“Of all the people I’ve diagnosed with a psychotic disorder,” he said, “I can’t think of a single person who didn’t also test positive for cannabis.”
Sultan, an assistant professor of clinical psychiatry at Columbia Irving Medical Center, is one of many experts who raise serious concerns about increased marijuana use by teens and young adults.
And there is growing evidence of marijuana’s association with psychiatric disorders such as depression, bipolar disorder and schizophrenia, especially in young men.
New research published this month, involving millions of people around the world over decades, is raising concerns that heavy use of high-potency marijuana and the legalization of recreational weed in many US states could exacerbate the crisis. country’s mental health in young adults.
“There is a great sense of urgency not just because more people are smoking marijuana, but because more people are using it in harmful ways with ever-increasing THC concentrations,” Dr. Nora Volkow, director of the National Institute on Drug Abuse (NIDA), said in an interview.
One of the studies, by researchers in Denmark in collaboration with the US National Institutes of Health, found evidence of an association between cannabis use disorder and schizophrenia. The finding was most striking in young men aged 21 to 30, but it was also seen in women of the same age.
The article, published in the journal Psychological Medicine, analyzed data from nearly 7 million men and women in Denmark over a few decades to look for a link between schizophrenia and cannabis use disorder.
The magnitude of the connection between cannabis and schizophrenia in young men surprised study author Volkow, who expected the number to be closer to 10%.
“This is concerning,” she said.
There are now 22 states that allow recreational marijuana use, with Minnesota will likely become the next state to legalize it.
It’s unclear whether recreational cannabis laws contribute to underage use, but Volkow has made addressing teen cannabis use one of NIDA’s top priorities. Daily marijuana use among youth has risen to record highs, with more than 1 in 10 19- to 30-year-olds reporting daily use and nearly half reporting use in the past year, according to the agency’s latest data.
Another study, led by researchers at Sultan and Columbia published earlier this month, found that teens who use marijuana only for recreational purposes are two to four times more likely to develop psychiatric disorders, including depression and suicidal tendencies, than teens who do not use it. marihuana.
Because research to date has been observational and does not directly prove cause and effect, the connection between marijuana and psychiatric disorders is controversial. It is unclear whether people who already have or are developing psychiatric conditions are more likely to turn to cannabis as a form of self-medication or whether cannabis use triggers mental problems.
Volkow is optimistic that a large ongoing study of adolescent brain development at the National Institutes of Health can help answer that question.
Sultan acknowledged the limitations of the evidence. “It’s kind of a feedback loop where they’re feeding off each other,” he said.
The Doctor. Deepak D’Souza, a psychiatrist at Yale University who has studied cannabis for 20 years, insists there are too many lines of evidence to ignore.
“We may be grossly underestimating the potential risks associated with cannabis,” he said.
Given the increasing legalization and increasing potency of cannabis products, D’Souza has never been more concerned about the effects of cannabis use on mental health among young people.
“This is a huge concern,” he said. “We have been woefully inept at educating the public and influencing policy.”
Is legalization affecting marijuana use rates?
Early data suggest that in young adults ages 18 to 25, legalization is leading to higher rates of cannabis use, particularly in Oregon and Washington, according to an analysis published earlier this month in the journal Substance Abuse.
The research, led by researchers at McMaster University in Canada, found evidence in other age groups to be somewhat less clear, and more research is needed to understand how legalization is affecting rates of cannabis use.
In areas where marijuana becomes legal and more readily available, Volkow’s concern is the ease with which products can be mixed, leading to a high total dose of marijuana consumed.
One of the biggest problems, she says, is the lack of regulations on the concentration of THC in products.
Marijuana consumed decades ago had concentrations of THC, the main psychoactive ingredient, of 2-3%, but cannabis products today can have THC levels of up to 90%.
“That’s not the case with alcohol, as you can’t put more than a certain percentage of alcohol in the drink,” she said. “Same thing with tobacco cigarettes, you regulate the amount of nicotine they have. Here, we have no regulations.”
The potency of THC is significant, Volkow said, because cannabis is more likely to be linked to psychosis with higher doses consumed.
What is the most vulnerable age?
Research has shown that the human brain is the last organ to fully develop and it doesn’t finish until the mid-20s. This makes teenagers and young adults particularly vulnerable to the effects of cannabis as their brains continue to mature.
“Really, the ideal time to consider using marijuana — if you’re going to use it — is 26 or later,” said Sultan.
People who wait at least until age 26 are much less likely to become addicted or develop mental disorders, said Dr. Sharon Levy, pediatrician and addiction specialist at Boston Children’s Hospital.
“The greatest risks are clearly in the adolescent and young adult age group,” she said.
However, people with a family history of psychotic disorder should not use marijuana, warned Sultan.
What does marijuana do to the brain?
While scientists are still learning about marijuana’s effects on the developing brain, studies so far suggest that marijuana use in teenagers may affect functions such as attention, memory and learning, several studies have found.
“It’s somehow interfering with the connections that we use in our brain to distinguish between what’s going on in our heads and what’s going on outside our heads,” Levy said in reference to the psychotic symptoms that can occur.
D’Souza added that cannabis use can have serious impacts on the developing brain because of its effects on the endocannabinoid system, a complex signaling system in the brain that marijuana targets.
“The endocannabinoid systems play an important role in brain sculpting during adolescence, which is when schizophrenia usually manifests,” he said.
Disturbing this system with cannabis use could have “complex far-reaching implications for brain development”.