Differentiating Between Us & Them: Reduced In-Group Bias as a Novel Mechanism Linking Childhood Violence Exposure with Internalizing Psychopathology

Strong in-group bonds may promote mental health across development. Violence exposure influences social information processing biases and may also relate to social categorization processes. We examined associations of violence exposure with psychopathology and behavioral and neural indices of implicit and explicit in-group bias after minimal group assignment in children followed longitudinally across three time points from ages 5 to 10 years old (n = 101). In a pre-registered analysis, violence exposure was associated with lower implicit in-group bias, which in turn was associated prospectively with higher internalizing symptoms and mediated the longitudinal association between violence exposure and internalizing symptoms. Violence-exposed children did not exhibit the negative functional coupling between the left vmPFC and left amygdala when classifying in-group vs. out-group members that was observed in children without violence exposure. Reduced implicit bias for one’s in-group may represent a novel mechanism linking violence exposure with the development of internalizing symptoms.

Childhood violence exposure and social deprivation are linked to adolescent threat and reward neural function

Background Childhood adversity is, unfortunately, highly prevalent and strongly associated with later psychopathology. Recent theories posit that two dimensions of early adversity, threat and deprivation, have distinct effects on brain development. The current study evaluated whether violence exposure (threat) and social deprivation (deprivation) were associated with adolescent amygdala and ventral striatum activation, respectively, in a prospective, well-sampled, longitudinal cohort using a pre-registered, open science approach. Methods One hundred and sixty-seven adolescents from the Fragile Families and Child Wellbeing Study completed functional magnetic resonance imaging (fMRI) scanning. Prospective longitudinal data from ages 3, 5 and 9 years were used to create indices of childhood violence exposure and social deprivation. We evaluated whether these dimensions were associated with adolescent brain function in response to threatening and rewarding faces. Results Childhood violence exposure was associated with decreased amygdala habituation (i.e. more sustained activation) and activation to angry faces in adolescence, whereas childhood social deprivation was associated with decreased ventral striatum activation to happy faces in adolescence. These associations held when adjusting for the other dimension of adversity (e.g., adjusting for social deprivation when examining associations with violence exposure), the interaction of the two dimensions of adversity, gender, internalizing psychopathology, and current life stress. Conclusions Consistent with recent theories, different forms of early adversity were associated with region-specific differences in brain activation.

Reduced Hippocampal and Amygdala Volumes as Mechanisms of Stress Sensitization to Depression following Childhood Violence Exposure

OBJECTIVEStressful 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. This study investigated whether reduced hippocampal and amygdala volumes are mechanisms of stress sensitization following childhood violence exposure.METHODSA sample of 149 youth (aged 8-17 years), with (N=76) and without (N=73) exposure to physical abuse, sexual abuse, or domestic violence participated. Participants completed a structural MRI scan and were assessed for symptoms of depression. Approximately two years later, stressful life events were assessed along with depression symptoms in 120 participants (57 violence-exposed).RESULTSChildhood violence exposure was associated with smaller hippocampal and amygdala volumes. 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 indirect effects of violence exposure on increasing depression over time through hippocampal and amygdala volumes, particularly among youths who experienced more stressful life events.CONCLUSIONSThese results provide novel evidence for reduced hippocampal and amygdala volumes as mechanisms of stress sensitization to depression following exposure to violence. These findings suggest that hippocampal and amygdala-mediated emotional and cognitive processes may contribute to vulnerability to stressful life events following childhood violence exposure.

Sexual and Gender Minority Intimate Partner Violence and Childhood Violence Exposure

Limited research on female-assigned-at-birth sexual and gender minorities (FAB SGM) suggests that their risk of psychological, physical, and sexual intimate partner violence (IPV) victimization and perpetration may be linked to childhood violence exposure (CVE), such as experiencing child abuse, or witnessing sibling or interparental abuse. That said, there is a dearth of research in this population examining whether there is typically a violence type match between CVE and IPV (e.g., physical CVE predicting physical IPV), a gender match between those involved in CVE and later IPV (e.g., witnessing the abuse of female parents predicting IPV among women), or an increase in IPV risk commensurate with the number of different CVE types experienced. Addressing these gaps, this article draws on the baseline survey data of FAB400, a merged cohort accelerated longitudinal study of 488 FAB SGM adolescents and young adults. Analyses focused on the subsample of 457 participants with prior intimate relationship experience. Findings revealed that each assessed form of CVE—parental verbal abuse victimization, parental physical maltreatment victimization, childhood sexual abuse victimization, witnessing sibling abuse, and witnessing interparental violence—predicted risk of IPV perpetration and victimization, without evidence of violence type match. Witnessing interparental violence was associated with IPV irrespective of the abused parent’s gender. In addition, exposure to a greater number of forms of CVE was associated with an increased risk of all types of IPV victimization and perpetration. Results offer preliminary evidence that the intergenerational transmission of violence is an applicable framework for FAB SGM, and as such this should be considered when screening and intervening for childhood, family, and partner violence in this population. Suggestions for future directions are discussed.