Abstract Cocaine and amphetamine-regulated transcript (CART) peptide has been established as a contributor to anxiogenic behavior. Genetic mutations in the CART gene are associated with anxiety and depression, and increased CART expression has been reported in suicide victims. Extensive research has focused on the role of CART peptide in mesolimbic neurocircuitry, but its involvement in the dorsal raphe nucleus (DRN) and serotonin (5HT) system remains unexplored.