Two psychiatric interviews of a 39-year old female with congenital leptin deficiency were conducted to define psychological changes 14 and 165 days after initiation of treatment with human recombinant leptin (metreleptin). The most pronounced initial experience related to the reduced preoccupation with food. An improved mood was reported by the patient, which she associated with this reduced preoccupation. Her mood remained elevated upon recontact, whereas she was no longer preoccupied with food. Overall, the interviews provide a vivid account of the subjective experiences upon the initiation of treatment. Some of the findings bear a resemblance to those reported recently in patients with anorexia nervosa who were treated with metreleptin for 1-3 weeks. This case report provides further evidence that metreleptin has strong psychopharmacological effects in patients with absolute or relative leptin deficiency. We strongly recommend profound psychological examinations of patients with congenital leptin deficiency at baseline and after intitiation of treatment with human recombinant leptin to gain further insight into the functions affected by this hormone.