A Brown University-led study finds that cannabis use may lead to less alcohol consumption in the short term, supporting the “California sober” trend. Researchers caution that further studies are needed to confirm long-term effects and real-world applications.
The “California sober” trend — favoring cannabis over alcohol — is spreading from Hollywood to homes across the nation. A new study from Brown University suggests that this trend might be backed by science. The research, published in the American Journal of Psychiatry, indicates that cannabis use can reduce alcohol consumption in the short term.
The study, led by researchers at Brown University, stands out as the first randomized, placebo-controlled trial to directly assess whether cannabis influences alcohol consumption. Standard laboratory conditions allowed the researchers to establish a cause-and-effect relationship, distinguishing this study from previous surveys and self-reported evaluations.
“What we found was consistent with this idea of the substitution effect popularized by the California sober trend,” first author Jane Metrik, a professor of behavioral and social sciences and of psychiatry and human behavior at Brown University, said in a news release. “Instead of seeing cannabis increase craving and drinking, we saw the opposite. Cannabis reduced the urge for alcohol in the moment, lowered how much alcohol people consumed over a two-hour period and even delayed when they started drinking once the alcohol was available.”
The study involved 157 adults aged 21 to 44, who drink heavily and use cannabis at least twice a week. Over three separate visits, participants smoked cannabis cigarettes containing either high or low THC levels, or a placebo. The researchers employed a placebo-controlled trial model, where neither the participants nor the researchers knew who received the placebo or the actual drug, ensuring an unbiased result.
After smoking, participants undertook the Alcohol Choice Task, a laboratory test designed to mirror real-world drinking behavior. In a bar-like setting, they were presented with their preferred alcoholic beverages and could choose to drink or earn small cash payments for abstaining. During each two-hour session, participants had access to enough alcohol to raise their blood alcohol level above the legal intoxication limit.
The results showed that participants who consumed cannabis with THC drank less alcohol compared to when they smoked the placebo. Specifically, those who smoked cannabis with a 3.1% THC concentration drank about 19% less, while those who consumed cannabis with a 7.2% THC concentration drank about 27% less.
Further, participants reported less immediate urges to drink after consuming cannabis with THC. Notably, those who smoked the higher THC dose took longer to start drinking compared to when they received the placebo.
“We saw that cannabis reduces the urge in the moment,” added Metrik. “What we don’t know from this study is what is the long-term effect.”
The researchers caution against viewing cannabis as a therapeutic substitute for alcohol due to its own addictive potential. They emphasized the need for further research to identify the long-term effects and real-world implications of using cannabis to reduce alcohol consumption.
Excessive drinking is the third leading cause of preventable death in the United States, costing an estimated $249 billion annually. Cannabis use often overlaps with alcohol problems, with around 60% of people with cannabis use disorder also meeting criteria for alcohol use disorder.
To explore the combined use of cannabis and alcohol, the team is conducting a new clinical trial funded by the National Institutes of Health, examining the effects of different cannabinoids in both laboratory and real-world settings.
For now, the study offers initial evidence that cannabis may reduce alcohol consumption, but further research is required before cannabis can be considered a viable tool for mitigating heavy drinking.
“Our job as researchers is to continue to answer these questions,” Metrik added. “We can’t tell anyone yet, ‘you should use cannabis as a substitute for problematic or heavy drinking.’”
Source: Brown University