The likelihood of developing an addictive disorder is a function of multiple simultaneous, pharmacologic, genetic, and environmental variables, such as the pharmacology of the drug, the route of administration, the personality of the individual, and the availability of the drug. There is increasing evidence that long-lasting changes in the brain result from the progression of casual user to addict. Moreover, the course of the progression of addiction is similar to that of other chronic diseases. In this paper, strategies for effective treatment of addiction, including long-term relapse management and new pharmacological therapies such as naltrexone and acamprosate, are discussed.