title: The effects of purchasing alcohol and marijuana among adolescents at-risk for future substance use.
abstract: BACKGROUND
  Among high-risk youth, those who may be at increased risk for adverse alcohol and other drug (AOD) use outcomes may benefit from targeted prevention efforts; how youth acquire AOD may provide an objective means of identifying youth at elevated risk.
  
  
  METHODS
  We assessed how youth acquired alcohol and marijuana (purchasing vs. other means), demographics, AOD behaviors/consequences, and environment among adolescents referred to a diversion program called Teen Court (N = 180) at two time points (prior to the program and 180 days from baseline). Participants were predominantly White and Hispanic/Latino(a).
  
  
  RESULTS
  In cross-sectional analyses among alcohol and marijuana users, purchasing marijuana was associated with more frequent marijuana use and consequences, time spent around teens who use marijuana, higher likelihood of substance use disorders, and lower resistance self-efficacy compared to non-purchasers. Teens who purchased both alcohol and marijuana experienced similar outcomes to those who purchased only marijuana, and also reported more frequent and higher quantity of drinking, greater alcohol-related consequences, time spent around teens who use other drugs, and prescription drug misuse. Longitudinally, purchasing alcohol and marijuana at baseline was associated with more frequent and higher quantity of drinking compared to non-purchasers at follow-up. Marijuana only purchasers had a greater likelihood of substance use disorders at follow-up compared to non-purchasers.
  
  
  CONCLUSIONS
  In an era where drinking is commonplace and attitudes towards marijuana use are becoming more tolerant, it is essential to evaluate how accessibility to AOD and subsequent purchasing behaviors affect youth consumption and intervene accordingly to prevent future consequences.
authors.affiliation: RAND Corporation, 1776 Main Street, P,O, Box 2138, Santa Monica, CA 90407-2138, USA. karenc@rand.org.
authors.forename: Karen Chan
authors.initials: KC
authors.lastname: Osilla
authors.forename: Eric R
authors.initials: ER
authors.lastname: Pedersen
authors.forename: Brett A
authors.initials: BA
authors.lastname: Ewing
authors.forename: Jeremy N V
authors.initials: JN
authors.lastname: Miles
authors.forename: Rajeev
authors.initials: R
authors.lastname: Ramchand
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: D'Amico
mesh_terms: D000293:Adolescent; D000428:Alcohol Drinking / Q000191:economics / Q000453:epidemiology; D000434:Alcoholic Beverages / Q000191:economics; D002188:Cannabis; D003132:Commerce; D003430:Cross-Sectional Studies; D064423:Drug Trafficking; D005260:Female; D006801:Humans; D008297:Male; D008385:Marijuana Smoking / Q000191:economics / Q000453:epidemiology; D018570:Risk Assessment; D019966:Substance-Related Disorders / Q000209:etiology*; D011795:Surveys and Questionnaires