• Posted June 21, 2023

Legalizing Marijuana Tied to More Binge Drinking in Folks Over 30

A growing number of states are legalizing marijuana for recreational use, and it may be leading to an unexpected side effect among millennials and Gen Xers: binge drinking.

Binge drinking is defined as five or more drinks at a time for men or four or more drinks for women, according to the U.S. National Institute on Alcohol Abuse and Alcoholism.

"Recreational cannabis laws can have spillover effects on binge drinking among adults,"said study author Priscila Dib Gonçalves, a post-doctoral fellow in the substance abuse epidemiology program at Columbia Mailman School of Public Health in New York City.

There was a decline in binge drinking among younger folks in states with recreational cannabis laws, the study found.

So how may marijuana laws affect alcohol use? The study wasn't designed to prove cause and effect, but researchers have some theories.

"As cannabis and alcohol are available, people can use both substances, which is called the complementary hypothesis,"Gonçalves said. "Our results showing increases in binge drinking among adults in the study are in line with this hypothesis."

For the study, researchers analyzed data from the National Survey on Drug Use and Health of people aged 12 and older from 2008 to 2019.

Over that period, binge drinking increased from 28% to 33% among 31- to 40-year-olds and from 13% to 17% among people aged 51 or older.

Binge drinking fell from 17.5% in 2008 to 11% in 2019 among 12- to 20-year-olds, and from 44% to 40% among 21- to 30-year-olds, the study showed.

Twenty-three states, two territories, and the District of Columbia allow marijuana for recreational purposes as of June 1, according to the National Conference of State Legislatures.

When researchers looked at binge drinking before and after recreational cannabis laws were put in place, they noted a 4.8% decrease in binge drinking among 12- to 20-year-olds, but increases in all other age groups: up 1.7% among 31- to 40-year-olds; 2.5% for those 41 to 50; and 1.8% for those aged 51 and older. The study did not look at cannabis use.

Gonçalves said it's time to raise awareness about the harms of binge drinking -- especially in states where recreational cannabis use is legal. There are short- and long-term consequences associated with binge drinking from drunken driving and car crashes to liver and other chronic diseases, she said.

The findings were published online June 15 in the International Journal of Drug Policy.

Marijuana policy experts not affiliated with the new research caution that it is still too early to draw any conclusions about how, or even if, legalizing marijuana will affect alcohol use patterns.

"The results "¦ add to a literature that has found differing and sometimes contrary effects of cannabis availability and legalization on alcohol use,"said Coleman Drake, an assistant professor in the University of Pittsburgh School of Public Health's department of health policy and management.

"This study uses fairly recent data from the National Survey on Drug Use and Health, which is the gold standard of large-scale surveys on substance use in the U.S.,"he said. "As such, the study's finding that recreational cannabis laws are associated with increased binge drinking among adults aged 31 and above is particularly interesting and potentially concerning."

On the flip side, the finding that recreational cannabis laws are associated with decreased binge drinking among people aged 12 to 20 may be good news, Drake said.

The question is whether recreational cannabis is a substitute or a complement to drinking alcohol.

"If recreational cannabis is a complement -- that is, its use increases alongside alcohol -- then we should see recreational cannabis laws leading to increased drinking,"Drake said.

Exactly why this may occur is not fully understood.

"Perhaps cannabis produces a disinhibition effect whereby people become less concerned about drinking when using cannabis,"he said. "On the other hand, maybe there's a substitution mechanism where people use cannabis instead of alcohol."

It may be different strokes for different-aged folks when it comes to how cannabis availability affects drinking habits.

"This study makes an important contribution, but I would caution against firmly concluding that recreational cannabis causes increased binge drinking,"Drake said.

Dr. Jonathan Samet agreed. He is the dean and professor at the Colorado School of Public Health, in Aurora.

"The study points to the difficulty of singling out the consequences of changing marijuana policy and regulation,"Samet said. "Given the number of states with recreational marijuana and more to come, we need to have the right surveillance systems in place to capture the consequences for youth and adults."

More information

The U.S. National Institute on Alcohol Abuse and Alcoholism has more on the dangers of binge drinking.

SOURCES: Priscila Dib Gonçalves, PhD, post-doctoral fellow, substance abuse epidemiology program, Columbia Mailman School of Public Health, New York City; Coleman Drake, PhD, assistant professor, University of Pittsburgh School of Public Health, Pittsburgh; Jonathan Samet, MD, MS, dean, professor, Colorado School of Public Health, Aurora; International Journal of Drug Policy, June 15, 2023, online