An epigenetic modification that occurs in a major cell type in the brain’s reward circuitry controls how stress early in life increases susceptibility to additional stress in adulthood, researchers at the Icahn School of Medicine at Mount Sinai have learned. In a study in Nature Neuroscience, the team also reported that a small-molecule inhibitor of the enzyme responsible for this modification, currently being developed as an anti-cancer drug, was able to reverse increased vulnerability to lifelong stress in animal models.