These results suggest that the differential persistent anhedonic response to psychosocial stress may be mediated by ventral tegmental area signaling molecules independent of brain-derived neurotrophic factor and indicate that greater stress-induced anhedonia is associated with resistance to antidepressant treatment. Consideration of these behavioral and neurobiological factors associated with resistance to stress and antidepressant action may promote the discovery of novel targets to treat stress-related mood disorders.