CONCLUSION: We hypothesize that estrogen replacement will (1) increase cognitive flexibility, reward responsiveness, and delay discounting, and (2) reduce ED pathology; and (3) 8-week changes in cognitive flexibility, reward responsiveness, and delay discounting will mediate 12-week changes in ED pathology. These data will systematically probe the role of estrogen in key neurocognitive features associated with poor ED outcomes to guide development of novel interventions for this population.