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Member Research & Reports

Member Research & Reports

Maryland Study Finds Trajectories of Marijuana Use in College Predict Health Outcomes Later in Life

Even occasional and limited marijuana use during college may have negative effects on a student’s long-term physical and mental health, according to researchers in the University of Maryland School of Public Health.

[Photo: Dr. Amelia Arria]

In a new study led by Dr. Amelia Arria, associate professor in the department of behavioral and community health, students evaluated over a nine-year period post-matriculation showed significant differences in health outcomes based on the course of their marijuana use during college.

The study used data from a 10-year study of a group of 1,253 young adults recruited as first-year college students, and assessed annually. Six trajectories of college marijuana use were established to examine the effects of types of use on later health outcomes: Non-Use, Low-Stable, Early-Decline, College-Peak, Late-Increase, and Chronic. Overall, young adults who followed a trajectory of minimal or non-use of marijuana during the first six years of the study had significantly better health outcomes in their late 20s than most of the other marijuana trajectory groups. Similarly, individuals whose marijuana use declined over time appeared to have better mental health outcomes than their counterparts who maintained stable marijuana use trajectories. Chronic and Late-Increase marijuana users fared the worse. The study accounted for background risk factors and related rates of change in alcohol and tobacco use.

Many studies have linked marijuana use to health outcomes in young people, but more research is needed to assess the long-term effects of college-age marijuana use, said Dr. Arria. In particular, the findings suggest that taking up marijuana use at a later age may not protect users from adverse mental health outcomes.

“College is an opportune time to identify and intervene to prevent further escalation of use, or to prevent initiation,” said Dr. Arria, who directs the Center on Young Adult Health and Development at the University of Maryland School of Public Health. “Despite the popular notion that marijuana use is benign, students should realize that marijuana use can have adverse impacts on health and functioning, and can especially raise the risk of mental health problems.”

The study, “Marijuana use trajectories during college predict health outcomes nine years post-matriculation,” is published in the international journal Drug and Alcohol Dependence.