Vulnerability to drug abuse among opioid addicts' siblings: individual, familial, and peer influences.

Vulnerability to drug abuse was explored among 132 siblings of opioid-addicted probands. Multiple risk factors at the levels of the individual, family, and peer group were examined, including sensation-seeking, teenage experimentation with drugs, ordinal position in the family relative to the addicted proband, birth order, and the extent to which peers used drugs and offered drugs to the individual during adolescence. Risk factors were assessed via questionnaire and interview data, while diagnoses of adult drug abuse were derived from structured interviews. Early experimentation with drugs was found to be a powerful risk variable: siblings who had tried drugs as teenagers were almost five times as likely as others to be drug abusers as adults. Other significant correlates of adult drug abuse included sensation-seeking and drug use among the adolescent peer group. Results of the study are discussed in terms of implications for preventive intervention in the field of substance abuse.