Figure 1.

Animal models of depression exhibiting female vulnerability A. Social instability stress (SIS) is based on experiencing an unstable social hierarchy. The animal is exposed to novel cagemates or sometimes isolated. B. Chronic unpredictable mild stress (CUMS) is composed of numerous types of stressors. The stressor types and durations vary. The stressors include food or water restriction, temperature stress (e.g. heat, cold), disturbance of housing (e.g. cage shaking or tilting, lighting), and direct physical stress (e.g. tail suspension or restraint). C. Subchronic variable stress (SCVS) shows prominent female specificity in depression. This paradigm consists of footshock, tail suspension, and restraint, and is repeated twice.