Research shows links to mental illness, lung capacity
When sociologist and drug-policy expert Andy Hathaway surveyed one of his first-year classes at the University of Guelph last fall, 80 per cent of students reported experience with cannabis.
Hathaway cautions that it was only a small pilot study (around 100 responses), and it took place at Guelph, which is, let’s face it, “a bit granola.”
Still, that 80 per cent figure isn’t surprising.
When twelfth graders are asked if they’ve tried marijuana, roughly half say yes.
Provincial rates of lifetime usage now range from a low of 40 per cent of Albertan twelfth-graders to a high of 63 per cent of those in Nova Scotia, according to the Canadian Centre on Substance Abuse. And that’s before university.
Smoking pot can’t be considered deviant anymore, says Hathaway. It’s simply the new normal.
A loosening of cultural attitudes, particularly in the media, helps explains the shift. “We had Cheech and Chong in the 1970s, but that was a very stereotypical portrayal,” says Hathaway. “Now we have shows like Weeds that show use of marijuana by very regular people—soccer moms and dads.”
But as attitudes toward marijuana soften, some campus health experts report that they’re more worried about students using the drug than ever. That’s because research increasingly shows links between marijuana and the number one health problem on Canadian campuses: mental illness.
Dr. Elizabeth Osuch, a psychiatrist who runs the First Episode Mood and Anxiety Program at a hospital in London, Ont., encounters mentally ill students who offer their own evidence of marijuana-related problems. “I hear the story frequently about how ‘I get paranoid when I smoke pot’, ‘I get anxious when I smoke pot’, or ‘I’ve been smoking pot a long time and now I’m depressed’,” she says.
That’s not surprising to Dr. Osuch. What’s surprising to her is how surprising that is to others.
“I’ve given talks across this community and when I talk about the effects of marijuana, it’s news to people,” she says, “unless I’m talking to a group of clinicians who interact with people in a medical or counselling setting. They know, because they’ve been seeing this for years.”
The best-established risk is that marijuana can trigger or exacerbate psychosis in a small number of people who are susceptible, based on their genes. To some, the link is not even debatable. “A number of prospective epidemiological studies put it beyond doubt that cannabis use increases the subsequent risk of schizophrenia,” wrote the authors of a 2007 review in Addictive Disorders.
Devastating as psychosis may be for those who experience it, diseases like schizophrenia only affect a small proportion of the population. But Dr. Osuch warns that marijuana may also be contributing to the most common health problems on Canadian campuses: depression and anxiety.
One study published in Drug and Alcohol Dependence in 2007 followed a group of 14 to 17-year-olds over a decade, checking up on their mental health and drug use along the way. They found that depression, bipolar disorder and, to a lesser extent, anxiety disorders, all coincided with previous cannabis use—and more use predicted more illness.
But that’s only the beginning. “I would predict that there will be more and more information out there in the coming years looking at the problematic effects of what’s no longer a ‘soft drug’,” says Dr. Osuch, who notes that there’s more Tetrahydrocannabinol (THC) in in marijuana today than ever.
Dr. Osuch is currently the lead researcher on one such study exploring the links to depression. She explains the theory behind that possible link: “Marijuana is very active on the neurocirciutry of reward processing. Anything that you do because you like doing it activates reward processing in the brain,” she says. “And if you slam that neurological system daily with a chemical [like THC], it becomes very difficult for the person to feel reward from doing normal things,” she adds.
Dr. Osuch is quick to point out that not everyone who smokes pot will have a problem. “But a significant percentage of them will,” she says, adding, “as long as you know what those percentages are, or a sense of what the risks are, you can make an intelligent decision.”
Right now, the students she meets when giving talks at the Western University in or London, Ont. high schools haven’t gotten the message. They perceive pot-smoking as low risk.
Part of the confusion is the conflicting messages young people get when they type “marijuana health effects” into Google. “What they’re getting is all kind of sites that say marijuana is great,” says Dr. Osuch, “what they aren’t getting is the scientific research.”
There are, of course, some well-funded and easy-to-find meassages about the risks online—those from the federal government. But Hathaway, the drug policy researcher at Guelph, says the federal government’s anti-drug messages aren’t trusted by youth, because they exaggerate the risk.
In one of the federal ads, called Fast Forward, a blonde boy refuses a puff on a joint after he envisions a life of violence and trouble with the law. In another ad, called Mirror, a girl in her bedroom ends up cutting her arm with a piece of glass after taking some unidentified drugs.
Such scare tactics cause teens to tune out drug messaging entirely, says Hathaway. “If you’re sending inaccurate messages about marijuana when they have enough experience to know this is basically propaganda, they’re going to have doubts about any message of that kind,” he explains.
Although Hathaway doesn’t advocate abstinence like Dr. Osuch, he does believe there’s room for better education about marijuana. “Effective social policy would account for the small minority who may run into trouble with drugs and be candidates for some kind of intervention,” says Hathaway.
The government might do better to educate youth about the dangers of smoking tobacco along with marijuana, for example, says Hathaway. Tobacco is known to reduce lung capacity and increase the risk of cancer. Meanwhile, a study in the Journal of the American Medical Association in January showed that smoking two to three joints actually increases lung capacity.
But because the JAMA article portrays marijuana as less harmful, it’s unlikely to would make it into the government’s messaging. Once again, the science is unlikely to reach young Canadians.
And if there’s one thing Dr. Osuch and Prof. Hathaway agree on, it’s that young people need better access to the facts. That way, they can determine the risks for themselves—whatever they may be.