Increased activation of the fear neurocircuitry in children exposed to violence

Abstract

Most studies investigating the effect of childhood trauma on the brain are retrospective and mainly focus on maltreatment, whereas different types of trauma exposure such as growing up in a violent neighborhood, as well as developmental stage, could have differential effects on brain structure and function. The current magnetic resonance imaging study assessed the effect of trauma exposure broadly and violence exposure more specifically, as well as developmental stage on the fear neurocircuitry in 8‐ to 14‐year‐old children and adolescents (N = 69). We observed reduced hippocampal and increased amygdala volume with increasing levels of trauma exposure. Second, higher levels of violence exposure were associated with increased activation in the amygdala, hippocampus, and ventromedial prefrontal cortex during emotional response inhibition. This association was specifically observed in children younger than 10 years. Finally, increased functional connectivity between the amygdala and brainstem was associated with higher levels of violence exposure. Based on the current findings, it could be hypothesized that trauma exposure during childhood results in structural changes that are associated with later risk for psychiatric disorders. At the same time, it could be postulated that growing up in an unsafe environment leads the brain to functionally adapt to this situation in a way that promotes survival, where the long‐term costs or consequences of these adaptations are largely unknown and an area for future investigations.

Migration‐related trauma and mental health among migrant children emigrating from Mexico and Central America to the United States: Effects on developmental neurobiology and implications for policy

“…Extensive literature suggests numerous deleterious consequences of exposure to trauma early in life on psychological well-being throughout the life span (Friis et al, 2002;Gibb et al, 2007;Horowitz et al, 1995;Reading, 2006). Specifically, exposure to traumatic events-such as those frequently experienced by migrant and refugee children prior to migration-places children at increased risk for developing both immediate and long-term psychiatric symptoms (Shonkoff et al, 2012), including posttraumatic stress disorder (PTSD; Dunn et al, 2017;Friis et al, 2002;Gibb et al, 2007;Horowitz et al, 1995;McLaughlin et al, 2010;Norman et al, 2012;Reading, 2006;van Rooij et al, 2020;Widom et al, 2007). Many of the aforementioned pre-migration experiences satisfy Criterion A of the DSM-5's definition of PTSD, meaning that these events are eligible to be considered as the precipitating event for the development of PTSD (American Psychiatric Association, 2013).…”

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

“…Similar to other areas of mental health research ( Fair et al, 2012 ; Feczko and Fair, 2020 ), investigators began their initial inquiries into understanding the neurobiological consequences of childhood adversity via direct comparisons between those with and without specific exposures (case vs control; e.g., Bremner et al, 1997 ; De Bellis et al, 1999 ; Stein et al, 1997 ). Some analyses further differentiated between subtypes of adversity by examining them in separate models (e.g., Edmiston et al, 2011 ; Gheorghe et al, 2020 ; van Rooij et al, 2019 ), while others turned to cumulative risk models tallying the total number of distinct exposures ( Evans et al, 2013 ). Although historically common, these approaches may fail to account for co-occurrence among exposures and/or assume that diverse types of adverse exposures affect development identically.…”

Neural correlates of emotional reactivity and regulation in traumatized North Korean refugees

“…In support of this idea, previous research has shown that increased emotional responses to negative stimuli contribute to increased demands for regulation of emotional distress [ 52 ]. Children with high levels of violence exposure also showed greater subcortical (i.e., amygdala and hippocampus) and prefrontal cortical (i.e., ventromedial PFC) activation during response inhibition [ 53 ]. Similar to NK refugees with trauma exposure, children exposed to violence may make more effort (e.g., increased attention) to inhibit inappropriate responses, possibly due to increased emotional vigilance and memory associated with negative information (e.g., fearful faces).…”