Community violence exposure in early adolescence: Longitudinal associations with hippocampal and amygdala volume and resting state connectivity

Threat, Emotion Dysregulation, and Parenting in a Clinical Sample of Children with Disruptive Behaviour

Early-life adversity is associated with the development of internalizing and externalizing problems in children. Despite this, there is a need to understand the mechanisms linking these experiences to psychopathology, especially in clinical samples. This cross-sectional study tested emotion dysregulation as a mechanism linking early-life threat to psychopathology in a clinical sample of children with disruptive behavior problems. We also explored parental positive reinforcement as a protective factor in these pathways. A clinical sample of 606 children aged 6-12 years, referred to a mental healthcare hospital, were included. Parent-reported child threat, and parent- and teacher-reported child emotion dysregulation and psychopathology, were collected. Path analysis was used to explore the mediating effect of emotion dysregulation in the relation between threat and psychopathology. The moderating effects of parental positive reinforcement were explored through moderated-mediation analyses. Emotion dysregulation partially mediated the association between threat and both internalizing (β = .18, P = .006) and externalizing (β = .19, P = .002) problems. Positive reinforcement did not buffer the association between threat and emotion dysregulation (β = .09, P = .62) or the association between emotion dysregulation and internalizing (β = - .003, P = .20) or externalizing (β = - .002, P = .35). Poor emotion regulation may be a transdiagnostic mechanism linking early-threat with internalizing and externalizing problems in clinic-referred children with disruptive behaviors. Factors aside from parental positive reinforcement should be explored as protective factors in these pathways, including those directly implicated in the purported mechanisms linking these factors over time.

Early life stress predicts trajectories of emotional problems and hippocampal volume in adolescence

Exposure to early life stress (ELS) has been consistently associated with adverse emotional and neural consequences in youth. The development of brain structures such as the hippocampus, which plays a significant role in stress and emotion regulation, may be particularly salient in the development of psychopathology. Prior work has documented smaller hippocampal volume (HCV) in relation to both ELS exposure and risk for psychopathology. We used longitudinal k-means clustering to identify simultaneous trajectories of HCV and emotional problems in 155 youth across three assessments conducted approximately two years apart (mean baseline age = 11.33 years, 57% female). We also examined depressive symptoms and resilience approximately two years after the third timepoint. We identified three clusters of participants: a cluster with high HCV and low emotional problems; a cluster with low HCV and high emotional problems; and a cluster with low HCV and low emotional problems. Importantly, severity of ELS was associated with greater likelihood of belonging to the low HCV/high symptom cluster than to the low HCV/low symptom cluster. Further, low HCV/high symptom participants had more depressive symptoms and lower resilience scores than did participants in the low HCV/low symptom, but not than in the high HCV/low symptom cluster. Our findings suggest that smaller HCV indexes biological sensitivity to stress. This adds to our understanding of the ways in which ELS can affect hippocampal and emotional development in young people and points to hippocampal volume as a marker of susceptibility to context.

Transcendent thinking counteracts longitudinal effects of mid-adolescent exposure to community violence in the anterior cingulate cortex

Adolescence involves extensive brain maturation, characterized by social sensitivity and emotional lability, that co-occurs with increased independence. Mid-adolescence is also a hallmark developmental stage when youths become motivated to reflect on the broader personal, ethical, and systems-level implications of happenings, a process we term transcendent thinking. Here, we examine the confluence of these developmental processes to ask, from a transdisciplinary perspective, how might community violence exposure (CVE) impact brain development during mid-adolescence, and how might youths' dispositions for transcendent thinking be protective? Fifty-five low-SES urban youth with no history of delinquency (32 female; 27 Latinx, 28 East Asian) reported their CVE and underwent structural MRI first at age 14-18, and again 2 years later. At the study's start, participants also discussed their feelings about 40 minidocumentaries featuring other teens' compelling situations in a 2-h private interview that was transcribed and coded for transcendent thinking. Controlling for CVE and brain structure at the start: (1) New CVE during the 2-year inter-scan interval was associated with greater gray matter volume (GMV) reduction over that interval in the anterior cingulate cortex (ACC), a central network hub whose reduced volume has been associated with posttraumatic stress disorder, and across multiple additional cortical and subcortical regions; (2) participants' transcendent thinking in the interview independently predicted greater GMV increase during the 2-year inter-scan interval in the ACC. Findings highlight the continued vulnerability of mid-adolescents to community violence and the importance of supporting teens' dispositions to reflect on the complex personal and systems-level implications and affordances of their civic landscape.

The neurophysiological consequences of racism-related stressors in Black Americans

Racism-related stressors, from experiences of both implicit and explicit racial discrimination to systemic socioeconomic disadvantage, have a cumulative impact on Black Americans' health. The present narrative review synthesizes peripheral (neuroendocrine and inflammation markers), psychophysiological (heart-rate variability, skin conductance), and neuroimaging (structural and functional) findings that demonstrate unique associations with racism-related stress. Emerging evidence reveals how racism-related stressors contribute to differential physiological and neural responses and may have distinct impacts on regions involved with threat and social processing. Ultimately, the neurophysiological effects of racism-related stress may confer biological susceptibility to stress and trauma-related disorders. We note critical gaps in the literature on the neurophysiological impact of racism-related stress and outline additional research that is needed on the multifactorial interactions between racism and mental health. A clearer understanding of the interactions between racism-related stress, neurophysiology, and stress- and trauma-related disorders is critical for preventative efforts, biomarker discovery, and selection of effective clinical treatments for Black Americans.

An Effect of Chronic Negative Stress on Hippocampal Structures and Functional Connectivity in Patients with Depressive Disorder

Purpose

Depressive disorder is a mental health disorder with complicated etiopathogenesis. Environmental stress and neurodevelopment combined with other factors contribute to the occurrence of depression. Especially for the depressive disorder with chronic negative stress, it has characteristics of recurrence and poor curative effect because of unclear mechanism. Here, we investigated the hippocampal structures and functional connectivity (FC) according to resting-state functional magnetic resonance imaging in patients with depression who underwent chronic negative stress.

Patients and Methods

A total of 65 patients with depression (34 underwent chronic negative stress and 31 non-underwent chronic negative stress) and 30 healthy controls who did not undergo chronic negative stress were included in the study. The volumes of hippocampal subfields, seed-based FCs between hippocampus and the whole brain voxels, and ROI-wise-based FC between hippocampal subfields were compared among the three groups.

Results

In the patients with depression who underwent chronic negative stress, the volumes of right_GC-ML-DG-head, right_CA4-head and right_CA3-head increased, FCs between Temporal_Mid_R, Precuneus_R, Frontal_Sup_R, Temporal_Sup_R, Angular_L, Frontal_Inf_Tri_R, Supp_Motor_Area_R, Precentral_L and hippocampus increased, and FCs between parasubiculum and CA3, and presubiculum and CA1 decreased. When compared to the patients who did not undergo chronic negative stress, the patients who underwent chronic negative stress had larger volumes of right_GC-ML-DG-head and right_CA3-head, higher FCs between Frontal_Sup_R, Frontal_Inf_Tri_R and hippocampus, and lower FCs between presubiculum and CA1.

Conclusion

The depression underwent chronic negative stress may experience disrupted hippocampal structures and functional connectivity. It may be one of potential depressive disorder subtypes.

Exposure to community violence as a mechanism linking neighborhood socioeconomic disadvantage and neural responses to reward

A growing literature links socioeconomic disadvantage and adversity to brain function, including disruptions in reward processing. Less research has examined exposure to community violence (ECV) as a specific adversity related to differences in reward-related brain activation, despite the prevalence of community violence exposure for those living in disadvantaged contexts. The current study tested whether ECV was associated with reward-related ventral striatum (VS) activation after accounting for familial factors associated with differences in reward-related activation (e.g. parenting and family income). Moreover, we tested whether ECV is a mechanism linking socioeconomic disadvantage to reward-related activation in the VS. We utilized data from 444 adolescent twins sampled from birth records and residing in neighborhoods with above-average levels of poverty. ECV was associated with greater reward-related VS activation, and the association remained after accounting for family-level markers of disadvantage. We identified an indirect pathway in which socioeconomic disadvantage predicted greater reward-related activation via greater ECV, over and above family-level adversity. These findings highlight the unique impact of community violence exposure on reward processing and provide a mechanism through which socioeconomic disadvantage may shape brain function.

