A study published in the Journal of Adolescent Health has found that the legalization of cannabis leads to lower use of alcohol, cigarettes, and pain medications by young adults.

The study, conducted by researchers with the University of Washington assessed trends in alcohol, nicotine, and non-prescribed pain drug use among a group of over 12,500 young adults aged 18 to 25 in Washington State following the legalisation of cannabis.

The study said “contrary to concerns about spillover effects, implementation of legalised nonmedical cannabis coincided with decreases in alcohol and cigarette use and pain reliever misuse. The weakening association of cannabis use with the use of other substances among individuals ages 21–25 requires further research but may suggest increased importance of cannabis-specific prevention and treatment efforts.”

Cannabis is often theorised to be a gateway drug, leading to further substance abuse, yet the results of numerous studies suggest this is untrue. A 2020 study, published in the International Journal of Drug Policy surveyed medical cannabis patients about their alcohol consumption after obtaining a cannabis prescription. The study found that 44% of patients reported drinking less frequently on a monthly basis, 34% consumed fewer drinks per week and 8% said they drank no alcohol in the 30 days prior to taking the survey. Research also suggests that cannabis legalisation reduces the risk of death from opioids, a 2014 study found that annual opioid overdoses were 25% lower in US states where medical cannabis was legal.