Peer victimization predicts heightened inflammatory reactivity to social stress in cognitively vulnerable adolescents

Social network structure as a biopsychosocial suicide prevention target for young people at clinical high-risk for psychosis

Young people who are at clinical high-risk for psychosis experience suicidal thoughts and behaviors at a greater rate than young people in the general population. However, no suicide prevention interventions have been specifically designed for or tested with this group of young people. To address this gap, we need to identify and leverage malleable potential intervention targets that can be measured at multiple levels of analysis. Here, we argue that social network structure, or the pattern of relationships in which a person is embedded, offers one potential target for intervention. We first provide a select review of what is currently known about social network structure and suicide risk, social network disruption among people at clinical high-risk for psychosis, and inflammatory processes as a potential underlying metric of social bond disruption. We then propose opportunities to advance suicide prevention research focused on young people at clinical high-risk for psychosis, with an eye toward establishing a foundation for future interventions that can account for biological, psychological, and social domains.

Lifetime adversity predicts depression, anxiety, and cognitive impairment in a nationally representative sample of older adults in the United States

OBJECTIVE

Although life stress and adversity are well-known risk factors for mental health problems and cognitive impairment among older adults, limited research has comprehensively examined the impact of both childhood and adulthood adversity on psychiatric and cognitive impairment symptoms over a prolonged period. To address this issue, we investigated how lifetime adversity exposure is related to symptoms of depression, anxiety, and cognitive impairment in a nationally representative, longitudinal sample of older adults in the United States.

METHOD

We analyzed data from the Health and Retirement Study (1992-2016). The sample included 3496 individuals (59.9% female), aged ≥64 years old (Mage = 76.0 ± 7.6 years in 2016). We used the individual-level panel data and ordinary least squares regressions to estimate associations between childhood and adulthood adversities, and later-life depression, anxiety, and cognitive impairment.

RESULTS

Many participants experienced a significant early life (38%) or adulthood (79%) stressor. Moreover, experiencing one childhood adversity (vs. none) was associated with a 17.4% increased risk of adulthood adversity. Finally, as hypothesized, childhood adversity exposure was related to experiencing more depression and anxiety symptoms in later life, whereas adulthood stressor exposure predicted more cognitive impairment as well as more depression and anxiety symptoms.

DISCUSSION

These findings demonstrate significant associations between lifetime adversity and symptoms of depression, anxiety, and cognitive impairment in older adults. Screening for lifetime stressors may thus help healthcare professionals and policymakers identify individuals who could potentially benefit from interventions designed to reduce stress and enhance resilience.

The Interplay of Peer Victimization and Parasympathetic Nervous System Activity on Acute Inflammatory Stress Responses in Adolescence

This study examined the extent to which adolescent peer victimization predicted acute inflammatory responses to stress, and whether both resting parasympathetic nervous system (PNS) activity and PNS stress reactivity moderated this association. 83 adolescents (Mage = 14.89, SDage = 0.52, 48% female) reported their history of peer victimization and were exposed to a standardized social stress task before and after which dried blood spot samples were collected to assay inflammatory markers. Inflammatory responses to the stress task were assessed with a latent inflammatory change factor using the cytokines interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-α (TNF-α). PNS functioning, indexed by high-frequency heart rate variability, was measured at rest and during the stressor. Contrary to hypotheses, analyses revealed no direct relation between peer victimization and acute inflammatory responses, and resting PNS activity did not moderate this association. However, peer victimization predicted stronger inflammatory responses among adolescents with weaker PNS reactivity to the stress task (b = 0.63, p = .02). This association was not observed among adolescents with stronger PNS reactivity, for whom a negative but non-significant trend was found. Weaker PNS reactivity may thus indicate victimized adolescents' vulnerability for acute inflammatory responses, whereas stronger PNS reactivity may indicate adolescents' resilience to a social stressor.

The biology of hope: Inflammatory and neuroendocrine profiles in ovarian cancer patients

INTRODUCTION

Although the concept of hope is highly relevant for cancer patients, little is known about its association with cancer-relevant biomarkers. Here we examined how hope was related to diurnal cortisol and interleukin-6 (IL-6), a pro-inflammatory cytokine previously associated with tumor biology and survival in ovarian cancer. Secondly, we examined whether hope and hopelessness are distinctly associated with these biomarkers.

METHOD

Participants were 292 high-grade ovarian cancer patients who completed surveys and provided saliva samples 4x/daily for 3 days pre-surgery to assess diurnal cortisol. Blood (pre-surgery) and ascites were assessed for IL-6. Hope and hopelessness were assessed using standardized survey items from established scales (Center for Epidemiological Studies Depression Scale; Profile of Mood States, Functional Assessment of Cancer Therapy). Two hopeless items were z-scored and combined into a composite for analysis. Regression models related these variables to nocturnal cortisol, cortisol slope, plasma and ascites IL-6, adjusting for cancer stage, BMI, age, and depression.

RESULTS

Greater hope was significantly related to a steeper cortisol slope, β = -0.193, p = 0.046, and lower night cortisol, β = -0.227, p = 0.018, plasma IL-6, β = -0.142, p = 0.033, and ascites IL-6, β = -0.290, p = 0.002. Secondary analyses including both hope and hopelessness showed similar patterns, with distinct relationships of hope with significantly lower nocturnal cortisol β = -0.233,p = 0.017 and ascites IL-6, β = -0.282,p = 0.003, and between hopelessness and a flatter cortisol slope, β = 0.211, p = 0.031.

CONCLUSIONS

These data suggest a biological signature of hope associated with less inflammation and more normalized diurnal cortisol in ovarian cancer. These findings have potential clinical utility but need replication with more diverse samples and validated assessments of hope.

Impacts of difficulties with emotion regulation on the longitudinal relationship between peer victimization and changes in adolescent nonsuicidal self-injury

INTRODUCTION

Research has found that peer victimization is associated with adolescent nonsuicidal self-injury (NSSI) behavior; however, most of these studies ignored the association between these constructs at the within-person level. Additionally, the association between peer victimization and NSSI may vary among adolescents with different personal characteristics. With a longitudinal design, this study investigated whether and how emotion regulation (ER) difficulties moderate the relationship between peer victimization and changes in NSSI, with particular attention given to the unique moderating role of different dimensions of ER difficulties.

METHODS

The study sample comprised 3,561 adolescents aged between 10 and 17 years old (Mage  = 13.22, SD = 0.85; 56.9% males). Self-report assessments were administered in December 2021 and June 2022 in Shanxi province, China.

RESULTS

The latent change score model showed that the adolescent NSSI increased during our assessments, with peer victimization as a significant predictor. ER difficulties moderated the association between peer victimization and NSSI changes, but interestingly, in an unexpected pattern. Specifically, peer victimization significantly predicted NSSI changes among adolescents with low ER difficulties but not for those with high ER difficulties. Moreover, among the multiple dimensions of ER difficulties, only nonacceptance of emotional responses and limited access to emotion regulation strategies interacted with peer victimization to predict NSSI changes and showed interaction patterns similar to those at the overall level of ER difficulties.

CONCLUSIONS

The current study revealed the moderating role of ER difficulties in the relationship between peer victimization and changes in NSSI. These findings provide intervention implications for adolescents who engage in NSSI.

Hormonal contraceptive use is associated with differences in women's inflammatory and psychological reactivity to an acute social stressor

Women using hormonal contraceptives (HCs) exhibit numerous signs of chronic inflammation, including elevated C-reactive protein levels and greater risk of developing mood and autoimmune disorders. However, users and non-users of HCs often have similar circulating proinflammatory cytokine levels, making the mechanism of association unclear. One possible explanation for this paradox is that HC users exhibit differences in their inflammatory responses to psychosocial stress that, over time, could contribute to chronic inflammation and its pathologies. Here, we tested this possibility by examining women's glucocorticoid, inflammatory, and psychological responses to the Trier Social Stress Test (TSST) in 67 naturally cycling (NC) and 60 oral HC-using women (Mage = 19.31, SDage = 1.95). As hypothesized, HC users and NC women exhibited different glucocorticoid and proinflammatory cytokine responses to the TSST. For NC women, TSST-induced increases in glucocorticoids were uncommon, and increases in glucocorticoids were accompanied by elevations in IL-6. In contrast, for women using HCs, increases in glucocorticoids in response to the TSST were common, and increases in glucocorticoids were accompanied by increases in TNF-α. HC users and NC women also differed in their psychological responses to the TSST, with HC users reporting elevated stress levels compared to NC women. Together, these results suggest that HC use impacts women's glucocorticoid, inflammatory, and psychological responses to psychosocial stress, potentially contributing to observed differences in these women's mental and physical health.

