The article used data from the screening phase and first two waves of a panel study to compare the home environments of families with a substance-abusing parent, families with a depressed parent, and families in a comparison group. Findings suggest that families in which parents display a substance use disorder are very similar to those in which parents suffer from affective disorder, in terms of negative life events and family cohesion. The results of structural equation modeling indicate that parental substance abuse disorder and parental affective disorder influence adolescent substance use and depressive symptoms. In addition, parental substance use disorder had a direct influence on adolescent substance use at the time the first-wave data were collected, but this effect does not persist over time. Figures, table, notes, references