In addition to suicidal behavior, adolescence is also the developmental period when drug experimentation frequently occurs, often progressing to substance dependence and substance-related problems. Estimates from a recent community-based survey of adolescents (12–17 year olds) indicated that 33% (more than 8 million) reported alcohol use, 20% (nearly 5 million) reported illicit substance use, and 17% (nearly 4 million) reported cigarette use during the past year (National Survey on Drug Use and Health, SAMHSA, OAS, 2007). Furthermore, self-reported use of alcohol, cigarettes, or other drug use increases systematically during adolescence (see Fig. 1). Risk for substance dependence is elevated for: alcohol between 15 and 35 years old (peaking at about age 20); marijuana between 15 and 25 years old (peaking at age 17); and cocaine between 15 and 30 (Wagner and Anthony, 2002). Early drug experimentation predicts later development of regular substance use, substance-use disorders, and substance-related problems (Anthony and Petronis, 1995; de Wit et al. 2000; Fergusson et al. 1996). Furthermore, substance use during adolescence may produce long-term negative effects on neurocognitive and behavior functioning (Ehrenreich et al. 1999; Schneider
