Marijuana finds a somewhat welcoming culture at the University of Oregon. When polled, students believed that nine out of 10 of their peers had smoked marijuana in the last 30 days. You only have to hang around certain parks at sunset to witness little circles of undergrads taking turns flicking a lighter in the twilight.
Last year, ESPN investigated marijuana culture within the UO football team in its “We Smoked It All” feature. When Colorado and Washington became the first two states to legalize marijuana for recreational use, it became clear by popular vote that society is more widely accepting of the drug. As marijuana becomes more culturally accepted, it’s important to note how the substance has changed and how it can affect mental health.
Experts have tracked the relationship between marijuana and psychosis since the ’80s. The initial study tracked individuals for 15 years and found that those who had used cannabis before age 18 were 2.4 times more likely to be diagnosed with schizophrenia. Many studies have drawn similar conclusions, but the counter argument remains that individuals predisposed to psychosis are twice as likely to use cannabis. While no study can claim that cannabis directly causes psychosis, these studies are interested in determining whether or not marijuana could be a possible trigger.
Most studies suggest that family history is a crucial element that links the use of cannabis to psychosis. A 2006 article in the “Canadian Journal of Psychiatry” by Louisa Degenhardt and Wayne Hall concluded that cannabis use likely precipitates schizophrenia in individuals who are vulnerable because of a personal or family history.
Adam Gorman is the post-doctoral resident in alcohol and drug therapy at the UO. In terms of marijuana and college students, Gorman points out that the human brain isn’t fully developed until age 23.
“When your brain is still developing and you have a genetic predisposition to psychosis, whether schizophrenia or some other form of delusion, and you smoke marijuana, it can be like pouring gasoline on a fire,” Gorman said. “You significantly increase your chances of having a psychotic break.”
There is no definitive evidence that says smoking marijuana will cause psychosis in a person who is genetically predisposed or has a family history, but current studies imply that it’s a risk.
“Think of it like a really dry forest,” Gorman said. “Is a forest fire bound to start? No. But if you flip a cigarette out your window, which could be the marijuana, that could be the ignition.”
UO senior Kody — whose name is being withheld due to concerns of discrimination based on his medical condition — experienced a manic episode at the beginning of his junior year in 2012, which resulted in his diagnosis of bipolar disorder. The late teens and early 20s are a common period for psychoses to show up in men, but what triggered Kody’s episode is not clear.
Kody’s case fits some of the information that suggests marijuana is a component trigger in the onset of psychosis. He was 17 the first time he smoked marijuana and says it affected him differently than most of his friends.
“Weed has always been a cerebral experience for me, in the sense changing my thought process heavily and thinking about things in new ways,” Kody said. “I think that happens to a lot of people who smoke weed.”
His experience fits studies that claim psychosis-prone individuals are more likely to experience symptoms that mimic psychosis after small uses of cannabis. But again, there is no way to definitively say that marijuana triggered his episode.
He doesn’t think it did.
If Kody had to guess, he would attribute his onset to other triggers, some of which are featured in the counterarguments of similar studies.
He thinks his episode had more to do with the recent passing of his good friend, his use of psychedelics and deep interest in philosophy, which he says makes him think of the world in more abstract ways.
“[The doctor(s)] never said that psychedelics caused bipolar,” Kody said. “It almost was more like if you have bipolar it was bound to happen. It wasn’t about your friend’s death. It wasn’t about this other stuff. Yeah, maybe that is what triggered the onset, but it was going to happen anyways.”
Ron Unger is a mental health therapist based in Eugene who frequently works with UO students who expeirence psychosis or psychotic symptoms.
“I doubt that this small increased risk might cause people to change their behavior,” Unger said. “The important thing about substances is that they affect different people in different ways.”
The majority of studies conclude that the age at which you first start smoking and the amount you smoke can make you more susceptible to psychosis — the earlier the age of onset of cannabis use, the greater the risk for psychotic outcomes.”
Most of these studies and professionals acknowledge issues and fallacies with their own findings. Many cite that basing studies on self-reporting is an issue. Unger said the issue with many studies is that they’re not randomized experiences and lack of control groups.
Another theory, which Unger says refutes marijuana as a component trigger, is the claim that people prone to psychosis are drawn to marijuana to self-medicate. The “Canadian Psychiatry” article analyzes six longitudinal studies on the issue and shows a large number of schizophrenic report using cannabis due to its euphoric effects in relieving negative symptoms and depression.
Correlations between marijuana use and early onset psychosis is only seen in a small population. The Society for the Study of Addiction claims that only one in 50 users would be at risk, compared with one in 100 non-users.
“I can’t say ‘Yes, you have a higher likelihood of having psychosis if you use.’” Gorman said. ”I look at it that if you party, you take a risk every time, and we don’t know why this one person has a psychotic break after smoking and a person who smoked the exact same amount wakes up and feels normal. We don’t know.”
While the risk of having a psychotic episode triggered by marijuana use remains low, the number of people who use marijuana continues to grow globally. The “UN World Drug Report” in 2013 reported that cannabis use among high school students in the US has increased — 1 in 15 high school seniors reported frequent cannabis use as of 2011.
In 2012, 28 percent of UO students reported using marijuana in the last 30 days and one-fifth of new and transfer students under the age of 21 reported using marijuana in the previous two weeks.
Data from the National Institute of Drug Abuse and the Drug Enforcement Administration has found that the THC potency of marijuana has increased from less than 1 percent in 1975 to between 3.5 and 5.1 percent in 2009. THC levels can get much higher, with types at dispensaries reaching up to 25 percent.
“Back in the ’60s marijuana was like a white wine spritzer,” Gorman said. “Now many of the strands can be like a shot of Everclear. That’s how much the potency has increased.”
While only two states have legalized marijuana for adults, medical use is legal in another 21 states.
“You’ve got to acknowledge that there’s a cultural shift happening,” Gorman said. “While marijuana potency continues to rise, the belief that the substance is harmless remains the same.”
Unger warned that one way to avoid the potential risks associated with marijuana is to assess your consumption based of how it is affecting your mental health.
“The main thing would be to pay attention to how it’s affecting you. If you’re becoming more confused or having a harder time handling things, consider backing off.”