A team of University of Washington researchers examined the connection between marijuana and alcohol – in particular, whether legalizing marijuana tempts pot users to consume more alcohol than pot or increase the use of both substances.

"We chose to focus on alcohol because even relatively small changes in alcohol consumption could have profound implications for public health, safety and related costs," Katarína Guttmannová, lead author of the study, said in a press release.

For their study researchers used information from over 750 studies on marijuana and alcohol use, including 15 studies that specifically examined the links between marijuana policies and drinking. However, the studys' conclusions varied greatly depending on the demographic in question and the type of alcohol and nature of the marijuana use.

One study in states where marijuana was decriminalized found a link between marijuana useand an increase in emergency room visits related. Another study reported that states with legal or medical marijuana dispensaries had increased rates of both alcohol and marijuana consumption, as well as higher populations enrolled in alcohol treatment facilities.

The researchers concluded that there is sufficient evidence to show that marijuana and alcohol are used as substitutes for each other as well as compliments to each other, so further research will be needed.

"This is a complicated issue and requires a nuanced approach," Guttmannová said. "We were hoping to have more clear-cut answers at the end of our research. But you know what? This is the science of human behavior, and it's messy, and that's OK."

The findings were published in the Dec. 21 issue of Alcoholism: Clinical and Experimental Research.