Exposure to neighborhood violence, and laboratory-based and ambulatory cognitive task performance in adulthood

OBJECTIVE

Exposure to neighborhood violence may have negative implications for adults' cognitive functioning, but the ecological sensitivity of these effects has yet to be determined. We first evaluated the link between exposure to neighborhood violence and two latent constructs of cognitive function that incorporated laboratory-based and ambulatory, smartphone-based, cognitive assessments. Second, we examined whether the effect of exposure to violence was stronger for ambulatory assessments compared to in-lab assessments.

METHODS

We used data from 256 urban-dwelling adults between 25 and 65 years old (M = 46.26, SD = 11.07); 63.18% non-Hispanic Black, 9.21% non-Hispanic White, 18.41% Hispanic White, 5.02% Hispanic Black, and 4.18% other. Participants completed baseline surveys on neighborhood exposures, cognitive assessments in a laboratory/research office, and ambulatory smartphone-based cognitive assessments five-times a day for 14 days.

RESULTS

Exposure to neighborhood violence was associated with poorer performance in a latent working memory construct that incorporated in-lab and ambulatory assessments, but was not associated with the perceptual speed construct. The effect of exposure to neighborhood violence on the working memory construct was explained by its effect on the ambulatory working memory task and not by the in-lab cognitive assessments.

CONCLUSION

This study shows the negative effect that exposure to neighborhood violence may have on everyday working memory performance in urban-dwelling adults in midlife. Results highlight the need for more research to determine the sensitivity of ambulatory assessments to quantify the effects of neighborhood violence on cognitive function.

How does the macroenvironment influence brain and behaviour-a review of current status and future perspectives

The environment influences brain and mental health, both detrimentally and beneficially. Existing research has emphasised the individual psychosocial 'microenvironment'. Less attention has been paid to 'macroenvironmental' challenges, including climate change, pollution, urbanicity, and socioeconomic disparity. Notably, the implications of climate and pollution on brain and mental health have only recently gained prominence. With the advent of large-scale big-data cohorts and an increasingly dense mapping of macroenvironmental parameters, we are now in a position to characterise the relation between macroenvironment, brain, and behaviour across different geographic and cultural locations globally. This review synthesises findings from recent epidemiological and neuroimaging studies, aiming to provide a comprehensive overview of the existing evidence between the macroenvironment and the structure and functions of the brain, with a particular emphasis on its implications for mental illness. We discuss putative underlying mechanisms and address the most common exposures of the macroenvironment. Finally, we identify critical areas for future research to enhance our understanding of the aetiology of mental illness and to inform effective interventions for healthier environments and mental health promotion.

Magnetoencephalographic detection of synchronized epileptic activity between the hippocampus and insular cortex

Most magnetoencephalographic signals are derived from synchronized activity in the brain surface cortex. By contrast, the contribution of synchronized activity in the deep brain to magnetoencephalography (MEG) has remained unclear. We compared stereotactic electroencephalography (sEEG) with simultaneous MEG findings in a patient with temporal lobe epilepsy to determine the conditions under which MEG could also detect sEEG findings. The synchrony and similarity of the waves were evaluated using visual inspection and wavelet coherence. A 45-year-old woman with intractable temporal lobe epilepsy underwent sEEG and MEG simultaneously to determine the laterality and precise location of the epileptic focus. When spike-and-waves were seen in the right hippocampal head alone, no distinct spike-and-waves were observed visually in the right temporal MEG. The seizure then spread to the right insula on sEEG with a rhythmic theta frequency while synchronous activity was observed in the right temporal MEG channels. When polyspikes appeared in the right hippocampus, the right temporal MEG showed electrical activity with relatively high similarity to that of the right hippocampal head and insular cortex but less similarity to that of the right lateral temporal lobe cortex. MEG might detect epileptic activity synchronized between the hippocampus and insular cortex.

Neighborhood disadvantage and parenting predict longitudinal clustering of uncinate fasciculus microstructural integrity and clinical symptomatology in adolescents

Parenting behaviors and neighborhood environment influence the development of adolescents' brains and behaviors. Simultaneous trajectories of brain and behavior, however, are understudied, especially in these environmental contexts. In this four-wave study spanning 9-18 years of age (N=224 at baseline, N=138 at final assessment) we used longitudinal k-means clustering to identify clusters of participants with distinct trajectories of uncinate fasciculus (UF) fractional anisotropy (FA) and anxiety symptoms; we examined behavioral outcomes and identified environmental factors that predicted cluster membership. We identified three clusters of participants: 1) high UF FA and low symptoms ("low-risk"); 2) low UF FA and high symptoms ("high-risk"); and 3) low UF FA and low symptoms ("resilient"). Adolescents in disadvantaged neighborhoods were more likely to be in the resilient than high-risk cluster if they also experienced maternal warmth. Thus, neighborhood disadvantage may confer neural risk for psychopathology that can be buffered by maternal warmth, highlighting the importance of considering multiple environmental influences in understanding emotional and neural development in youth.

Preliminary examination of the effects of an early parenting intervention on amygdala-orbitofrontal cortex resting-state functional connectivity among high-risk children: A randomized clinical trial

We examined the long-term causal effects of an evidence-based parenting program delivered in infancy on children's emotion regulation and resting-state functional connectivity (rs-fc) during middle childhood. Families were referred to the study by Child Protective Services (CPS) as part of a diversion from a foster care program. A low-risk group of families was also recruited. CPS-involved families were randomly assigned to receive the target (Attachment and Biobehavioral Catch-up, ABC) or a control intervention (Developmental Education for Families, DEF) before infants turned 2. Both interventions were home-based, manualized, and 10-sessions long. During middle childhood, children underwent a 6-min resting-state functional MRI scan. Amygdala seed-based rs-fc analysis was completed with intervention group as the group-level predictor of interest. Fifty-seven children (NABC = 21; NDEF = 17; NCOMP = 19; Mage = 10.02 years, range = 8.08-12.14) were scanned successfully. The DEF group evidenced negative left amygdala↔OFC connectivity, whereas connectivity was near zero in the ABC and comparison groups (ABCvsDEF: Cohen's d = 1.17). ABC may enhance high-risk children's regulatory neurobiology outcomes ∼8 years after the intervention was completed.

The Effects of Childhood Adversity and Self-Regulation on the Well-Being of Adults with Delinquency Histories: A Mediation Model

PURPOSE

Most youth with delinquency histories experience childhood adversity leaving them vulnerable to poor adult well-being. Previous research indicates that self-regulation difficulties could explain how childhood adversity affects adult well-being. Yet, very few studies target adult self-regulation intervention. Therefore, this study examined the intervening effects of emerging adult self-regulation on the association between childhood adversity and adult well-being.

METHOD

Using data from the first four waves of the Add Health Study, the researchers conducted structural equation modeling for mediation with bootstrapping. The researchers tested the mediation effects of emerging adult self-regulation on the association between childhood adversity (child maltreatment and violent victimization) and later adult well-being (mental health problems, alcohol and drug use, criminal behaviors) among people with delinquency histories and/or arrest prior to age 18 (N = 1,792).

RESULTS

Several significant direct effects and one partial mediation effect were found. For example, child maltreatment significantly predicted adult mental health problems and criminal behaviors. Self-regulation (via the dissatisfaction with life and self subscale) mediated the association between child maltreatment and adult mental health problems.

DISCUSSION

Findings highlight the need for social workers to focus on prevention services and trauma-informed treatment for people with delinquency histories. In addition, evidence-based practice requires self-regulation interventions for adults with histories of childhood adversity and delinquency to focus on their emotional and cognitive functioning as well as self-esteem.

CONCLUSION

Implementing self-regulation interventions during emerging adulthood can be useful to mitigate later adult mental health problems among people with histories of childhood adversity and delinquency.

How does the macroenvironment influence brain and behaviour - a review of current status and future perspectives

The environment influences mental health, both detrimentally and beneficially. Current research has emphasized the individual psychosocial 'microenvironment'. Less attention has been paid to 'macro-environmental' challenges including climate change, pollution, urbanicity and socioeconomic disparity. With the advent of large-scale big-data cohorts and an increasingly dense mapping of macroenvironmental parameters, we are now in a position to characterise the relation between macroenvironment, brain, and behaviour across different geographic and cultural locations globally. This review synthesises findings from recent epidemiological and neuroimaging studies, aiming to provide a comprehensive overview of the existing evidence between the macroenvironment and the structure and functions of the brain, with a particular emphasis on its implications for mental illness. We discuss putative underlying mechanisms and address the most common exposures of the macroenvironment. Finally, we identify critical areas for future research to enhance our understanding of the aetiology of mental illness and to inform effective interventions for healthier environments and mental health promotion.

