title: Early alcohol or tobacco onset and transition to other drug use among students in the state of Morelos, Mexico.
abstract: In this study, we explored if patterns in the transition from alcohol/tobacco in the Mexican State of Morelos, Mexico are similar to those observed in other countries.
  
  
  METHODS
  The data were from a representative sample of youth age 11-21 years (n = 13,105), who participated in a paper-and-pencil survey in middle schools, high schools, and colleges in the State of Morelos, Mexico. Drug use was assessed via the standardized instrument mostly used in Mexican student surveys. Cox's models for discrete time-survival analyses, stratified by school and age group were used to estimate the risk of drug use in relation to age of alcohol and tobacco use initiation by gender, while accommodating the complex survey design.
  
  
  RESULTS
  About 5% of the students were estimated to have used drugs in their life. Male early users of alcohol or tobacco were more likely to use other drugs, compared to students who did not have an early alcohol or tobacco onset.
  
  
  CONCLUSIONS
  Further studies on social mechanisms might help to account for observed similarities in patterns of drug involvement in different countries, even in the context of important differences in rates of drug use.
authors.affiliation: Drug Abuse Research Program, Public Health Program, Morgan State University. Morgan-Hopkins Center for Health Disparities Solutions, Baltimore, MD 21251, USA. fwagner@jewel.morgan.edu
authors.forename: F A
authors.initials: FA
authors.lastname: Wagner
authors.forename: H E
authors.initials: HE
authors.lastname: Velasco-Mondragón
authors.forename: M
authors.initials: M
authors.lastname: Herrera-Vázquez
authors.forename: G
authors.initials: G
authors.lastname: Borges
authors.forename: E
authors.initials: E
authors.lastname: Lazcano-Ponce
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000428:Alcohol Drinking / Q000453:epidemiology*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D016016:Proportional Hazards Models; D012907:Smoking / Q000453:epidemiology*; D013334:Students; D019966:Substance-Related Disorders / Q000453:epidemiology*