Investigating Associations Between Early Life Stress, Neural Response to Reward, and Depression

The link between exposure to early life stress (ELS), such as child maltreatment, and the development of depression has been well-replicated. However, the mechanisms that underlie this connection remain poorly understood. One potential mechanism may be neural alterations in reward-related brain regions, such as the ventral striatum and sub-regions of the prefrontal cortex. Recent research indicates that exposure to child maltreatment is associated with aberrant reward-related brain activity. A separate body of work implicates similar reward-related neural alterations in the etiology and maintenance of depression. The current study investigated whether altered neural response to reward plays a mechanistic role in explaining the association between ELS and depression. Here, we examined associations between history of child maltreatment, depressive symptoms, and neural response to reward during a reward processing fMRI task in a sample of adult men (N = 165; 30.5% White, 60.6% Black) who were a part of the Pittsburgh Youth Study (PYS), a longitudinal study examining the development of negative mental health outcomes. History of child maltreatment was assessed via referrals prior to age 18 from the Allegheny County’s Office of Children, Youth, and Families. Neuroimaging data and self-reported depressive symptoms were collected in adulthood (M age = 32.64, SD age = 3.62). Child maltreatment significantly predicted greater depressive symptoms. Child maltreatment and depressive symptoms were, however, not significantly associated with altered neural response to reward. Findings from the current study suggest directions for future work probing characteristics of adversity (e.g., chronicity, timing), as well as specific factors likely to moderate neural responses to reward (e.g., reward phase, magnitude of gains)