Perceptions of neighborhood threat and caregiver support in early adolescence: Sex differences in neural and behavioral correlates in the ABCD study

BACKGROUND

Adolescents, particularly racial and ethnic minorities, are at increased risk for neighborhood threat and violence exposure, which impacts behavioral and neural outcomes. Caregiver support is associated with healthy socioemotional adjustment and self-regulatory and coping behaviors; however, it remains unclear whether caregiver support, specifically, consolation, can moderate the behavioral and neural impacts of neighborhood threat.

OBJECTIVE

The aim of this study was to examine the role of youth-perceived neighborhood threat on neural and behavioral correlates and to test the moderating potential of caregiver support. Sex differences in associations were examined.

PARTICIPANTS AND SETTING

11,559 nine- and ten-year old youth enrolled in the multi-site Adolescent Brain Cognitive Development (ABCD) Study at baseline.

METHODS

Associations were examined via linear regression models employing youth-perceived neighborhood threat and caregiver support. Regression and interaction models controlled for youth age, sex, race and ethnicity, primary caregiver's education, family income, family structure, youth-perceived school threat, and intracranial volume when examining neural outcomes. An ANOVA employing a Chi-square test and simple slopes analysis were used to identify significant interactions in moderation models.

RESULTS

Neighborhood threat is associated with structural alterations in the left amygdala (p = .004). Meanwhile, caregiver support interacts in a dose-response fashion with neighborhood threat to attenuate its relationship with left amygdala volume (p = .008). Among youth reporting neighborhood threat, problematic behaviors were more common (p < .0001). While not significant, males reported higher rates of neighborhood threat than females (p = .267). Females reported greater levels of caregiver support (p = .017). Lastly, racial and ethnic differences in neighborhood threat and caregiver support were evident (p < .001).

CONCLUSIONS

While youth may not have been exposed to direct or immediate sources of threat and violence, these findings shed light on the impact of neighborhood threat perception on problematic behaviors and amygdala volume among nine- and ten-year olds. Future research should identify other culturally inclusive sources and measures of support and resiliency.

A data-driven approach to categorizing early life adversity exposure in the ABCD Study

BACKGROUND

Adversity occurring during development is associated with detrimental health and quality of life outcomes, not just following exposure but throughout the lifespan. Despite increased research, there exists both overlapping and distinct definitions of early life adversity exposure captured by over 30 different empirically validated tools. A data-driven approach to defining and cataloging exposure is needed to better understand associated outcomes and advance the field.

METHODS

We utilized baseline data on 11,566 youth enrolled in the ABCD Study to catalog youth and caregiver-reported early life adversity exposure captured across 14 different measures. We employed an exploratory factor analysis to identify the factor domains of early life adversity exposure and conducted a series of regression analyses to examine its association with problematic behavioral outcomes.

RESULTS

The exploratory factor analysis yielded a 6-factor solution corresponding to the following distinct domains: 1) physical and sexual violence; 2) parental psychopathology; 3) neighborhood threat; 4) prenatal substance exposure; 5) scarcity; and 6) household dysfunction. The prevalence of exposure among 9-and 10-year-old youth was largely driven by the incidence of parental psychopathology. Sociodemographic characteristics significantly differed between youth with adversity exposure and controls, depicting a higher incidence of exposure among racial and ethnic minoritized youth, and among those identifying with low socioeconomic status. Adversity exposure was significantly associated with greater problematic behaviors and largely driven by the incidence of parental psychopathology, household dysfunction and neighborhood threat. Certain types of early life adversity exposure were more significantly associated with internalizing as opposed to externalizing problematic behaviors.

CONCLUSIONS

We recommend a data-driven approach to define and catalog early life adversity exposure and suggest the incorporation of more versus less data to capture the nuances of exposure, e.g., type, age of onset, frequency, duration. The broad categorizations of early life adversity exposure into two domains, such as abuse and neglect, or threat and deprivation, fail to account for the routine co-occurrence of exposures and the duality of some forms of adversity. The development and use of a data-driven definition of early life adversity exposure is a crucial step to lessening barriers to evidence-based treatments and interventions for youth.

Behavioral and neurostructural correlates of childhood physical violence victimization: Interaction with family functioning

Violence victimization may cause child behavior problems and neurostructural differences associated with them. Healthy family environments may buffer these effects, but neural pathways explaining these associations remain inadequately understood. We used data from 3154 children (x̅age  = 10.1) to test whether healthy family functioning moderated possible associations between violence victimization, behavior problems, and amygdala volume (a threat-responsive brain region). Researchers collected data on childhood violence victimization, family functioning (McMaster Family Assessment Device, range 0-3, higher scores indicate healthier functioning), and behavior problems (Achenbach Child Behavior Checklist [CBCL] total problem score, range 0-117), and they scanned children with magnetic resonance imaging. We standardized amygdala volumes and fit confounder-adjusted models with "victimization × family functioning" interaction terms. Family functioning moderated associations between victimization, behavior problems, and amygdala volume. Among lower functioning families (functioning score = 1.0), victimization was associated with a 26.1 (95% confidence interval [CI]: 9.9, 42.4) unit higher CBCL behavior problem score, yet victimized children from higher functioning families (score = 3.0) exhibited no such association. Unexpectedly, victimization was associated with higher standardized amygdala volume among lower functioning families (ŷ = 0.5; 95% CI: 0.1, 1.0) but lower volume among higher functioning families (ŷ = -0.4; 95% CI: -0.7, -0.2). Thus, healthy family environments may mitigate some neurobehavioral effects of childhood victimization.

Stress-induced Changes in Autonomic Reactivity Vary with Adolescent Violence Exposure and Resting-state Functional Connectivity

Exposure to violence during childhood can lead to functional changes in brain regions that are important for emotion expression and regulation, which may increase susceptibility to internalizing disorders in adulthood. Specifically, childhood violence exposure can disrupt the functional connectivity among brain regions that include the prefrontal cortex (PFC), hippocampus, and amygdala. Together, these regions are important for modulating autonomic responses to stress. However, it is unclear to what extent changes in brain connectivity relate to autonomic stress reactivity and how the relationship between brain connectivity and autonomic responses to stress varies with childhood violence exposure. Thus, the present study examined whether stress-induced changes in autonomic responses (e.g., heart rate, skin conductance level (SCL)) varied with amygdala-, hippocampus-, and ventromedial prefrontal cortex (vmPFC)-whole brain resting-state functional connectivity (rsFC) as a function of violence exposure. Two hundred and ninety-seven participants completed two resting-state functional magnetic resonance imaging scans prior to (pre-stress) and after (post-stress) a psychosocial stress task. Heart rate and SCL were recorded during each scan. Post-stress heart rate varied negatively with post-stress amygdala-inferior parietal lobule rsFC and positively with post-stress hippocampus-anterior cingulate cortex rsFC among those exposed to high, but not low, levels of violence. Results from the present study suggest that post-stress fronto-limbic and parieto-limbic rsFC modulates heart rate and may underlie differences in the stress response among those exposed to high levels of violence.

Positive parenting moderates associations between childhood stress and corticolimbic structure

Childhood stress has a deleterious impact on youth behavior and brain development. Resilience factors such as positive parenting (e.g. expressions of warmth and support) may buffer youth against the negative impacts of stress. We sought to determine whether positive parenting buffers against the negative impact of childhood stress on youth behavior and brain structure and to investigate differences between youth-reported parenting and caregiver-reported parenting. Cross-sectional behavioral and neuroimaging data were analyzed from 482 youth (39% female and 61% male, ages 10-17) who participated in an ongoing research initiative, the Healthy Brain Network (HBN). Regression models found that youth-reported positive parenting buffered against the association between childhood stress and youth behavioral problems (β = -0.10, P = 0.04) such that increased childhood stress was associated with increased youth behavior problems only for youth who did not experience high levels of positive parenting. We also found that youth-reported positive parenting buffered against the association between childhood stress and decreased hippocampal volumes (β = 0.07, P = 0.02) such that youth who experienced high levels of childhood stress and who reported increased levels of positive parenting did not exhibit smaller hippocampal volumes. Our work identifies positive parenting as a resilience factor buffering youth against the deleterious impact of stressful childhood experiences on problem behaviors and brain development. These findings underscore the importance of centering youth perspectives of stress and parenting practices to better understand neurobiology, mechanisms of resilience, and psychological well-being.

