Addicted Rats

Abstract
What accounts for the transition from drug use to drug addiction, and why are some individuals more susceptible to this transition than others? Answers to these questions are crucial for understanding the addiction of some individuals to drugs of abuse, but they have been difficult to address because the available animal models are insufficiently realistic. In a Perspective, Robinson discusses complementary studies ( Deroche-Gamonet et al.; Vanderschuren and Everitt) in which a realistic rat model has been developed that should help to unravel the psychology and neurobiology of human addiction.