Early Childhood Adverse Experiences, Inferior Frontal Gyrus Connectivity, and the Trajectory of Externalizing Psychopathology

Objective: Early adverse childhood experiences (ACEs) have been linked to the development of both internalizing and externalizing psychopathology. In our prior work, we found that ACEs predicted reductions in the volume of the inferior frontal gyrus (IFG), a brain region important for impulse control and emotion regulation. Here we tested the hypothesis that ACES might influence child behavioral outcomes through an impact on IFG functional connectivity, which may influence impulsive or risk-taking behavior. Method: We examined the effects of prospectively assessed ACEs on IFG connectivity in childhood, and their relationship to the trajectory of subsequent psychopathology from late school age and early adolescence, using data from an 11-year longitudinal study of children starting in preschool that included 3 waves of resting state functional connectivity across childhood and early adolescence. Results: ACEs predicted functional connectivity of both left and right IFG. Multi-level modeling of symptoms across 3 waves of assessments indicated that more ACEs predicted both internalizing and externalizing symptoms. However, altered IFG connectivity specifically predicted greater externalizing symptoms over time in middle childhood and early adolescence, as compared to internalizing symptoms. Longitudinal modeling indicating that the relationships between externalizing and functional connectivity were maintained across 3 waves of functional connectivity assessment. Conclusion: These findings underscore the relationship of ACEs to later psychopathology, and suggest that connectivity of the IFG, a region known to play an important role in impulse control and emotion regulation, may play a key role in the risk trajectory of ACEs to externalizing problems. However, further work is needed to understand whether these relationships reflect a direct effect of ACEs or whether ACEs are a marker for other environmental or genetic factors that may also influence brain development and behavior.