title: Cannabis use and violence: Is there a link?
abstract: BACKGROUND
  While several studies suggest that cannabis users are at increased risk of interpersonal violence, it is not clear to what extent the association is causal. Our paper aims to assess the association between cannabis use and violence by using a method that diminishes the risk of confounding.
  
  
  METHODS
  We analysed data on cannabis use and violent behaviour from the second (1994) and third (1999) waves of the Young in Norway Longitudinal Study (cumulative response rate: 68.1%, n = 2681). We applied fixed-effects modelling to estimate the association between these behaviours, implying that changes in the frequency of violence were regressed on changes in the frequency of cannabis use. The effects of time-invariant confounders were hence eliminated. In addition, we included two time-varying covariates.
  
  
  RESULTS
  The elasticity estimate implies that a 10% increase in cannabis use frequency is associated with a 0.4% increase in frequency of violence (p=.024).
  
  
  CONCLUSIONS
  Analyses of panel data on Norwegian youths reveals a statistically significant association between cannabis use and violence.
authors.affiliation: Swedish Institute for Social Research (SOFI), Stockholm University, Stockholm, Sweden Norwegian Institute for Alcohol and Drug Research (SIRUS), Oslo, Norway totto@sofi.su.se.
authors.forename: Thor
authors.initials: T
authors.lastname: Norström
authors.affiliation: Norwegian Institute for Alcohol and Drug Research (SIRUS), Oslo, Norway.
authors.forename: Ingeborg
authors.initials: I
authors.lastname: Rossow
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D002189:Marijuana Abuse / Q000523:psychology*; D009664:Norway; D014754:Violence / Q000706:statistics & numerical data*; D055815:Young Adult
keywords: Cannabis; Norway; panel data; violence