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

Theoretically informed models estimate the temporal relationships betw een illicit drug use and dropping out of school, and the variables tha t mediate these relationships. Subjects are tested in the seventh grad e (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 s chool (measured at Time 3), controlling for gender, father's education , race/ethnicity, and Time 1 measures of deviance, distress, self-cont rol, and grades. This effect is decomposed by the addition of three hy pothesized mediating variables in the relationships. Time 2 measures o f low motivation, negative social sanctions, and premature performance of competing social roles. The addition of Time 1 measures of these v ariables does not obviate the relationship, but the addition of Time 2 measures of the three hypothesized mediating variables to the equatio n reduces to nonsignificance the effect of drug use on not graduating from high school.