Abstract
A vast challenge within neuropsychiatric research has been the development of animal models that accurately reflect symptoms associated with affective disorders. An ethologically valid model that has been shown to be effective in studying depression is the chronic social defeat stress model. In this model, C57BL/6J mice are subjected to chronic social defeat stress induced by CD-1 aggressor mice for 10 consecutive days. Discussed here is a protocol describing the screening process of the CD-1 aggressor mice, the confrontations between the C57BL/6J and CD-1 aggressor mice, and analysis of social avoidance scores as an indication of depression-like behaviors.