Violence Exposure and Mental Health Consequences Among Urban Youth

Urban residents are disproportionately affected by violence exposure and mental health consequences as compared to non-urban residents. The present study examined the prevalence of violence exposure and associated mental health consequences among urban and non-urban youth. Urban participants were drawn from Detroit, Michigan, a city that has led the nation for most of the last decade as one of the most violent big cities in the U.S. Participants included 32 Detroit youth and 32 youth recruited from the surrounding non-urban areas, matched on age (M=10.4±2.8 years) and sex (49% male). Youth completed validated measures of violence exposure, anxiety, and depression symptoms. Urban youth reported more violence exposures than their non-urban counterparts, including hearing gunshots (69% vs. 19%, respectively), witnessing a shooting (24% vs. 6%), and witnessing an arrest (58% vs. 27%). Overall, greater violence exposure was associated with more anxiety symptoms, particularly among urban youth. Although violence exposure was not associated with depressive symptoms overall, urban youth reported significantly higher depressive symptoms than non-urban youth. Exposure to specific violence types, particularly hearing gunshots, was associated with higher anxiety and depressive symptoms among urban but not non-urban youth. Being beat up predicted depressive symptoms among non-urban but not urban youth. Household income and community distress did not predict mental health outcomes. Taken together, urban youth have more exposure to violence, particularly firearm violence, and associated mental health problems than their non-urban counterparts. Targeted community-wide initiatives to prevent violence and identify exposed youth are needed to improve mental health in at-risk communities.

Neurobiology of Aggression-Review of Recent Findings and Relationship with Alcohol and Trauma

Aggression can be conceptualized as any behavior, physical or verbal, that involves attacking another person or animal with the intent of causing harm, pain or injury. Because of its high prevalence worldwide, aggression has remained a central clinical and public safety issue. Aggression can be caused by several risk factors, including biological and psychological, such as genetics and mental health disorders, and socioeconomic such as education, employment, financial status, and neighborhood. Research over the past few decades has also proposed a link between alcohol consumption and aggressive behaviors. Alcohol consumption can escalate aggressive behavior in humans, often leading to domestic violence or serious crimes. Converging lines of evidence have also shown that trauma and posttraumatic stress disorder (PTSD) could have a tremendous impact on behavior associated with both alcohol use problems and violence. However, although the link between trauma, alcohol, and aggression is well documented, the underlying neurobiological mechanisms and their impact on behavior have not been properly discussed. This article provides an overview of recent advances in understanding the translational neurobiological basis of aggression and its intricate links to alcoholism and trauma, focusing on behavior. It does so by shedding light from several perspectives, including in vivo imaging, genes, receptors, and neurotransmitters and their influence on human and animal behavior.

Longitudinal changes in within-salience network functional connectivity mediate the relationship between childhood abuse and neglect, and mental health during adolescence

BACKGROUND

Understanding the neurobiological underpinnings of childhood maltreatment is vital given consistent links with poor mental health. Dimensional models of adversity purport that different types of adversity likely have distinct neurobiological consequences. Adolescence is a key developmental period, during which deviations from normative neurodevelopment may have particular relevance for mental health. However, longitudinal work examining links between different forms of maltreatment, neurodevelopment, and mental health is limited.

METHODS

In the present study, we explored associations between abuse, neglect, and longitudinal development of within-network functional connectivity of the salience (SN), default mode (DMN), and executive control network in 142 community residing adolescents. Resting-state fMRI data were acquired at age 16 (T1; M = 16.46 years, s.d. = 0.52, 66F) and 19 (T2; mean follow-up period: 2.35 years). Mental health data were also collected at T1 and T2. Childhood maltreatment history was assessed prior to T1.

RESULTS

Abuse and neglect were both found to be associated with increases in within-SN functional connectivity from age 16 to 19. Further, there were sex differences in the association between neglect and changes in within-DMN connectivity. Finally, increases in within-SN connectivity were found to mediate the association between abuse/neglect and lower problematic substance use and higher depressive symptoms at age 19.

CONCLUSIONS

Our findings suggest that childhood maltreatment is associated with altered neurodevelopmental trajectories, and that changes in salience processing may be linked with risk and resilience for the development of depression and substance use problems during adolescence, respectively. Further work is needed to understand the distinct neurodevelopmental and mental health outcomes of abuse and neglect.

Executive Network Activation Moderates the Association between Neighborhood Threats and Externalizing Behavior in Youth

Neighborhood threats can increase risk for externalizing problems, including aggressive, oppositional, and delinquent behavior. Yet, there is substantial variability in how youth respond to neighborhood threats. Difficulty with cognitive functioning, particularly in the face of emotional information, may increase risk for externalizing in youth who live in neighborhoods with higher threats. However, little research has examined: 1) associations between neighborhood threats and executive networks involved in cognitive functioning or 2) whether executive networks may amplify risk for externalizing in the context of neighborhood threats. Further, most research on neighborhood threats does not account for youth's experiences in other social contexts. Utilizing the large, sociodemographically diverse cohort of youth (ages 9-10) included in the Adolescent Brain Cognitive Development^SM Study, we identified four latent profiles of youth based on threats in their neighborhoods, families, and schools: low threat in all contexts, elevated family threat, elevated neighborhood threat, and elevated threat in all contexts. The elevated neighborhood threat and elevated all threat profiles showed lower behavioral performance on an emotional n-back task relative to low threat and elevated family threat profiles. Lower behavioral performance in the elevated neighborhood threat profile specifically was paralleled by lower executive network activity during a cognitive challenge. Moreover, among youth with lower executive network activity, higher probability of membership in the elevated neighborhood threat profile was associated with higher externalizing. Together, these results provide evidence that interactions between threats that are concentrated in youth's neighborhoods and attenuated executive network function may contribute to risk for externalizing problems.

Warmth and reciprocity with mothers, and young children's resilience to exposure to community violence in Colombia: findings from the La Sabana Parent-Child Study

BACKGROUND

Exposure to community violence is common worldwide and is associated with emotional and behavioural problems in children. Little is known about sources of resilience. Building on our previous work on the contribution of callous-unemotional (CU) traits to child aggression in Colombia, we examined whether positive parenting is protective for children whose families are exposed to community violence.

METHODS

Families were recruited from three demographically contrasting regions of Colombia. The sample comprised 235 children aged 3.5 years and their mothers, of whom 220 (93%) were followed up at age 5.0 years. Positive parenting was assessed as the average of maternal warmth and reciprocity, and as praise, and negative parenting as the average of negative affect and conflict seen in video recordings of standardized procedures. CU traits and oppositional defiant disorder were assessed by maternal report at ages 3.5 and 5.0 years, and mothers reported exposure to community violence over the 18 months between assessments. A range of potential confounds was included in adjusted analyses.

RESULTS

In the families who were exposed to community violence, but not in the unexposed, maternal warmth and reciprocity were associated prospectively with lower CU traits (interaction, p = .007). In the exposed group maternal warmth and reciprocity explained 10% of the variance (β = -.34, p = .001). Maternal praise was not associated with CU traits. Maternal negative parenting predicted higher CU traits as the main effect but not in interaction with community violence exposure.

CONCLUSIONS

Maternal warmth and reciprocity with young children may promote resilience in the face of community violence. Programmes to enhance these protective processes may be needed especially where prospects for reducing community violence are limited. The centrality of parents for these children highlights the plight of those exposed to community violence, and also either separated from parents or orphaned.