Examination of proinflammatory activity as a moderator of the relation between momentary interpersonal stress and suicidal ideation

INTRODUCTION

Peer-related interpersonal stress can increase risk for suicidal thoughts among adolescents and young adults. However, not all individuals who undergo peer-related interpersonal stressors experience suicidal thoughts. Heightened proinflammatory activity is one factor that may amplify the relation between interpersonal stress and suicidal thinking.

METHODS

This pilot study examined the relation between interpersonal stress and suicidal ideation in real time, as well as whether proinflammatory cytokine (IL-6 and TNF-α) activity across a laboratory social stressor moderated this association in a sample of 42 emerging adults with recent suicidal ideation. Participants completed 28 days of 6×/daily ecological momentary assessment that assessed for suicidal ideation (presence vs. absence, ideation intensity), occurrence of negative peer events, and feelings of exclusion.

RESULTS

There was a trend for within-person increases in feelings of exclusion to be associated with increases in concurrent suicidal ideation intensity. Additionally, within-person increases in negative peer events were associated with increased odds of subsequent suicidal ideation among individuals with very low IL-6 activity. However, this finding is considered preliminary.

CONCLUSION

Interventions targeting perceptions of exclusion and increasing social support may be of benefit. However, findings require replication in larger samples, and thus must be interpreted with caution.

What Works for Whom in School-Based Anti-bullying Interventions? An Individual Participant Data Meta-analysis

The prevalence of bullying worldwide is high (UNESCO, 2018). Over the past decades, many anti-bullying interventions have been developed to remediate this problem. However, we lack insight into for whom these interventions work and what individual intervention components drive the total intervention effects. We conducted a large-scale individual participant data (IPD) meta-analysis using data from 39,793 children and adolescents aged five to 20 years (Mage = 12.58, SD = 2.34) who had participated in quasi-experimental or randomized controlled trials of school-based anti-bullying interventions (i.e., 10 studies testing nine interventions). Multilevel logistic regression analyses showed that anti-bullying interventions significantly reduced self-reported victimization (d =  - 0.14) and bullying perpetration (d =  - 0.07). Anti-bullying interventions more strongly reduced bullying perpetration in younger participants (i.e., under age 12) and victimization for youth who were more heavily victimized before the intervention. We did not find evidence to show that the inclusion of specific intervention components was related to higher overall intervention effects, except for an iatrogenic effect of non-punitive disciplinary methods-which was strongest for girls. Exploratory analyses suggested that school assemblies and playground supervision may have harmful effects for some, increasing bullying perpetration in youth who already bullied frequently at baseline. In conclusion, school-based anti-bullying interventions are generally effective and work especially well for younger children and youth who are most heavily victimized. Further tailoring of interventions may be necessary to more effectively meet the needs and strengths of specific subgroups of children and adolescents.

Examining implications of the developmental timing of maternal trauma for prenatal and newborn outcomes

Separate literatures have demonstrated that mothers' experiences with trauma during childhood or pregnancy are associated with maternal prenatal health risks, adverse childbirth outcomes, and offspring internalizing and externalizing disorders. These literatures largely align with the intergenerational transmission or fetal programming frameworks, respectively. However, few studies have tested the effects of maternal childhood and prenatal trauma simultaneously on mothers' and infants' health outcomes, and no studies have examined these effects on newborn neurobehavioral outcomes. Thus, in the present study, we examined how the developmental timing of pregnant women's traumatic life experiences associated with their physical health and psychopathology (Aim 1) as well as their newborns' birth and neurodevelopmental outcomes (Aim 2; for pre-registered aims and hypotheses, see https://osf.io/ygnre/?view_only=cbe17d0ac7f24af5a4d3e37e24eebead). One hundred and fifty-two 3rd trimester pregnant women (Mage = 29 years; 17.1% Hispanic/Latina) completed measures of trauma history and psychopathology. Then, 24-48 h after birth, trained clinicians conducted newborn neurobehavioral exams (n = 118 newborns; 52.6% female). Results indicated that lifetime traumatic experiences associated with multiple prenatal maternal health outcomes, including depression, anxiety, emotion dysregulation, and pregnancy complications. Pregnant women's experiences with childhood trauma, but not adulthood or prenatal trauma, predicted higher neurobehavioral attention scores among female newborns. Our discussion highlights the importance of considering the developmental timing of maternal trauma on perinatal outcomes and contextualizes our findings within the intergenerational transmission and fetal programming literatures. DATA AVAILABILITY: Data pertaining to R01MH119070 (MPIs Crowell & Conradt) and that support these findings are uploaded to the NIMH repository.

Interpersonal stress and proinflammatory activity in emerging adults with a history of suicide risk: A pilot study

Interpersonal stress during adolescence and young adulthood can threaten healthy developmental trajectories. A "primed" proinflammatory response to acute stress may serve as an underlying process that results in negative outcomes for youth. The present pilot study examined the relation between interpersonal stress and two proinflammatory cytokines in a sample of 42 university-recruited emerging adults with recent suicidal thoughts and behaviors. Participants completed self-report measures of mood, suicidal thoughts and behaviors, recent peer-related stressors, and interpersonal sensitivity. They also participated in an acute laboratory social stress task and provided three saliva samples to measure their proinflammatory responses (IL-6 and TNF-α) to the stressor. Participants reported significant increases in sadness and exclusion, and significant decreases in inclusion, following task participation. Importantly, no participants reported an increase in or onset of suicidal thoughts. No significant associations between interpersonal stress and proinflammatory cytokines were found. Changes in affect during the task coupled with lack of increased suicidal thoughts indicate it is acceptable to use this exclusion and rejection paradigm with this population, with proper debriefing and positive mood induction procedures. Given all other nonsignificant associations, future research considerations are discussed, including impact of COVID-19 on task potency and incorporation of multiple stress response systems.

Interpersonal Life Stress and Inflammatory Reactivity as Prospective Predictors of Suicide Attempts in Adolescent Females

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.

Risk for Depressive Symptoms Among Adolescents with a History of Adversity: Unique Role of Stress Appraisals

Lifetime social adversity predicts elevated depressive symptoms in adolescence. However, most adversity-exposed youth do not develop depression, highlighting the importance of examining risk and protective factors. The present study leveraged a multi-method approach, incorporating self-report, interview, and independent coding to examine whether appraisals of recent stressors moderate the effect of social adversity on depressive symptoms in 81 adolescent girls (M_age = 16.30 years, SD = .85). We utilized semi-structured interviews of lifetime adversity and recent stressors and semi-structured interviews and self-reports of depressive symptoms. Stress appraisals were calculated by regressing youths' subjective estimations of event stressfulness and dependence on estimations of independent coders. Lifetime social adversity predicted elevated depressive symptoms more strongly in girls who appraised interpersonal events as more stressful and dependent on their actions, providing insight into individual differences in depressive symptoms in adversity-exposed adolescents.

Childhood Social Isolation as a Predictor of Retinal Neuronal Thickness in Middle Age: A Lifecourse Birth Cohort Study

OBJECTIVE

We investigated whether childhood social isolation was associated with retinal neural layer changes in adulthood, and whether this association was independent of other childhood or adulthood risk factors, including adult social isolation.

METHODS

Participants were members of the Dunedin Multidisciplinary Health and Development Study, a longitudinal population-based birth cohort from Aotearoa New Zealand ( n = 1037), born 1972 to 1973 and followed until age 45 years, with 94% of the living cohort still participating. Social isolation was recorded prospectively at ages 5, 7, 9, and 11 years, from teacher and parent report. Retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer thicknesses were measured via optical coherence tomography at age 45 years.

RESULTS

Childhood social isolation was associated with thinner average RNFL ( B = -0.739, p = .02), nasal RNFL ( B = -1.118, p = .005), and inferior RNFL ( B = -1.524, p = .007), although only nasal RNFL remained significant after adjustment. These associations were not fully explained by other psychosocial or physical health risk factors in childhood or adulthood, nor were they mediated by adult loneliness or social support.

CONCLUSIONS

Childhood social isolation was an independent predictor of RNFL thickness in middle age. Highlighting prospective links between childhood psychosocial adversity and retinal neuronal measures will help to inform future research into the utility of retinal neuronal thickness as a biomarker for neurodegeneration.

