Community violence and cellular and cytokine indicators of inflammation in adolescents

Ripple Effects of Early Life Stress on Vascular Health

The term early life stress encompasses traumatic events occurring before the age of 18 years, such as physical abuse, verbal abuse, household dysfunctions, sexual abuse, childhood neglect, child maltreatment, and adverse childhood experiences. Adverse psychological experiences in early life are linked to enduring effects on mental and physical health in adulthood. In this review, we first describe the effects and potential mechanisms of early life stress on the components of the vasculature. Next, we dive into the impact of early life stress on the vasculature across the lifespan through alterations of the epigenetic landscape. Finally, we consolidate the critical gaps in knowledge for focusing future research including the potential for resilience in combatting the impact of early life stress on vascular health.

Associations between social behaviour and proinflammatory immune activation are modulated by age in a free-ranging primate population

The effect of the social environment on the proinflammatory immune response may mediate the relationship between social environment and fitness but remains understudied outside captive animals and human populations. Age can also influence both immune function and social behaviour, and hence may modulate their relationships. This study investigates the role of social interactions in driving the concentrations of two urinary markers of proinflammatory immune activation, neopterin and soluble urokinase plasminogen activator receptor (suPAR), in a free-ranging population of rhesus macaques, Macaca mulatta. We collected 854 urine samples from 172 adult monkeys and quantified how urinary suPAR and neopterin concentrations were related to affiliative behaviour and agonistic behaviour received over 60 days. In females, but not in males, higher rates of affiliative interactions were associated with lower neopterin concentrations, while conversely, experiencing more agonistic interactions was associated with higher neopterin concentrations. The association between affiliation and neopterin concentration was modulated by age, with older females experiencing a stronger negative association between affiliative behaviour and neopterin concentration. There were no associations between suPAR concentration and social environment for either sex. This study demonstrates that proinflammatory immune activity is a potential mechanism mediating the association between social environment and fitness under naturalistic conditions and that age can be an important modulator of the effect of social environment on the immune system.

Interpersonal violence exposure and inflammation during adolescence and young adulthood

Exposure to violence increases young peoples' risk of developing mental and physical health problems. Chronic stress-related upregulation of innate immune system activity and the development of low-grade inflammation may partially underlie this health risk. However, much of the previous research has been limited to cross-sectional studies utilizing between-person analytic designs, susceptible to confounding by unmeasured factors. In this six-wave panel study of N=157 female adolescents and young adults, we tested within-person associations between interpersonal violence exposure and multiple measures of inflammatory activity. Ex vivo culture studies suggested that participants' immune cells were more reactive to microbial stimulation and less sensitive to inhibition by glucocorticoids after violence. Numbers of circulating monocyte cells increased after violence, but serum levels of interleukin-6 and c-reactive protein did not. Findings from this within-person analysis suggest that violence exposure up-regulates innate immune system activity during adolescence and young adulthood in ways that may increase mental and physical health risk.

A multiscale inflammatory map: linking individual stress to societal dysfunction

As populations worldwide show increasing levels of stress, understanding emerging links among stress, inflammation, cognition, and behavior is vital to human and planetary health. We hypothesize that inflammation is a multiscale driver connecting stressors that affect individuals to large-scale societal dysfunction and, ultimately, to planetary-scale environmental impacts. We propose a 'central inflammation map' hypothesis to explain how the brain regulates inflammation and how inflammation impairs cognition, emotion, and action. According to our hypothesis, these interdependent inflammatory and neural processes, and the inter-individual transmission of environmental, infectious, and behavioral stressors - amplified via high-throughput digital global communications - can culminate in a multiscale, runaway, feed-forward process that could detrimentally affect human decision-making and behavior at scale, ultimately impairing the ability to address these same stressors. This perspective could provide non-intuitive explanations for behaviors and relationships among cells, organisms, and communities of organisms, potentially including population-level responses to stressors as diverse as global climate change, conflicts, and the COVID-19 pandemic. To illustrate our hypothesis and elucidate its mechanistic underpinnings, we present a mathematical model applicable to the individual and societal levels to test the links among stress, inflammation, control, and healing, including the implications of transmission, intervention (e.g., via lifestyle modification or medication), and resilience. Future research is needed to validate the model's assumptions, expand the factors/variables employed, and validate it against empirical benchmarks. Our model illustrates the need for multilayered, multiscale stress mitigation interventions, including lifestyle measures, precision therapeutics, and human ecosystem design. Our analysis shows the need for a coordinated, interdisciplinary, international research effort to understand the multiscale nature of stress. Doing so would inform the creation of interventions that improve individuals' lives and communities' resilience to stress and mitigate its adverse effects on the world.

