As the debate about legalizing marijuana heats up in Canada, a new study suggests the drug might be riskier for teens to consume than had been previously thought.
Researchers from the Université de Montréal and New York's Icahn School of Medicine at Mount Sinai Hospital conducted a review of 120 studies examining cannabis and teenage brain development, and concluded there is strong evidence early cannabis use puts some teens at risk of developing addiction and mental health problems as adults.
Dr. Didier Jutras-Aswad, with the Université de Montréal's psychiatry department, is a co-author of the review, which was published this month in the journal Neuroparmacology. He says that in adolescence, the brain is still fine-tuning how different areas, such as learning and memory, interact and it appears that marijuana use alters that process.
"When you disrupt this, actually, development, during adolescence, notably through cannabis use, you can have very pervasive, very negative effects in the long-term, including on mental health and addiction risk," he told CBC News.
Some studies have also found links between early cannabis use and schizophrenia, but Jutras-Aswad says it seems clear there is a wide risk profile that includes genetics and behavioural traits in addition to age.
"For me, the question is not about whether cannabis is good or bad, but who is more likely to suffer from problems in cannabis, because we know for most people that will not happen," he said.
However, the study's authors point out that there is a widespread perception that marijuana is of little harm and the current discussions about access, such as Liberal Leader Justin Trudeau's calls for legalization, ignore the drug's impact on vulnerable populations — in particular, teenagers.
Vancouver pot activist Jodie Emery says she questions how conclusive the evidence about cannabis's harmful effects on the teenage brain is, but also says legalization for adults doesn't have to mean open access for youth.
"We're not saying legalize marijuana for teenagers. That's not the message here. That's not what we're talking about. We're saying legalize it for responsible adults, who are right now being arrested and persecuted," Emery said.
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Soulja Boy, Wiz Khalifa
Is that smoke, or a new Instagram filter? Soulja Boy<a href="http://www.huffingtonpost.com/2013/01/03/soulja-boy-wiz-khalifa-smoke-up-photo_n_2402221.html"> tweeted a photo </a>of what appears to be him and pal Wiz Khalifa smoking out a giant bong on Jan. 3.
"Oh don't worry," Brown wrote on this <a href="http://instagram.com/p/SzQdSKPpVR/">Instagram photo </a>he shared in December, from Amsterdam. "It's medicinal!! Lol."
<a href="http://www.vanityfair.com/online/daily/2012/06/kristen-stewart-responds-critics-shit-eaters-vanity-fair">In a 2012 Vanity Fair article</a>, Stewart addressed the photos taken of her smoking out of a pipe in 2008. "You can Google my name and one of the first things that comes up is images of me sitting on my front porch smoking a pipe with my ex-boyfriend and my dog," she said. "I was a kid. I had just turned 18. In [the tabloids] the next day it was like I was a delinquent slimy idiot, whereas I’m kind of a weirdo, creative Valley Girl who smokes pot. Big deal.”
Dressing up as <a href="http://www.huffingtonpost.com/2012/11/02/rihanna-topless-singer-post-halloween-lok_n_2066153.html">"The Bride of Mary Jane"</a> (get it?) for Halloween wasn't enough. Rihanna shared this controversial picture at the start of the New Year, with the caption: "This nug look like a skull or am I just....?"
A video of <a href="http://www.tmz.com/2010/12/10/miley-cyrus-video-bong-hit-smoking-salvia-herb-pyschedelic-birthday-party-hannah-montana/">Miley Cyrus partying with a bong </a>just after her 18th birthday became instant tabloid fodder when it hit the internet in 2010. Her reps say that she was actually smoking the herb salvia.
Yup. That's Olympic Gold medalist <a href="http://sports.espn.go.com/oly/swimming/news/story?id=3876804">Michael Phelps smoking out of a bong</a>, published in the now-defunct British rag News of the World in 2009.
Lady Gaga smoked a spliff onstage at a concert in -- duh -- Amsterdam. About marijuana, <a href="http://www.huffingtonpost.com/2012/09/19/lady-gaga-weed-singer-wondrous-marijuana_n_1897486.html">she told the audience</a>: "I want you to know it has totally changed my life and I've really cut down on drinking. It has been a totally spiritual experience for me with my music."