Social Safety Theory: Conceptual foundation, underlying mechanisms, and future directions

Classic theories of stress and health are largely based on assumptions regarding how different psychosocial stressors influence biological processes that, in turn, affect human health and behavior. Although theoretically rich, this work has yielded little consensus and led to numerous conceptual, measurement, and reproducibility issues. Social Safety Theory aims to address these issues by using the primary goal and regulatory logic of the human brain and immune system as the basis for specifying the social-environmental situations to which these systems should respond most strongly to maximize reproductive success and survival. This analysis gave rise to the integrated, multi-level formulation described herein, which transforms thinking about stress biology and provides a biologically based, evolutionary account for how and why experiences of social safety and social threat are strongly related to health, well-being, aging, and longevity. In doing so, the theory advances a testable framework for investigating the biopsychosocial roots of health disparities as well as how health-relevant biopsychosocial processes crystalize over time and how perceptions of the social environment interact with childhood microbial environment, birth cohort, culture, air pollution, genetics, sleep, diet, personality, and self-harm to affect health. The theory also highlights several interventions for reducing social threat and promoting resilience.

Sex differences in inflammation in the hippocampus and amygdala across the lifespan in rats: associations with cognitive bias

Background

Cognitive symptoms of major depressive disorder, such as negative cognitive bias, are more prevalent in women than in men. Cognitive bias involves pattern separation which requires hippocampal neurogenesis and is modulated by inflammation in the brain. Previously, we found sex differences in the activation of the amygdala and the hippocampus in response to negative cognitive bias in rats that varied with age. Given the association of cognitive bias to neurogenesis and inflammation, we examined associations between cognitive bias, neurogenesis in the hippocampus, and cytokine and chemokine levels in the ventral hippocampus (HPC) and basolateral amygdala (BLA) of male and female rats across the lifespan.

Results

After cognitive bias testing, males had more IFN-γ, IL-1β, IL-4, IL-5, and IL-10 in the ventral HPC than females in adolescence. In young adulthood, females had more IFN-γ, IL-1β, IL-6, and IL-10 in the BLA than males. Middle-aged rats had more IL-13, TNF-α, and CXCL1 in both regions than younger groups. Adolescent male rats had higher hippocampal neurogenesis than adolescent females after cognitive bias testing and young rats that underwent cognitive bias testing had higher levels of hippocampal neurogenesis than controls. Neurogenesis in the dorsal hippocampus was negatively associated with negative cognitive bias in young adult males.

Conclusions

Overall, the association between negative cognitive bias, hippocampal neurogenesis, and inflammation in the brain differs by age and sex. Hippocampal neurogenesis and inflammation may play greater role in the cognitive bias of young males compared to a greater role of BLA inflammation in adult females. These findings lay the groundwork for the discovery of sex-specific novel therapeutics that target region-specific inflammation in the brain and hippocampal neurogenesis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12979-022-00299-4.

• Adolescent male rats had more hippocampal inflammation than females after cognitive bias testing.

• Adult female rats had more basolateral amygdalar inflammation than males after cognitive bias testing.

• HPC neurogenesis was negatively associated to cognitive bias in young adult male rats.

The brain in social context: A systematic review of substance use and social processing from adolescence to young adulthood

Substance use escalates between adolescence and young adulthood, and most experimentation occurs among peers. To understand underlying mechanisms, research has focused on neural response during relevant psychological processes. Functional magnetic resonance imaging (fMRI) research provides a wealth of information about brain activity when processing monetary rewards; however, most studies have used tasks devoid of social stimuli. Given that adolescent neurodevelopment is sculpted by the push-and-pull of peers and emotions, identifying neural substrates is important for intervention. We systematically reviewed 28 fMRI studies examining substance use and neural responses to stimuli including social reward, emotional faces, social influence, and social stressors. We found substance use was positively associated with social-reward activity (e.g., in the ventral striatum), and negatively with social-stress activity (e.g., in the amygdala). For emotion, findings were mixed with more use linked to heightened response (e.g., in amygdala), but also with decreased response (e.g., in insula). For social influence, evidence supported both positive (e.g., cannabis and nucleus accumbens during conformity) and negative (e.g., polydrug and ventromedial PFC during peers' choices) relations between activity and use. Based on the literature, we offer recommendations for future research on the neural processing of social information to better identify risks for substance use.

Factors of Obesity and Metabolically Healthy Obesity in Asia

The East Asian region (China, Japan, and South Korea) is comprised of almost 1.5 billion people and recent industrialization has brought with it a pandemic of rising obesity, even in children. As these countries are rapidly aging and functioning at sub-replacement birthrates, the burgeoning costs of obesity-related care may threaten socialized healthcare systems and quality of life. However, a condition called metabolically healthy obesity (MHO) has been found to be without immediate cardiopulmonary or diabetic risk. Thus, maintenance of the MHO condition for the obese in East Asia could buffer the burden of long-term obesity care on medical systems and knowledge of the biochemical, genetic, and physiological milieu associated with it could also provide new targets for intervention. Diverse physiological, psychological, environmental, and social factors play a role in obesogenesis and the transition of MHO to a metabolically unhealthy obesity. This review will give a broad survey of the various causes of obesity and MHO, with special emphasis on the East Asian population and studies from that region.

Adverse childhood experiences, bullying, inflammation and BMI in 10-year-old children: The biological embodiment

Exposure to adversity during the first years of life might already be biologically embedded well before adult life. Thus, the impact of different stressful experiences needs to be explored. This study aims to examine if the association between being victimized (adverse childhood experiences—ACEs and bullying) and (hs-) C-Reactive Protein (CRP) is explained by the influence of adversity on the body mass index (BMI) of the child. We included children from the Portuguese birth cohort Generation XXI (n = 3712) that at 10 years of age completed a questionnaire on the exposure to ACEs and bullying victimization, assessed by an adaptation from the original ACEs study and an adaptation of The Bully Scale Survey, respectively. Following an overnight fast, a venous blood sample was collected by trained nurses and hs-CRP was assayed in fresh blood samples. Weight and height were measured with the child in underwear and bare feet. Weight was measured to the nearest one-tenth of a kilogram with the use of a digital scale (Tanita), and height was measured to the nearest one-tenth of a centimetre with the use of a wall stadiometer (seca®). BMI was calculated as the value of weight (kg) over squared height (m), and computed as an age- and sex-specific BMI standard deviation (SD) score (z-score), according to the World Health Organization Child Growth Standards (5–19 years). Regression coefficients and respective 95% Confidence Interval [β(95%CI)] were computed using path analysis. We observed that ACEs had a positive total effect on hs-CRP at the age of 10 years (β = 0.06; 95%CI: -0.02; 0.15). A direct effect (β = 0.02; 95%CI: -0.01; 0.06) accounted for 66.1% of the association between ACEs and hs-CRP. A positive total effect of bullying victimization on hs-CRP (β = 0.20; 95%CI: 0.06; 0.34) was observed. A direct effect (β = 0.08; 95%CI: -0.05; 0.21) accounted for 40.0% of the association, while an indirect effect through BMI (β = 0.12; 95%CI: 0.06; 0.18) explained 60.0% of the pathway between bullying victimization and hs-CRP. Results suggest that there might be different mechanisms involved in the biological embedding of childhood experiences. BMI seems to explain a great part of the association between exposure to bullying victimization and hs-CRP at 10 years of age. Further research is still needed to better understand the mechanisms explaining the emergence and persistence of health poorer outcomes later in life for victims of abuse.

A prospective study of peer victimization and depressive symptoms among left-behind children in rural China: the mediating effect of stressful life events

BACKGROUND

The Ministry of Civil Affairs of the People's Republic of China reported that in 2018, 6.97 million left-behind children (LBC), children who live in rural areas away from their parents, were being cared for by grandparents, relatives, elder siblings, or often living alone. Their parents have migrated to cities for better income opportunities. While a number of studies have detailed elevated depressive symptoms among LBC, relatively little is known about the causes of poorer mental health in LBC.

METHODS

This study used longitudinal data to examine associations between peer victimization, stressful life events, and depressive symptom severity in LBC from four randomly-selected middle schools in Guizhou Province, China. A total of 862 children aged 11-18 years, with 472 LBC (54.76%) and 390 non-left-behind children (NLBC) (45.24%), were included in the analysis. T-test was used to compare the depressive symptoms, peer victimization, and stressful life events between LBC and NLBC at baseline and follow-up (6 months later). Multivariable linear regression models were used to examine the mediation effect of follow-up stressful life events on the relationship between baseline peer victimization and follow-up depressive symptoms among LBC.

RESULTS

Results suggested that LBC had higher peer victimization and stressful life events than NLBC (β = 1.28, p = 0.04), and peer victimization and stressful life events at baseline were associated with increased follow-up depressive symptoms among LBC (Peer victimization: β = 0.25, p < 0.0001; Stressful life events: β = 0.15, p < 0.001). Peer victimization affected depressive symptoms partially through stressful life events for female LBC and completely through stressful life events for male LBC, controlling for age, perceived socioeconomic status, and school.

