n = 16). KD-fed mice maintained ketosis from adolescence until the fourth VSD/EXP session, after which they switched to a standard diet. The Social Interaction Test was performed 24 h after the last VSD session. Three weeks post-VSD, the Drinking in the Dark test and Oral Ethanol Self-Administration assessed ethanol consumption. The results showed that the KD blocked the increase in ethanol consumption induced by VSD in females. Moreover, among other changes, the KD increased the expression of the ADORA1 and CNR1 genes, which are associated with mechanisms modulating neurotransmission. Our results point to the KD as a useful tool to increase resilience to social stress in female mice.

Numerous studies have evidenced that neuropsychiatric disorders (mental illness and emotional disturbances) with aggression (or violence) pose a significant challenge to public health and contribute to a substantial economic burden worldwide. Especially, social disorganization (or social inequality) associated with childhood adversity has long-lasting effects on mental health, increasing the risk of developing neuropsychiatric disorders. Intestinal bacteria, functionally as an endocrine organ and a second brain, release various immunomodulators and bioactive compounds directly or indirectly regulating a host’s physiological and behavioral homeostasis. Under various social challenges, stress-induced dysbiosis increases gut permeability causes serial reactions: releasing neurotoxic compounds, leading to neuroinflammation and neuronal injury, and eventually neuropsychiatric disorders associated with aggressive, violent, or impulsive behavior in humans and various animals via a complex bidirectional communication of the microbiota–gut–brain (MGB) axis. The dysregulation of the MGB axis has also been recognized as one of the reasons for the prevalence of social stress-induced injurious behaviors (feather pecking, aggression, and cannibalistic pecking) in chickens. However, existing knowledge of preventing and treating these disorders in both humans and chickens is not well understood. In previous studies, we developed a non-mammal model in an abnormal behavioral investigation by rationalizing the effects of gut microbiota on injurious behaviors in chickens. Based on our earlier success, the perspective article outlines the possibility of reducing stress-induced injurious behaviors in chickens through modifying gut microbiota via cecal microbiota transplantation, with the potential for providing a biotherapeutic rationale for preventing injurious behaviors among individuals with mental disorders via restoring gut microbiota diversity and function.

Psychosocial stress is a top predictor of peripartum mood disorders in human mothers. In the present study, we developed a novel paradigm testing the effects of direct and vicarious social stress on maternal and mood-related behaviors in B6 mice. Using a novel housing paradigm, we examined the extent to which postpartum dams withdrew from litters following psychosocial stress. Repeated acute direct social stress involved exposing dams to a virgin male mouse for 7 min/day on postpartum days 5-7 during a brief (15-min) mother-pup separation. To remove the effects of direct stress, the vicarious social stress dams were housed in the same vivarium as direct social stressed dams, but without direct exposure to intruders. Control dams were given mock intruder exposure and housed in a separate vivarium room containing breeding mice. All dams experienced pup separation, and maternal care was investigated upon reunion. Direct and vicarious social stress induced significant deficits in maternal care and increased maternal anxiety relative to controls. Although vicarious stress effects were more likely to occur on days when there was acute stress exposure, direct stress sustained maternal deficits 24 h after the final stressor. Together, these data suggest psychosocial stress induces aberrant maternal phenotypes in mice.

Abstract Background Increasing evidence shows low-wage migrant workers experience a high prevalence of mental health disorders and adverse health outcomes. Significant disparities in health services usage among migrant workers create added vulnerability to health complications. However, much remains unclear about how vulnerabilities are constructed in migrant worker populations. Additionally, no studies in Singapore have attempted to critically examine the degree to which social environment and structures affect the health and wellbeing of migrant workers. Therefore, this study aimed to critically situate the socio-structural factors creating conditions of vulnerability among migrant workers using a social stress perspective. Methods We conducted semi-structured individual and group interviews with migrant workers focused on individual life experiences, community experiences (individual and collective social capital), health (mental and physical health concerns) and stress response behaviours. We used a grounded theory approach to identify sources of stress and stress responses and uncover pathways to social vulnerabilities. Results Findings from 21 individual and 2 group interviews revealed that migrant workers were embedded in a cycle of chronic stress driven by structural factors that were mutually reinforced by stressors arising from their social environment. Socio-structural stressors enacted as poor living, working and social conditions resulted in their negative quality-of-life appraisal. Stressors arising from being “foreign” resulted in anticipated stigma, concealment, and healthcare avoidance. These factors synergistically created a persistent mental health burden for migrant workers. Conclusions Findings highlight the need to address the mental health burden placed on migrant workers and create avenues for migrant workers to seek psychosocial support to manage their stressors.

Adolescent-onset depression is a prevalent and debilitating condition commonly associated with treatment refractory depression and non-response to first-line antidepressants. There are, however, no objective tests to determine who may or may not respond to antidepressants. As depressed adolescents are especially vulnerable to the lifelong consequences of ineffectively-treated depression, it is critical to identify neurobiological predictors of treatment non-response in this population. Here, we describe the scientific rationale and protocol for the Teen Inflammation Glutamate Emotion Research (TIGER) study, a prospective 18-month investigation of 160 depressed adolescents who will be assessed before and after treatment with selective serotonin reuptake inhibitors. TIGER will be using ultra-high field imaging to test the effects of acute stress and antidepressant treatment on inflammatory and glutamatergic processes hypothesized to underlie depression maintenance. Results from this work will motivate future studies testing alternative therapeutics for depressed adolescents at risk for treatment resistant depression. ClinicalTrials.gov Identifier: NCT05329441.

Despite women representing most of those affected by major depression, preclinical studies have focused almost exclusively on male subjects, partially due to a lack of ideal animal paradigms. As the persistent need regarding the sex balance of neuroscience research and female-specific pathology of mental disorders surges, the establishment of natural etiology-based and systematically validated animal paradigms for depression with female subjects becomes an urgent scientific problem. This study aims to establish, characterize, and validate a “Multiple Integrated Social Stress (MISS)” model of depression in female C57BL/6J mice by manipulating and integrating daily social stressors that females are experiencing. Female C57BL/6J mice randomly experienced social competition failure in tube test, modified vicarious social defeat stress, unescapable overcrowding stress followed by social isolation on each day, for ten consecutive days. Compared with their controls, female MISS mice exhibited a relatively decreased preference for social interaction and sucrose, along with increased immobility in the tail suspension test, which could last for at least one month. These MISS mice also exhibited increased levels of blood serum corticosterone, interleukin-6 L and 1β. In the pharmacological experiment, MISS-induced dysfunctions in social interaction, sucrose preference, and tail suspension tests were amended by systematically administrating a single dose of sub-anesthetic ketamine, a rapid-onset antidepressant. Compared with controls, MISS females exhibited decreased c-Fos activation in their anterior cingulate cortex, prefrontal cortex, nucleus accumbens and some other depression-related brain regions. Furthermore, 24 h after the last exposure to the paradigm, MISS mice demonstrated a decreased center zone time in the open field test and decreased open arm time in the elevated plus-maze test, indicating anxiety-like behavioral phenotypes. Interestingly, MISS mice developed an excessive nesting ability, suggesting a likely behavioral phenotype of obsessive-compulsive disorder. These data showed that the MISS paradigm was sufficient to generate pathological profiles in female mice to mimic core symptoms, serum biochemistry and neural adaptations of depression in clinical patients. The present study offers a multiple integrated natural etiology-based animal model tool for studying female stress susceptibility.