Animal models as simulations of depression.

The most familiar usage of animal models of depression is as antidepressant screening tests. Paul Willner reviews their usage in a different context--as simulations of depression. The behavioural features of animal models of depression are compared with clinical symptomatology, and the contribution of animal models to understanding the following aspects of depression are reviewed: sources of population variability, natural history, psychological aspects, symptomatology and mechanisms of antidepressant action. Finally, the role of animal models of depression is considered as a critical interface between basic behavioural neuroscience and the clinic.