A LONGITUDINAL ANALYSIS OF MEDIATING VARIABLES IN THE DRUG-USE DROPPING-OUT RELATIONSHIP

Theoretically informed models estimate the temporal relationships between illicit drug use and dropping out of school, and the variables that mediate these relationships. Subjects are tested in the seventh grade (Time 1), in the eighth grade (Time 2), and during young adulthood (Time 3) (N=2,805). Models are estimated by using logistic regression. Time 1 drug use has a significant effect on not graduating from high school (measured at Time 3), controlling for gender, father's education, race/ethnicity, and Time 1 measures of deviance, distress, self-control, and grades. This effect is decomposed by the addition of three hypothesized mediating variables in the relationships. Time 2 measures of low motivation, negative social sanctions, and premature performance of competing social roles. The addition of Time 1 measures of these variables does not obviate the relationship, but the addition of Time 2 measures of the three hypothesized mediating variables to the equation reduces to nonsignificance the effect of drug use on not graduating from high school.