Peer and sibling substance use: predictors of substance use among adolescents in Mexico.

OBJECTIVE To examine the extent to which peer drug use and sibling drug use predict alcohol abuse/dependence disorder status and the use of drugs other than alcohol among school-based youth in Mexico. METHODS Data were collected on 1 203 middle and high school students in northern Mexico in May 1998. Participation was voluntary, and responses were confidential. Logistic regression analyses estimated the association that peer drug use and that sibling drug use had with alcohol abuse/dependence diagnosis and the lifetime use of drugs other than alcohol. RESULTS Students who had siblings or peers who used alcohol and other drugs were more likely to meet the standard alcohol abuse/dependence criteria defined by the Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM-IV), and were more likely to have used drugs other than alcohol. Controlling for potentially important confounders, we found that adolescents with the highest level of peer substance use were eight times as likely to meet alcohol abuse/dependence criteria and four times as likely to use other drugs. Youth who had siblings who used drugs were about twice as likely to meet alcohol abuse/dependence criteria and about 2.5 times as likely to use drugs other than alcohol when compared to youth with no sibling substance use. CONCLUSIONS Consistent with extant findings among youth in the United States of America, peer and sibling substance use are major risk factors for substance use among school-based youth in Mexico. Students in Mexico may benefit from prevention strategies found to be effective among students in the United States.