Alcohol and drug use disorders, often referred to as substance use disorders, are chronic and frequently require multiple episodes of treatment. These conditions are prevalent in the United States. According to the Substance Abuse and Mental Health Services Administration, an estimated 22.6 million people in 2006 were affected by substance use disorders, but national data analyzed by Emily Cohen and colleagues estimate that only about 15% of the general population that experiences alcohol abuse or dependence in their lifetime ever seeks treatment or attends support groups. Although individuals with substance use disorders may recover on their own, a concept known as natural recovery, Cohen and colleagues found that those who receive treatment tend to experience better substance use and lifestyle outcomes compared with individuals who ...