Another federally funded study suggests that marijuana legalization may be linked to a “substitution effect,” with young adults in California “significantly” reducing their use of alcohol and cigarettes after the cannabis reform was enacted. The study, published in the Journal of Psychoactive Drugs last week, involved surveys of people aged 18-20 living in Los Angeles before and after the state implemented adult-use marijuana legalization under a 2016 voter initiative.
Research showed that “despite the possibilities of increased access to cannabis via a diversion from the adult-use market and increased normalization of cannabis use,” legalizing recreational marijuana “did not lead to increased frequency of cannabis use” among the subjects. The study, which the National Institute on Drug Abuse funded, also found that changes in the use of illicit and prescription drugs “did not significantly differ” between pre-legalization and post-legalization cohorts, which the researchers said is “notable since some critics predicted that early adult cannabis use would lead to increased other drug use” via the so-called “gateway theory.” They also noticed significantly fewer days of alcohol and cigarette use among the post-legalization cohort compared to the pre-legalization cohort.
