Reward dysregulation following early-life adversity: pathways to externalising behaviours

• Early-life adversity is linked to blunted reward sensitivity and internalising behaviours • Externalising behaviours following early-life adversity are associated with both a blunted and a heightened sensitivity to reward • Affective state and regulation consistently interact with reward sensitivity • A mood-related reward dysregulation could underlie the pathway from early-life adversity to externalising behaviours Early-life adversity (ELA) has long-lasting effects on mental health by disrupting the neurodevelopment of key pathways, including reward-related circuitry. While ELA is often linked to blunted reward sensitivity and internalising disorders, empirical evidence identifies both hyposensitivity and hypersensitivity to reward in association with externalising behaviours. These contradictory findings complicate our understanding of how ELA shapes reward processes. We systematically reviewed studies examining ELA, reward sensitivity, and externalising behaviours. Amongst 34 studies, near-equal evidence supported hyposensitivity (n = 12) and hypersensitivity (n = 12) to reward in individuals with a history of ELA. Additionally, reviewed studies highlighted mood and emotion regulation as potential modulators of reward responses. We propose a mood-related reward dysregulation model, where ELA disrupts mood-related processes that dynamically determine the direction of reward sensitivity. This framework reconciles inconsistent findings and suggests that reward dysregulation following ELA is context-dependent rather than fixed. Testing this model could refine theoretical frameworks to understand trauma-related psychopathology and guide interventions targeting reward dysregulation in mood and externalising disorders.