Marijuana use among college students is going up, and at a decidedly higher rate in states where recreational use is legal, according to a new Oregon State University study.
But work by another OSU researcher, using the same data base, points to a decline in binge drinking on campuses in states with legal pot.
Washington and Colorado became the first two states to legalize, tax and regulate use of marijuana for recreation in 2012. Numerous other states, notably California, have followed.
Canada has recently legalized cannabis, largely to wrestle production away from gangs.
The OSU study, published in the journal Addiction, found that occasional lighting up and more frequent cannabis use has increased most where it can be done legally.
RELATED: UW study to examine marijuana use during pregnancy and its impacts on fetal and infant development
Overall use is up, but up 18% more in “legal” states, with an equal jump among those who use cannabis frequently.
The study was undertaken by Harold Bea of the OSU College of Public Health and David Kerr of the College of Liberal Arts.
They engaged data from seven states and 135 campuses where marijuana is legal, and from 41 states and 454 pot use was not (yet) legal.
The researchers used data compiled by the National Collegiate Health Assn. from 2008 to 2018, which came from 850,000 students.
An OSU doctoral student, Zoe Alley, using the same data, found a steeper decline in binge drinking on campuses in states where cannabis use is legal.
“In these two studies, we saw changes after legalization that really differed by substance,” said Kerr. “For marijuana, we saw state-specific increases that went beyond nationwide increases, whereas binge drinking was the opposite, a greater decrease in the context of nationwide decreases.”