Substance abuse and addiction pose a worldwide threat to public health and have a devastating social and economic impact on individuals and their families. The World Health Organization (144) has estimated that there are 2 billion alcohol users, 1.3 billion tobacco users, and 185 million illicit drug users worldwide. In the 2010 National Survey on Drug Use and Health conducted by the Substance Abuse and Mental Health Administration (SAMHSA) (119a), 51.8% of Americans aged 12 or older (131.3 million people) reported being current drinkers of alcohol, and 23.1% reported participating in binge drinking (defined as having five or more drinks on the same occasion on at least 1 day in the 30 days prior to the survey). The World Health Organization (143) has also estimated that approximately 20%–30% of esophageal cancer, liver cancer, cirrhosis of the liver, homicide, epilepsy, and motor vehicle accidents worldwide result from the harmful use of alcohol.
