Next steps for research regarding marijuana policy’s effect on alcohol usage

Andrew Chan

Marijuana and alcohol study

The University of Washington Center for the Study of Health and Risk Behaviors has conducted studies on the correlation between marijuana and alcohol consumption. Without more precise, statistical methods, the findings thus far have been ambiguous.

Nathan Lim 

Changes to marijuana policies may extend much deeper than popularly publicized medicinal and economic benefits, according to a new UW study.

Katarina Guttmannova, Ph.D. in experimental and developmental psychology and principal investigator in the Social Development Research Group at the UW, along with fellow researchers and the Center for the Study of Health and Risk Behaviors, recently published a study titled “Impacts of Changing Marijuana Policies on Alcohol Use in the United States.”

The study, published Dec. 21 in the journal Alcoholism: Clinical and Experimental Research, sought to find and analyze previous research studies done in the United States that illustrated correlations between marijuana legalization and alcohol usage.

 

“One thing that tends to happen is that the media focus on findings from individual studies, without reviewing all the research,” Guttmannova said. “What we need now is scientific evidence from a broad range of carefully conducted studies that examine the effects of marijuana-related policies on substance use.”

With 751 published articles located through the EBSCO Information host database, the research team systematically narrowed the pool down to 15 studies relevant to their scope of research. These selected articles involved data from states involved in marijuana decriminalization, medical marijuana legalization, and recreational marijuana legalization.

“We used online scientific search databases to get the published, peer-reviewed scientific studies,” Guttmannova said. “Ultimately, 15 studies fulfilled the criteria for the systematic, critical review and were included in our study.”

Through analysis of these articles, Guttmannova and her research team found mixed evidence on the effect of marijuana-related policies on alcohol use, with some studies reporting decreases in alcohol use in states with medical marijuana legalization. However, there was also evidence showing increases in heavy alcohol consumption and its consequences in states with medical marijuana legalization.

“The source of those discrepant findings is tied to the fact that marijuana policy and its impact on substance use is a complex issue,” Guttmannova said. “Studies should pay close attention to the various dimensions of marijuana policies across states and within states over time.”

However, researchers didn’t walk away from the study empty-handed. The study was a reminder of the difficulties of studying human behavior in the current cultural context.

“Our work on this study was a reminder that when we try to answer questions about human behavior in the context of many forces — economic, legal, and social — the answers are always complicated,” Guttmannova said.

Guttmannova suggested further research is needed, particularly some that pays close attention to marijuana policy changes that affect the supply and demand of marijuana, the timing of policy change and implementation, and different aspects of marijuana use including age, frequency of use, and amount of use.

Guttmannova has partaken in numerous studies pertaining to child and adolescent substance use and behavioral problems. Her interest in this particular demographic has influenced her to base further research studies on adolescents and young adults.

“Adolescence is a period of rapid physical, social, emotional, and cognitive development,” Guttmannova said. “Substance use during this developmental period can be particularly harmful.”

With medical marijuana legalized in 23 states, and recreational marijuana legalized in four, there is an increasing amount of statistics pertaining to marijuana usage in the United States.

Guttmannova has already begun researching the effects of marijuana policies on substance use among adolescents in five states and is looking to expand the scope of her study nationwide.

“I think we will move, albeit incrementally, to a fuller and more nuanced understanding of the impact of marijuana policy changes.”