CONCLUSIONS

This study highlights the vulnerability of LBC exhibiting negative mental health outcomes as they were found to experience more peer victimization and feel more stressed when stressful life events happened, compared with NLBC. Results of this study suggested that protecting LBC from peer victimization experiences can potentially prevent LBC from experiencing an increased impact of other stressful life events, thus decreasing the likelihood of their depressive symptoms. Intervention design should consider the different mediating effects of stressful life events on the relationship between peer victimization and depressive symptoms among female and male LBC.

Social Safety Theory: Understanding social stress, disease risk, resilience, and behavior during the COVID-19 pandemic and beyond

Many of life's most impactful experiences involve either social safety (e.g., acceptance, affiliation, belonging, inclusion) or social threat (e.g., conflict, isolation, rejection, exclusion). According to Social Safety Theory, these experiences greatly impact human health and behavior because a fundamental goal of the brain and immune system is to keep the body biologically safe. To achieve this crucial goal, social threats likely gained the ability to activate anticipatory neural-immune responses that would have historically benefited reproduction and survival; the presence of social safety, in turn, likely dampened these responses. Viewing positive and negative social experiences through this lens affords a biologically based evolutionary account for why certain stressors are particularly impactful. It also provides an integrated, multi-level framework for investigating the biopsychosocial roots of psychopathology, health disparities, aging, longevity, and interpersonal cognition and behavior. Ultimately, this work has the potential to inform new strategies for reducing disease risk and promoting resilience.

Integrative Brain Dynamics in Childhood Bullying Victimization: Cognitive and Emotional Convergence Associated With Stress Psychopathology

Bullying victimization is a form of psychological stress that is associated with poor outcomes in the areas of mental health and learning. Although the emotional maladjustment and memory impairment following interpersonal stress are well documented, the mechanisms of complex cerebral dysfunctions have neither been outlined nor studied in depth in the context of childhood bullying victimization. As a contribution to the cross-disciplinary field of developmental psychology and neuroscience, we review the neuropathophysiology of early life stress, as well as general psychological stress to synthesize the data and clarify the versatile dynamics within neuronal networks linked to bullying victimization. The stress-induced neuropsychological cascade and associated cerebral networks with a focus on cognitive and emotional convergence are described. The main findings are that stress-evoked neuroendocrine reactivity relates to neuromodulation and limbic dysregulation that hinder emotion processing and executive functioning such as semantic cognition, cognitive flexibility, and learning. Developmental aspects and interacting neural mechanisms linked to distressed cognitive and emotional processing are pinpointed and potential theory-of-mind nuances in targets of bullying are presented. The results show that childhood stress psychopathology is associated with a complex interplay where the major role belongs to, but is not limited to, the amygdala, fusiform gyrus, insula, striatum, and prefrontal cortex. This interplay contributes to the sensitivity toward facial expressions, poor cognitive reasoning, and distress that affect behavioral modulation and emotion regulation. We integrate the data on major brain dynamics in stress neuroactivity that can be associated with childhood psychopathology to help inform future studies that are focused on the treatment and prevention of psychiatric disorders and learning problems in bullied children and adolescents.

Longitudinal associations between adolescents' individualised risk for depression and inflammation in a UK cohort study

Inflammation is associated with poor physical and mental health including major depressive disorder (MDD). Moreover, there is evidence that childhood adversity - a risk factor for MDD - becomes biologically embedded via elevated inflammation. However, the risk of developing MDD arises from multiple sources and yet there has been little investigation of the links between individuals' constellation of MDD risk and subsequent inflammation. We therefore examined associations between individual risk for MDD calculated in early adolescence and levels of inflammation six years later. We use data from the Environmental Risk (E-Risk) Longitudinal Twin Study, a nationally representative UK birth cohort of 2,232 children followed to age 18 with 93% retention. Participants' individual risk for developing future MDD was calculated at age 12 using a recently developed prediction model comprising multiple psychosocial factors. Plasma levels of three inflammation biomarkers were measured at age 18: C-reactive protein (CRP), interleukin-6 (IL-6), and a newer biomarker, soluble urokinase plasminogen activator receptor (suPAR), which is thought to reflect the level of systemic chronic inflammation. MDD risk scores calculated at age 12 were positively associated with levels of suPAR (but not CRP or IL-6) at age 18 after adjusting for key covariates (b = 1.70, 95% CI = 0.46 - 2.95, p = 0.007). Adolescents at high risk of MDD (risk scores ≥ 90th centile) had significantly higher mean levels of suPAR six years later than adolescents who had been identified as low risk (risk scores ≤ 10th centile) (b = 0.41, 95% CI = 0.18 - 0.64, p < 0.001). Findings support the notion that childhood psychosocial risk for MDD leads to increased levels of low-grade inflammation. If replicated in studies with repeated assessments of inflammation biomarkers throughout childhood and adolescence, these findings would support targeted interventions to reduce inflammation, as measured by suPAR, for adolescents at high risk of MDD to potentially prevent development of depression and physical health problems related to chronic inflammation.

Exploring joint HPA-inflammatory stress response profiles in adolescent girls: Implications for developmental models of neuroendocrine dysregulation

Prior research has struggled to differentiate cortisol stress response patterns reflective of well-regulated versus dysregulated hypothalamic-pituitary-adrenal (HPA) axis function among adolescents. Here, we show how exploring profiles of joint HPA-inflammatory stress responsivity, and linking those profiles to pubertal development and peer stress exposure may aid such distinction. Adolescent girls (N = 157, Mage  = 14.72 years, SD = 1.38) at risk for psychopathology completed assessments of salivary cortisol and pro-inflammatory cytokines (i.e., tumor necrosis factor-α, interleukin-1β, and interleukin-6) prior to and following the Trier Social Stress Test. Adolescents, a close friend, and a caregiver completed questionnaire measures of peer stress and pubertal status. Multitrajectory modeling of adolescents' cortisol and cytokine levels revealed three profiles: low cortisol response-stably low cytokine (n = 75), high cortisol response-stably moderate cytokine (n = 47), and low cortisol response-stably high cytokine (n = 35). Relative to low cortisol response-stably low cytokine, adolescents exhibiting the high cortisol response-stably moderate cytokine profile were more advanced in their pubertal development, but presented with similarly low levels of peer stress exposure. Despite showing cortisol responses that were indistinguishable from low cortisol response-stably low cytokine, adolescents exhibiting the low cortisol response-stably high cytokine profile were more pubertally advanced, but also more likely to have experienced chronic peer strain (self-report) and relational peer victimization (close friend-report). These findings thus illustrate the potential value of taking a multisystem approach to studying adolescent stress responsivity and underscore the importance of considering developmental and social factors when interpreting cortisol stress response patterns. Ultimately, such work may help inform developmental models of neuroendocrine dysregulation and related risk for psychopathology.

Neurobiological correlates of the social and emotional impact of peer victimization: A review

Peer victimization is very common during late childhood and adolescence. Despite the relatively reduced number of studies, the neurobiological underpinnings of the negative impact of peer victimization experiences have received increasing attention in recent years. The present selective review summarizes the most recent available evidence and provides a general overview of the impact of peer victimization experiences on social processing and decision-making at the neurobiological level, highlighting the most pressing areas requiring further research. Three key cognitive areas show a clear negative impact of peer victimization and bullying experiences: social valuation processing, reward and reinforcement learning and self-regulation processes. Victims show enhanced activation in key regions of the limbic system including the amygdala, rostral and dorsal anterior cingulate cortices, suggestive of enhanced sensitivity to social stimuli. They also show enhanced recruitment of lateral prefrontal regions crucially involved in cognitive and emotional regulation processes, and abnormal reward-related striatal function. The presence of psychopathology is a complex factor, increased as a consequence of peer victimization, but that also constitutes vulnerability to such experiences.

A short Mindfulness retreat can improve biological markers of stress and inflammation

OBJECTIVE

Mindfulness practice, a form of meditation, has shown benefit for psychological and physical health. In this study, we investigated the effect of an intensive period of Mindfulness practice on some biological mediators of stress and inflammation during a 3-day residential retreat.

METHODS

A total of 95 healthy individuals (aged 18-67) were recruited and randomized to a Mindfulness retreat arm or an active control arm. Before (t0) and after (t1) the intervention, all the participants were assessed for salivary cortisol levels and for a panel of pro- and anti-inflammatory cytokines measured in saliva. Psychometric measures on stress, anxiety and awareness were carried out using PSS, STAI-Y and MAAS questionnaires, respectively.

