Adolescent Cannabis Use Does Not Increase In States With Legal Medical Marijuana

Because there is some evidence that regular marijuana use can alter brain function in adolescents — whose brains are still developing — good marijuana policy requires legislators to take into account the potential effect that legalization might have upon youth and marijuana use.

In this context, a new study confirms that legalizing medical cannabis is sound policy.

Research published in the journal Prevention Science finds that adolescent cannabis use has not increased in states that have legalized medical marijuana. These findings should dispel public and legislative concern that legalizing medical marijuana encourages teenage adoption of marijuana use. The data is unequivocal in showing that legalization has not boosted the number of adolescents that use cannabis.

After analyzing data from the National Survey on Drug Use and Health, which included data from between 2004 and 2013, researchers considered how the legalization of medical cannabis at the state level affects marijuana use as well as the prevalence of marijuana use disorders such as abuse or dependence. For young individuals aged 12-25, cannabis use, whether regular or occasional, did not increase after the legalization of medical cannabis.

Increased Cannabis Use in Specific Demographics

Interestingly, more people ages 26 and older use cannabis in states with legalized medical marijuana. The primary driver of this increase, which occurred between 2007 and 2014, is found among men.

Furthermore, the study found no significant shift in cannabis abuse or dependence for any age group, despite a statistically significant increase in marijuana usage by adults aged 26 or older.

In states that had enacted medical marijuana laws, occasional or “past-month” use of cannabis by men ages 26 and older increased from seven percent to nearly nine percent after medical marijuana legislation. Prevalence of medical marijuana use among women increased from about three percent to over four percent.

Adding to a Mounting Body of Evidence

The same federal government report on drug use also concluded that fewer adolescents are using cannabis, regardless of whether it is legally available to some members of the public. The rate of marijuana use among youth aged 12-17 has dropped to its lowest point since 1994 and has been on a downward trajectory since 2002, even though recreational marijuana shops opened in 2014.

In contrast, the rate of marijuana use among adults aged 18 to 34 is at its highest rate since 1985. Usage in this age group has steadily risen for several decades, so analysts do not attribute the increased use to increased access to legal medical marijuana.