Significance Although mutations in the neuroligin-3 and neuroligin-4 genes are implicated in autism syndromes, very little is known about the contribution of neuroligin-2 to neuropsychiatric disease states. We report a decrease in neuroligin-2 gene expression in the postmortem nucleus accumbens (NAc) of depressed patients. Reverse translation of this finding in chronic social defeat stress, an animal model of depression that enables investigation of both susceptibility and resiliency mechanisms, uncovers an important functional role for NAc neuroligin-2 in stress susceptibility. We detail a cell-type-specific role for NAc neuroligin-2 in modulating social avoidance behavior and dominance behaviors important for resiliency. Together, these findings describe a role for NAc neuroligin-2 in depression and chronic stress behaviors.