title: [Initiation of ecstasy use in Québec senior high school adolescents: distal and proximal predictors].
abstract: OBJECTIVE
  To identify distal and proximal predictors of ecstasy use initiation during adolescence.
  
  
  METHODS
  The sample included 2162 adolescents from Québec disadvantaged community high schools, with an annual follow-up for 5 years. Path analysis was used to predict ecstasy use initiation in secondary 5 (aged 16 to 17 years) from predictors in secondary 1 and 2 (aged 12 to 14 years) and in secondary 4 (aged 15 to 16 years).
  
  
  RESULTS
  Secondary 5 adolescents initiating ecstasy use showed a higher risk on multiple factors, compared with nonusers. Initiation was mainly predicted by proximal risk factors related to individual use as well as peer use and deviance. Nevertheless, many proximal factors developed consistently with their corresponding distal factor (indirect link). Marijuana use was the strongest predictor of ecstasy use initiation. All things being equal, relative risk was 2.04 times higher in adolescents having used marijuana in the past year (secondary 4).
  
  
  CONCLUSIONS
  Ecstasy use initiation in secondary 5 seems to be globally related to an externalized, rather than internalized, profile. This ecstasy use was strongly associated with other substance use and likely shares many risk factors with other substance use, specifically marijuana use.
authors.affiliation: Département de psychologie, Université de Montréal, Montréal, Québec.
authors.forename: Valérie
authors.initials: V
authors.lastname: Gagnon
authors.forename: Jean-Sébastien
authors.initials: JS
authors.lastname: Fallu
authors.forename: Frédéric N
authors.initials: FN
authors.lastname: Brière
authors.forename: Michel
authors.initials: M
authors.lastname: Janosz
mesh_terms: D000124:Achievement; D000293:Adolescent; D017668:Age of Onset; D000428:Alcohol Drinking / Q000453:epidemiology / Q000517:prevention & control / Q000523:psychology; D019969:Amphetamine-Related Disorders / Q000453:epidemiology* / Q000523:psychology / Q000534:rehabilitation; D002648:Child; D015897:Comorbidity; D019955:Conduct Disorder / Q000453:epidemiology / Q000523:psychology / Q000534:rehabilitation; D003430:Cross-Sectional Studies; D005260:Female; D006213:Hallucinogens; D006801:Humans; D007604:Juvenile Delinquency / Q000523:psychology / Q000534:rehabilitation / Q000706:statistics & numerical data; D008137:Longitudinal Studies; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology / Q000523:psychology / Q000534:rehabilitation; D018817:N-Methyl-3,4-methylenedioxyamphetamine; D016487:Parenting / Q000523:psychology; D010379:Peer Group; D011792:Quebec; D012307:Risk Factors; D012932:Social Facilitation; D012959:Socioeconomic Factors
chemical_list: D006213:Hallucinogens; D018817:N-Methyl-3,4-methylenedioxyamphetamine