We know that marijuana is dangerous for an adolescent’s developing brain. We know that 23 states and the District of Columbia have medical marijuana laws. We also know that adolescent use of marijuana continues to go up even while use of other drugs among this age group is leveling off or declining.
Studies show that marijuana use in adolescents is higher in states that have legalized medical marijuana, so it stands to reason that legalizing medical marijuana could increase adolescent marijuana use.1,2 However, sometimes reason does not match the scientific evidence. A review of adolescent marijuana use in more than 1 million adolescents surveyed over 24 years across 48 states provided definitive evidence that legalizing medical marijuana does not increase use among adolescents. The study was published in The Lancet.1,2
“The argument that legalizing medical marijuana leads to increased use by adolescents was compelling. We went into the study with an attitude of ‘let’s figure this out.’ We found that out that association does not mean cause in this case,” says Deborah S. Hasin, PhD, professor of clinical epidemiology at Columbia University in New York City, and lead author of the study.
What the Study Found
The study was based on two questions: Do states that have passed medical marijuana laws have higher rates of adolescent use? And did passing these laws increase that use? To find the answers, the researchers used results from the Monitoring the Future study that includes data gained from self-administered questionnaires given to more than 1 million adolescents, ages 13 to 18 years, in 400 schools.1,2