Although certain politicians and other public figures have claimed that the use of marijuana by teenagers leads to criminal activity in later life, recent research suggests there is no causal relationship.
In 2009, for instance, the scientific journal Addiction published a study that investigated the association between cannabis use in adolescence and criminal activity.
The study, which was conducted by Willy Pedersen and Torbjørn Skardhamar, was based on data from the Young in Norway Longitudinal Study, a 13 year long study that followed 1,353 Norwegians from adolescence to adulthood.
The study found an association between cannabis use and subsequent criminal charges, even when taking into account such variables as socio-economic status, parental support, educational achievement, previous criminal charges, use of other illicit drugs, and marriage.
However, once Pederse and Skardhamar removed drug-related offenses from the data, there was no longer a statistically significant relationship between cannabis use and criminal activity. In other words, the association found between cannabis use and crime was due to the increased risk of being arrested for the use and possession of illegal drugs.
“Thus, from our findings there is no evidence that use of cannabis—or any other substances—is associated with increased risk of subsequent non-drug-specific criminal charges, such as criminal gain or violence. […] none of these substances seems to play an independent causal role when it comes to non-drug-specific crime during adolescence and young adulthood in a Norwegian context.”
Reference:
Pederse, W. & Skardhamar, T. (2009). Cannabis and crime: findings from a longitudinal study. Addiction, Vol 105, No 1: 109 – 118.