The primary data collection instrument was the Adolescent Drug Abuse Diagnosis instrument, a 150-item survey with a structured interview format and modeled after the Addiction Severity Index. Predictor variables included six measures of family structure: subject lived with both natural parents, subject lived with biological mother and stepfather, subject lived with mother only, subject lived with biological father and stepmother, subject lived with biological father only, and subject lived with relatives or foster parents. There were 33 variables related to family relationships and family functioning. Of the 33 family relationship variables, 3 predicted at the 0.01 level of significance to the degree of recent substance use and 2 predicted to the recent frequency of drug trafficking. If the subject considered his mother to have an alcohol problem, this was found to be the strongest single predictor in the degree of the son's substance abuse. 21 references and 2 tables