For the first time, daily marijuana use has surpassed daily cigarette use among college students in the US, with around 1 in every 17 college students smoking the substance on a daily or near-daily basis - the highest rate since 1980.
These findings form part of the University of Michigan's Monitoring The Future (MTF) study, a nationally representative annual survey that has tracked the substance use of college students in the US since 1980.
"It's clear that for the past 7 or 8 years there has been an increase in marijuana use among the nation's college students," reports principal investigator Lloyd Johnston. "And this largely parallels an increase we have been seeing among high school seniors."
Alongside regular users, the number of occasional marijuana users has also increased. Between 2006 and 2014, the percentage of students who reported using marijuana once or more in the prior 30 days increased from 17% to 21%. During the same period, the percentage reporting use in the past year increased from 30% to 34%.
Changing opinions may be behind these increases. The study finds that marijuana is not perceived to be dangerous by as many people as it has been in the past. In 2006, 55% of high school graduates aged 19-22 saw regular marijuana use as dangerous. By 2014, this percentage had fallen to 35%.
Cigarette smoking rates have also declined in recent years. While the percentage of students who reported smoking in the past 30 days fell from 14% to 13% between 2013 and 2014, this figure stood at 31% in 1999. While only 5% of students reported smoking cigarettes daily in 2014, 19% did so in 1999.
Rates of illicit substance use in students compared with noncollege peers
Several illicit drugs were found to be used less frequently than they have been in recent years. The researchers noted falls in the prevalence of use of synthetic marijuana (also referred to as K-2 or spice), salvia, inhalants, hallucinogens and the nonmedical use of narcotic drugs, sedatives and tranquilizers.
Johnston says that the study leaves some room for positivity:
"There is some more welcome news for parents as they send their children off to college this fall. Perhaps the most important is that 5 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."
The MTF also compared drug use rates in college students with their noncollege peers. The researchers found that in 2014, the prevalence of use for most illicit substances was lower among college students in comparison with noncollege peers.
Two notable exceptions were in amphetamine use and alcohol consumption. Amphetamine use among college students has leveled in recent years and was 10.1% in 2014, in comparison with 9.2% among noncollege peers.
"It seems likely that this increase in amphetamine use on the college campus resulted from more students using these drugs to try to improve their studies and test performance," Johnston suggests.
College students were also more likely to report heavy drinking - defined as five or more drinks in a row in the previous 2 weeks - than noncollege peers. The researchers noted that 35% of students reported heavy drinking compared with 29% of noncollege peers.
A total of 43% of college students also reported having been drunk in the past 30 days, compared with 34% of noncollege peers.
"Despite the modest improvements in drinking alcohol at college, there are still a sizable number of students who consume alcohol at particularly dangerous levels," says Johnston.
Recently, Medical News Today reported on a study investigating the drinking habits of students from Canada and the Netherlands. The study authors suggest that drinking water or eating directly after heavy alcohol consumption cannot prevent a hangover.