Peer support as moderator of association between socioeconomic status and low-grade inflammation in adolescents

OBJECTIVE

Individuals who grow up in low-socioeconomic status (SES) families are at an increased risk of health problems across the lifespan. Although supportive social relationships are postulated to be a protective factor for the health of these individuals, the role of friend support in adolescence is not well understood. Given that low-grade inflammation is one key biological mechanism proposed to explain links between family SES and health outcomes, we examined whether adolescents' friend support buffers the association between family SES and low-grade inflammation among adolescents.

METHOD

277 dyads of adolescents (63.5% female; 39.4% White, 38.3% Black, and 32.1% Hispanic; Mage = 13.92 years) and one of their parents participated in this longitudinal study (two waves approximately 2 years apart). Parents reported family objective SES (i.e., income, savings, and education) and family subjective SES (i.e., subjective social status). Adolescents reported perceived friend support. Fasting antecubital blood was drawn from adolescents at both visits. Low-grade inflammatory activity was represented by a composite of inflammatory biomarkers and numbers of classical monocytes.

RESULTS

Adolescents' friend support moderated the associations of family subjective SES with both the inflammation composite and classical monocyte counts across cross-sectional, longitudinal, and prospective change (only significant for the inflammation composite) analyses. Specifically, lower family subjective SES was associated with higher levels of low-grade inflammation only among adolescents lower, but not higher, in friend support. No moderation was observed for objective SES.

CONCLUSION

Supportive peer relationships buffer the link between family subjective, but not objective, SES and low-grade inflammation in adolescence. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Neuroimmune mechanisms connecting violence with internalizing symptoms: A high-dimensional multimodal mediation analysis

Violence exposure is associated with worsening anxiety and depression symptoms among adolescents. Mechanistically, social defeat stress models in mice indicate that violence increases peripherally derived macrophages in threat appraisal regions of the brain, which have been causally linked to anxious behavior. In the present study, we investigate if there is a path connecting violence exposure with internalizing symptom severity through peripheral inflammation and amygdala connectivity. Two hundred and thirty-three adolescents, ages 12-15, from the Chicago area completed clinical assessments, immune assays and neuroimaging. A high-dimensional multimodal mediation model was fit, using violence exposure as the predictor, 12 immune variables as the first set of mediators and 288 amygdala connectivity variables as the second set, and internalizing symptoms as the primary outcome measure. 56.2% of the sample had been exposed to violence in their lifetime. Amygdala-hippocampus connectivity mediated the association between violence exposure and internalizing symptoms (ζ ̂ Hipp π ̂ Hipp = 0.059 $$ {\hat{\zeta}}_{\mathrm{Hipp}}{\hat{\pi}}_{\mathrm{Hipp}}=0.059 $$ ,95 % CI boot = 0.009,0.134 $$ 95\%{\mathrm{CI}}_{\mathrm{boot}}=\left[\mathrm{0.009,0.134}\right] $$ ). There was no evidence that inflammation or inflammation and amygdala connectivity in tandem mediated the association. Considering the amygdala and the hippocampus work together to encode, consolidate, and retrieve contextual fear memories, violence exposure may be associated with greater connectivity between the amygdala and the hippocampus because it could be adaptive for the amygdala and the hippocampus to be in greater communication following violence exposure to facilitate evaluation of contextual threat cues. Therefore, chronic elevations of amygdala-hippocampal connectivity may indicate persistent vigilance that leads to internalizing symptoms.

Neighborhood Poverty Prospectively Predicts PTSD Symptoms Six-Months Following Trauma Exposure

Introduction

Individuals living in areas with high rates of poverty are disproportionately affected by posttraumatic stress disorder (PTSD). Despite this association, little is known about how neighborhood poverty rates impact risk for PTSD development. In the current prospective study, we determined the relationship between neighborhood poverty rate and PTSD symptoms six-months after experiencing a traumatic event in a sample of varied race, gender, and socioeconomic status.

Methods

Participants (N=252) were enrolled in a hospital emergency department after experiencing a traumatic event. Demographic information (including zip code of residence), baseline PTSD symptoms, and baseline trauma history was assessed in the emergency department. PTSD symptoms were again assessed six-months post-trauma. Neighborhood poverty rate was determined using the American Community Survey.

