University Health Service
Key info for U-M students to know (see more below):
- It’s illegal to:
- Possess or use cannabis if under age 21
- Possess or use at any age on U-M property
- Use in public
Cannabis 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 cannabis for medical and/or limited recreational purpose.
- New research is better identifying the effects of cannabis. 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 cannabis in order to make informed decisions and reduce harm:
How common is cannabis use on campus? According to the 2018 U-M National College Health Assessment, 81% of U-M students had NOT used cannabis in the past 30 days. That’s more than 35,000 students.
Is it possible to have a bad reaction to cannabis?
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 cannabis can be unpredictable because:
- Cannabis products are not standardized or regulated.
- With edibles, it takes time to feel the full effects, and people may be inclined to consume more and then have a bad reaction. Learn more at Marijuana Edibles Fact Sheet by the County of Los Angeles Public Health.
How does cannabis affect the brain?
According to the CDC, cannabis 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 cannabis can have short-term problems with attention, memory, and learning, which can affect relationships and mood.
- Cannabis 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 cannabis.
How does cannabis affect mental health?
According to the CDC,
- Cannabis 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.
- Cannabis 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).
- Cannabis 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 cannabis 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 cannabis, in any form, can harm lung tissues and cause scarring and damage to small blood vessels. Smoke from cannabis contains many of the same toxins, irritants, and carcinogens as tobacco smoke. Smoking cannabis can also lead to a greater risk of bronchitis, cough, and phlegm production.
How does cannabis affect a baby during pregnancy and breastfeeding?
According to the CDC,
- Cannabis use by mothers during pregnancy may be linked to problems with attention, memory, problem-solving skills, and behavior problems in their children.
- Using cannabis while breastfeeding can allow harmful chemicals to pass from the mother to the infant through breast milk or secondhand smoke exposure.
How does cannabis affect drivers?
According to the CDC (PDF), cannabis 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 cannabis?
Yes, according to the CDC, about 1 in 10 cannabis users will become addicted, called cannabis use disorder. For people who begin using before age 18, that number rises to 1 in 6.
What students need to know about cannabis-related laws in the state of Michigan:
- The use of recreational or medicinal cannabis in any form, including edibles and extracts, is prohibited on university property by university policy and federal law. This is because federal law prohibiting cannabis preempts state laws that legalize the drug.
- Possession of cannabis on U-M property is a misdemeanor with the possible consequences of fines, arrest, and jail time. For anyone under 21, possession of cannabis 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 cannabis in public or drive under the influence of cannabis.
- For more information about laws, please see Marijuana FAQs from the U-M Department of Public Safety and Security
Resources to explore cannabis use and get early intervention or treatment, as needed:
is a confidential, non-judgemental conversation offered free to all U-M students who want to explore their cannabis use. (Marijuana e-CHECKUP TO GO) is an online, personalized, brief screening tool that lets you see how your cannabis use, family risk and campus norms affect your life and future. suggests ways to talk with someone else about their use. are available to talk about concerns related to cannabis 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 cannabis, 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.
The CDC offers several excellent resources about the health and well-being effects of cannabis:
Proposed bill would set a legal limit for THC in bloodstream for Michigan drivers
MACOMB COUNTY, Mich. (WXYZ) — One Michigan lawmaker wants to make sure those who drive while high are held accountable. A new bill is aiming to set a legal limit for the amount of THC a driver has in their system.
Rep. Pamela Hornberger of Macomb County has introduced HB 4727, which would set the legal limit of THC a driver can have in their system to 5 nanograms per milliliter of blood.
For the family of 3 1/2-year-old Liliana Leas or “Lily”, a law like this could have made the difference in receiving justice for the death of their daughter.
“There are no words, you can’t explain perfection, you can say a million things over and over and over and explain her in a hundred different ways but there is no way to describe who she was,” said Lily’s mother, Joann Salas.
Lily’s step-grandmother, Nicole Leas of Warren, is accused of running over Lily a year ago while driving high. However, with no set limit of how high is too high on the books, prosecutors say they only able to charge her with is a misdemeanor in Lily’s death, up to a year in jail.
“She killed our baby and she’s doesn’t, what we feel gets nothing, like a slap on the wrist,” said Salas.
It was Lily’s story that inspired Hornberger to work with Macomb County Prosecutor Peter Lucido to introduce this bill.
“Would that make your case easier today?” Asked 7 Action News Reporter Ali Hoxie in regards to Lily’s case.
“Absolutely, 100%,” said Lucido. “It would have been a real easier case as it relates to how high is one too high to drive a vehicle even if it is moving a car six feet.”
“We’ve already had, that we know of, one child killed by a person that was strictly under the influence of THC, no alcohol in their system no other drugs in their system so no is not an option,” said Hornberger.
However, experts say taking blood measurements of THC is an inaccurate way of determining if someone is driving high.
“This is a very difficult question, you know, I mean, it certainly can impact many many people,” said Norbert Kaminski.
Kaminski is a professor of pharmacology and toxicology at Michigan State University. He also is one of six who sat on the Impaired Driving Safety Commission; made up of professors, physicians and representatives from Michigan State Police. It was in 2019 the commission determined no THC level should be set for Michigan drivers.
Kaminski explains when a person gets high, THC levels spike and decline quickly within the body and then plateau. Unlike blood-alcohol levels which have a clear correlation.
The concern Kaminski had along with the board, is THC levels plateau out and remaining in the blood system for days even after the high has dissipated. He says it could lead to false convictions.
“We also don’t want to charge people with impaired driving if they are not impaired,” said Kaminski. “You can imagine somebody who is above that legal limit serval days after they have smoke cannabis are not going to be impaired anymore but they would certainly be over some of these limits that we are discussing.”
Similar laws are already on the books in six states; Illinois, Montana, Nevada, Ohio, Pennsylvania and Washington. The legal limit ranges between one to five nanograms of THC in a driver’s bloodstream.
Here in Michigan, there is a zero-tolerance policy for driving high, but determining if someone is high is left up to a sobriety test conducted by law enforcement. Lucido says having a set limit in place would strengthen legal cases for those who do drive high.
“We lost a little girl, Lily is a little girl and that is what this law is about,” said Lucido.
Hornberger says the five nanograms proposed is just a starting point. She and Lucido are hoping this bill starts a conversation here in Michigan to try and set a THC limit. Both say if other states can do it, Michigan can too.
Kaminski did say he feels there is room to develop more accurate ways of determining impairment in roadside sobriety test. That being said, Lucido says there are a lack of law enforcement properly trained to conduct those sobriety test for those driving high.