Unique neurobiology during the sensitive period for attachment produces distinctive infant trauma processing

BACKGROUND: Trauma has neurobehavioral effects when experienced at any stage of development, but trauma experienced in early life has unique neurobehavioral outcomes related to later life psychiatric sequelae. Recent evidence has further highlighted the context of infant trauma as a critical variable in determining its immediate and enduring consequences. Trauma experienced from an attachment figure, such as occurs in cases of caregiver child maltreatment, is particularly detrimental. METHODS: Using data primarily from rodent models, we review the literature on the interaction between trauma and attachment in early life, which highlights the role of the caregiver’s presence in engagement of attachment brain circuitry and suppressing threat processing by the amygdala. We then consider how trauma with and without the caregiver produces long-term changes in emotionality and behavior, and suggest that these experiences initiate distinct pathways to pathology. RESULTS: Together these data suggest that infant trauma processing and its enduring effects are impacted by both the immaturity of brain areas for processing trauma and the unique functioning of the early-life brain, which is biased toward processing information within the attachment circuitry. CONCLUSION: An understanding of developmental differences in trauma processing as well as the critical role of the caregiver in further altering early life brain processing of trauma is important for developing age-relevant treatment and interventions. HIGHLIGHTS OF THIS ARTICLE: Trauma experienced in early life has been linked with life-long outcomes for mental health through a mechanism that remains unclear. Trauma experienced in the presence of a caregiver has unique consequences. The infant brain is predisposed toward processing information using attachment circuitry rather than threat circuitry. Data from rodent models suggest that repeated trauma in the presence of a caregiver prematurely engages brain areas important for threat, which may play a role in deleterious outcome.