title: Pathways into ecstasy use: the role of prior cannabis use and ecstasy availability.
abstract: OBJECTIVE
  To explore the role of cannabis use for the availability of ecstasy as a potential pathway to subsequent first ecstasy use.
  
  
  METHODS
  Baseline and 4-year follow-up data from a prospective-longitudinal community study of originally 3021 adolescents and young adults aged 14-24 years at baseline were assessed using the standardized M-CIDI and DSM-IV criteria.
  
  
  RESULTS
  Baseline cannabis users reported at follow-up more frequent access to ecstasy than cannabis non-users. Higher cannabis use frequencies were associated with increased ecstasy availability reports. Logistic regression analyses revealed that cannabis use and availability of ecstasy at baseline are predictors for incident ecstasy use during the follow-up period. Testing simultaneously the impact of prior cannabis use and ecstasy availability including potential confounders, the association with cannabis use and later ecstasy use was confirmed (OR=6.3; 95%CI=3.6-10.9). However, the association with ecstasy availability was no longer significant (OR=1.2; 95%CI=0.3-3.9).
  
  
  CONCLUSIONS
  Results suggest that cannabis use is a powerful risk factor for subsequent first onset of ecstasy use and this relation cannot be sufficiently explained by availability of ecstasy in the observation period.
authors.affiliation: Max Planck Institute of Psychiatry, Clinical Psychology and Epidemiology, Kraepelinstrasse 2, 80804 Munich, Germany. pzimmer@mpipsykl.mpg.de
authors.forename: Petra
authors.initials: P
authors.lastname: Zimmermann
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Wittchen
authors.forename: Florian
authors.initials: F
authors.lastname: Waszak
authors.forename: Agnes
authors.initials: A
authors.lastname: Nocon
authors.forename: Michael
authors.initials: M
authors.lastname: Höfler
authors.forename: Roselind
authors.initials: R
authors.lastname: Lieb
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D015897:Comorbidity; D003625:Data Collection / Q000706:statistics & numerical data; D003627:Data Interpretation, Statistical; D005260:Female; D005500:Follow-Up Studies; D005858:Germany / Q000453:epidemiology; D006213:Hallucinogens / Q000009:adverse effects* / Q000600:supply & distribution*; D006801:Humans; D013287:Illicit Drugs / Q000009:adverse effects / Q000600:supply & distribution; D015994:Incidence; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology*; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000009:adverse effects* / Q000600:supply & distribution*; D015995:Prevalence; D011446:Prospective Studies; D019966:Substance-Related Disorders / Q000453:epidemiology* / Q000523:psychology
chemical_list: D006213:Hallucinogens; D013287:Illicit Drugs; D018817:N-Methyl-3,4-methylenedioxyamphetamine