Does legalization of marijuana lead to adolescent use?

A major worry with marijuana legalization, whether medical or recreational, has been that it would increase adolescent use of the substance. Has this concern been proven true in states that have legalized?

Although it remains illegal on the federal level, medical marijuana, to date, is legal in 36 states with recreational use legal in 18. Many states where marijuana hasn’t been legalized have upcoming ballot measures over the next 2 years on the subject. With this rapid increase in legalization, pediatric organizations such as the American Academy of Pediatrics have worried that this might encourage children and teenagers to use the substance, which, for developing brains, can negatively impact areas in the prefrontal cortex. A new study that used data from the Youth Risk Behavior Survey assessed whether those concerns have a factual basis.1

The investigators used data from the Youth Risk Behavior Survey for the period 1993-2019. Data on pre- and post-recreational marijuana laws were available for 10 states. Seven states had more than 1 wave of post-recreational marijuana law data and were also able to provide data for before and after the start of dispensary sales.

The average age of the respondent was 15.9 years. The cohort skewed slightly more female (51.4%)as well as non-Hispanic White (57.6%). Based on the pooled data, the adoption of recreational marijuana laws was not linked to either frequent marijuana use (odds ratio [OR], 0.98; 95% CI, 0.90-1.07) or current marijuana use (OR, 1.00; 95% CI, 0.92-1.10). Furthermore, the adoption of medical marijuana laws was tied to a 6% decrease in the odds of current marijuana use (OR, 0.94; 95% CI, 0.89-0.98) and a 7% decrease in the odds of frequent use (OR, 0.93; 95% CI, 0.87-0.99), in fully adjusted models. The link between the first recreational dispensary and marijuana use was considered qualitatively similar. Two or more years after the adoption of recreational marijuana laws, a decrease in marijuana use was noted (OR, 0.85; 95% CI, 0.76, 0.95).

The investigators concluded that there appears to be little connection between either recreation or medical marijuana laws and increased marijuana use in children and adolescents, with the link between recreational laws and marijuana use essentially equaling zero. They did note that recreational marijuana laws are a fairly new occurrence and with more data, firmer conclusions can be drawn about whether a relationship exists between the legalization of recreational marijuana and adolescent marijuana use.

Reference

1. Anderson D, Rees D, Sabia J, Safford S. Association of marijuana legalization with marijuana use among US high school students, 1993-2019. JAMA Netw Open. 2021;4(9):e2124638. doi:10.1001/jamanetworkopen.2021.24638