Psychoactive harm done by weed?

Vanessa Richmond: Documentary Links Marijuana Use with Psychosis, Schizophrenia

Documentary Links Marijuana Use with Psychosis, Schizophrenia

Most anti-drug education is about as effective as encouraging teens to get up at dawn on the weekends. Maybe, just maybe, because the delivery style (earnest videos, posters with smiling teens, italic fonts and exclamation marks!) tends to both misunderstand and misrepresent teen culture.

In most cases, it's as if the whole effort was designed by aliens. Or about as ridiculous as teens telling boomers how to behave. When I was a high school teacher, I sometimes wondered if the anti-drug efforts had the same effect on decreasing drug use as teen abstinence campaigns do on decreasing teen sex and pregnancy: i.e. the opposite.

So I raised an eyebrow when one of the main researchers profiled in a new documentary called The Downside of High, said, with a little smile, that most people have fun on weed and no problems. The documentary, which follows the stories of three teenagers, takes a scientific and surprisingly nonjudgmental approach.

"The vast majority of us drink alcohol; the vast majority of us come to no harm. Same with cannabis. The vast majority of people have nothing but enjoyment from it," said Dr. Robin Murray from the Institute of Psychiatry at the University of London.

However, he goes on to explain why--even though he was initially dismissive of patients' questions about the possible link between weed smoking and their psychosis and even schizophrenia--he was convinced after reading a now-famous Swedish paper that followed the health of 50,000 Swedish military recruits over 15 years, and the subsequent research that has come out over the last decade or so. In short, people who start smoking marijuana before the age of 16 are four times more likely to develop schizophrenia.

Another researcher, Dr. Jim Van Os of the University of Maastricht said, "by the mid-'80s, we started to observe that 80 to 85 percent of people who came in with their first psychotic episode were smoking marijuana."

Even in response to these numbers, Murray is cautious. He says that "everyone varies in their genetic susceptibility. Some of us can happily take cannabis without developing a problem; others of us are more prone." But it turns out the very few who are "prone" have a pretty bad time with it.

Ben, one of the teens profiled in the documentary, says most of his friends regularly smoke pot with no problems. But that when he was about 16 and smoking weed, he started thinking there was an exorcist demon in his house. He says he then started to think there was a little guy with a knife creeping around his house trying to kill him and an anaconda snake that was going to get him, then digest him slowly.

At a screening of the film at North Vancouver's Balmoral high school, he told an audience of 250 grade-eight kids that he thought there were voices speaking to him through the TV, and that he started seeing trolls. "I looked out of my window at the terrace and thought I saw trolls. You know like in Harry Potter, that big guy? Like that."

After jumping off the roof twice, he was admitted to hospital, where he stayed for over a year. At the screening, he said that the reason he didn't stop smoking weed right away was that the psychosis came on so gradually. "It's kind of like landing a plane. It's slow. You lose your memory. You lose you cognitive skills." Shaking, but speaking loudly over the loud, grating noise of the cafeteria's fridge and fans, he said, "But then you end up spending a lot of time in the hospital which is, um, lonely. You don't want to be in the hospital: you just kind of talk in blather. And, um, you have to take your medication or it gets like that again." Gulp.

David Suzuki, the narrator, says that psychosis is a temporary but frightening state filled with intense anxiety and hallucinations, and when people attribute too much meaning to routine or mundane events. For some people, it's a symptom of schizophrenia.

Dr. Shimi Kang, a psychiatrist from B.C.'s Children's Hospital who specializes in drug and alcohol-related psychosis, and who was at the screening, says psychosis often comes with paranoia: like if you're paying for something at the supermarket and the clerk calls for a price check. "You think they're actually calling someone over to harm or kill you."

Dr. Kang says they're seeing "lots and lots more problems with marijuana than we ever have before. Patients will say to me, 'Dr. Kang, I don't see why I have to come and see you and why I'm having these problems. My dad used to smoke pot and he was just fine."

So what is the problem? As kids at the screening pointed out, people have been smoking weed for centuries. It's organic. Hippies and happy people smoke it to relax and feel good. Teens' parents smoked and smoke weed, and are totally fine.

Turns out weed has changed a lot since the 1960s and 1970s, so much that the U.N. is discussing reclassifying it as a different product. Basically, there's a lot more THC, a hallucinatory chemical, in it now.

Health Canada regularly tests the strength of marijuana confiscated from illegal grow-ops and reports back to the Royal Canadian Mounted Police. Corp. Richard DeLong says in the film that in the 1960s and 1970s, the THC levels were between 1 percent and 3 percent. "We know today what is coming out of our labs is THC of anywhere between 18 percent ... to 25 percent. And that is significant," he says. Given that it's the most widely used illegal drug in the world, that usage in North America doubled in the 1990s, and that it's still rising: that's all pretty different from the 1960s.

For those of you wondering, here's the science of THC and psychosis, as explained by Suzuki. THC, the hallucinogen, triggers an increase in dopamine in the brain. Dopamine is a chemical that controls mood. Dopamine makes us more aware. Too much THC in the brain's circuits, for some people, can trigger too much heightened awareness and cause misplaced meaning.

The film says that though it's conclusive that increased dopamine leads to psychosis and schizophrenia, the basis of the link remains illusive. Researchers suspect that any damaging effects happen when the THC in marijuana interacts with the cannabinoid system, a little-known family of brain chemicals and receptors that is critical to how we process the world around us. Our body's own cannabinoids attach to receptors on the brain's nerve cells. There, they regulate signals passing between the cells.

But THC is also a member of the cannabinoid family. So Murray says that, in some cases, the body's own cannabinoid system is overwhelmed by the cannabis.

Over the last 15 years, since that initial Swedish study, there have been many more studies done in other countries. Os has analyzed them all, and says definitively and conservatively, smoking cannabis nearly doubles a person's risk of developing future psychotic states including schizophrenia, and if someone smokes it before the age of 16, they are four times more at risk.

As the kids file noisily out of the cafeteria, with the backdrop of the green rainforest and gray skies through the windows, a few stopped to talk nervously to the teens, Ben and Tyler, who had their hands in their pockets, shoulders slumped. It's hard not to have an emotional reaction to the stories of the three teens.

But the documentary covers the science and teens' stories without angle, judgment or emotion, which is an unusual approach to the topic of marijuana.

Murray says, "The problem with cannabis is that you have those on the one hand that say it's a sacred herb, and on the other extreme you have people that say cannabis is the work of the devil. But neither of those extremes is practical. What we need is a situation where people know that if you smoke cannabis heavily, particularly if you smoke the potent brands of cannabis, that you're more likely to go psychotic."


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