Results

Correlation analyses revealed that neighborhood poverty was significantly associated with baseline PTSD symptoms (r=.181, p=.004) and PTSD symptoms six-months post-trauma (r=.163, p=.009). A regression analysis controlling for baseline trauma exposure, clinician-rated trauma severity, and individual socioeconomic status demonstrated that neighborhood poverty predicted PTSD symptoms six-months post-trauma (R2= 0.099, B= 0.15, p=0.04), but this relationship was no longer significant when baseline PTSD symptoms was added as an additional covariate (R2=.304, B= 0.07, p>0.05).

Conclusion

Overall, results suggest that neighborhood poverty generally increases PTSD symptom severity, and the context in which an individual lives should be considered when conceptualizing risk for PTSD.

Neighborhood socioeconomic deprivation and individual-level socioeconomic status are associated with dopamine-mediated changes to monocyte subset CCR2 expression via a cAMP-dependent pathway

Social determinants of health (SDoH) include socioeconomic, environmental, and psychological factors that impact health. Neighborhood socioeconomic deprivation (NSD) and low individual-level socioeconomic status (SES) are SDoH that associate with incident heart failure, stroke, and cardiovascular mortality, but the underlying biological mechanisms are not well understood. Previous research has demonstrated an association between NSD, in particular, and key components of the neural-hematopoietic-axis including amygdala activity as a marker of chronic stress, bone marrow activity, and arterial inflammation. Our study further characterizes the role of NSD and SES as potential sources of chronic stress related to downstream immunological factors in this stress-associated biologic pathway. We investigated how NSD, SES, and catecholamine levels (as proxy for sympathetic nervous system activation) may influence monocytes which are known to play a significant role in atherogenesis. First, in an ex vivo approach, we treated healthy donor monocytes with biobanked serum from a community cohort of African Americans at risk for CVD. Subsequently, the treated monocytes were subjected to flow cytometry for characterization of monocyte subsets and receptor expression. We determined that NSD and serum catecholamines (namely dopamine [DA] and norepinephrine [NE]) associated with monocyte C-C chemokine receptor type 2 (CCR2) expression (p < 0.05), a receptor known to facilitate recruitment of monocytes towards arterial plaques. Additionally, NSD associated with catecholamine levels, especially DA in individuals of low SES. To further explore the potential role of NSD and the effects of catecholamines on monocytes, monocytes were treated in vitro with epinephrine [EPI], NE, or DA. Only DA increased CCR2 expression in a dose-dependent manner (p < 0.01), especially on non-classical monocytes (NCM). Furthermore, linear regression analysis between D2-like receptor surface expression and surface CCR2 expression suggested D2-like receptor signaling in NCM. Indicative of D2-signaling, cAMP levels were found to be lower in DA-treated monocytes compared to untreated controls (control 29.78 pmol/ml vs DA 22.97 pmol/ml; p = 0.038) and the impact of DA on NCM CCR2 expression was abrogated by co-treatment with 8-CPT, a cAMP analog. Furthermore, Filamin A (FLNA), a prominent actin-crosslinking protein, that is known to regulate CCR2 recycling, significantly decreased in DA-treated NCM (p < 0.05), indicating a reduction of CCR2 recycling. Overall, we provide a novel immunological mechanism, driven by DA signaling and CCR2, for how NSD may contribute to atherogenesis. Future studies should investigate the importance of DA in CVD development and progression in populations disproportionately experiencing chronic stress due to SDoH.

Cumulative life-course victimization and inflammation in a U.S. national sample: Comparing intersections based on sexual orientation, gender, race/ethnicity, and education

Violence victimization has been associated with low-grade inflammation. Lesbian, Gay, and Bisexual (LGB) individuals are at greater risk for victimization in childhood and young adulthood compared to heterosexuals. Moreover, the intersection of LGB identity with gender, race/ethnicity, and educational attainment may be differentially associated with victimization rates. However, no previous study has examined the role of cumulative life-course victimization during childhood and young adulthood in the association between 1) LGB identity and low-grade inflammation during the transition to midlife, and 2) intersection of LGB identity with gender, race/ethnicity, and educational attainment and low-grade inflammation during the transition to midlife. We utilized multi-wave data from a national sample of adults entering midlife in the United States- the National Longitudinal Study of Adolescent to Adult Health (Add Health; n = 4573) - and tested four bootstrapped mediation models. Results indicate LGB identity, LGB and White, and LGB and Black identities were indirectly associated with low-grade inflammation during the transition to midlife via higher levels of cumulative life-course victimization. Moreover, among LGB adults, the association between 1) less than college education and 2) some college education, and low-grade inflammation was mediated by cumulative life-course victimization. For LGB females, there was a direct association between identity and low-grade inflammation and this association was mediated by cumulative life-course victimization . Reducing accumulation of victimization could be critical for preventing biological dysregulation and disease onset among LGB individuals, particularly for those with multiple marginalized identities.