Sex-dependent risk factors for PTSD: a prospective structural MRI study

Female individuals are more likely to be diagnosed with PTSD following trauma exposure than males, potentially due, in part, to underlying neurobiological factors. Several brain regions underlying fear learning and expression have previously been associated with PTSD, with the hippocampus, amygdala, dorsal anterior cingulate cortex (dACC), and rostral ACC (rACC) showing altered volume and function in those with PTSD. However, few studies have examined how sex impacts the predictive value of subcortical volumes and cortical thickness in longitudinal PTSD studies. As part of an emergency department study completed at the Grady Trauma Project in Atlanta, GA, N = 93 (40 Female) participants were enrolled within 24 h following a traumatic event. Multi-echo T1-weighted MRI images were collected one-month post-trauma exposure. Bilateral amygdala and hippocampal volumes and rACC and dACC cortical thickness were segmented. To assess the longitudinal course of PTSD, the PTSD Symptom Scale (PSS) was collected 6 months post-trauma. We investigated whether regional volume/thickness interacted with sex to predict later PTSD symptom severity, controlling for PSS score at time of scan, age, race, and trauma type, as well as intracranial volume (ICV) for subcortical volumes. There was a significant interaction between sex and rACC for 6-month PSS, such that right rACC thickness was positively correlated with 6-month PSS scores in females, but not in males. In examining PTSD symptom subtypes and depression symptoms, greater rACC thickness in females predicted greater avoidance symptoms, while smaller rACC thickness in males predicted greater depression symptoms. Amygdala and hippocampus volume and dACC thickness showed no main effect or interaction with sex. The current findings provide evidence for sex-based differences in how brain volume predicts future PTSD severity and symptoms and supports the rACC as being a vital region regarding PTSD. Gender differences should be assessed in future longitudinal PTSD MRI studies for more accurate identification of future PTSD risk following trauma.

Radically reframing studies on neurobiology and socioeconomic circumstances: A call for social justice-oriented neuroscience

Socioeconomic circumstances are associated with symptoms and diagnostic status of nearly all mental health conditions. Given these robust relationships, neuroscientists have attempted to elucidate how socioeconomic-based adversity "gets under the skin." Historically, this work emphasized individual proxies of socioeconomic position (e.g., income, education), ignoring the effects of broader socioeconomic contexts (e.g., neighborhood socioeconomic disadvantage) which may uniquely contribute to chronic stress. This omission represented a disconnect between neuroscience and other allied fields that have recognized health is undeniably linked to interactions between systems of power and individual characteristics. More recently, neuroscience work has considered how sociopolitical context affects brain structure and function; however, the products of this exciting line of research have lacked critical sociological and historical perspectives. While empirical evidence on this topic is burgeoning, the cultural, ethical, societal, and legal implications of this work have been elusive. Although the mechanisms by which socioeconomic circumstances impact brain structure and function may be similar across people, not everyone is exposed to these factors at similar rates. Individuals from ethnoracially minoritized groups are disproportionally exposed to neighborhood disadvantage. Thus, socioeconomic inequities examined in neuroscience research are undergirding with other forms of oppression, namely structural racism. We utilize a holistic, interdisciplinary approach to interpret findings from neuroscience research and interweave relevant theories from the fields of public health, social sciences, and Black feminist thought. In this perspective piece, we discuss the complex relationship that continues to exist between academic institutions and underserved surrounding communities, acknowledging the areas in which neuroscience research has historically harmed and/or excluded structurally disadvantaged communities. We conclude by envisioning how this work can be used; not just to inform policymakers, but also to engage and partner with communities and shape the future direction of human neuroscience research.

The Effects of Prenatal Exposure to Neighborhood Crime on Neonatal Functional Connectivity

BACKGROUND

Maternal exposure to adversity during pregnancy has been found to affect infant brain development; however, the specific effect of prenatal crime exposure on neonatal brain connectivity remains unclear. Based on existing research, we hypothesized that living in a high-crime neighborhood during pregnancy would affect neonatal frontolimbic connectivity over and above other individual- and neighborhood-level adversity and that these associations would be mediated by maternal psychosocial stress.

METHODS

Participants included 399 pregnant women, recruited as part of the eLABE (Early Life Adversity, Biological Embedding, and Risk for Developmental Precursors of Mental Disorders) study. In the neonatal period, 319 healthy, nonsedated infants were scanned using resting-state functional magnetic resonance imaging (repetition time = 800 ms; echo time = 37 ms; voxel size = 2.0 × 2.0 × 2.0 mm3; multiband = 8) on a Prisma 3T scanner and had at least 10 minutes of high-quality data. Crime data at the block group level were obtained from Applied Geographic Solution. Linear regressions and mediation models tested associations between crime, frontolimbic connectivity, and psychosocial stress.

RESULTS

Living in a neighborhood with high property crime during pregnancy was related to weaker neonatal functional connectivity between the thalamus-anterior default mode network (aDMN) (β = -0.15, 95% CI = -0.25 to -0.04, p = .008). Similarly, high neighborhood violent crime was related to weaker functional connectivity between the thalamus-aDMN (β = -0.16, 95% CI = -0.29 to -0.04, p = .01) and amygdala-hippocampus (β = -0.16, 95% CI = -0.29 to -0.03, p = .02), controlling for other types of adversity. Psychosocial stress partially mediated relationships between the thalamus-aDMN and both violent and property crime.

CONCLUSIONS

These findings suggest that prenatal exposure to crime is associated with weaker neonatal limbic and frontal functional brain connections, providing another reason for targeted public policy interventions to reduce crime.

Environmental Conditions to Promote Healthy Childhood Brain/Behavioral Development: Informing Early Preventive Interventions for Delivery in Routine Care

Environmental experiences early in life have strong and enduring consequences for cognitive, emotional, and neurobiological development and related physical and mental health trajectories. The powerful influence of early caregiver nurturance and stimulation on promoting positive neurodevelopmental outcomes has been demonstrated across species. These findings elucidate the environmental conditions known to facilitate healthy neurodevelopment and underscore the potential for modifiable psychosocial factors in the environment to be harnessed to inform early preventive interventions to promote health and adaptive development. A framework for early preventive interventions to enhance nurturing and responsive caregiving for implementation during early sensitive periods of brain development delivered within existing health or educational infrastructures is proposed. Emotional development during sensitive periods is an important, under-recognized, and abundantly modifiable predictor of mental and physical health outcomes that warrants investment of resources and integration of interventions into public health infrastructure for children worldwide. Future studies are needed to further clarify whether and when sensitive periods are present for key developmental domains to inform the optimal timing and targets of these interventions. Numerous available empirically supported early interventions may be modified and applied in briefer and more feasible modalities of delivery to broader populations of developing children. As well established in growth and development across species, essential environmental inputs that are particularly important at specified developmental periods facilitate optimal growth trajectories. Such principles hold great potential in application to early child neurodevelopment to facilitate a thriving and resilient human population.

Neighborhood Disadvantage Associated With Blunted Amygdala Reactivity to Predictable and Unpredictable Threat in a Community Sample of Youth

BACKGROUND

Childhood socioeconomic disadvantage is a form of adversity associated with alterations in critical frontolimbic circuits involved in the pathophysiology of psychiatric disorders. Most work has focused on individual-level socioeconomic position, yet individuals living in deprived communities typically encounter additional environmental stressors that have unique effects on the brain and health outcomes. Notably, chronic and unpredictable stressors experienced in the everyday lives of youth living in disadvantaged neighborhoods may impact neural responsivity to uncertain threat.

METHODS

A community sample of children (N = 254) ages 8 to 15 years (mean = 12.15) completed a picture anticipation task during a functional magnetic resonance imaging scan, during which neutral and negatively valenced photos were presented in a temporally predictable or unpredictable manner. Area Deprivation Index (ADI) scores were derived from participants' home addresses as an index of relative neighborhood disadvantage. Voxelwise analyses examined interactions of ADI, valence, and predictability on neural response to picture presentation.

RESULTS

There was a significant ADI × valence interaction in the middle temporal gyrus, anterior cingulate cortex, hippocampus, and amygdala. Higher ADI was associated with less amygdala activation to negatively valenced images. ADI also interacted with predictability. Higher ADI was associated with greater activation of lingual and calcarine gyri for unpredictably presented stimuli. There was no three-way interaction of ADI, valence, and predictability.

CONCLUSIONS

Neighborhood disadvantage may impact how the brain perceives and responds to potential threats. Future longitudinal work is critical for delineating how such effects may persist across the life span and how health outcomes may be modifiable with community-based interventions and policies.

