In a makeshift bar on a college campus, researchers studied how smoking cannabis affected alcohol consumption.
Countless college students have conducted the experiment: What happens when you mix alcohol and cannabis?
But few have done so in a lab, under the watchful eye of scientists, carefully calibrating their breathing as they take hits of research-grade marijuana.
In a new study, investigators corralled around 150 adults into a makeshift bar on campus at Brown University in order to test how much people wanted to drink after they smoked cannabis. It is one of the first rigorous trials to examine how marijuana affects drinking.
“This is basically a very carefully, precisely designed study of cross-fading,” said Dr. James MacKillop, the director of the Michael G. DeGroote Center for Medicinal Cannabis Research at McMaster University and an author on the study. (Cross-fading means getting simultaneously drunk and high.)
The researchers found that people drank considerably less after they smoked cannabis.
The new paper, published Wednesday, arrives at a time when going “California sober” — using marijuana and other drugs, but not alcohol — has become trendy. Researchers attribute its popularity to the growing legalization and availability of cannabis in an array of forms, including prepackaged edibles and beverages, as well as a rising awareness about the health harms of alcohol.
“We too often study drugs in isolation,” said Ryan Vandrey, a professor of psychiatry and behavioral sciences at Johns Hopkins Medicine, who studies cannabis and was not involved with the new research. But in reality, he said, people commonly combine alcohol and cannabis.