Previous exposure to violence among emergency department patients without trauma-related complaints: A cross sectional analysis

INTRODUCTION

The Emergency Department (ED) is a critical setting for the treatment of acute violence-related complaints and violent victimization is associated with numerous long-term negative health outcomes. A trauma-informed care framework can prevent re-traumatization of victims within the healthcare setting, but currently there are insufficient mechanisms to detect previous exposures to community violence within the ED. The current study sought to determine the prevalence of community violence and characterize the types of violence exposures among adult ED patients without trauma-related complaints to determine if there may be a need for expanded screening for previous exposure to violence for ED patients.

METHODS

This was a prospective cross-sectional observational study of adult ED patients without a trauma-related chief complaint at an urban public hospital. Adult patients were approached by trained research staff and answered questions adapted from the Survey of Exposure to Community Violence (SECV), which measures lifetime exposure to community violence, including both witnessing and victimization. The SECV was modified for clarity, brevity, and to assess exposure to violence within the previous 3 months and 3 years from enrollment, in addition to lifetime exposure. Enrollment occurred from June 2019 to September 2022 with a 19-month gap due to the COVID-19 pandemic. Demographics and results within SECV domains were analyzed using descriptive statistics. Comparisons between males and females in types of violence experienced during one's lifetime were made by fitting logistic regression models adjusting for age.

RESULTS

A total of 222 respondents completed some or all of the modified SECV. Ages ranged from 19 to 88, with 47.7% of respondents identifying as female and 50.9% as male. Of all respondents, 43.7% reported directly witnessing violence during their lifetime, 69.4% being personally victimized by violence, and 55.4% personally knowing someone killed by a violent act. Of those personally victimized, 47.4% occurred within the preceding 3 years and 20.1% within 3 months. Among all respondents, lifetime victimization was reported in the following domains: slapping, hitting, or punching (45.9%); robbings or muggings (33.8%); physical threats (28.8%); verbal or emotional abuse (27.5%); being shot at (18.0%); uncomfortable physical touch (15.3%); forced entry while home (14.4%); sexual assault, molestation, or rape (13.5%); or being attacked with a knife (13.5%). Comparing male and female respondents, 63.5% of females and 76.6% of males reported any violent victimization over their lifetime (aOR 1.88; 95% CI 1.04-3.43). Additionally, 31.7% of females and 56.3% of males reported witnessing violence (aOR 2.86; 95% CI 1.64-5.06). Males were more commonly exposed to physical violence, violence with weapons, and threats while females more commonly reported sexual assault, molestation, and rape.

CONCLUSION

Both lifetime and recent exposure to community violence was common among adult ED patients without trauma-related complaints. Broader adoption of a trauma-informed care framework and the development of efficient ED screening tools for previous exposure to trauma is reasonable in areas where community violence exposure is highly prevalent.

Violent behavior, perceived safety, and assault experiences among adolescents: results from the Brazilian National Adolescent School-based Health Survey

OBJECTIVE

To investigate factors associated with violent behavior in a large nationally representative sample of Brazilian adolescents.

METHODS

The data were derived from the 2015 National Adolescent School-based Health Survey (Pesquisa Nacional de Saúde do Escolar [PeNSE]). The independent variables of interest included feelings of safety while on the way to and at school. The outcome was violent behavior, including bullying. Logistic regression models were developed to examine the relationship between violent behavior and each independent and control variable.

RESULTS

In the adjusted regression model, male sex (aOR: 1.75; 95%CI 1.65-1.86), being assaulted by a family member (aOR: 1.74; 95%CI 1.59-1.90), and being assaulted in the past year (aOR: 1.70; 95%CI 1.57-1.85) all increased the chance of violent behavior. Feeling safe on the way to school (aOR: 0.82; 95%CI 0.74-0.92) and at school (aOR: 0.82; 95%CI 0.73-0.92) reduced the chance of violent behavior.

CONCLUSIONS

This study extends the body of literature on violent behavior among adolescents, demonstrating a correlation between school, domestic, family, or community violence and violent behavior. Our research supports the idea that adolescents who experience violence act violently with greater frequency. This finding has significant implications for pediatricians, child psychiatrists and psychologists, other health care professionals, school professionals, and other professionals involved in adolescent health. School professionals must be prepared to identify adolescents with violent behavior due to its potential consequences for their mental and physical health.