The effects of early life adversity on children's mental health and cognitive functioning

Emerging evidence suggests that partially distinct mechanisms may underlie the association between different dimensions of early life adversity (ELA) and psychopathology in children and adolescents. While there is minimal evidence that different types of ELA are associated with specific psychopathology outcomes, there are partially unique cognitive and socioemotional consequences of specific dimensions of ELA that increase transdiagnostic risk of mental health problems across the internalizing and externalizing spectra. The current review provides an overview of recent findings examining the cognitive (e.g., language, executive function), socioemotional (e.g., attention bias, emotion regulation), and mental health correlates of ELA along the dimensions of threat/harshness, deprivation, and unpredictability. We underscore similarities and differences in the mechanisms connecting different dimensions of ELA to particular mental health outcomes, and identify gaps and future directions that may help to clarify inconsistencies in the literature. This review focuses on childhood and adolescence, periods of exquisite neurobiological change and sensitivity to the environment. The utility of dimensional models of ELA in better understanding the mechanistic pathways towards the expression of psychopathology is discussed, with the review supporting the value of such models in better understanding the developmental sequelae associated with ELA. Integration of dimensional models of ELA with existing models focused on psychiatric classification and biobehavioral mechanisms may advance our understanding of the etiology, phenomenology, and treatment of mental health difficulties in children and youth.

Left amygdala structure mediates longitudinal associations between exposure to threat and long-term psychiatric symptomatology in youth

Traumatic experiences during childhood can have profound effects on stress sensitive brain structures (e.g., amygdala and hippocampus) and the emergence of psychiatric symptoms. Recent theoretical and empirical work has delineated dimensions of trauma (i.e., threat and deprivation) as having distinct neural and behavioral effects, although there are few longitudinal examinations. A sample of 243 children and adolescents were followed for three time points, with each assessment approximately 1 year apart (ages 9–15 years at Time 1; 120 males). Participants or their caregiver reported on youths' threat exposure, perceived stress (Time 1), underwent a T1‐weighted structural high‐resolution MRI scan (Time 2), and documented their subsequent psychiatric symptoms later in development (Time 3). The primary findings indicate that left amygdala volume, in particular, mediated the longitudinal association between threat exposure and subsequent internalizing and externalizing symptomatology. Greater threat exposure related to reduced left amygdala volume, which in turn differentially predicted internalizing and externalizing symptoms. Decreased bilateral hippocampal volume was related to subsequently elevated internalizing symptoms. These findings suggest that the left amygdala is highly threat‐sensitive and that stress‐related alterations may partially explain elevated psychopathology in stress‐exposed adolescents. Uncovering potential subclinical and/or preclinical predictive biomarkers is essential to understanding the emergence, progression, and eventual targeted treatment of psychopathology following trauma exposure.

Amygdala and hippocampal subregions mediate outcomes following trauma during typical development: Evidence from high-resolution structural MRI

The vast majority of individuals experience trauma within their lifetime. Yet, most people do not go on to develop clinical levels of psychopathology. Recently, studies have highlighted the potential protective effects of having larger amygdala and hippocampal volumes, such that larger volumes may promote adaptive functioning following trauma. However, research has not yet elucidated whether certain subregions of these stress-sensitive structures have specific protective effects. Herein, we examined the mediating effects of amygdala and hippocampal subregions on the relationship between traumatic exposure and concurrent or longitudinal changes in psychiatric symptom levels in typically developing youth (9-15 years of age). Using high-resolution T1-and T2-weighted structural MRI scans, we found that the volume of the right basolateral complex of the amygdala mediated associations between trauma exposure and internalizing symptoms. Specifically, greater levels of childhood trauma related to larger volumes, and larger volumes were associated with fewer internalizing symptoms. The volume of the right CA4/dentate gyrus (DG) of the hippocampus yielded similar mediation results, such that greater trauma was related to larger volumes, which in turn were associated with decreases in internalizing symptoms across time. These findings provide initial support for potentially protective effects of larger right amygdala and hippocampal subregion volumes against internalizing symptomology concurrently and longitudinally during adolescence.

The impact of neighborhood disadvantage on amygdala reactivity: Pathways through neighborhood social processes

Youth growing up in disadvantaged neighborhoods are more likely than their advantaged peers to face negative behavioral and mental health outcomes. Although studies have shown that adversity can undermine positive development via its impact on the developing brain, few studies have examined the association between neighborhood disadvantage and neural function, and no study has investigated potential social mechanisms within the neighborhood that might link neighborhood disadvantage to altered neural function. The current study evaluated the association between neighborhood disadvantage and amygdala reactivity during socioemotional face processing. We also assessed whether and which neighborhood-level social processes were related to amygdala reactivity, and whether these social processes mediated or moderated the association between neighborhood disadvantage and altered amygdala reactivity. We examined these aims in a registered report, using a sample of twins aged 7-19 years (N = 354 families, 708 twins) recruited from birth records with enrichment for neighborhood disadvantage. Twins completed a socioemotional face processing fMRI task and a sample of unrelated participants from the twins' neighborhoods were also recruited to serve as informants on neighborhood social processes. We found that neighborhood disadvantage was associated with greater right amygdala reactivity to threat, but only when neighborhood informants perceived norms in the neighborhood to be more permissive regarding general safety and management. The findings from this research add to the growing literature highlighting the influence of neighborhood disadvantage on amygdala function and the ways that supportive social processes may buffer the impact of adversity on brain function.

Individual differences in amygdala volumes predict changes in functional connectivity between subcortical and cognitive control networks throughout adolescence

Adolescence is a critical period of structural and functional neural maturation among regions serving the cognitive control of emotion. Evidence suggests that this process is guided by developmental changes in amygdala and striatum structure and shifts in functional connectivity between subcortical (SC) and cognitive control (CC) networks. Herein, we investigate the extent to which such developmental shifts in structure and function reciprocally predict one another over time. 179 youth (9-15 years-old) completed annual MRI scans for three years. Amygdala and striatum volumes and connectivity within and between SC and CC resting state networks were measured for each year. We tested for reciprocal predictability of within-person and between-person changes in structure and function using random-intercept cross-lagged panel models. Within-person shifts in amygdala volumes in a given year significantly and specifically predicted deviations in SC-CC connectivity in the following year, such that an increase in volume was associated with decreased SC-CC connectivity the following year. Deviations in connectivity did not predict changes in amygdala volumes over time. Conversely, broader group-level shifts in SC-CC connectivity were predictive of subsequent deviations in striatal volumes. We did not see any cross-predictability among amygdala or striatum volumes and within-network connectivity measures. Within-person shifts in amygdala structure year-to-year robustly predicted weaker SC-CC connectivity in subsequent years, whereas broader increases in SC-CC connectivity predicted smaller striatal volumes over time. These specific structure function relationships may contribute to the development of emotional control across adolescence.

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.

Neural contributors to trauma resilience: a review of longitudinal neuroimaging studies

Resilience in the face of major life stressors is changeable over time and with experience. Accordingly, differing sets of neurobiological factors may contribute to an adaptive stress response before, during, and after the stressor. Longitudinal studies are therefore particularly effective in answering questions about the determinants of resilience. Here we provide an overview of the rapidly-growing body of longitudinal neuroimaging research on stress resilience. Despite lingering gaps and limitations, these studies are beginning to reveal individual differences in neural circuit structure and function that appear protective against the emergence of future psychopathology following a major life stressor. Here we outline a neural circuit model of resilience to trauma. Specifically, pre-trauma biomarkers of resilience show that an ability to modulate activity within threat and salience networks predicts fewer stress-related symptoms. In contrast, early post-trauma biomarkers of subsequent resilience or recovery show a more complex pattern, spanning a number of major circuits including attention and cognitive control networks as well as primary sensory cortices. This novel synthesis suggests stress resilience may be scaffolded by stable individual differences in the processing of threat cues, and further buttressed by post-trauma adaptations to the stressor that encompass multiple mechanisms and circuits. More attention and resources supporting this work will inform the targets and timing of mechanistic resilience-boosting interventions.

Adverse Childhood Events and Health Biomarkers: A Systematic Review

Background: This systematic review aimed to summarize evidence reporting epigenetic and/or neuro-immuno-endocrine embedding of adverse childhood events (ACEs) in children, with a particular focus on the short-term biological effect of those experiences.

Methods: A search was conducted in PsycINFO®, PubMed®, Isi Web of Knowledge and Scopus, until July 2019, to identify papers reporting the short-term biological effects of exposure to ACEs.

Results: The search identified 58 studies, that were included in the review. Regarding exposure, the type of ACE more frequently reported was sexual abuse (n = 26), followed by life stressors (n = 20) and physical abuse (n = 19). The majority (n = 17) of studies showed a positive association between ACEs and biomarkers of the immune system. Regarding DNA methylation 18 studies showed more methylation in participants exposed to ACEs. Two studies presented the effect of ACEs on telomere length and showed that exposure was associated with shorter telomere length.