RESULTS

As to the within-group differences, we observed a statistically significant decrease in perceived stress (β = -8.85, p < 0.0001), and anxiety scores (β = -12.39, p < 0.0001), while awareness increased (β = 15.26, p < 0.0001) between t0 to t1 in retreat participants. In the mindfulness intervention group, we also observed a statistically significant reduction in the levels of pro-inflammatory cytokines IL-6 (β = -0.94 p = 0.001) and IL-8 (β = -176.40, p < 0.0001), and an increase in anti-inflammatory IL-10 (β = 0.89 p < 0.0001) levels at the end of the retreat. At t1 we observed a highly significant correlation between cortisol levels and both anxiety (r = 0.56, p < 0.0001) and perceived stress (r = 0.92, p < 0.0001) scores.

CONCLUSIONS

Mindfulness retreat participants showed a significant reduction in perceived stress and anxiety levels, as well as an improved balance of some key mediators of inflammatory states. Our data provide evidence that a mindfulness retreat may be effective in improving physical and mental health. Future studies with larger numbers of subjects and follow-up periods may examine mindfulness practice as a non-pharmacological alternative to promote stress reduction and overall health and wellbeing.

Timing, duration, and differential susceptibility to early life adversities and cardiovascular disease risk across the lifespan: Implications for future research

Early life adversities (ELA), include experiences such as child maltreatment, household dysfunction, bullying, exposure to crime, discrimination, bias, and victimization, and are recognized as social determinants of cardiovascular disease (CVD). Strong evidence shows exposure to ELA directly impacts cardiometabolic risk in adulthood and emerging evidence suggests there may be continuity in ELA's prediction of cardiometabolic risk over the life course. Extant research has primarily relied on a cumulative risk framework to evaluate the relationship between ELA and CVD. In this framework, risk is considered a function of the number of risk factors or adversities that an individual was exposed to across developmental periods. The cumulative risk exposure approach treats developmental periods and types of risk as equivalent and interchangeable. Moreover, cumulative risk models do not lend themselves to investigating the chronicity of adverse exposures or consider individual variation in susceptibility, differential contexts, or adaptive resilience processes, which may modify the impact of ELA on CVD risk. To date, however, alternative models have received comparatively little consideration. Overall, this paper will highlight existing gaps and offer recommendations to address these gaps that would extend our knowledge of the relationship between ELA and CVD development. We focus specifically on the roles of: 1) susceptibility and resilience, 2) timing and developmental context; and 3) variation in risk exposure. We propose to expand current conceptual models to incorporate these factors to better guide research that examines ELA and CVD risk across the life course.

Inflammation, depressive symptoms, and emotion perception in adolescence

BACKGROUND

Individuals with depression often demonstrate an altered peripheral inflammatory profile, as well as emotion perception difficulties. However, correlations of inflammation with overall depression severity are inconsistent and inflammation may only contribute to specific symptoms. Moreover, measurement of the association between inflammation and emotion perception is sparse in adolescence, despite representing a formative window of emotional development and high-risk period for depression onset.

METHODS

Serum interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-1β were measured in 34 adolescents aged 12-17 with DSM-IV depressive disorders (DEP) and 29 healthy controls (HC). Participants were evaluated using the Children's Depression Rating Scale-Revised (CDRS-R) and symptom subscales were extracted based on factor analysis. Participants also completed a performance-based measure of emotion perception, the Facial Emotion Perception Test (FEPT), which assesses the accuracy of categorizing angry, fearful, sad, happy, and neutral facial emotions.

RESULTS

IL-6 and TNF-α correlated with reported depressed mood and somatic symptoms, respectively, but not total CDRS-R score, anhedonia or observed mood, across both DEP and HC. DEP demonstrated lower accuracy for identifying angry facial expressions. Higher IL-6 was inversely related to accuracy and discrimination of angry and neutral faces across all participants. IL-1β was associated with reduced discrimination of fearful faces.

CONCLUSIONS

Inflammatory markers were sensitive to affective and somatic symptoms of depression and processing of emotional threat in adolescents. In particular, IL-6 was elevated in depressed adolescents and therefore may represent a specific target for modulating depressive symptoms and emotion processing.

A Closer Look at the Emotional Intelligence Construct: How Do Emotional Intelligence Facets Relate to Life Satisfaction in Students Involved in Bullying and Cyberbullying?

Adolescents’ perception of their own emotional abilities has been related to psychological adjustment and well-being. However, there are still few studies focusing on specific emotional dimensions in relation to bullying and well-being in adolescence. This study analysed the relationship between emotional intelligence (EI) facets, satisfaction with life, bullying and cyberbullying in adolescents. The sample consisted of 3520 high school students (51.5% females) aged between 12 and 18 years (M = 14.37; SD = 1.67). The correlation analyses showed that the majority of EI facets were positively related to satisfaction with life and negatively with both types of violence. As was expected, bullying and cyberbullying victims and bully–victims scored lower in satisfaction with life and the majority of EI facets. Controlling for sex, age, and grade, self-emotion appraisal, use of emotions and regulation of emotion were the best predictors of life satisfaction in bully–victims of bullying and cyberbullying. Finally, we discuss the relevance of these findings for clinical and educational practice on EI seeking to promote subjective well-being among adolescents involved in bullying and cyberbullying.

Inflammatory cytokine levels implicated in Alzheimer's disease moderate the effects of sex on verbal memory performance

Despite having an initial verbal memory advantage over men, women have greater rates of Alzheimer's disease and more rapid cognitive decline once diagnosed. Moreover, although Alzheimer's disease is influenced by inflammation, which itself has known sex differences, no study has investigated whether sex differences in memory are moderated by peripheral inflammatory activity. To address this issue, we analyzed data from 109 individuals (50 women, M_age = 71.62, range = 55-87) diagnosed as cognitively normal, or having mild cognitive impairment or Alzheimer's disease dementia. We then followed the sample for 12 months, as part of a longitudinal study of aging and Alzheimer's disease. At baseline, we assessed levels of the inflammatory cytokines interleukin (IL)-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α) in plasma. At baseline and 12 months, we assessed verbal memory using the Rey Auditory Verbal Learning Test and nonverbal memory using the Brief Visuospatial Memory Test-Revised. As hypothesized, for the full sample, women exhibited stronger verbal (but not nonverbal) memory than men. In women, but not men, higher IL-1β at baseline related to poorer verbal learning across both time points and delayed recall at 12 months. The effect of sex on memory also differed by IL-1β level, with women exhibiting a memory advantage both at baseline and 12 months, but only for those with low-to-moderate IL-1β levels. Therefore, high peripheral inflammation levels may lead to a sex-specific memory vulnerability relevant for Alzheimer's disease.

Leveraging the developmental science of psychosocial risk to strengthen youth psychotherapy

More than 50 years of randomized clinical trials for youth psychotherapies have resulted in moderate effect sizes for treatments targeting the most common mental health problems in children and adolescents (i.e., anxiety, depression, conduct problems, and attention disorders). Despite having psychotherapies that are effective for many children, there has been a dearth of progress in identifying the contextual factors that likely influence who will respond to a given psychotherapy, and under what conditions. The developmental psychopathology evidence base consistently demonstrates that psychosocial risk exposures (e.g., childhood adversities, interpersonal stressors, family dysfunction) significantly influence the onset and course of youth psychopathology. However, the developmental psychopathology framework remains to be well integrated into treatment development and psychotherapy research. We argue that advances in basic developmental psychopathology research carry promising implications for the design and content of youth psychotherapies. Research probing the effects of psychosocial risks on youth development can enrich efforts to identify contextual factors in psychotherapy effectiveness and to personalize treatment. In this article we review empirically supported and hypothesized influences of individual- and family-level risk factors on youth psychotherapy outcomes, and we propose a framework for leveraging developmental psychopathology to strengthen psychotherapies.

