In Some States, Legalization Affects Cannabis Use in Unexpected Ways

Drug policy affects individual states differently.

Marijuana is now legalized in some form across 33 states and the District of Columbia, and subsequently, the statistics show that marijuana use is expanding. As cannabis use rises, researchers and policymakers are concerned that we’ll see a rise in cannabis use disorders as well. But according to a study published Wednesday in the International Journal of Drug Policy, it’s not a one-size-fits-all situation.

Most cannabis-focused policy work, the Columbia University Mailman School of Public Health team explains, assumes a “one policy, one outcome” approach. However, it appears that a state’s broader policy climate complicates health-related outcomes. The new study shows that, while adolescents and young adults who live in more liberal states report higher average rates of past-year cannabis use than those who live in conservative states, rates of cannabis use disorders among teens between 12 and 17 were significantly lower in the states with the more liberal policies and marginally lower for those 26 and older.

First author and assistant professor Morgan Philbin, Ph.D. tells Inverse says that this association emphasizes that “policies don’t exist in a vacuum.” The study is not saying that just because someone lives in a liberal state then it’s certain that they are less likely to develop cannabis use disorder. Instead, it suggests that the effects of legalization are influenced by a variety of factors. Cannabis-specific policies are being passed into different policy contexts across states, and in turn, state-level contexts influence cannabis outcomes.

“Now that this study is out in the world, we hope that policy-makers, researchers, and key stakeholders consider not just the potential impact of a specific policy, but also how that policy might have a differential impact based on the context in which it is being implement,” Philbin says.

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Rates of cannabis use disorder are lower in states with more liberal policies.

She reasons that there could be important state differences around factors like serviceability or stigma, which could impact cannabis-related knowledge, attitudes, and care access.

“We think this is potentially important with the increasing passage of recreational cannabis laws,” Philbin says. “Policies legalizing cannabis may have different impacts on cannabis use depending on the state in which it is passed, and it is important for policymakers to be aware of and discuss those factors when considering legalization.”

Philbin and her team examined state-level prevalence of past-year cannabis use and cannabis use disorder among users aged 12 to 17, 18 to 25, and 26 and older from the 2004 to 2006 and 2010 to 2012 National Surveys on Drug Use and Health. States were then categorized as liberal, moderate, or conservative based on standings determined by the State Rank on Policy Liberalism Index in 2005 and 2011. This index ranks state from 1 (most liberal) to 50 (most conservative) based on policies connected to factors like gun control, abortion access, and tax structure.

They found that cannabis use was consistently higher in liberal compared to conservative states and, while it wasn’t the primary goal of the study, they did find that overall, cannabis use disorder among past year cannabis users ages 12 to 17 and ages 18 to 25 dropped when they compared the periods 2004 to 2006 to 2010 to 2012. There wasn’t a significant change for those older than 26.

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Marijuana consumption is increasing in the U.S.

Philbin points out that this result aligns with data pulled from the National Epidemiological Survey on Alcohol and Related Conditions, which found that the prevalence of cannabis use disorder among cannabis users decreased significantly from 2001 to 2002 to 2012 to 2013. This possibly suggests that more individuals are using cannabis now compared to 12 to 15 year ago, but they don’t meet the clinical criteria for a cannabis use disorder.

Meanwhile, within all this increase, cannabis use was still higher in liberal compared to conservative states. The data also revealed that while for 12 to 17 year olds cannabis use disorder decreased in conservative states during that comparative window, the disorder remained 24 percent higher than in liberal states. Overall, they found that when they looked at cannabis use disorder among those aged 18 to 25 in conservative states, it dropped from an average of 22 percent to 18 percent. In liberal states, the change was a drop of 20 percent to 17 percent.

People are worried about cannabis use disorder because it’s associated with a risk of psychiatric comorbidities, cognitive deficits, and respiratory problems. It’s characterized by a pattern of problematic use and is often accompanied by withdrawal symptoms and increased tolerance to the drug. In the United States, a third of all current cannabis users meet the diagnostic criteria for the disorder, and more than 250,000 people were admitted for cannabis abuse treatment in 2016.

So it’s worth figuring out the factors that lead cannabis use to turn into a bigger problem. That’s something that this team hopes is explored further in future studies — there are still so many questions about what marijuana does to us, both negatively and positively. This study affirms that policymakers shouldn’t base their opinions on the drug on data collected from one region — each state is different, and those differences affect how people are affected by marijuana.