Developmental trade-offs following early life stress: Assessing the cost of accelerated maturation in emotion regulation circuitry

Abstract

Experiences of early life stress begin a developmental cascade that alters a number of stress biology systems. These physiological stress systems interact with atypical early environments to shape the development of crucial brain systems in the context of early life stress. Among the differences in brain development following early life stress are decreased cortical volume, blunted activity in the ventral striatum, and increased amygdala activity to negative images following early institutional care and childhood maltreatment (Goff et al., 2013; Hodel et al., 2018; Tottenham et al., 2011). Further, previous research has reported accelerated maturation of the functional connectivity of the amygdala – medial prefrontal cortex emotion regulation circuit following early life stress (Gee et al., 2013). Differences in behavior have also been reported, including lower executive function scores, increased impulsivity, and difficulty with risky-decision making following childhood maltreatment and institutional care (Cowell et al., 2015; Herzberg et al., 2018). The studies in this dissertation investigated the possibility of a developmental trade-off between emotion circuitry and higher-order cognition circuits underlying the behaviors known to be affected by early life stress. Two studies, one studying youth adopted from international institutions and another examining adults with prospectively assessed histories of childhood maltreatment, investigated the possibility of a developmental trade-off. Results indicated more mature patterns of amygdala – medial prefrontal cortex functional connectivity in adopted compared to non-adopted youth, consistent with previous research. Further, group differences in the within-system connectivity of the dorsal attention network were found. In contrast, no group differences were evident between adults with childhood maltreatment histories compared to those without. There was however, a significant relationship between adaptive behavior functioning in adulthood and variance in community size, a whole-brain measure of resting-state network maturity. Measures of functional connectivity were significant predictors of behavioral function in both samples. Taken together, the results of these studies do not support the notion of a developmental trade-off in resting-state functional connectivity following early life stress. Future research using longitudinal imaging designs is needed to extend this work and to fully address the question of a developmental trade-off following early adversity.