Reward system function stabilizes positive affect to foster resilience

A well-functioning reward system has been proposed to buffer the adverse effects of stress on mental health and thereby play a crucial role in stress resilience. However, empirical evidence linking reward processing to resilience remains indirect, as research to date has lacked prospective longitudinal mental health assessments and failed to control for interindividual variability in severity of stressor exposure. In a longitudinal study of at-risk individuals (N=230), we assessed reward system function at the neural level and in real life, while monitoring mental health and stressor exposure over time. Greater ventromedial prefrontal cortex (vmPFC) activity during reward outcome and higher positive affect predicted higher stress resilience, whereas greater real-life positive affective reactivity predicted lower resilience. Crucially, blunted positive affective reactivity mediated the vmPFC association with higher resilience. These findings suggest that a well-functioning reward system buffers the negative impact of stress by promoting emotional stability in response to pleasant experiences.