Racial Disparities in School Belonging and Prospective Associations With Diabetes and Metabolic Syndrome

Importance

School belonging has important implications for academic, psychological, and health outcomes, but the associations between racial disparities in school belonging and health have not been explored to date.

Objective

To examine associations between school-level racial disparities in belonging and cardiometabolic health into adulthood in a national sample of Black and White children, adolescents, and young adults.

Design, Setting, and Participants

Prospective cohort study of a US national sample of 4830 Black and White students (National Longitudinal Study of Adolescent Health) followed up for 13 years. The study was conducted from 1994 to 1995 for wave 1 and in 2008 for wave 4. Data were analyzed from June 14 to August 13, 2021.

Main Outcomes and Measures

School-level racial disparities in belonging at baseline were calculated as the mean level of school belonging for Black students minus the mean level of school belonging for White students at the school that they attended when they were aged 12 to 20 years. Diabetes and metabolic syndrome were measured as outcomes for these same participants at 24 to 32 years of age.

Results

The study included 4830 students. For wave 1, mean (SD) age was 16.1 (1.7) years, and for wave 4, 29.0 (1.7) years. A total of 2614 (54.1%) were female, 2219 were non-Hispanic Black (45.9%), and 2611 were non-Hispanic White (54.1%). Among Black students, attending a school with a greater Black-White disparity in school belonging (more negative scores) was associated with an increased risk for diabetes (odds ratio, 0.66 [95% CI, 0.46-0.95]) and more risk factors for metabolic syndrome (rate ratio, 0.95 [95% CI, 0.90-1.00]) in adulthood 13 years later. These associations persisted above individual-level controls (age, sex, and body mass index) and school-level controls (school size, percentage of Black students, and percentage of Black teachers) and were not explained by either an individual's own perception of school belonging or the mean level of belonging across the whole school.

Conclusions and Relevance

In this prospective cohort study of US students, racial disparities in school belonging were associated with risks for diabetes and metabolic syndrome in Black students. Among students, fostering a more equal sense of school belonging across racial groups may have implications for health disparities in the cardiometabolic domain into adulthood.

Incarceration exposure and epigenetic aging in neighborhood context

OBJECTIVE

Research has implicated incarceration exposure as a social determinant of health, with recent work suggesting incarceration may trigger a stress response that accelerates physiological deterioration. The objective of the current study is to assess whether neighborhood stressors intensify the health consequences of incarceration exposure.

METHODS

We test whether two neighborhood context measures - socioeconomic disadvantage and perceived crime - moderate the association between incarceration exposure and a measure of accelerated epigenetic aging based on the GrimAge index. Our sample included 408 African American young adults from the Family and Community Health study.

RESULTS

Results from regression analyses with inverse probability of treatment weights suggest that incarceration exposure and neighborhood disadvantage are independently associated with accelerated biological aging. The results also show that the impact of incarceration exposure on accelerated aging is amplified for individuals in neighborhoods with higher levels of perceived crime.

CONCLUSIONS

These findings indicate that the neighborhood contexts where formerly incarcerated individuals return have a substantial impact on their pace of biological aging. Policies aimed at reducing ambient stressors after release may promote healthy aging among formerly incarcerated African American adults.

Residence in High-Crime Neighborhoods Moderates the Association Between Interleukin 6 and Social and Nonsocial Reward Brain Responses

BACKGROUND

Residence in high-crime neighborhoods, especially in childhood, is linked to mental health issues later. Detecting distinct neurobiological processes underlying the effects of this environmental stressor may be critical to identifying prevention and intervention targets. This study examined the relationships of levels of a circulating inflammatory protein with social and monetary reward-related brain function among adolescents who lived in high- versus low-crime neighborhoods during childhood.

METHODS

A total of 70 participants (mean age = 16.3 years; 57% female) completed measures of inflammatory markers, depression history, and health and 2 functional magnetic resonance imaging tasks assessing responsivity to monetary and social rewards. Multivariate linear regression tested whether individuals with higher interleukin 6, an inflammatory cytokine, who also lived in neighborhoods with higher crime had distinct orbitofrontal cortex and nucleus accumbens activation to monetary reward and social acceptance.

RESULTS

For adolescents who lived in neighborhoods with more crime, higher interleukin 6 was associated with higher nucleus accumbens responses to social acceptance. We did not detect significant moderating effects of neighborhood crime rates on the associations of interleukin 6 with orbitofrontal cortex responses to social acceptance or orbitofrontal cortex/nucleus accumbens activation during monetary reward anticipation or outcome. These results were obtained before and after adjusting for neighborhood income and other covariates. We did not detect significant moderating effects of neighborhood income.

