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Pre-frontal limbic circuitry is vulnerable to effects of stress and injury. We examined microstructure of pre-frontal limbic circuitry after traumatic brain injury (TBI) or extracranial injury (EI) and its relation to post-traumatic stress symptoms (PTSS). Participants aged 8 to 15 years who sustained mild to severe TBI (n = 53) or EI (n = 26) in motor vehicle incidents were compared with healthy children (n = 38) in a prospective longitudinal study. At the seven-week follow-up, diffusion tensor imaging was obtained in all groups; injured children completed PTSS ratings using a validated scale. Using probabilistic diffusion tensor tractography, pathways were seeded from bilateral amygdalae and hippocampi to estimate the trajectory of white matter connecting them to each other and to targeted pre-frontal cortical (PFC) regions. Microstructure was estimated using fractional anisotropy (FA) in white matter and mean diffusivity (MD) in gray matter. Prefrontal limbic microstructure was similar across groups, except for reduced FA in the right hippocampus to orbital PFC pathway in the injured versus healthy group. We examined microstructure of components of pre-frontal limbic circuitry with concurrently obtained PTSS cluster scores in the injured children. Neither microstructure nor PTSS scores differed significantly in the TBI and EI groups. Across PTSS factors, specific symptom clusters were related positively to higher FA and MD. Higher hyperarousal, avoidance, and re-experiencing symptoms were associated with higher FA in amygdala to pre-frontal and hippocampus to amygdala pathways. Higher hippocampal MD had a central role in hyperarousal and emotional numbing symptoms. Age moderated the relation of white and gray matter microstructure with hyperarousal scores. Our findings are consistent with models of traumatic stress that implicate disrupted top-down PFC and hippocampal moderation of overreactive subcortical threat arousal systems. Alterations in limbic pre-frontal circuitry and PTSS place children with either brain or body injuries at elevated risk for both current and future psychological health problems.

Children with both types of traumatic injury demonstrated higher SD and internalizing problems than healthy children. Internalizing problems occurring either prior to or following pediatric injury may be a risk factor for posttraumatic SD. Consequently, internalizing problems may be a promising target of intervention to improve both SD and related adjustment concerns. (PsycINFO Database Record

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This longitudinal study examined the psychosocial adjustment of adolescents who affiliate with antisocial crowds in a gang-impacted urban environment. We followed 405 adolescents (219 boys, 186 girls; average age of 11.51 years, SD = .61; 84% Latino, 9% Asian, and 7% other or unclassified) for one academic year. These youth attended a middle school located in an economically distressed neighborhood with documented high rates of gang violence. We assessed crowd membership with a structured focus group procedure. In addition, we administered a peer nomination inventory to assess aggression and social standing, obtained self-reports of depressive symptoms, and derived grade point averages (GPA) directly from school records. Adolescents used gang-related imagery to describe antisocial crowds in their school, referring to "cholos" and "taggers." Membership in these crowds was associated with aggression and low GPA but, paradoxically, predicted small decreases in depression and increases in popularity over time. Taken together, our results highlight the complex role of affiliations with antisocial crowds in high-risk settings.