Annual Research Review: Social relationships and the immune system during development

A child's social relationships serve critical functions during development. The interface between a child's social world and their immune system, particularly innate immunity, which helped children survive in the face of infections, nutritional scarcity, and violence throughout human history, is the focus of this Annual Research Review. This article reviews the state of research on social relationships and innate immune inflammation during childhood. Warmth and rejection in childhood social relationships, as well as physical trauma and unpredictable social environments, were not consistently related to circulating inflammatory markers such as interleukin-6 and C-reactive protein during childhood. Instead, links between social environments and inflammation were observed in studies that focus on children with greater background risk factors, such as low family socioeconomic status, family history of mood disorders, or presence of chronic interpersonal stressors combined with acute episodic stressors. In addition, studies on worse childhood social environments and greater inflammation in adulthood were more consistent. Warmth and rejection in the social environment may be related to sensitivity of immune cells to the anti-inflammatory actions of glucocorticoids, though this is primarily observed in adolescent women at risk for depression. Additional mechanistic evidence suggests that greater warmth and less rejection are related to processes that regulate inflammation, including greater expression of the glucocorticoid receptor gene and lower expression of genes that are responsive to the pro-inflammatory transcription factor NF-kappa B. The article concludes by discussing implications of the interface between a child's social relationships and inflammation for mental health and other recent (on evolutionary timescales) health threats, as well as recommendations for future research, and recommendations for researchers interested in integrating inflammatory measures in developmental research.

Peripheral immune correlates of childhood and adolescent peer relationships: A systematic review

The objective of this review was to comprehensively evaluate the literature investigating associations between peripheral immune correlates and youth peer relationship dimensions. We aimed to identify potential aspects of peer relationships in childhood and adolescence that may be associated with immune profiles and to identify gaps in the field to provide suggestions for future research in this area. We conducted a systematic electronic search in health-related databases from the earliest records to December 2020. Search terms included domains related to youth, immune correlates, and peers. We summarized studies by the time between the peer measurement and the immune outcome. In the 17 included studies, associations between peer dimensions and immune outcomes varied substantially. Peer victimization in youth demonstrated the most consistent negative associations with immune health across development, including within 1 week of measurement, 1-3 years later, and 10 or more years later. This review indicated that that peer relationships during youth may have important associations with immune processes; however, there are several gaps in the literature regarding the operationalization of peer relationships, the timing of the immune measurement, and the type of immune outcome to be addressed by future research.

Inflamed Mind: Multiple Genetic Variants of IL6 Influence Suicide Risk Phenotypes in Interaction With Early and Recent Adversities in a Linkage Disequilibrium-Based Clumping Analysis

Background: Understanding and predicting suicide remains a challenge, and a recent paradigm shift regarding the complex relationship between the immune system and the brain brought attention to the involvement of inflammation in neuropsychiatric conditions including suicide. Among cytokines, IL-6 has been most frequently implicated in suicide, yet only a few candidate gene studies and without considering the effect of stress investigated the role of IL6 in suicidal behaviour. Our study aimed to investigate the association of IL6 variation with a linkage disequilibrium-based clumping method in interaction with childhood adversities and recent stress on manifestations along the suicide spectrum. Methods: One thousand seven hundred and sixty-two participants provided information on previous suicide attempts, current suicidal ideation, thoughts of death, and hopelessness, and were genotyped for 186 variants in IL6. Early childhood adversities were recorded with an instrument adapted from the Childhood Trauma Questionnaire, recent life events were registered using the List of Threatening Life Events. Following a 3-step quality control, logistic and linear regression models were run to explore the effect of genotype and gene-environment interactions on suicide phenotypes. All regression models were followed by a clumping process based on empirical estimates of linkage disequilibrium between clumps of intercorrelated SNPs. Interaction effects of distinct types of recent life events were also analysed. Results: No clumps with significant main effects emerged, but we identified several clumps significantly interacting with childhood adversities on lifetime suicide attempts, current suicidal ideation, and current thoughts of death. We also identified clumps significantly interacting with recent negative life events on current suicidal ideation. We reported no clumps with significant effect on hopelessness either as a main effect or in interaction with childhood adversities or recent stress. Conclusion: We identified variant clumps in IL6 influencing suicidal behaviour, but only in interaction with childhood or recent adversities. Our results may bring us a step further in understanding the role of neuroinflammation and specifically of IL-6 in suicide, towards identifying novel biological markers of suicidal behaviour especially in those exposed to stressful experiences, and to fostering the adaptation of a new paradigm and identifying novel approaches and targets in the treatment of suicidal behaviour.

Pregnancy associated epigenetic markers of inflammation predict depression and anxiety symptoms in response to discrimination

Latina mothers, who have one of the highest fertility rates among ethnic groups in the United States (US), often experience discrimination. Psychosocial influences during pregnancy, such as discrimination stress, promotes inflammation. However, the role of epigenetic markers of inflammation as a mediator between, and predictor of, maternal discrimination stress and neuropsychiatric outcomes has not been extensively studied. The current study investigates the role of DNA methylation at FOXP3 Treg-cell-specific demethylated region (TSDR), as a marker of regulatory T (Treg) cells that are important negative regulators of inflammation, and the promoter of tumour necrosis factor-alpha (TNF-α) gene, an important pro-inflammatory cytokine, in relation to discrimination stress during pregnancy and depression and anxiety symptomatology.

A sample of 148 Latina women residing in the US (mean age 27.6 years) were assessed prenatally at 24–32 weeks’ gestation and 4–6 weeks postnatally for perceived discrimination exposure (Everyday Discrimination Scale, EDS), emotional distress (depression, anxiety, perinatal-specific depression), acculturation, and acculturative stress. DNA methylation levels at the FOXP3 and TNFα promoter regions from blood samples collected at the prenatal stage were assessed by bisulphite pyrosequencing.

Regression analyses showed that prenatal EDS associated with postnatal emotional distress, depression and anxiety symptoms only in those individuals with higher than mean levels of FOXP3 TSDR and TNFα promoter methylation; no such significant associations were found in those with lower than mean levels of methylation for either. We further found that these relationships were mediated by TNFα only in those with high FOXP3 TSDR methylation, implying that immunosuppression via TNFα promoter methylation buffers the impact of discrimination stress on postpartum symptomatology. These results indicate that epigenetic markers of immunosuppression and inflammation play an important role in resilience or sensitivity, respectively, to prenatal stress.

Health Disparities in COVID-19: Addressing the Role of Social Determinants of Health in Immune System Dysfunction to Turn the Tide

It is evident that health disparities exist during the COVID-19 pandemic, a pandemic caused by the novel coronavirus SARS-CoV-2. Underlying reasons for COVID-19 health disparities are multi-factorial. However, social determinants, including those regarding socioeconomic status, social inequalities, health behaviors, and stress, may have implications on these disparities. Exposure to one or more of these social determinants is associated with heightened inflammatory responses, particularly increases in the cytokine interleukin-6 (IL-6), as well as immune system dysfunction. Thus, an amplified effect during COVID-19 could occur, potentially resulting in vulnerable patients experiencing an intensified cytokine storm due to a hyperactive and dysfunctional immune response. Further understanding how social determinants play a mechanistic role in COVID-19 disparities could potentially help reduce health disparities overall and in future pandemics.

Autonomic nervous system activity predicts increasing serum cytokines in children

Systemic inflammation is associated with increased risk for prevalent and costly diseases, and animal models implicate the autonomic nervous system in the control of inflammatory processes. In humans, research on autonomic-immune connections has been much more limited, and has focused on single branch autonomic measures (i.e., either parasympathetic or sympathetic). The current study utilized cardiac autonomic balance (CAB), derived from dual-branch cardiac autonomic recordings, to test the relation between resting autonomic function and inflammatory reactivity to challenge in children.

METHODS

Participants included 96 children (51 boys, 45 girls) ages 9-11 years (mean age = 9.93 years, SD = 0.57 years). CAB values were calculated from standardized measures of parasympathetic and sympathetic activity, namely resting respiratory sinus arrhythmia and pre-ejection period data, respectively. Children provided two blood samples, one before and one following exposure to an acute social stressor or control condition. Serum was assayed for four cytokines that orchestrate inflammation: interleukin-6 (IL6), interleukin-8 (IL8), interleukin-10 (IL10), and tumor necrosis factor-alpha (TNFa).

RESULTS

We discovered large individual differences in inflammatory marker production across children, and no average main effect of stress condition. CAB significantly predicted these individual differences, such that children lower on CAB showed increasing serum cytokines from time 1 to time 2. In contrast, children with greater CAB tended to show declining inflammatory markers across the session.

DISCUSSION

Low cardiac autonomic balance (i.e., the combination of low parasympathetic and high sympathetic activity) may be a useful marker of proinflammatory tendencies in children, suggesting novel paths for early risk detection and intervention.

