In a fast-fail trial of aticaprant (see Table 1 for aliases) for the treatment of anhedonia, it was found that KOR antagonism reduced anhedonia as measured by ventral striatal activation to reward-predicting cues, reward learning, and self-report of the symptom (notably without reducing overall depression levels) [13, 14]. The gene discussed is OPRK1; the disease is depressive symptom measurement.