title: The role of drug use sequencing pattern in further problematic use of alcohol, tobacco, cannabis, and other drugs.
abstract: BACKGROUND
  There has been considerable debate regarding what typically occurs after experimentation with drugs throughout the life of young people who used various drugs.
  
  
  OBJECTIVE
  To evaluate the clinical importance of the most common sequence for the first use of a drug by two models (the "gateway model" and the "alternative model", which is the most popular sequence for Brazilian university students according to a previous study) regarding the problematic use of alcohol, tobacco, cannabis and other illegal drugs, assessed by ASSIST.
  
  
  METHODS
  People who had already experimented with three or more drugs across different stages of the two models were selected from a representative sample of university students from 27 Brazilian capitals (n = 12 711).
  
  
  RESULTS
  There were no differences regarding the problematic use of the most consumed drugs in Brazil (alcohol, tobacco and cannabis) between the models. Multiple drug seekers and violators had more problematic use of illegal drugs other than cannabis than individuals in the model sequence. However, in the case of violators, this was only evident in the alternative model.
  
  
  CONCLUSIONS
  Multiple drug seekers and violators deserve special attention due to their increased risk of problematic use of other illegal drugs.
authors.affiliation: Department of Psychiatry, Medical School, University of São Paulo , São Paulo , Brazil .
authors.forename: João Mauricio
authors.initials: JM
authors.lastname: Castaldelli-Maia
authors.forename: Silvia S
authors.initials: SS
authors.lastname: Martins
authors.forename: Lúcio Garcia
authors.initials: LG
authors.lastname: de Oliveira
authors.forename: Arthur Guerra
authors.initials: AG
authors.lastname: de Andrade
authors.forename: Sérgio
authors.initials: S
authors.lastname: Nicastri
mesh_terms: D000328:Adult; D000437:Alcoholism / Q000453:epidemiology; D055030:Drug Users / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology; D012044:Regression Analysis; D019966:Substance-Related Disorders / Q000453:epidemiology*; D014029:Tobacco Use Disorder / Q000453:epidemiology; D055815:Young Adult
keywords: Abuse; dependence; problematic use; sequence of drug experimentation; university students