University Health Service

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HEALTH ALERT: The Centers for Disease Control and Prevention (CDC) recommends that you should not use e-cigarette or vaping products that contain THC (the primary psychoactive cannabinoid in cannabis) due to risk of serious lung injury.


Marijuana is a rapidly evolving topic because:

  • Cultivation of the plant is producing more potent and more specialized strains.
  • More products, and more ways to use products, are available now.
  • Some states, including Michigan, have legalized the use of marijuana for medical and/or limited recreational purpose.
  • New research is better identifying the effects of marijuana. This is due in large part to data collected from states that have legalized limited recreational use and because a ban on medical research has been lifted.

University Health Service helps students navigate this evolving issue and offers the following information and resources.


What students need to know about marijuana in order to make informed decisions and reduce harm:

How common is marijuana use on campus? According to the 2018 U-M National College Health Assessment, 81% of U-M students had NOT used marijuana in the past 30 days. That's more than 35,000 students.

Is it possible to have a bad reaction to marijuana?
Yes. Signs of a bad reaction may include extreme confusion, anxiety, paranoia, panic, fast heart rate, delusions or hallucinations, increased blood pressure, and severe nausea or vomiting. (Note that the Medical Amnesty law protects people who call for help, if they invoke it at the time they call.) 

The effects of marijuana can be unpredictable because:

How does marijuana affect the brain?
According to the CDC, marijuana use directly affects the brain, specifically the parts of the brain responsible for memory, learning, attention, decision making, coordination, emotions, and reaction time.

  • Heavy users of marijuana can have short-term problems with attention, memory, and learning, which can affect relationships and mood.
  • Marijuana also affects brain development. When marijuana users begin using as teenagers, the drug may reduce attention, memory, and learning functions and affect how the brain builds connections between the areas necessary for these functions. Marijuana’s effects on these abilities may last a long time or even be permanent. 
  • Developing brains, like those in babies, children, and teenagers are especially susceptible to the harmful effects of marijuana. 

How does marijuana affect mental health?
According to the CDC,

  • Marijuana use, especially frequent (daily or near daily) use and use in high doses, can cause disorientation, and sometimes cause unpleasant thoughts or feelings of anxiety and paranoia. 
  • Marijuana users are significantly more likely than non-users to develop temporary psychosis (not knowing what is real, hallucinations and paranoia), and individuals with frequent use during adolescence may be more likely to develop chronic psychosis (most likely those individuals with a genetic vulnerability).
  • Marijuana use has also been linked to depression and anxiety, and suicide among teens. However, it is not known whether this is a causal relationship or simply an association.

How does marijuana affect the lungs?
According to the CDC,

  • HEALTH ALERT: The Centers for Disease Control and Prevention recommends that you should not use e-cigarette or vaping products that contain THC due to risk of serious lung injury.
  • Smoked marijuana, in any form, can harm lung tissues and cause scarring and damage to small blood vessels. Smoke from marijuana contains many of the same toxins, irritants, and carcinogens as tobacco smoke. Smoking marijuana can also lead to a greater risk of bronchitis, cough, and phlegm production. 

How does marijuana affect a baby during pregnancy and breastfeeding?
According to the CDC,

  • Marijuana use by mothers during pregnancy may be linked to problems with attention, memory, problem-solving skills, and behavior problems in their children. 
  • Using marijuana while breastfeeding can allow harmful chemicals to pass from the mother to the infant through breast milk or secondhand smoke exposure. 

How does marijuana affect drivers?
According to the CDC (PDF), marijuana can slow drivers' reaction time and ability to make decisions, impair coordination, distort perception, and lead to memory loss and difficulty in problem-solving.

Is it possible to become addicted to marijuana? 
Yes, according to the CDC, about 1 in 10 marijuana users will become addicted, called marijuana use disorder.  For people who begin using before age 18, that number rises to 1 in 6.


What students need to know about marijuana-related laws in the state of Michigan:

  • The use of recreational or medicinal marijuana in any form, including edibles and extracts, is prohibited on university property by university policy and federal law. This is because federal law prohibiting marijuana preempts state laws that legalize the drug.
  • Possession of marijuana on U-M property is a misdemeanor with the possible consequences of fines, arrest, and jail time. For anyone under 21, possession of marijuana in the City of Ann Arbor is a civil infraction with a fine that increases with each additional infraction.
  • In the City of Ann Arbor, it is illegal for anyone to to use marijuana in public or drive under the influence of marijuana.
  • For more information about laws, please see Marijuana FAQs from the U-M Department of Public Safety and Security 

Resources to explore marijuana use and get early intervention or treatment, as needed:

  • Wellness Coaching for Alcohol and Other Drugs is a confidential, non-judgemental conversation offered free to all U-M students who want to explore their marijuana use.
  • e-TOKE (Marijuana e-CHECKUP TO GO) is an online, personalized, brief screening tool that lets you see how your marijuana use, family risk and campus norms affect your life and future. 
  • Helping a Friend suggests ways to talk with someone else about their use.
  • UHS Care Managers are available to talk about concerns related to use marijuana use and can help connect to resources.
  • See more Resources for Alcohol and Other Drugs or you may call Wolverine Wellness at 734-763-1320 for help in navigating resources. 

Are you in recovery from use of marijuana, alcohol or other drugs? 

Consider joining the Collegiate Recovery Program, which provides holistic, tailored support to U-M students who are in recovery from alcohol or other drug problems.


More information:

The CDC offers several excellent resources about the health and well-being effects of marijuana:

The Legalization of Marijuana in Colorado: The Impact (PDF) documents changes from 2013 to 2019 in Colorado.