Conclusion: Overall the associations observed across studies followed the hypothesis that ACEs are associated with biological risk already at early ages. This is supporting evidence that ACEs appear to get “under the skin” and induce physiological changes and these alterations might be strongly associated with later development of disease.

Preventing Childhood Toxic Stress: Partnering With Families and Communities to Promote Relational Health

By focusing on the safe, stable, and nurturing relationships (SSNRs) that buffer adversity and build resilience, pediatric care is on the cusp of a paradigm shift that could reprioritize clinical activities, rewrite research agendas, and realign our collective advocacy. Driving this transformation are advances in developmental sciences as they inform a deeper understanding of how early life experiences, both nurturing and adverse, are biologically embedded and influence outcomes in health, education, and economic stability across the life span. This revised policy statement on childhood toxic stress acknowledges a spectrum of potential adversities and reaffirms the benefits of an ecobiodevelopmental model for understanding the childhood origins of adult-manifested disease and wellness. It also endorses a paradigm shift toward relational health because SSNRs not only buffer childhood adversity when it occurs but also promote the capacities needed to be resilient in the future. To translate this relational health framework into clinical practice, generative research, and public policy, the entire pediatric community needs to adopt a public health approach that builds relational health by partnering with families and communities. This public health approach to relational health needs to be integrated both vertically (by including primary, secondary, and tertiary preventions) and horizontally (by including public service sectors beyond health care). The American Academy of Pediatrics asserts that SSNRs are biological necessities for all children because they mitigate childhood toxic stress responses and proactively build resilience by fostering the adaptive skills needed to cope with future adversity in a healthy manner.

Association of Local Variation in Neighborhood Disadvantage in Metropolitan Areas With Youth Neurocognition and Brain Structure

Importance

Neighborhood disadvantage is an important social determinant of health in childhood and adolescence. Less is known about the association of neighborhood disadvantage with youth neurocognition and brain structure, and particularly whether associations are similar across metropolitan areas and are attributed to local differences in disadvantage.

Objective

To test whether neighborhood disadvantage is associated with youth neurocognitive performance and with global and regional measures of brain structure after adjusting for family socioeconomic status and perceptions of neighborhood characteristics, and to assess whether these associations (1) are pervasive or limited, (2) vary across metropolitan areas, and (3) are attributed to local variation in disadvantage within metropolitan areas.

Design, Setting, and Participants

This cross-sectional study analyzed baseline data from the Adolescent Brain and Cognitive Development (ABCD) Study, a cohort study conducted at 21 sites across the US. Participants were children aged 9.00 to 10.99 years at enrollment. They and their parent or caregiver completed a baseline visit between October 1, 2016, and October 31, 2018.

Exposures

Neighborhood disadvantage factor based on US census tract characteristics.

Main Outcomes and Measures

Neurocognition was measured with the NIH Toolbox Cognition Battery, and T1-weighted magnetic resonance imaging was used to assess whole-brain and regional measures of structure. Linear mixed-effects models examined the association between neighborhood disadvantage and outcomes after adjusting for sociodemographic factors.

Results

Of the 11 875 children in the ABCD Study cohort, 8598 children (72.4%) were included in this analysis. The study sample had a mean (SD) age of 118.8 (7.4) months and included 4526 boys (52.6%). Every 1-unit increase in the neighborhood disadvantage factor was associated with lower performance on 6 of 7 subtests, such as Flanker Inhibitory Control and Attention (unstandardized Β = -0.5; 95% CI, -0.7 to -0.2; false discovery rate (FDR)-corrected P = .001) and List Sorting Working Memory (unstandardized Β = -0.7; 95% CI, -1.0 to -0.3; FDR-corrected P < .001), as well as on all composite measures of neurocognition, such as the Total Cognition Composite (unstandardized Β = -0.7; 95% CI, -0.9 to -0.5; FDR-corrected P < .001). Each 1-unit increase in neighborhood disadvantage was associated with lower whole-brain cortical surface area (unstandardized Β = -692.6 mm2; 95% CI, -1154.9 to -230.4 mm2; FDR-corrected P = .007) and subcortical volume (unstandardized Β = -113.9 mm3; 95% CI, -198.5 to -29.4 mm3; FDR-corrected P = .03) as well as with regional surface area differences, primarily in the frontal, parietal, and temporal lobes. Associations largely remained after adjusting for perceptions of neighborhood safety and were both consistent across metropolitan areas and primarily explained by local variation in each area.

Conclusions and Relevance

This study found that, in the US, local variation in neighborhood disadvantage was associated with lower neurocognitive performance and smaller cortical surface area and subcortical volume in young people. The findings demonstrate that neighborhood disadvantage is an environmental risk factor for neurodevelopmental and population health and enhancing the neighborhood context is a promising approach to improving the health and development of children and adolescents.

Community Violence Exposure is Associated with Hippocampus-Insula Resting State Functional Connectivity in Urban Youth

Our previous work has linked childhood violence exposure in Black youth to functional changes in the hippocampus, a brain region sensitive to stress. However, different contexts of violence exposure (e.g., community, home, school) may have differential effects on circuitry. We investigated the unique effect of community violence in predicting resting-state functional connectivity (rsFC) in the hippocampus. Fifty-two (26F) violence-exposed Black youth ages 8-15 performed resting-state functional neuroimaging scans while looking at a fixation cross for seven minutes with eyes open. Seed-based analyses were conducted to examine the association between total violence exposure and rsFC of the hippocampus to the whole brain. Follow-up hierarchical regression analysis were performed to specifically investigate community violence. Violence exposure was associated with higher hippocampus rsFC with a core node of the Default Mode Network (i.e., posterior cingulate cortex) and lower hippocampal rsFC with a core node of the Salience Network (i.e., insula). Community violence uniquely associated with lower hippocampus-insula rsFC, after controlling for home and school violence, sex and age. Age-related decreases in hippocampus-insula rsFC were also present in youth with lower violence exposure, but not in youth with higher violence exposure. This is one of the first studies to investigate the unique impact of community violence, above home and school violence, on threat circuitry. Our data suggest functional alterations in the hippocampus in violence-exposed youth, and that violence in the community may be a more salient form of threat exposure compared to other forms of violence experienced by youth.

Amygdala Allostasis and Early Life Adversity: Considering Excitotoxicity and Inescapability in the Sequelae of Stress

Early life adversity (ELA), such as child maltreatment or child poverty, engenders problems with emotional and behavioral regulation. In the quest to understand the neurobiological sequelae and mechanisms of risk, the amygdala has been of major focus. While the basic functions of this region make it a strong candidate for understanding the multiple mental health issues common after ELA, extant literature is marked by profound inconsistencies, with reports of larger, smaller, and no differences in regional volumes of this area. We believe integrative models of stress neurodevelopment, grounded in "allostatic load," will help resolve inconsistencies in the impact of ELA on the amygdala. In this review, we attempt to connect past research studies to new findings with animal models of cellular and neurotransmitter mediators of stress buffering to extreme fear generalization onto testable research and clinical concepts. Drawing on the greater impact of inescapability over unpredictability in animal models, we propose a mechanism by which ELA aggravates an exhaustive cycle of amygdala expansion and subsequent toxic-metabolic damage. We connect this neurobiological sequela to psychosocial mal/adaptation after ELA, bridging to behavioral studies of attachment, emotion processing, and social functioning. Lastly, we conclude this review by proposing a multitude of future directions in preclinical work and studies of humans that suffered ELA.

Decomposing complex links between the childhood environment and brain structure in school-aged youth

Childhood experiences play a profound role in conferring risk and resilience for brain and behavioral development. However, how different facets of the environment shape neurodevelopment remains largely unknown. Here we sought to decompose heterogeneous relationships between environmental factors and brain structure in 989 school-aged children from the Adolescent Brain Cognitive Development Study. We applied a cross-modal integration and clustering approach called 'Similarity Network Fusion', which combined two brain morphometrics (i.e., cortical thickness and myelin-surrogate markers), and key environmental factors (i.e., trauma exposure, neighborhood safety, school environment, and family environment) to identify homogeneous subtypes. Depending on the subtyping resolution, results identified two or five subgroups, each characterized by distinct brain structure-environment profiles. Notably, more supportive caregiving and school environments were associated with greater myelination, whereas less supportive caregiving, higher family conflict and psychopathology, and higher perceived neighborhood safety were observed with greater cortical thickness. These subtypes were highly reproducible and predicted externalizing symptoms and overall mental health problems. Our findings support the theory that distinct environmental exposures are differentially associated with alterations in structural neurodevelopment. Delineating more precise associations between risk factors, protective factors, and brain development may inform approaches to enhance risk identification and optimize interventions targeting specific experiences.

