title: Adolescent substance use and educational attainment: An integrative data analysis comparing cannabis and alcohol from three Australasian cohorts.
abstract: BACKGROUND
  The relative contributions of cannabis and alcohol use to educational outcomes are unclear. We examined the extent to which adolescent cannabis or alcohol use predicts educational attainment in emerging adulthood.
  
  
  METHODS
  Participant-level data were integrated from three longitudinal studies from Australia and New Zealand (Australian Temperament Project, Christchurch Health and Development Study, and Victorian Adolescent Health Cohort Study). The number of participants varied by analysis (N=2179-3678) and were assessed on multiple occasions between ages 13 and 25. We described the association between frequency of cannabis or alcohol use prior to age 17 and high school non-completion, university non-enrolment, and degree non-attainment by age 25. Two other measures of alcohol use in adolescence were also examined.
  
  
  RESULTS
  After covariate adjustment using a propensity score approach, adolescent cannabis use (weekly+) was associated with 1½ to two-fold increases in the odds of high school non-completion (OR=1.60, 95% CI=1.09-2.35), university non-enrolment (OR=1.51, 95% CI=1.06-2.13), and degree non-attainment (OR=1.96, 95% CI=1.36-2.81). In contrast, adjusted associations for all measures of adolescent alcohol use were inconsistent and weaker. Attributable risk estimates indicated adolescent cannabis use accounted for a greater proportion of the overall rate of non-progression with formal education than adolescent alcohol use.
  
  
  CONCLUSIONS
  Findings are important to the debate about the relative harms of cannabis and alcohol use. Adolescent cannabis use is a better marker of lower educational attainment than adolescent alcohol use and identifies an important target population for preventive intervention.
authors.affiliation: National Drug and Alcohol Research Centre, UNSW Australia, Sydney, Australia. Electronic address: e.silins@unsw.edu.au.
authors.forename: Edmund
authors.initials: E
authors.lastname: Silins
authors.affiliation: Christchurch Health and Development Study, Department of Psychological Medicine, University of Otago, Christchurch, New Zealand.
authors.forename: David M
authors.initials: DM
authors.lastname: Fergusson
authors.affiliation: Centre for Adolescent Health, Murdoch Childrens Research Institute, Royal Children's Hospital, Melbourne, VIC, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia.
authors.forename: George C
authors.initials: GC
authors.lastname: Patton
authors.affiliation: Christchurch Health and Development Study, Department of Psychological Medicine, University of Otago, Christchurch, New Zealand.
authors.forename: L John
authors.initials: LJ
authors.lastname: Horwood
authors.affiliation: Centre for Adolescent Health, Murdoch Childrens Research Institute, Royal Children's Hospital, Melbourne, VIC, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia; Centre for Social and Early Emotional Development, School of Psychology, Deakin University, VIC, Australia.
authors.forename: Craig A
authors.initials: CA
authors.lastname: Olsson
authors.affiliation: National Drug and Alcohol Research Centre, UNSW Australia, Sydney, Australia; Centre for Adolescent Health, Murdoch Childrens Research Institute, Royal Children's Hospital, Melbourne, VIC, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia; Centre for Social and Early Emotional Development, School of Psychology, Deakin University, VIC, Australia.
authors.forename: Delyse M
authors.initials: DM
authors.lastname: Hutchinson
authors.affiliation: National Drug and Alcohol Research Centre, UNSW Australia, Sydney, Australia; Centre for Adolescent Health, Murdoch Childrens Research Institute, Royal Children's Hospital, Melbourne, VIC, Australia; School of Population and Global Health, University of Melbourne, Melbourne, VIC, Australia; Department of Global Health, School of Public Health, University of Washington, Seattle, WA, USA.
authors.forename: Louisa
authors.initials: L
authors.lastname: Degenhardt
authors.affiliation: National Drug Research Institute, Faculty of Health Sciences, Curtin University, Perth, WA, Australia.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Tait
authors.affiliation: Centre for Adolescent Health, Murdoch Childrens Research Institute, Royal Children's Hospital, Melbourne, VIC, Australia; School of Population and Global Health, University of Melbourne, Melbourne, VIC, Australia.
authors.forename: Rohan
authors.initials: R
authors.lastname: Borschmann
authors.affiliation: Centre for Adolescent Health, Murdoch Childrens Research Institute, Royal Children's Hospital, Melbourne, VIC, Australia.
authors.forename: Carolyn
authors.initials: C
authors.lastname: Coffey
authors.affiliation: Centre for Social and Early Emotional Development, School of Psychology, Deakin University, VIC, Australia.
authors.forename: John W
authors.initials: JW
authors.lastname: Toumbourou
authors.affiliation: School of Public Health and School of Social Science, The University of Queensland, Brisbane, QLD, Australia.
authors.forename: Jake M
authors.initials: JM
authors.lastname: Najman
authors.affiliation: National Drug and Alcohol Research Centre, UNSW Australia, Sydney, Australia.
authors.forename: Richard P
authors.initials: RP
authors.lastname: Mattick
mesh_terms: D000124:Achievement; D000293:Adolescent; D000428:Alcohol Drinking / Q000453:epidemiology; D000437:Alcoholism / Q000453:epidemiology*; D001315:Australia / Q000453:epidemiology; D002188:Cannabis; D015331:Cohort Studies; D004522:Educational Status; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology*; D008385:Marijuana Smoking / Q000453:epidemiology*; D009520:New Zealand / Q000453:epidemiology; D012307:Risk Factors; D019966:Substance-Related Disorders / Q000453:epidemiology; D000066608:Underage Drinking / Q000706:statistics & numerical data*
keywords: Adolescence; Alcohol; Cannabis; Educational outcomes