Contributions of childhood abuse and neglect to reward neural substrates in adolescence

Abstract

Background: Childhood adverse experiences may come to bear particularly during adolescence, when neural reward systems are developing rapidly and psychopathology spikes. Despite prior work differentiating threat- (abuse) vs. deprivation- (neglect) related adversity, no research has yet identified their relative nor interactive contributions to reward neural substrates during adolescence. In the present study, we leveraged a diverse sample of adolescents with different childhood adversity profiles to examine neural responses to reward in relation to varying degrees of abuse vs. neglect.

Methods: Adolescents (N = 45; 23 females; mean age = 14.9 years, SD = 1.9) completed a child-friendly monetary incentive delay task during fMRI acquisition. The self-report Childhood Trauma Questionnaire assessed childhood abuse and neglect. Whole brain ANCOVA analyses evaluated reward anticipation (reward vs. no reward expected) and feedback (hitting vs. missing the target with a reward vs. no reward) in relation to abuse and neglect dimensions.

Results: Whole-brain analyses revealed that abuse, adjusted for neglect, is associated with greater differences between task conditions (reward vs. no reward, hit vs. miss) in regions associated with threat/emotion regulation (prefrontal and temporal cortices, as well as posterior regions including fusiform and posterior cingulate/precuneus). Additionally, level of neglect modulated neural response associated with abuse in prefrontal and temporoparietal regions, such that youths with high levels of both abuse and neglect showed qualitatively different, more exaggerated neural patterns compared to youths with elevated adversity in only one dimension.

Conclusions: Our findings suggest that early experiences of abuse and neglect have a long developmental reach resulting in reward-related neural alterations in adolescence. Moreover, our results bolster theoretical conceptualizations of adversity along threat and deprivation dimensions and provide evidence that "adding up" adverse life events may not be sufficient to capture the qualitatively different neural profiles produced by differing combinations of types of adversity, which may in turn necessitate different treatment approaches.

Keywords: Abuse; Adverse childhood experiences; Functional MRI; Neglect; Reward.