Neural interactions between reward and inhibition in preadolescent irritability: a dual-task design

Aberrant reward and inhibitory control processing have been implicated in mechanistic models of irritability theorizing that better inhibitory control may be an effective modulator of exaggerated reward responses and thus, irritable behavior. Despite emerging research supporting the roles of both inhibition and reward independently in irritability, research has yet to examine the interplay of neural networks subserving these processes. Leveraging fMRI baseline data from the Adolescent Brain Cognitive Development Study (N = 4664, M_age = 9.98, SD_age = 0.62), interactions between preadolescent irritability, inhibitory control, and reward processing were examined. The stop signal task and monetary incentive delay task were used to probe inhibitory control (successful and failed) and reward (receipt/non-receipt of possible reward), respectively. Neural activation and functional connectivity with amygdala and ventral striatal regions were explored through whole brain analyses. Preadolescents with higher levels of irritability exhibited aberrant associations in activation as well as ventral striatal connectivity during successful and failed inhibitory control and reward receipt. While exact patterns varied by region, these interactions were largely driven by (1) opposite patterns of activation/connectivity across reward conditions or (2) stronger associations between inhibition and reward non-receipt in preadolescents with higher levels of irritability. This study observed inhibitory control and reward processing functional differences within the same neural networks, supporting the previously theorized interplay of hypersensitive bottom-up reward processing and deficient top-down inhibitory control in youth irritability. Understanding this interplay is essential to develop targeted preadolescent irritability interventions that enhance inhibitory control and mitigate exaggerated reward responses.