Utilizing rewards to dampen fear and its recovery.

Fearful memories can be extinguished by repeated exposure, without aversive outcomes. Fear extinction as the basis for exposure therapy, is a common treatment for anxiety and fear-related disorders, but it can be unpleasant and does not always work. In two independent studies, we investigated whether a novel compound extinction procedure (simultaneous presentation of a rewarded and a feared stimulus, reward-fear deepened extinction) attenuates fear while tracking physiological, neural and subjective changes in pleasantness. The reward-fear deepened extinction showed comparable effects to the fear-fear deepened extinction (two-fear compound extinction) in effectively enhancing fear extinction and protecting against the return of fear 1 week later. Moreover, fear extinction accompanying a reward cue was perceived as more pleasant. On the neural level, we identified a network involving hippocampus and amygdala that underlies the benefit of deepened extinction, where connectivity changes also predicted changes in subjective pleasantness. Our study identifies the effects of deepened extinction in regulating long-term fear recovery and its underlying neural mechanism. We shed light on an innovative method to enhance fear extinction, with high translational potential for therapy.