CONCLUSIONS

High-threat residence environment and specific demands of the social context in childhood may have shaped the effect of peripheral immune activation on reward-related neural function in adolescence. The prevailing view that inflammation-associated behaviors are characterized by blunted responsiveness to reward may be oversimplistic.

Prospective associations between neighborhood violence and monocyte pro-inflammatory transcriptional activity in children

Individuals exposed to persistent neighborhood violence are at increased risk for developing mental and physical health problems across the lifespan. The biological mechanisms underlying this phenomenon are not well understood. Thus, we examined the relationship between children's exposure to neighborhood violence and inflammatory activity, a process involved in the pathogenesis of multiple health problems. 236 children from the Chicago area participated in a two-year longitudinal study (mean age at baseline, 13.9 years; 67% female; 39% White, 34% Black, 33% Hispanic). Neighborhood violence was measured as the homicide frequency in a child's Census block group in the five years before study entry. Fasting blood was drawn at study entry and two years later (in eighth and tenth grade). The blood was used to quantify protein biomarkers of systemic inflammatory activity and perform genome-wide expression profiling of isolated monocytes. Neighborhood violence was associated with higher systemic inflammatory activity at both assessments. It also was associated with a monocyte transcriptional profile indicative of increased signaling along the nuclear factor-kappa B (NF-κB) and activator protein 1 (AP-1) control pathways, which are key orchestrators of pro-inflammatory effector functions. Neighborhood violence also was associated with transcriptional indications of higher beta-adrenergic and lower glucocorticoid signaling, which could function as neuroendocrine conduits linking threatening experiences with inflammatory activity. Neighborhood violence was not associated with two-year changes in protein biomarkers, although it did presage a transcriptional profile indicative of increasing AP-1 and declining glucocorticoid signaling over follow-up. Collectively, these observations highlight cellular and molecular pathways that could underlie health risks associated with neighborhood violence.

Complaints about excessive use of police force in women's neighborhoods and subsequent perinatal and cardiovascular health

There are substantial, unexplained racial disparities in women’s health. Some of the most pronounced involve elevated rates of preterm delivery (PTD) and cardiovascular disease (CVD) among Black women. We hypothesized that stress associated with excessive use of force by police may contribute to these disparities. In two prospective cohorts derived from electronic health records (pregnancy cohort, N = 67,976; CVD cohort, N = 6773), we linked formal complaints of excessive police force in patients’ neighborhoods with health outcomes. Exposed Black women were 1.19 times as likely to experience PTD [95% confidence interval (CI): 1.04 to 1.35] and 1.42 times as likely to develop CVD (95% CI: 1.12 to 1.79), even after adjustment for neighborhood disadvantage and homicide. The excess risks of PTD were also observed in maternal fixed-effects analyses comparing births to the same woman. These findings suggest police violence may be an unrecognized contributor to health inequity for Black women.

Psychological Stress During Childhood and Adolescence and Its Association With Inflammation Across the Lifespan: A Critical Review and Meta-Analysis

Psychological stress during childhood and adolescence increases risk of health problems across the lifecourse, and inflammation is implicated as an underlying mechanism. To evaluate the viability of this hypothesis, we used meta-analysis to quantify the association between childhood/adolescent stress and inflammation over the lifecourse. Furthermore, we addressed three unresolved conceptual questions: (a) Does the strength of this association change over the lifecourse? (b) Are different types of childhood/adolescent stressors differentially associated with inflammation? (c) And which components of the inflammatory response are involved? A systematic search identified 187 articles reporting 922 associations. Meta-analyses were conducted using a three-level multilevel approach and controlled for study quality, conversion confidence, and whether effect sizes were unadjusted or adjusted (n = 662, 72%). Results indicated a small but reliable overall adjusted association ( r ^ = .04 ) . The magnitude of the association strengthened across the lifecourse-effect sizes were smallest in studies that measured inflammation in childhoodr ^ = .02 and became progressively larger in studies of adolescencer ^ = .04 and adulthoodr ^ = .05 , suggesting the impact of early stress strengthens with time. By contrast, effect sizes did not vary by adversity type (socioeconomic disadvantage, maltreatment, other interpersonal stressors, and cumulative exposure across stressors), or component of inflammation (circulating biomarkers of low-grade inflammation vs. cytokine responses to microbial stimuli). Implications and future directions are discussed.

