ANN ARBOR—Marijuana use among U.S. college students in 2016 was at the highest level seen in the past three decades, according to the most recent findings from the national Monitoring the Future follow-up study.

College student marijuana use has been showing a steady increase over the past decade.

In 2016, 39 percent of full-time college students aged 19-22 indicated that they used marijuana at least once in the prior 12 months, and 22 percent indicated that they used at least once in the prior 30 days. Both of these 2016 percentages are the highest found since 1987, and represent a steady increase since 2006, when they were 30 and 17 percent, respectively.

But the 2016 percentages are still below the peaks in use found in the early 1980s when 12-month and 30-day prevalence reached more than 50 percent and 33 percent, respectively (findings on college students were first available in the study in 1980).

Daily or near daily use of marijuana—defined as having used 20 or more times in the prior 30 days—was at 4.9 percent in 2016; this is among the highest levels seen in more than 30 years, though it has not shown any further rise in the past two years.

“These continuing increases in marijuana use, particularly heavy use, among the nation’s college students deserve attention from college personnel as well as students and their parents,” said John Schulenberg, the current principal investigator of the Monitoring the Future follow-up study. “We know from our research and that of others that heavy marijuana use is associated with poor academic performance and noncompletion of college.

“Colleges are not simply inheriting this problem from high schools. Marijuana use has remained steady in recent years among the nation’s high school seniors, so this increase among college students suggests it has something to do with college and young adulthood experiences.”

One likely reason marijuana use is increasing among college students and their peers who aren’t in college, according to the study results, is the ongoing decline in perceptions of risk of harm from regular marijuana use. In 2016, 30 percent of those aged 19-22 perceived regular use of marijuana as carrying great risk of harm, the lowest level reached since 1980.

“This percentage peaked at 75 percent in 1991, when marijuana use among college students and their noncollege-age mates was at historic lows,” said Lloyd Johnston, the original principal investigator of the Monitoring the Future study. “We have consistently seen this inverse relationship between perceptions of risks of harm and actual use, with changes in perceptions of risk typically preceding changes in use.”

In 2016, 12-month and 30-day marijuana use were similar for full-time college males and females, but daily marijuana use was higher for college males at 6.6 percent than college females at 3.9 percent. Twelve-month and 30-day marijuana use tend to be lower among full-time college students than among their same-age peers who are not in college full-time. This is particularly true for daily marijuana use, with daily use among noncollege youth being two-and-one-half times as high—at 12.8 percent in 2016, the highest level since this panel study began in 1980—versus 4.9 percent among full-time college students.

These findings come from the long term Monitoring the Future study, which has been tracking substance use of all kinds among American college students for the past 37 years. It is conducted by a team of U-M researchers and is funded by the National Institute on Drug Abuse. These results are based on full-time students who are one to four years beyond high school graduation and are enrolled in a two- or four-year college in March of the given year.

The follow-up study also examined the use of other illicit drugs and alcohol. Use of these substances mainly remained steady, and the study’s results include:

• Annual use of other illicit drugs among college students has leveled in recent years, with about one in five students reporting using an illicit drug other than—and usually in addition to—marijuana at least once in the prior 12 months. Annual use increased from 2008 through 2014, but has stalled at a relatively high level over the past few years.
• Alcohol continues to remain the drug of choice among college students, with 63 percent reporting they drank, and 41 percent saying they were drunk, at least once in the prior 30 days. There has been some modest falloff in these percentages since the early 1980s.
• In 2016, 32 percent of college students reported binge drinking—defined as having five or more drinks per occasion at least once in the past two weeks. It has gradually declined over the years for college males, but not college females, resulting in some closing of the gender gap. It is more common among college students than noncollege youth.
• Across 2012 through 2016, 10.1 percent of college students reported having 10 or more drinks per occasion at least once in the past two weeks. According to Schulenberg, “Having 10 or more drinks in a row, which is happening for one in six college males at least once per two-week period, can result in alcohol poisoning, serious accidents, and a host of unwise decisions and dangerous behaviors that adversely affect them and those around them.”
• In 2016, 30-day cigarette smoking among college students was 8.9 percent, a record low since 1980, consistent with continuing the decline over the past 17 years. Cigarette smoking is much higher among noncollege youth, with 30-day use being 18.8 percent in 2016.

More information:

• Study: National Survey Results On Drug Use, 1975–2016
• Tables/figures
• John Schulenberg
• Monitoring the Future