Neural mechanisms of reward processing in adolescent irritability.

Abstract

Irritability is impairing and prevalent across pediatric psychiatric disorders and typical development, yet its neural mechanisms are largely unknown. This study evaluated the relation between adolescent irritability and reward-related brain function as a candidate neural mechanism. Adolescents from intervention-seeking families in the community (N=52; mean age=13.80, SD=1.94) completed a monetary incentive delay task to assess reward anticipation and feedback (reward receipt and omission) during fMRI acquisition. Whole-brain analyses, controlling for age, examined brain activation and striatal and amygdala connectivity in relation to irritability. Irritability was measured using the parent- and youth-reported Affective Reactivity Index. Irritability was associated with altered reward processing-related activation and connectivity in multiple networks during reward anticipation and feedback, including increased striatal activation and altered ventral striatum connectivity with prefrontal areas. Our findings suggest that irritability is associated with altered neural patterns during reward processing and that aberrant prefrontal cortex-mediated top-down control may be related to irritability. These findings inform our understanding of the etiology of youth irritability and the development of mechanism-based interventions.