Can be used to test the effect of SSRIs and tricyclic antidepressants and to idenify new drugs with potential anyidepressant acitvity.

The test is based on the assumption that an animal will try to escape an aversive (stressful) stimulus. If escape is impossible, the animal eventually stops trying and gives up. In the forced swim test (FST), the animal is placed in a cylindrical container filled with water from which it cannot escape. Most animals will attempt to escape by actively swimming. When the animal stops swimming and starts to float on the surface of the water it is considered to have “given up”. An animal that gives up relatively quickly is thought to be displaying characteristics similar to human depression. Antidepressants reduce passivity, increase swimming time and/or escape-related climbing activity.

This model is not suitable for animals with motor deficiencies which cause difficulties in swimming.