Childhood Violence Exposure, Inflammation, and Cardiometabolic Health

Exposure to interpersonal violence during childhood, a severe and often traumatic form of social stress, is an enduring problem that an emerging body of work suggests may be relevant to cardiometabolic health and the progression of cardiovascular disease (CVD) across the life course. Less is known about this association causally, and consequently, the biological mechanisms that may confer risk for, and resilience to, poor health outcomes in the aftermath of violence are not well understood. Drawing on recent theoretical insights and empirical research in both humans and non-human animal models, the current paper articulates a hypothesis for one way that childhood violence could get "under the skin" to influence CVD. Based on this emerging literature, one plausible way that childhood violence exposure could increase susceptibility to CVD in later life is by sensitizing stress-response neurobiology and immune processes that regulate and promote inflammation, which is a key pathogenic mechanism in CVD. This is inherently a developmental process that begins in early life and that unfolds across the life course, although less is known about the specific mechanisms through which this occurs. The goal of this paper is to articulate some of these plausible mechanisms and to suggest areas for future research that aims to reduce the burden of disease among individuals who are exposed to violence.

Neural impact of neighborhood socioeconomic disadvantage in traumatically injured adults

Nearly 14 percent of Americans live in a socioeconomically disadvantaged neighborhood. Lower individual socioeconomic position (iSEP) has been linked to increased exposure to trauma and stress, as well as to alterations in brain structure and function; however, the neural effects of neighborhood SEP (nSEP) factors, such as neighborhood disadvantage, are unclear. Using a multi-modal approach with participants who recently experienced a traumatic injury (N = 185), we investigated the impact of neighborhood disadvantage, acute post-traumatic stress symptoms, and iSEP on brain structure and functional connectivity at rest. After controlling for iSEP, demographic variables, and acute PTSD symptoms, nSEP was associated with decreased volume and alterations of resting-state functional connectivity in structures implicated in affective processing, including the insula, ventromedial prefrontal cortex, amygdala, and hippocampus. Even in individuals who have recently experienced a traumatic injury, and after accounting for iSEP, the impact of living in a disadvantaged neighborhood is apparent, particularly in brain regions critical for experiencing and regulating emotion. These results should inform future research investigating how various levels of socioeconomic circumstances may impact recovery after a traumatic injury as well as policies and community-developed interventions aimed at reducing the impact of socioeconomic stressors.

Resting-State Functional Connectivity of the Central Executive Network Moderates the Relationship Between Neighborhood Violence and Proinflammatory Phenotype in Children

BACKGROUND

Neighborhood violence increases children's risk for a variety of health problems. Yet, little is known about biological pathways involved or neural mechanisms that might render children more or less vulnerable. Here, we address these questions by considering whether neighborhood violence is associated with the expression of a proinflammatory phenotype and whether this relationship is moderated by resting-state functional connectivity (rsFC) of the central executive network (CEN).

METHODS

The study involved 217 children (13.9 years old; 66.4% female; 36.9% Black; 30.9% Latinx), enrolled in eighth grade and reassessed 2 years later. At time 1, geocoding was used to estimate murder frequency in children's neighborhoods, and functional magnetic resonance imaging was used to characterize CEN rsFC. At both visits, children gave antecubital blood for ex vivo studies, where leukocytes were incubated with stimulators and inhibitors of inflammation, and cytokine production was measured.

RESULTS

Consistent with our hypotheses, the relationship between neighborhood murder and inflammatory activity was moderated by CEN rsFC. Among children with lower rsFC, neighborhood violence covaried with a proinflammatory phenotype, reflected in larger cytokine responses to triggering stimuli and lower sensitivity to inhibitory agents. These associations were generally not apparent for children with higher rsFC, although occasionally they ran in the opposite direction. The same patterns were apparent 2 years later.

CONCLUSIONS

These results advance the understanding of neighborhood violence and its relationship with processes involved in the initiation and resolution of inflammation. They also deepen understanding of variability in children's immunologic responses to stress and suggest that the CEN may be a neurobiological contributor to resilience.

Psychological and Gender Differences in a Simulated Cheating Coercion Situation at School

This study aimed to analyze gender, anxiety, and psychological inflexibility differences of high school students’ behaviors in a simulated situation of peer coercion into academic cheating. Method: A total of 1147 volunteer adolescents participated, (Men: N = 479; Mage = 16.3; Women: N = 668; Mage = 16.2). The participants saw 15 s animated online video presenting peer coercion into an academic cheating situation, including a questionnaire about their reactions to face the situation. They also answered the State–Trait Anxiety Inventory for children and adolescents and the Avoidance and Fusion Questionnaire for Youth (AFQ-Y). Gender was associated with the behaviors facing the situation. Higher state anxiety and inflexibility were present in those participants that avoided aggressive behaviors facing the situation; on the other hand, trait anxiety was present in those who reacted aggressively. Finally, higher anxiety and inflexibility were associated with the used moral disengagement mechanisms, but also with peers’ perception as sanctioning or being against the participants’ decision. The most aggressive students were more flexible and less stressed than those who tried to solve assertively. Expectations about peers seem to be relevant to the decision-making facing moral dilemmas and peer victimization.

