Is cannabis a “gateway drug” that increases the risk of young people trying more harmful substances?
Multiple studies have backed up the claim, including a 25-year study of adolescents that showed regular or heavy weed use increases chances of using other illicit drugs. But the long-held theory is controversial. Scientists are questioning whether other factors – such as trauma, homelessness and poverty – could be more significant contributing variables that weren’t taken into account in the original methodology.
That’s why researchers at BC’s Centre for Substance Use wanted to dig deeper into the relationship between cannabis use and, specifically, injectable drugs. From 2005 to 2015, a team led by research student Hudson Reddon tracked and interviewed 481 street-involved people between the ages of 14 and 26 who had reported using illicit drugs. Their research found daily cannabis use correlated to a 34 per cent decrease of the hazard rate – the number scientists calculated would normally try heroin or other injectable drugs for the first time.
“The decreased rate of injection initiation among frequent cannabis users challenges the claim of the gateway hypothesis that there is a causal link between cannabis use and initiation of subsequent so-called hard drug use,” reads the study, published in the March issue of the Drug and Alcohol Review.