Abstract

The timing of pubertal maturation has been associated with substance use in both boys and girls, but the exact mechanisms by which maturation influences substance use are unclear. Early maturing girls are more likely to initiate substance use at an early age compared to non-early maturers, while both early and late maturing boys appear to be at increased risk for substance use compared to on-time maturers. This study utilized an existing data set of over 1000 mostly at-risk children to examine moderators and mediators of the relation between pubertal maturation and initiation and use of cigarettes, alcohol, marijuana, and inhalants. This investigation focused on three domains–family, peer, and individual differences. The study: (1) examined initiation of substances in early maturing children and levels of substance use in early, on-time, and late maturing adolescents; (2) tested moderation of the association between pubertal timing and substance initiation by parental monitoring and quality of parent-child relationships; (3) tested mediation of the association between pubertal timing and substance initiation and use by affiliation with deviant peers, social competence, and athletic ability; and (4) examined gender differences in proposed moderator and mediator variables. Both early maturing boys and girls were more likely to try alcohol and cigarettes compared to non-early maturers. By adolescence, however, there were no significant differences between early, on-time, or late pubertal maturers and rates of substance use. Parental monitoring moderated the relation between early pubertal timing and alcohol initiation for boys and girls, and affiliation with deviant peers mediated the relation between early pubertal timing and cigarette and alcohol initiation for girls but not for boys. In addition, early maturing boys showed positive growth in social competence but early maturing girls showed negative growth in social competence over time, and higher social competence was associated with less affiliation with deviant peers for both boys and girls. Athletic competence was not associated with early pubertal timing for either sex. Knowledge of risk and protective factors associated with off-time maturation can aid in identifying populations at risk of early substance initiation and use and can help target and refine prevention programs.