Rationale: Among all animal models, the forced swimming test (FST) remains one of the most used tools for screening antidepressants.
Objective: This paper reviews some of the main aspects of the FST in mice. Most of the sensitivity and variability factors that were assessed on the FST are summarized.
Mechanisms: We have summarized data found in the literature of antidepressant effects on the FST in mice. From this data set, we have extrapolated information on baseline levels of strain, and sensitivity against antidepressants.
Results: We have shown that many parameters have to be considered in this test to gain good reliability. Moreover, there was a fundamental inter-strain difference of response in the FST.
Conclusions: The FST is a good screening tool with good reliability and predictive validity. Strain is one of the most important parameters to consider. Swiss and NMRI mice can be used to discriminate the mechanisms of action of drugs. CD-1 seems to be the most useful strain for screening purposes, but this needs to be confirmed with some spontaneous locomotor activity studies.