by Anders Gilliand was only 17 years old when he started to lose touch with reality.
“He thought there were higher beings communicating with him to tell him what to do or who he was,” said his mother, Kristin Gilliand, who lives in Nashville.
Her son, who had been using marijuana since he was 14, was diagnosed with schizophrenia, a chronic psychiatric disorder that can include symptoms such as delusions, hallucinations and disorganized speech.
He started taking antipsychotic medication but eventually stopped because of the side effects. To try to silence the voices in his head, he started using heroin and died of an accidental drug overdose in 2019 when he was 22.
“If he had never started using cannabis, he could still be here,” said Gilliand, a neuroscientist at Vanderbilt University. Although there is a family history of schizophrenia, she believes her son’s marijuana use led to psychotic episodes and triggered the condition.
Anders was among a growing number of young adults, especially men, who are at increased risk of developing psychosis due to marijuana use. Evidence from separate studies from Denmark and Britain, among others, suggests a link between heavy marijuana use and psychiatric disorders such as depression, bipolar disorder and schizophrenia. Researchers believe that high levels of THC – the psychoactive component in the cannabis plant that causes the high – may offset these conditions in people at genetic risk. THC levels in marijuana have been getting stronger for years.
“We are definitely seeing an increase in cannabis-induced psychosis among teenagers,” said child psychiatrist Dr. Christian Thurstone, an addiction specialist at the University of Colorado School of Medicine in Denver.
Is higher potency marijuana more dangerous?
The more potent the cannabis products, the more likely users will experience adverse effects, said Nora Volkow, director of the National Institute on Drug Abuse.
“The people who consume the highest doses are the ones who are at the greatest risk of becoming psychotic,” she said.
There is limited research on the harmful effects of high levels of THC, although a European study published in 2020 found that high potency cannabis products had a greater risk of hallucinations and delusions compared to lower potency varieties.
“There appears to be an association between cannabis strength and an increased risk of psychosis, but more work needs to be done,” said Ziva Cooper, director of the cannabis and cannabinoids center at UCLA.
Up to half of people with cannabis-induced psychosis may go on to develop schizophrenia or bipolar disorder, according to research.
Young adults and teenagers should be of particular concern, Thurstone said
“The studies we’ve done so far clearly show that the risk for psychosis is dose dependent, meaning the more marijuana someone is exposed to especially in adolescence, the greater the risk of psychosis, schizophrenia and develop severe mental illness,” he said.
Another issue with higher strength products is the possibility of developing cannabis use disorder, or addiction to marijuana. When people are frequently exposed to higher strengths of cannabis, they may be more likely to develop a cannabis use disorder, although more research is needed to say definitively.
“There is no longer any scientific debate that marijuana can be not only psychologically addictive or habit forming, but also physically habit forming,” Thurstone said. “It’s a tolerance-producing substance so people have to use more and more to get the same effect.”
According to the Centers for Disease Control, about 1 in 10 people who start using cannabis will become addicted.
How can cannabis potency be linked to psychosis
Marijuana overactivates molecules in our brain called cannabinoid receptors, causing the high. When these brain receptors are stimulated, it can cause difficulty with thinking and problem solving, as well as impaired memory.
How marijuana use can trigger psychosis is not fully understood, although scientists believe it is interfering with our brain’s ability to distinguish between what is going on in our heads and the real world.
“Marijuana in the ’60s, ’70s, ’80s and early ’90s was about 2% to 3% THC,” said Thurstone, who traced the rise of high-potency THC products to smoke shops and dispensaries. “Nowadays, with the commercialized products, they’re usually 20 plus percent – so about 10 times more powerful.”
Patrick Johnson, assistant store manager at Frost Exotic dispensary in Colorado, has been in the cannabis industry since 2009 and the potential is just increasing. Johnson said THC levels really started to take off after marijuana was legalized for recreational use in Colorado in 2014.
Since then, 24 states, two territories and Washington, DC have legalized marijuana for medical and recreational use.
With more people around the country using weed legally, consumer demand for more potent weed is growing, experts say.
“After recreation [legalization] that’s when I personally saw it go from 19 or 20% up to like 30 or 35%,” Johnson said.
In their store they currently carry strains as low as 14% up to 30%. Most customers prefer the strong stuff, Johnson said.
One reason that potency has become stronger over the years in cannabis products is because customers may develop a tolerance to the drug, said Mahmoud ElSohly, a professor of pharmacy and cannabis researcher at the University of Mississippi. He is studying this issue in collaboration with the National Institute on Drug Abuse, it was found that the average power has increased from 3% to 15% from 1995 to 2021.
“People are always looking for higher and higher potency products to get the high they’re looking for,” he said.
In the past, a compound with 2% THC might have been enough to get most people high, ElSohly said. With heavier use, many people have now built up a tolerance and may need to smoke multiple joints with 2% THC or buy one joint with 6% to get the same feeling.
Is one type of marijuana safer?
Cannabis strength primarily refers to the THC content in the marijuana flower or buds, which is the rejected part of the plant.
While THC levels can be close to 40% in the flower, other products, such as concentrates or oils, can contain amounts as high as 95%.
The problem, UCLA’s Cooper said, is that there isn’t a widely accepted standard dose like there is for alcohol yet, so it can be difficult to predict how a person will react to different cannabis products.
Developing a unit dose for inhaled burn products is also challenging. While a typical joint may contain between 100 and 200 milligrams of THC, that doesn’t tell the whole story, Cooper said.
The amount of THC a marijuana smoker is exposed to can change. How long and how deeply are they inhaling? Or how long they wait between puffs because a lot of THC is lost due to “downstream” smoke, which comes from the burning end of the joint between times.
In comparison, marijuana edibles such as gummies, cookies and brownies typically contain between 5 and 10 milligrams per dose. There is a movement towards establishing a unit dose for edibles and limiting the amount of THC that can be consumed at one time. In New York state, for example, that number is 10 mg per serving.
How high can the THC go?
“I don’t think it’s going to go up much more,” said Volkow, of the National Institute on Drug Abuse. “There can be a level at which too much can become unsettling at times so people smoke and become very unsettling or paranoid.”
She is optimistic that the THC levels of the available marijuana flower will not rise as high as 50%.
There is a limit to the amount of THC the plant can produce, although manufacturers are finding clever ways to boost the chemical, Cooper said.
“The industry is adding more THC to the plant products,” including infusing pre-rolled cannabis cigarettes with extra THC, she said. “We’re starting to see people being exposed to levels of THC that we haven’t seen before.
This article was originally published on NBCNews.com
