ABSTRACT
In chapter 4, we showed that substance use had already started early in the lives of boys in the youngest sample and was quite prevalent in boys in the middle and oldest samples. In this chapter, we address factors that may explain different degrees of substance use involvement and how such factors differ for different age groups. We first examine the relationship among different substances, particularly to investigate the view that substance use develops in a generally orderly fashion and that the strength of relations among the use of different substances varies with age. We then show how substance use is related to the severity of delinquency and petitions to the juvenile court. We then turn to explanatory factors for substance use and correlates of use. We show which combination of explanatory factors in multiple regression analyses best accounts for substance use in each of the three samples, discuss interaction effects, and then show how a risk index of such factors is associated with substance use. The methodological issues discussed in chapter 5 and the Methodological Appendix also apply to this and the following chapters, and are no longer raised here.
