title: Patterns of cannabis use among 13-14 year old New Zealanders.
abstract: OBJECTIVE
  The aims of this study were to document the prevalence and frequency of use of cannabis, the sources of supply of cannabis and reactions to cannabis use in a sample of 949 Christchurch born children studied to the age of 15 years.
  
  
  METHODS
  Data on cannabis use was collected on the basis of parental and self report at ages 14 and 15 years.
  
  
  RESULTS
  By the age of 15 years, 9.8% of this cohort had used cannabis on one or more occasions and 2.2% of the cohort reported using cannabis on more than 10 occasions. Rates of cannabis use amongst boys and girls were identical. Most of those using cannabis had been provided with the drug by same aged or older teenagers and in most cases it was supplied free. In most cases cannabis was used in small informal groups of 2-8 young people. The majority of cannabis users (75.3%) reported positive reactions to cannabis use and many (58%) said that they would use cannabis again. However, just under one third (30.9%) of users reported some adverse reaction to cannabis use including feeling ill, dizzy or frightened.
  
  
  CONCLUSIONS
  By the age of 15 years approximately 10% of young people reported using cannabis. This rate of utilisation appears to be supported by the presence of informal peer networks which provide a source of supply and support for young people experimenting with the use of cannabis. It is conjectured that the source of supply for these informal networks reflects a trickle down of the relatively large amounts of cannabis which circulate amongst adolescent and young adult populations.
authors.affiliation: Christchurch School of Medicine, Christchurch Hospital.
authors.forename: D M
authors.initials: DM
authors.lastname: Fergusson
authors.forename: M T
authors.initials: MT
authors.lastname: Lynskey
authors.forename: L J
authors.initials: LJ
authors.lastname: Horword
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D008297:Male; D008385:Marijuana Smoking / Q000009:adverse effects / Q000453:epidemiology*; D009520:New Zealand / Q000453:epidemiology; D010379:Peer Group; D015995:Prevalence