Longitudinal changes in amygdala, hippocampus and cortisol development following early caregiving adversity

Although decades of research have shown associations between early caregiving adversity, stress physiology and limbic brain volume (e.g., amygdala, hippocampus), the developmental trajectories of these phenotypes are not well characterized. In the current study, we used an accelerated longitudinal design to assess the development of stress physiology, amygdala, and hippocampal volume following early institutional care. Previously Institutionalized (PI; N = 93) and comparison (COMP; N = 161) youth (ages 4–20 years old) completed 1–3 waves of data collection, each spaced approximately 2 years apart, for diurnal cortisol (N = 239) and structural MRI (N = 156). We observed a developmental shift in morning cortisol in the PI group, with blunted levels in childhood and heightened levels in late adolescence. PI history was associated with reduced hippocampal volume and reduced growth rate of the amygdala, resulting in smaller volumes by adolescence. Amygdala and hippocampal volumes were also prospectively associated with future morning cortisol in both groups. These results indicate that adversity-related physiological and neural phenotypes are not stationary during development but instead exhibit dynamic and interdependent changes from early childhood to early adulthood.

Beyond family-level adversities: Exploring the developmental timing of neighborhood disadvantage effects on the brain

A growing literature suggests that adversity is associated with later altered brain function, particularly within the corticolimbic system that supports emotion processing and salience detection (e.g., amygdala, prefrontal cortex [PFC]). Although neighborhood socioeconomic disadvantage has been shown to predict maladaptive behavioral outcomes, particularly for boys, most of the research linking adversity to corticolimbic function has focused on family-level adversities. Moreover, although animal models and studies of normative brain development suggest that there may be sensitive periods during which adversity exerts stronger effects on corticolimbic development, little prospective evidence exists in humans. Using two low-income samples of boys (n = 167; n = 77), Census-derived neighborhood disadvantage during early childhood, but not adolescence, was uniquely associated with greater amygdala, but not PFC, reactivity to ambiguous neutral faces in adolescence and young adulthood. These associations remained after accounting for several family-level adversities (e.g., low family income, harsh parenting), highlighting the independent and developmentally specific neural effects of the neighborhood context. Furthermore, in both samples, indicators measuring income and poverty status of neighbors were predictive of amygdala function, suggesting that neighborhood economic resources may be critical to brain development.

Characterizing the impact of adversity, abuse, and neglect on adolescent amygdala resting-state functional connectivity

Characterizing typologies of childhood adversity may inform the development of risk profiles and corresponding interventions aimed at mitigating its lifelong consequences. A neurobiological grounding of these typologies requires systematic comparisons of neural structure and function among individuals with different exposure histories. Using seed-to-whole brain analyses, this study examined associations between childhood adversity and amygdala resting-state functional connectivity (rs-fc) in adolescents aged 11–19 years across three independent studies (N = 223; 127 adversity group) in both general and dimensional models of adversity (comparing abuse and neglect). In a general model, adversity was associated with altered amygdala rs-fc with clusters within the left anterior lateral prefrontal cortex. In a dimensional model, abuse was associated with altered amygdala rs-fc within the orbitofrontal cortex, dorsal precuneus, posterior cingulate cortex, and dorsal anterior cingulate cortex/anterior mid-cingulate cortex, as well as within the dorsal attention, visual, and somatomotor networks. Neglect was associated with altered amygdala rs-fc with the hippocampus, supplementary motor cortex, temporoparietal junction, and regions within the dorsal attention network. Both general and dimensional models revealed unique regions, potentially reflecting pathways by which distinct histories of adversity may influence adolescent behavior, cognition, and psychopathology.

Violence exposure, affective style, and stress-induced changes in resting state functional connectivity

Chronic childhood stress is linked to greater susceptibility to internalizing disorders in adulthood. Specifically, chronic stress leads to changes in brain connectivity patterns, and, in turn, affects psychological functioning. Violence exposure, a chronic stressor, increases stress reactivity and disrupts emotion regulation processes. However, it is unclear to what extent violence exposure affects the neural circuitry underlying emotion regulation. Individual differences in affective style also moderate the impact of stress on psychological function and can thus alter the relationship between violence exposure and brain function. Resting-state functional connectivity (rsFC) is an index of intrinsic brain activity. Stress-induced changes in rsFC between the amygdala, hippocampus, and prefrontal cortex (PFC) are associated with emotion dysregulation and may elucidate how affective style modulates the relationship between violence exposure and brain connectivity. Therefore, the present study examined the impact of violence exposure and affective style on stress-induced changes in rsFC. Participants (n = 233) completed two 6-minute resting-state functional magnetic resonance imaging scans, one before (pre-stress) and one after (post-stress) a psychosocial stress task. The bilateral amygdala, hippocampus, and ventromedial prefrontal cortex (vmPFC) were used as seed regions for rsFC analyses. Significant stress-induced changes in the prefrontal, fronto-limbic, and parieto-limbic rsFC were observed. Further, pre-stress to post-stress differences in rsFC varied with violence exposure and affective style. These findings suggest that prefrontal, fronto-limbic, and parieto-limbic connectivity is associated with the emotional response to stress and provide new insight into the neural mechanisms through which affective style moderates the impact violence exposure has on the brain.

Reduced hippocampal and amygdala volume as a mechanism underlying stress sensitization to depression following childhood trauma

BACKGROUND

Stressful life events are more likely to trigger depression among individuals exposed to childhood adversity. However, the mechanisms underlying this stress sensitization remain largely unknown. Any such mechanism must be altered by childhood adversity and interact with recent stressful life events, magnifying their association with depression.

AIM

This study investigated whether reduced hippocampal and amygdala volume are potential mechanisms underlying stress sensitization following childhood violence exposure.

METHOD

A sample of 149 youth (aged 8-17 years), with (N = 75) and without (N = 74) exposure to physical abuse, sexual abuse, or domestic violence participated. Participants completed a structural MRI scan and assessments of depression. Approximately 2 years later, stressful life events were assessed along with depression symptoms in 120 participants (57 violence exposed).

RESULTS

Childhood violence exposure was associated with smaller hippocampal and amygdala volume. Stressful life events occurring during the follow-up period predicted worsening depression over time, and this association was magnified among those with smaller hippocampal and amygdala volumes. Significant moderated mediation models revealed the indirect effects of violence exposure on increasing depression over time through hippocampal and amygdala volumes, particularly among youths who experienced more stressful life events.

CONCLUSIONS

These results provide evidence for reduced hippocampal and amygdala volume as potential mechanisms of stress sensitization to depression following exposure to violence. More broadly, these patterns suggest that hippocampal and amygdala-mediated emotional and cognitive processes may confer vulnerability to stressful life events among children who have experienced violence.

Childhood socio-economic disadvantage predicts reduced myelin growth across adolescence and young adulthood

Socio-economic disadvantage increases exposure to life stressors. Animal research suggests early life stressors impact later neurodevelopment, including myelin developmental growth. To determine how early life disadvantage may affect myelin growth in adolescence and young adulthood, we analysed data from an accelerated longitudinal neuroimaging study measuring magnetisation transfer (MT), a myelin-sensitive marker, in 288 participants (149 female) between 14 and 25 years of age at baseline. We found that early life economic disadvantage before age 12, measured by a neighbourhood poverty index, was associated with slower myelin growth. This association was observed for magnetization transfer in cortical, subcortical and core white matter regions, and also in key subcortical nuclei. Participant IQ at baseline, alcohol use, body mass index, parental occupation and self-reported parenting quality did not account for these effects, but parental education did so partially. Specifically, positive parenting moderated the effect of socio-economic disadvantage in a protective manner. Thus, early socioeconomic disadvantage appears to alter myelin growth across adolescence. This finding has potential translational implications, including clarifying whether reducing socio-economic disadvantage during childhood, and increasing parental education and positive parenting, promote normal trajectories of brain development in economically disadvantaged contexts.