Marijuana use in College Linked to Poor Health Years Later

Kim Krisberg


Nations Health. 2016;46(2):e7 

Even limited amounts of marijuana use during college could have adverse health effects later in life, according to a new study.

Published in the February issue of Drug and Alcohol Dependence, the study is based on data from more than 1,200 young adults recruited during their first year of college in 2004. Researchers followed the first-year college students for 10 years, collecting data on their marijuana use as well as their physical and mental health outcomes.

Overall, students with minimal or no marijuana use during the first six years of the study had significantly better health outcomes by their late 20s than those who used marijuana chronically or increased their use in the latter part of the study's first six years. Even students who reported low marijuana use had worse health outcomes than those who never used marijuana.

"We think these findings add to the substantial body of literature that demonstrates that marijuana does have health risks," said APHA member and study co-author Amelia Arria, PhD, an associate professor in the Department of Behavioral and Community Health at the University of Maryland School of Public Health. "We think it's really important to dispel the myth that marijuana is a benign drug. In and of itself, marijuana does come with health risks."

Specifically, Arria and fellow researchers found that when compared to those who never used marijuana, chronic users and those whose marijuana use peaked during college reported more sick days and visits to a health provider. Students on a trajectory of low-but-stable marijuana use in the first six years had significantly more injury days by year 10 than those who never used. However, there was no difference in sick days or visits to a health care provider.

Chronic marijuana users and people whose marijuana use increased or declined over their college years fared worse on life satisfaction indicators, mental health visits and emotional health days. However, the groups did not fare worse on psychological distress measures than those who never used marijuana.

Compared to those with low-but-stable marijuana use, students whose marijuana use increased later in the study fared worse on emotional health days, mental health visits and life satisfaction scores. Overall, students who increased marijuana use late in their college careers reported particularly poorer health outcomes than all other user groups.

Arria noted that because the study adjusted for other factors such as alcohol and tobacco use over time, researchers can say "more confidently" that the study's findings were associated with marijuana use.

"We cannot say whether any of the observed differences might be considered clinically significant, yet the differences in service utilization alone highlight the potential for substantial long-term personal and economic impacts of marijuana use," the study stated.

Even though many studies have examined the health risks of marijuana, Arria said this study is unique because it characterized marijuana use over time, instead of simply comparing users against non-users. In addition, the study focused on young college students, who are at particular risk of marijuana use. In fact, Arria said that while much research has focused on the effects of marijuana use in adolescents and young teens, less is known about the impacts of increasing marijuana use after age 18.

"It's important to really stress that there are opportunities within higher education and on college campuses to do something about college student drug use because it can impair health and academic performance," Arria told The Nation's Health. "We need to identify users and provide the right types of intervention and prevention."

She also noted that while the nation is currently experiencing a drug use and overdose epidemic related to prescription drugs and opioids, all substance use is connected.

"You cannot separate out marijuana use as a separate public health issue," she said. "It's a different facet of an overall issue of substance abuse in this country."

According to data released last year from the University of Michigan's Monitoring the Future study, daily marijuana use among college students is on the rise, surpassing daily cigarette smoking for the first time in 2014.

For more information, visit