US researchers have found the legalisation of recreational cannabis leads to a decrease in cigarette smoking, alcohol consumption and opioid use.
Scientists analysed survey data from nearly 13,000 adults aged 18 to 25 in Washington State between 2014 and 2019. Recreational cannabis use was legalised in the state in 2012.
Published in the Journal of Adolescent Health, the team found past-month alcohol use, heavy episodic drinking, cigarette use and past-year pain reliever misuse all decreased among the cohort.
While the prevalence of e-cigarette use rose, the team said this was more likely a result of the overall growth in vaping during the period rather having any causal link to cannabis legalisation.
The researchers wrote: “Contrary to concerns about spillover effects, implementation of legalised non-medical cannabis coincided with decreases in alcohol and cigarette use and pain reliever misuse.”
That said, the prevalence of substance use other than cannabis was higher among occasional and frequent cannabis users compared to non-users, an area the research team said requires further study.