Sex Differences in the Inflammatory Consequences of Stress: Implications for Pharmacotherapy

Women are at significantly greater risk of developing stress-related disorders such as depression. The increased risk begins during puberty and continues throughout life until menopause, suggesting a role for ovarian hormones in this increased susceptibility. Importantly, inflammation has been gaining momentum in its role in the pathogenesis of depression. Herein, clinical and preclinical studies have been reviewed to better understand how sex differences within the immune system may contribute to exaggerated risk of depression in females. First, studies that investigate the ability of psychologic stress episodes to engage the inflammatory systems both in the brain and periphery are reviewed with a special focus on sex-specific effects. Moreover, studies are discussed that identify whether imbalanced inflammatory milieu contributes to the development of depression in males versus females and whether these effects are regulated by estradiol. Importantly, we propose a locus coeruleus-norepinephrine-cytokine circuit as a conduit through which stress could increase stress susceptibly in females. Finally, the anti-inflammatory capacity of traditional and nontraditional antidepressants is investigated, with the goal of providing a better understanding of pharmacotherapeutics to enhance strategies to personalize antidepressant treatments between the sexes. The studies reviewed herein strongly support the need for further studies to elucidate whether females are especially sensitive to anti-inflammatory compounds as adjuvants to traditional therapies. SIGNIFICANCE STATEMENT: Women have hve an increased risk of developing stress-related disorders such as depression. In this review, literature from clinical and preclinical studies are integrated to define sex differences in stress-induced inflammatory responses as a potential source for the etiology of sex differences in depressive disorders. Moreover, the anti-inflammatory capacity of traditional and nontraditional antidepressants is reviewed to inform on potential pharmacotherapeutic strategies to personalize antidepressant therapy in a sex-dependent manner.

Neuroimmune Mechanisms and Sex/Gender-Dependent Effects in the Pathophysiology of Mental Disorders

Innate and adaptive immune mechanisms have emerged as critical regulators of CNS homeostasis and mental health. A plethora of immunologic factors have been reported to interact with emotion- and behavior-related neuronal circuits, modulating susceptibility and resilience to mental disorders. However, it remains unclear whether immune dysregulation is a cardinal causal factor or an outcome of the pathologies associated with mental disorders. Emerging variations in immune regulatory pathways based on sex differences provide an additional framework for discussion in these psychiatric disorders. In this review, we present the current literature pertaining to the effects that disrupted immune pathways have in mental disorder pathophysiology, including immune dysregulation in CNS and periphery, microglial activation, and disturbances of the blood-brain barrier. In addition, we present the suggested origins of such immune dysregulation and discuss the gender and sex influence of the neuroimmune substrates that contribute to mental disorders. The findings challenge the conventional view of these disorders and open the window to a diverse spectrum of innovative therapeutic targets that focus on the immune-specific pathophenotypes in neuronal circuits and behavior. SIGNIFICANCE STATEMENT: The involvement of gender-dependent inflammatory mechanisms on the development of mental pathologies is gaining momentum. This review addresses these novel factors and presents the accumulating evidence introducing microglia and proinflammatory elements as critical components and potential targets for the treatment of mental disorders.

Social Safety Theory: A Biologically Based Evolutionary Perspective on Life Stress, Health, and Behavior

Social Safety Theory hypothesizes that developing and maintaining friendly social bonds is a fundamental organizing principle of human behavior and that threats to social safety are a critical feature of psychological stressors that increase risk for disease. Central to this formulation is the fact that the human brain and immune system are principally designed to keep the body biologically safe, which they do by continually monitoring and responding to social, physical, and microbial threats in the environment. Because situations involving social conflict, isolation, devaluation, rejection, and exclusion historically increased risk for physical injury and infection, anticipatory neural-immune reactivity to social threat was likely highly conserved. This neurocognitive and immunologic ability for humans to symbolically represent and respond to potentially dangerous social situations is ultimately critical for survival. When sustained, however, this multilevel biological threat response can increase individuals' risk for viral infections and several inflammation-related disease conditions that dominate present-day morbidity and mortality.

Longitudinal changes of inflammatory biomarkers moderate the relationship between recent stressful life events and prospective symptoms of depression in a diverse sample of urban adolescents

This study investigated whether longitudinal changes in inflammatory physiology moderated the relationship between recent stressful life events and subsequent depressive symptoms in adolescence. A diverse sample of adolescents representative of an urban community (N = 129; Age at baseline = 12.5 years; 48.8% female; 55.0% African American) completed measures of stressful life events, depressive symptoms, and two annual blood draws (BD1 and BD2). Controlling for inflammatory activity at BD1, depression at BD1, demographics and the time between assessments, increases in interleukin-6 (IL-6; b = 0.878, p = .007) and C-reactive protein (CRP; b = 0.252, p = .024) from BD1 to BD2 interacted with recent stressful life events before BD1 to predict severity of depressive symptoms at BD2. Similar associations were evident for IL-6 (b = 2.074, p = .040) and CRP (b = 0.919, p = .050) when considering acute stressful life events that had occurred within the two weeks before the first blood collection. More frequent stressful life events before BD1 predicted significantly more severe depressive symptoms at BD2, but only for adolescents with moderate (50th percentile) and high (84th percentile) levels of IL-6 and CRP at BD2. In conclusion, adolescents who experienced both recent stressful life events and larger increases in inflammatory activity following these stressors were at increased risk for more severe depressive symptoms after approximately one year. The findings indicate that the interaction of stress and larger changes in inflammatory activity following these stressors are prognostic risk factors for depression severity in adolescents.

Future Directions in Peer Relations Research

Peer relationships among youth have been examined as predictors of mental health outcomes for at least fifty years, revealing dozens of discrete peer constructs that each are associated with adjustment in childhood, adolescence, and later in adulthood. Future research may benefit by examining a range of new outcomes and psychological processes that have been discussed recently in related literatures. This paper reviews recent research on interpersonal determinants of physical health outcomes, and opportunities for greater examination of 1) peer influence processes toward health risk behaviors; 2) neural correlates of peer adversity; 3) adverse peer experiences that may affect physiological markers of stress response; and 4) immune system markers of peer adversity. Additional future directions include the study of differences in the forms and functions of peer interactions within the digital age.

Interpersonal life stress, inflammation, and depression in adolescence: Testing Social Signal Transduction Theory of Depression

BACKGROUND

Depression rates increase markedly for girls across the adolescent transition, but the social-environmental and biological processes underlying this phenomenon remain unclear. To address this issue, we tested a key hypothesis from Social Signal Transduction Theory of Depression, which posits that individuals who mount stronger inflammatory responses to social stress should exhibit greater increases in depressive symptoms following interpersonal life stress exposure than those who mount weaker inflammatory responses to such stress.

METHOD

Participants were 116 adolescent girls (M_age  = 14.71) at risk for psychopathology, defined as having a history of mental health concerns (e.g., psychiatric treatment, significant symptoms) over the past 2 years. At baseline, we characterized their inflammatory reactivity to social stress by quantifying their salivary proinflammatory cytokine responses to a laboratory-based social stressor. Then, 9 months later, we assessed the interpersonal and noninterpersonal stressful life events that they experienced over the prior 9 months using an interview-based measure of life stress.

RESULTS

As hypothesized, greater interpersonal life stress exposure was associated with significant increases in depression over time, but only for girls exhibiting stronger salivary tumor necrosis factor-α and interleukin-1β reactivity to social stress. In contrast, noninterpersonal stress exposure was unrelated to changes in depression longitudinally, both alone and when combined with youths' cytokine reactivity scores.

DISCUSSION

These results are consistent with Social Signal Transduction Theory of Depression and suggest that heightened inflammatory reactivity to social stress may increase adolescents' risk for depression. Consequently, it may be possible to reduce depression risk by modifying inflammatory responses to social stress.

Executive Control, Cytokine Reactivity to Social Stress, and Depressive Symptoms: Testing the Social Signal Transduction Theory of Depression

Social Signal Transduction Theory of Depression hypothesizes that social stress upregulates inflammatory activity, which in turn contributes to depression for some individuals. However, the specific cognitive processes underlying social stress-induced increases in inflammatory activity remain unclear. We addressed this issue by examining two separate relations: (1) between executive control measured following a laboratory-based social stress induction and individuals' pro-inflammatory cytokine responses to the same stress induction and (2) between pro-inflammatory cytokine responses and participants' depressive symptom levels. Healthy young participants (Mage = 18.58 years old) were randomly assigned to either a stress condition or control condition. Executive control, and the inflammatory cytokines interleukin-1β, interleukin-6, and tumor necrosis factor-α, were measured before and after the social stress induction or control task. Regression analyses (stress condition, n = 20; control condition, n = 16) demonstrated that in the stress condition only, greater increases in interleukin-6 were associated with more depressive symptoms. Additional analyses in the stress condition (n = 16) indicated that greater impairment in executive control following the social stress induction was related to greater social stress-induced increases in interleukin-6. These findings are consistent with Social Signal Transduction Theory of Depression and with the hypothesis that impairment in executive control during times of stress may be one process that contributes to stress-induced inflammatory activity, which may in turn increase risk for depression.Lay SummarySocial Signal Transduction Theory of Depression hypothesizes that social stress upregulates inflammatory activity, which in turn contributes to depression, and that cognitive processes play a role in structuring these effects. Consistent with this theory, greater social stress-induced increases in the inflammatory cytokine interleukin-6 were associated with more depressive symptoms. In addition, greater impairment in executive control following the social stress induction was related to greater social stress-induced increases in interleukin-6, highlighting potential links between social stress, cognition, inflammation, and depression.

