Substance abuse/dependence remains a serious worldwide problem. The estimated annual U.S. economic cost of substance abuse is more than $414 billion. In the United States, 18% of the population experiences a substance use disorder at some point in life. Furthermore, an average of 20% of patients in general medical facilities and 35% in general psychiatric units present with substance use disorders, and in some settings, the percentage is much higher. Although the sequelae of addiction—such as cirrhosis, psychopathology, trauma, and infection—generally receive proper medical attention, patients' primary addictive problems often go untreated.