Goal-striving tendencies moderate the relationship between reward-related brain function and peripheral inflammation

Inflammation is associated with both lower and higher activity in brain regions that process rewarding stimuli. How can both low and high sensitivity to rewards be associated with higher inflammation? We propose that one potential mechanism underlying these apparently conflicting findings pertains to how people pursue goals in their environment. This prediction is based on evidence that both an inability to disengage from unattainable goals and low interest in and pursuit of important life goals are associated with poor health outcomes, including inflammation. Accordingly, this study examined the relationship between reward-related brain function and peripheral inflammation among individuals with different levels of ambitious goal-striving tendencies. Eighty-three participants completed an ambitious goal-striving tendency measure, an fMRI Monetary Incentive Delay task assessing orbitofrontal cortex (OFC) and nucleus accumbens (NAc) activation during reward anticipation and outcome, and a venous blood draw to assess the inflammatory biomarkers interleukin (IL)-6, IL-8, tumor necrosis factor-alpha, and C-reactive protein, from which we computed an inflammation composite score. We observed a reward anticipation by goal-striving interaction on inflammation, such that high OFC and NAc activation to reward anticipation (but not outcome) were associated with more inflammation, among high goal-striving individuals. By contrast, low NAc activation during reward anticipation (but not outcome) was associated with more inflammation, among low goal-striving individuals. The current study provides further evidence that both blunted and elevated reward function can be associated with inflammation. It also highlights the role that goal-striving tendencies may play in moderating the relationship between neural reward anticipation and inflammation.

Neighborhood Characteristics and Inflammation among Older Black Americans: The Moderating Effects of Hopelessness and Pessimism

BACKGROUND

Research documents the adverse health effects of systemic inflammation. Overall, older Black Americans tend to have higher inflammation than older non-Hispanic white adults. Given that inflammation is related to a range of chronic health problems that disproportionately affect Blacks compared to whites, this racial disparity in inflammation may contribute to racial disparities in particular chronic health problems. Thus, a better understanding of its determinants in the older Black population is of critical importance. This analysis examined the association between neighborhood characteristics and inflammation in a national sample of older non-Hispanic Black Americans. An additional aim of this study was to determine whether hopelessness and pessimism moderates the association between neighborhood characteristics and inflammation.

METHODS

A sample of older non-Hispanic Black Americans aged 60+ were drawn from the Health and Retirement Study (N=1,004). Neighborhood characteristics included neighborhood physical disadvantage and neighborhood social cohesion. Inflammation was assessed by C-reactive protein (CRP).

RESULTS

The analyses indicated that neighborhood physical disadvantage and social cohesion were not associated with CRP. Hopelessness and pessimism moderated the association between neighborhood physical disadvantage and CRP.

CONCLUSIONS

Knowledge regarding the role of hopelessness and pessimism as moderator in the neighborhood-inflammation association can inform cognitive-behavioral interventions targeted at changes in cognition patterns.

Gender, Anxiety, and Legitimation of Violence in Adolescents Facing Simulated Physical Aggression at School

We analyzed gender and anxiety differences in middle school students facing a physical peer aggression situation. The participants were 1147 adolescents aged between 12 and 18 years (male: n = 479; female: n = 668) who watched a 12 s animation representing the situation and filled out a questionnaire to analyze the legitimation of violent behaviors and anxiety levels. We registered their decisions to solve the situation using a categorical scale that included assertive, avoidant, aggressive, submissive, and supportive behaviors. Gender was not associated with the adolescent's behaviors in facing a simulated peer aggression situation. However, male teenagers tended to perceive adults as sanctioners and neutrals; those who used the diffusion of responsibility and dehumanization to justify their behavior also showed a higher state of anxiety. Female teenagers who expected legitimation from their peers, presented higher anxiety as well. Educational interventions may use these results, helping adolescents to understand that their acts have substantial implications in the lives of others. It is essential to develop group interventions that modify how adolescents manage their conflicts and change gender stereotypes that significantly impact health. We highlight the need for linking families in educational programs facing the challenges of transforming the legitimization of violence in parental practices.