legally sanctioned only for adults in the United States, the onset of alcohol and nicotine dependence is concentrated in adolescence and young adulthood and does not increase with increasing age beyond the early 20’s (Grant et al, 2004), and imaging studies show that the human brain areas involved in judgment and self-control do not reach their adult form until the early 20’s (Lenroot and Giedd, 2006; Crews et al 2007). However, the results of experimental studies using animal models are mixed, with some studies finding significant long-term effects of adolescent exposure on voluntary consumption of alcohol in adulthood (e.g., Barron et al 2005, and Pautassi et al 2008), and other studies finding no effect (Vetter 2007, Tambour et al 2008).
