The Impact of Early Life Adversity on Neural Reward Reactivity in Early Childhood

Early Life Adversity (ELA), defined as childhood experiences which require significant adaptation beyond the child’s developmental stage, is of critical concern, as it is predictive of increased risk for the leading causes of morbidity and increased severity, chronicity, and overall risk for psychiatric disorders. Dysfunction in neural reward systems may represent a mechanism through which ELA increases risk for later psychopathology; however, few studies have examined the proximal impact of ELA on reward processing in early childhood, prior to periods of enhanced risk for psychopathology onset. Conceptual models suggest that different forms of ELA may differentially impact neural reactivity, and indeed, studies find that exposure to deprivation, such as neglect, may be more strongly tied to blunted reward processing than experiences of threat to one’s safety. The reward positivity (RewP) is an event-related potential component which indexes neural reward responsiveness. Preliminary evidence indicates support for dysregulated processing styles (i.e., reduced RewP) related to greater ELA exposure; however, this relationship has been relatively unexamined in children. In addition, decomposition of the RewP into frequency (i.e., delta, theta) rather than time-domain represents an innovative, novel method for enhancing nuanced understanding of the targeted influence of ELA on neuroaffective processing. The current study examined relations between ELA composites, including threat and deprivation dimensions, with RewP and underlying delta activity from 350-425 at a pooling of frontal, central, and parietal electrodes in 80 5–6-year-old children, half of which were risk-enriched through maternal depression history. Linear regressions examining the relation between ELA composites and RewP and underlying delta demonstrated that ELA composites were not significantly related to neural reward processing. Moderation by parenting styles was explored, which revealed that parenting styles did not exert interactive effects with ELA on reward processing. In exploratory analyses, current maternal depression symptoms moderated the relation between deprivation and RewP, such that youth with higher maternal depression symptoms and greater deprivation exposure demonstrated more blunted reward reactivity. Taken together, these results suggest that ELA composites alone are not significantly related to reward reactivity in early childhood. However, maternal depression symptoms may be among several factors that moderate ELA and reward reactivity relations, indicating a subgroup of youth at enhanced risk for reward processing alterations in association with adverse childhood experiences. Further research could help to identify youth at highest risk for reward processing alterations and to inform which youth may benefit most from interventions targeting enhancing positive valence system functioning.