title: Impact of age at onset of cannabis use on cannabis dependence and driving under the influence in the United States.
abstract: OBJECTIVE
  There is growing evidence that driving under the influence of cannabis is associated with a higher risk of motor vehicle crash. Cannabis dependence has been reported to be associated with a three-fold increased risk of motor vehicle crash. The impact of the age at onset of cannabis use on the risk of both cannabis dependence and driving under the influence of cannabis has not been evaluated so far.
  
  
  METHODS
  Data were drawn from the 2001-2002 National Epidemiological Survey on Alcohol and Related Conditions (NESARC), a survey of 43,093 adults aged 18 years and older. We limited our analyses to the sample of participants who reported having ever used cannabis (n=8172), of whom 8068 had a known age at onset of cannabis use.
  
  
  RESULTS
  Of the 8068 participants included, 5.15% reported having driven under the influence of cannabis. Among those, only a minority (14.46%) were diagnosed with cannabis dependence. Compared to those who start using cannabis at age 21 years or after, participants who used cannabis before the age of 14 years were 4 times more likely to have a history of cannabis dependence and 3 times more likely to reported having driven under the influence of cannabis. An inverse relationship between the age at onset of cannabis use and driving under the influence and risk of cannabis dependence was found.
  
  
  CONCLUSIONS
  Starting to smoke cannabis younger than 21 years is associated with both cannabis dependence and driving under the influence of cannabis.
authors.affiliation: Translational Addiction Research Laboratory, Centre for Addiction and Mental Health, Toronto, ON, Canada; Department of Psychiatry, Louis Mourier Hospital, AP-HP, Colombes, France; INSERM U894, Team 1, Centre for Psychiatry and Neurosciences, 2 Ter Rue d'Alesia, 75014 Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Faculty of Medicine, France. Electronic address: yann.lestrat@inserm.fr.
authors.forename: Yann
authors.initials: Y
authors.lastname: Le Strat
authors.affiliation: Department of Psychiatry, Louis Mourier Hospital, AP-HP, Colombes, France; INSERM U894, Team 1, Centre for Psychiatry and Neurosciences, 2 Ter Rue d'Alesia, 75014 Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Faculty of Medicine, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Dubertret
authors.affiliation: Translational Addiction Research Laboratory, Centre for Addiction and Mental Health, Toronto, ON, Canada; Addiction Program, Centre for Addiction and Mental Health, Toronto, Canada; Departments of Family and Community Medicine, Psychiatry, Pharmacology and Toxicology, Institutes of Medical Sciences, University of Toronto, Toronto, Canada.
authors.forename: Bernard
authors.initials: B
authors.lastname: Le Foll
mesh_terms: D000063:Accidents, Traffic / Q000706:statistics & numerical data; D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000066448:Driving Under the Influence / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology*; D008875:Middle Aged; D012306:Risk; D014481:United States
keywords: Age at onset; Cannabis; Dependence; Driving under the influence; NESARC; Survey