A genetic mouse model of helplessness sensitive to imipramine.

Lines of mice were selectively bred to diverge in their spontaneous helplessness in the tail suspension test. By the second generation of selection, only mice of the helpless line were sensitive to the antidepressant imipramine. Genetic factors substantially contribute to the susceptibility to helplessness in this mouse model. These selectively bred lines may represent potentially useful animal models to investigate behavioural, neurochemical and neuroendocrine correlates of antidepressant action.