Consistent with hypotheses, parental knowledge had a stronger relationship to substance use for middle school students than high school students, particularly for other drugs and any drugs. This finding is consistent with research that suggests parental knowledge may be effective in influencing substance use during early adolescence but that as adolescent autonomy increases, other strategies for parents to obtain knowledge of adolescent activities, whereabouts, and associations may become more effective (Darling, Cumsille, Caldwell, & Dowdy, 2006; McElhaney et al., 2008). Some research has shown that among older adolescents, parent-child communication and adolescent self-disclosure may be more effective in obtaining such information (Borawski et al., 2003; Stattin & Kerr, 2000; Soenens et al., 2006).
