Students at at least one Oregon university are using marijuana more heavily since it was legalized in the state, a new study found.
Researchers at Oregon State University surveyed undergraduate students at seven institutions, including one large public Oregon university that went unidentified. The other colleges were based in states that had not legalized marijuana.
The authors of the study compared the rates of marijuana use both before and after its legalization in 2015. Oregon voters approved recreational use in 2014.
Almost all the institutions saw increased marijuana use, but use at the Oregon institution was significantly more prevalent.
Students who reported binge drinking -- defined as consuming four to five or more drinks in a period of about two hours -- were significantly (about 73 percent) more likely to use marijuana.
Those under 21 were more likely to use marijuana too, though the legal age of consumption in Oregon is 21.
Male students, those living in Greek housing and those who did not identify as heterosexual also were more likely to use marijuana.
The results were published Wednesday in the journal Addiction.
“It’s an important current issue, and even the most basic effects have not been studied yet, especially in Oregon,” the study’s lead author, David Kerr, an associate professor in Oregon State’s school of psychological science, said in a statement. “There are a lot of open questions about how legalization might affect new users, existing users and use of other substances.”