Figure 1: The pathway from drug use to addiction. Drug use often begins with social drug-taking and acute reinforcement, and often, but not always, escalates to compulsive use, leading then to dependence and withdrawal. During withdrawal
and abstinence, relapse to compulsive drug use is common. Many factors
including genetics, the environment, stress, and conditioning contribute to the vulnerability of entering this cycle of substance abuse and dependence (from Koob & Le Moal, 2006, with permission from Elsevier).