Marijuana use in the States has been steadily on the rise for over a decade. With the COVID-19 pandemic leaving large swaths of Americans anxiety-ridden and homebound, many dispensaries have seen massive upticks in sales. It makes sense that people are turning to cannabis to help cope with these difficult times, but according to a new study, this is hardly a novel phenomenon.
To help policymakers be more informed, a recent study out of Harvard set out to analyze the changes in cannabis use nationwide. Researchers examined data from before and after the majority of states adopted legislation legalizing at least some form of cannabis.
The study, authored by William Mitchell, Roma Bhatia, and Nazlee Zebardast, used data collected by the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2018.
The survey measured three subcategories of marijuana use:
- Lifetime use
- First-time use before the age of eighteen
- Use in the last year
The NHANES is a biennial survey that is weighted to represent the entire US population. Participants range in age from 18 to 69. A total of 3,512 adults were surveyed in the seven cycles examined in this study. Those who partake in the survey are given a physical examination as well as an interview that includes a drug-use questionnaire.
Researchers discovered some interesting things about America’s marijuana habits.
First of all, the data showed that the amount of people who have used cannabis sometime in their life has hardly changed in the last 14 years. In 2005, 61.5 percent of participants reported having at least one marijuana experience in their lifetime. In 2018, that figure was 60.9 percent. In the five cycles in between, the data never varied more than four percentage points.
Similarly, the seven cycles showed very little difference in the prevalence of cannabis use before the age of eighteen. The lowest figure reported was 59.6 percent in 2005, and the highest was 62.7 percent in 2009, making for a range of only 3.1 percent.
The big variance that the study found was in the prevalence of people who reported using marijuana in the last year. Of Americans surveyed by the NHANES, 19.1 percent described having used cannabis in the last year in 2005. Compare that number to 2018, where 29.1 percent of those surveyed reported consuming marijuana in the last year. The 10 percent range is by far the largest in the study, and the prevalence steadily increases throughout every iteration of the survey, unlike the other two measured two outcomes.
What Does it Mean?
Since state-level legislation to end marijuana prohibition has become more common, so has marijuana use. The findings are not exceptionally surprising—legalization makes cannabis more accessible through legal dispensaries and removes the barrier of potential criminal repercussions that may have otherwise dissuaded potential users. With more people consuming marijuana, there has never been a better time to invest in the cannabis industry.
Even though more people are accessing cannabis in legal markets, the use among minors has not increased the way proponents of prohibition argued it would.
Concern about medical cannabis legalization leading to teens feeling encouraged to use the plant recreationally and more frequently has been widely expressed. However, a recent study published in The Lancet Psychiatry concluded there are no significant links between adolescent cannabis use and the legalization of medical marijuana.
The comprehensive study, “Medical marijuana laws and adolescent marijuana use in the USA from 1991 to 2014: results from annual, repeated cross-sectional surveys,” spanned a period of 24 years from 1991 though 2014. Over one million teens from the ages of 13 to 18 completed the government-funded survey. Given to 8th, 10th and 12th graders in 48 states, the periodic questionnaire focused on cannabis consumption in the previous month.
While it is important to note that teen cannabis use was generally higher in states that went on to legalize medical consumption, researchers did not see an additional spike in the plant’s usage after laws were passed. In fact, overall use by 8th graders decreased in states with legal medical marijuana. Some scientists speculated that the fall was due to children viewing the now ‘adult-approved’ plant to be less of an enjoyable recreational activity. Others considered that parents might be working harder to stop their children from trying cannabis.
Deborah Hasin, a reviewer of the data and Professor of Epidemiology at Columbia University Medical Center in New York stated:
“Our findings provide the strongest evidence to date that marijuana use by teenagers does not increase after a state legalizes medical marijuana.”
However, this is not the only report or study that points to this conclusion. In 2013, the Colorado Department of Health and Environment showed that high school cannabis consumption decreased from 22 percent to 20 percent over the course of 2011 to 2013. Dr. Larry Wolk, CDPHE’s director, suggested that as with tobacco, youth prevention campaigns likely ensure that adult legalization does not impact the health of the state’s children.
The 13th Biennial California Student Survey found that marijuana consumption in teens was less than in years before medical cannabis was legal. The researchers also noted that the plant’s usage increased in states where medical marijuana was prohibited.
Dr. Kevin Hill from McLean Hospital’s Division of Alcohol and Drug Abuse said of Hasin’s most recent study:
“Future decisions that states make about whether or not to enact medical marijuana laws should be at least partly guided by this evidence. The framework of using a scientific method to challenge what might be ideological beliefs must remain an important driver of future research on marijuana policy.”
Harvard Univeristy’s 2014 Harvard Public Opinion Project, found that legalization does not encourage marijuana use. This study focused on full legalization rather than solely on medical marijuana legalization. Nearly 90 percent of participants who have not used marijuana responded that they are not likely to change behavior if it is legalized.
Why has teen cannabis use decreased as a result of legalization? Although one exact answer is not yet known, it may have something to do with increased knowledge about cannabis. The answer to this question is a complicated and multifaceted one that will require more study. However, this most recent research signals a new wave of understanding for this fascinating plant.