P3AR in preadolescence increases the odds of substance misuse or developing a SUD later in adolescence or young adulthood (Berman, Whipple, Fitch, & Noble, 1993; Habeych, et al., 2005; Hill, et al., 2009). In addition, P3AR in healthy 17-year olds is a risk factor for the subsequent development of SUDs at age 20 and 24 (Carlson, McLarnon, & Iacono, 2007; Iacono, et al., 2002). Monozygotic twins who are discordant for alcohol disorder in adolescence nevertheless show P3AR (Carlson, Iacono, & McGue, 2002). In fact, those twin pairs who are disorder-free at age 17 but who become discordant for subsequently developing a disorder have P3AR relative to twin pairs who remain healthy (Carlson, Iacono, & McGue, 2004).
