Models of Affective Illness: Forced Swimming and Tail Suspension Tests in Rodents

Abstract Rodents forced to swim in a narrow space from which there is no escape adopt, after an initial period of vigorous activity, a characteristic immobile posture, moving only when necessary to keep their heads above the water. The animals immobility was hypothesized to show they had learned that escape was impossible and had given up hope. Immobility was therefore given the name behavioral despair. It was subsequently found that immobility could be reduced by a wide range of clinically active antidepressant drugs. This simple behavioral procedure has since become a widely used test for screening novel antidepressants. Rodents forced to swim in a narrow space from which there is no escape adopt, after an initial period of vigorous activity.