Published online by Cambridge University Press: 20 April 2017
Early maturation, indexed by pubertal development (PD), has been associated with earlier initiation and greater frequency of adolescent substance use, but this relationship may be biased by confounding factors and effects that change across development. Using a population-based Finnish twin sample (N = 3,632 individuals), we conducted twin modeling and multilevel structural equation modeling of the relationship between PD and substance use at ages 12–22. Shared environmental factors contributed to early PD and heavier substance use for females. Biological father absence was associated with early PD for boys but not girls, and did not account for the relationship between PD and substance use. The association between early PD and heavier substance use was partially due to between-family confounds, although early PD appeared to qualitatively alter long-term trajectories for some substances (nicotine), but not others (alcohol). Mediation by peer and parental factors did not explain this relationship within families. However, higher peer substance use and lower parental monitoring were themselves associated with heavier substance use, strengthening the existing evidence for these factors as targets for prevention/intervention efforts. Early maturation was not supported as a robust determinant of alcohol use trajectories in adolescence and young adulthood, but may require longer term follow-up. Subtle effects of early PD on nicotine and illicit drug use trajectories throughout adolescence and adulthood merit further investigation.
Jeanne E. Savage is supported by Award T32MH020030 from the National Institute of Mental Health and UL1TR000058 from the National Institutes of Health's National Center for Advancing Translational Science. Nathan Gillespie is supported by Grant R00DA023549 from the National Institute on Drug Abuse. Danielle M. Dick is supported by Award K01AA018755 from the National Institute on Alcohol Abuse and Alcoholism. The Finnish Twin studies were supported by the National Institute on Alcohol Abuse and Alcoholism (Grants AA12502, AA00145, and AA-09203 to R.J.R. and AA015416 to D.M.D.), the Academy of Finland (Grants 100499, 205585, 141054, 118555, 265240, 263278, and 264146 to J.K. and 266592 to K.S.), and the Academy of Finland Centre of Excellence Programme (to L.P. and J.K.). The funding sources had no further role in the study design, data analysis, writing of the report, or decision to submit this manuscript for publication. The authors have no conflicts of interest.