ANN ARBOR, Mich., Sept. 3 (UPI) -- Daily marijuana use by college students is the highest it has been since 1980 and has surpassed daily cigarette smoking for the first time, according to a new study by the University of Michigan.
About half of all college students reported they had not used any illicit drug in the previous year and three-quarters reported they hadn't used drugs in the previous month. The use of many drugs, marijuana especially, has seen several years of increase though.
"It's clear that for the past seven or eight years there has been an increase in marijuana use among the nation's college students," said Lloyd Johnston, a professor at the University of Michigan, in a press release. "And this largely parallels an increase we have been seeing among high school seniors."
Researchers collected data as part of the national Monitoring the Future survey of teenagers and college students for the 35th year, which includes following up with previous participants in the study dating to its start.
The survey found that daily use of marijuana by college students, defined as use 20 or more times in the previous 30 days, continued a nine-year rise to 5.9 percent -- meaning that 1 out of every 17 students is consuming the drug in some form every day.
Use of marijuana once or more in the previous 30 days also rose to 21 percent, and the number of students who had used in the previous year increased to 34 percent.
The researchers noted that some of the increase in use could be blamed on shifting opinions that marijuana is detrimental, based on the percentage of high school graduates between the ages of 19 and 22 who view it negatively decreasing from 55 percent in 2006 to 35 percent in 2014.
For drugs other than marijuana, researchers found nonmedical use of amphetamines -- likely to improve attention in class and test scores -- nearly doubled from 2008 to 2011, but researchers found it leveled off in 2014, with 10.1 percent reporting use in the last 12 months. Ecstasy use has leveled off, with just under 6 percent reporting use in the last 12 months, but that comes after a spike between 2007 and 2012.
Cocaine use reported in the previous year also increased from 2.7 percent in 2013 to 4.4 percent in 2014. "We are being cautious in interpreting this one-year increase, which we do not see among high school students; but we do see some increase in cocaine use in other young adult age bands, so there may in fact be an increase in cocaine use beginning to occur," Johnston said.
Overall use of illicit drugs by college students in the previous year has increased from 15 percent in 2008 to 21 percent in 2014. Researchers attribute some portion of this to an increased use of amphetamines without a prescription and an unexpected increase in use of ecstasy. Even so, about 5 out of every 10 college students reported not having used an illicit drug in the previous year.
"There is some more welcome news for parents as they send their children off to college this fall," Johnston said. "Perhaps the most important is that five out of every 10 college students have not used any illicit drug in the past year, and more than three quarters have not used any in the prior month."