A healthy peer status: Peer preference, not popularity, predicts lower systemic inflammation in adolescence

In adolescence, sensitivity to peers is heightened, which makes peer experiences highly salient. Recent work suggests that these experiences may influence individuals' immune system functioning. Although there is a need to investigate which types of developmental salient social experiences affect inflammation, no studies have examined the role of peer status in inflammatory activity so far. This study is the first to examine the unique role of different types of peer status (i.e., peer preference and peer popularity) on systemic inflammation in adolescence, and the extent to which this association is moderated by early childhood adversity. Participants were 587 Dutch adolescents from the TRacking Adolescents´ Individual Lives Survey (TRAILS). Data were collected when participants were 11 (SD = .56), 13 (SD = .53) and 16 (SD = .71) years old, respectively. At age 11, early childhood adversity (e.g., hospitalization, death within the family) between 0-5 years was assessed via parent interviews. At age 13, peer preference and peer popularity were assessed with peer nominations of classmates. At age 16, high sensitive C-reactive protein (hsCRP), a marker of low-grade systemic inflammation, was assessed with a venipuncture blood draw. Results showed that adolescents who were rated low on peer preference at age 13 exhibited higher levels of hsCRP at age 16. Importantly, these effects remained after controlling for several covariates, including age, sex, peer victimization, smoking behavior, SES, fat percentage, physical activity and temperament. Additionally, we found a positive effect of peer popularity on hsCRP that depended on early childhood adversity exposure. This suggests that for those adolescents who experienced little early childhood adversity, high levels of peer popularity were associated with high levels of hsCRP. Overall, these findings suggest that it is important to take into account the independent roles of peer preference and peer popularity, as specific types of peer status, to better understand adolescent systemic inflammation.

Pathways between early-life adversity and adolescent self-harm: the mediating role of inflammation in the Avon Longitudinal Study of Parents and Children

BACKGROUND

Adverse childhood experiences (ACEs) such as physical and emotional abuse are strongly associated with self-harm, but mechanisms underlying this relationship are unclear. Inflammation has been linked to both the experience of ACEs and self-harm or suicide in prior research. This is the first study to examine whether inflammatory markers mediate the association between exposure to ACEs and self-harm.

METHODS

Participants were 4,308 young people from the Avon Longitudinal Study of Parents and Children (ALSPAC), a population-based birth cohort in the United Kingdom. A structural equation modelling approach was used to fit a mediation model with the number of ACEs experienced between ages 0 and 9 years old (yo), levels of the inflammatory markers interleukin-6 and C-reactive protein measured at 9.5 yo, and self-harm reported at 16 yo.

RESULTS

The mean number of ACEs young people experienced was 1.41 (SE 0.03). Higher ACE scores were associated with an increased risk of self-harm at 16 yo (direct effect relative risk (RR) per additional ACE 1.11, 95% CI 1.05, 1.18, p < 0.001). We did not find evidence of an indirect effect of ACEs on self-harm via inflammation (RR 1.00, 95% CI 1.00, 1.01, p = 0.38).

CONCLUSIONS

Young people who have been exposed to ACEs are a group at high risk of self-harm. The association between ACEs and self-harm does not appear to be mediated by an inflammatory process in childhood, as indexed by peripheral levels of circulating inflammatory markers measured in childhood. Further research is needed to identify alternative psychological and biological mechanisms underlying this relationship.

Stress, sex hormones, inflammation, and major depressive disorder: Extending Social Signal Transduction Theory of Depression to account for sex differences in mood disorders

Social Signal Transduction Theory of Depression is a biologically plausible, multi-level theory that describes neural, physiologic, molecular, and genomic mechanisms that link experiences of social-environmental adversity with internal biological processes that drive depression pathogenesis, maintenance, and recurrence. Central to this theory is the hypothesis that interpersonal stressors involving social threat (e.g., social conflict, evaluation, rejection, isolation, and exclusion) upregulate inflammatory processes that can induce several depressive symptoms, including sad mood, anhedonia, fatigue, psychomotor retardation, and social-behavioral withdrawal. The original article describing this formulation (Psychol Bull 140:774-815, 2014) addressed critical questions involving depression onset and recurrence, as well as why depression is strongly predicted by early life stress and comorbid with anxiety disorders and certain physical disease conditions, such as asthma, rheumatoid arthritis, chronic pain, and cardiovascular disease. Here, we extend the theory to help explain sex differences in depression prevalence, which is a defining feature of this disorder. Central to this extension is research demonstrating that ovarian hormone fluctuations modulate women's susceptibility to stress, brain structure and function, and inflammatory activity and reactivity. These effects are evident at multiple levels and are highly context-dependent, varying as a function of several factors including sex, age, reproductive state, endogenous versus exogenous hormones, and hormone administration mode and dose. Together, these effects help explain why women are at greater risk for developing inflammation-related depressed mood and other neuropsychiatric, neurodevelopmental, and neurodegenerative disorders during the reproductive years, especially for those already at heightened risk for depression or in the midst of a hormonal transition period.

Stress and inflammation - The need to address the gap in the transition between acute and chronic stress effects

Stress responses help us navigate our environment and respond appropriately to threats. Stress systems communicate threats to the entire organism, and as such, also stimulate inflammatory mechanisms. This modulation might serve protective functions in the short term, but sustained low-grade inflammation has severe long-term health consequences. While we have reached a reasonable level of understanding of acute, as well as chronic stress effects on inflammatory mechanisms, there is a significant gap in our understanding of the transitional phase between acute and chronic stress. The purpose of this review is to first summarize current knowledge of our understanding of acute stress effects on inflammation, as well as of chronic stress effects on inflammation, and to then analyze the state of knowledge about the transitional phase between acute and chronic stress. Research discussed here shows that we are beginning to understand the early phase of repeated acute stress, but lack information on longer term exposure to repeated acute stress experiences. More research is needed to bridge this important gap und our conceptualization and understanding of the stress and health relationship.

Turning a Blind Eye? Punishment of Friends and Unfamiliar Peers After Observed Exclusion in Adolescence

In order to decrease the occurrence of social exclusion in adolescence, we need to better understand how adolescents perceive and behave toward peers involved in exclusion. We examined the role of friendships in treatment of perpetrators and victims of social exclusion. Eighty-nine participants (aged 9-16) observed exclusion of an unfamiliar peer (victim) by their best friend and another unfamiliar peer. Subsequently, participants could give up valuable coins to altruistically punish or help peers. Results showed that participants altruistically compensated victims and punished unfamiliar excluders, but refrained from punishing their friends. Our findings show that friendship with excluders modulates altruistic punishment of peers and provide mechanistic insight into how friendships may influence treatment of peers involved in social exclusion during adolescence.

Motivational Climate in Sport Is Associated with Life Stress Levels, Academic Performance and Physical Activity Engagement of Adolescents

The present study sought to define and contrast an explanatory model incorporating motivational climate towards sport, life stress, academic performance, and engagement in physical activity, and to analyze the existing relationships between these variables as a function of sex. A total of 2452 adolescents of both sexes (42.7% males and 57.3% females) participated in the present study, with self-reported ages between 13 and 16 years (M = 14.43; SD = 1.15). Participants were from Granada (Spain) and perceived motivational climate towards sport (PMCSQ-2), life stress (PSS), academic performance, and engagement in physical activity (PAQ-A) were analyzed. A multi-group structural equation model was constructed, which demonstrated excellent fit to the observed data (χ² = 309.402; DF = 40; p < 0.001; CFI = 0.973; NFI = 0.970; IFI = 0.973; and RMSEA = 0.052). A negative and direct association exists between ego climate and task climate. A positive association was found between motivational climate, task climate (males r = 0.336/females r = 0.238), and ego climate (males r = 0.198/ females r = 0.089) and engagement in physical activity. A task climate was associated with better academic performance and lower levels of life stress. The main conclusions of this study highlight that a task-involving climate and engagement in physical activity are both associated with lower levels of life stress and higher levels of academic performance.