The role of self-control in early escalation of substance use: a time-varying analysis.

This research tested predictions about the role of temperament and self-control in early substance use (tobacco, alcohol, and marijuana). A sample of 1,526 participants was assessed in 6th grade (mean age = 11.5 years) and followed with yearly assessments through 9th grade. Latent growth models showed temperament dimensions were related to early substance use, and their effects were mediated through generalized self-control ability. Time-varying effects indicated rate of growth in substance use was higher among participants who showed increases in poor self-control and lower among participants who showed increases in good self-control. Results in self-report data were corroborated by independent teacher ratings. Findings are discussed with reference to epigenetic models of protection and vulnerability.