Last week, <a href="http://www.huffingtonpost.com/2013/01/05/justin-bieber-smoking-pot-photos-emerge-teen-star-partying_n_2415401.html">photos emerged </a>of what appears to be Bieber smoking marijuana inside a Newport Beach hotel room on Jan. 2. "Everyday growing and learning. trying to be better. u get knocked down, u get up," Bieber tweeted not long after the reports trickled through. "Back on tour tomorrow. ready to see u all smile. time to do what im supposed to be doing. performing. #BELIEVEtour."
UP NEXT: Successful People Who Have Smoked Pot
President Barack Obama has admitted to smoking marijuana and using cocaine <a href="http://www.nytimes.com/2008/02/09/us/politics/09obama.html?pagewanted=all&_r=0">during his high school and college days</a>. "When I was a kid, I inhaled often," <a href="http://www.nytimes.com/2006/10/24/world/americas/24iht-dems.3272493.html">he once told magazine editors, according to The New York Times</a>. "That was the point."
Apple co-founder Steve Jobs' use of LSD in his younger days is well-documented. He once called the experience <a href="http://www.thefiscaltimes.com/Articles/2011/10/24/Steve-Jobs-10-Revealing-Quotes-from-His-Biography.aspx#zqEbfO6jmqxtvYKB.99">"one of the most important things in my life."</a> His use of the drug was even noted in an <a href="http://www.wired.co.uk/news/archive/2012-02/10/steve-jobs-fbi">FBI background check</a>, according to Wired.
President Bill Clinton famously admitted to trying marijuana while completing his Rhodes scholarship at Oxford. "When I was in England I experimented with marijuana a time or two, and I didn’t like it," <a href="http://www.nytimes.com/1992/03/30/us/the-1992-campaign-new-york-clinton-admits-experiment-with-marijuana-in-1960-s.html?gwh=B1648339901F9BBAADA0D9EC8C030343">The New York Times reported in 1992</a>. "I didn’t inhale it, and never tried it again.”
Virgin Group chairman and founder <a href="http://www.cnn.com/2012/12/06/opinion/branson-end-war-on-drugs">Richard Branson is an outspoken advocate of marijuana legilization</a>, once writing an op-ed for CNN that called for an end to the war on drugs. He reportedly asked <a href="http://www.politico.com/news/stories/0312/74111.html">President Obama during a White House visit if he could "have a spliff"</a> in 2012. "They didn't have any," he added.
New York City Mayor and Bloomberg L.P. founder Michael Bloomberg found himself in hot water when he admitted to smoking marijuana back in 2002, The New York Times reports. When asked by a reporter if he had ever tried pot, he responded: <a href="http://www.nytimes.com/2002/04/10/nyregion/bloomberg-says-he-regrets-marijuana-remarks.html">"You bet I did. And I enjoyed it."</a>
Playboy founder Hugh Hefner credits his use of marijuana later in life with changing his perspective on sex. "I didn't know what making love was all about for all those years," Hefner <a href="http://www.foxnews.com/entertainment/2010/11/23/hugh-hefner-talks-monogomy-miley-cyrus-marijuana/">who supports legalization</a> is quoted as saying in <em><a href="http://www.amazon.com/High-In-America-Politics-Marijuana/dp/0670119903">High In America: The True Story Behind NORML</a></em>. <a href="http://www.druglibrary.org/special/anderson/highinamerica8.htm">"Smoking helped put me in touch with the realm of the senses."</a>
Billionaire investor George Soros is a known supporter of marijuana legalization and even wrote a 2010 Wall Street Journal op-ed rather straight-forwardly entitled <a href="http://online.wsj.com/article/SB10001424052702303467004575574450703567656.html">"Why I Support Legal Marijuana."</a> His <a href="http://www.aim.org/special-report/the-hidden-soros-agenda-drugs-money-the-media-and-political-power/">use of the drug may be far less proflific</a>, however. He told Reuters in 1997 that while he had "enjoyed" trying marijuana, <a href="http://www.mpp.org/outreach/top-50-marijuana-users-list.html">"it did not become a habit and I have not tasted it in many years."</a>
Jimmy Cayne, former CEO of Bear Stearns, kept an<a href="http://www.businessinsider.com/wall-street-cocaine-stories-2012-7?op=1"> antacid bottle full of cocaine</a> in his desk, according to the book <a href="http://books.google.com/books/about/The_Sellout.html?id=Jq030Cp_SjQC">The Sellout</a>.
The former vice presidential candidate and reality TV star told Anchorage Daily News back in 2006 that she couldn't <a href="http://www.cbsnews.com/stories/2008/08/29/politics/politico/thecrypt/main4397109.shtml">"claim a Bill Clinton and say that I never inhaled,”</a> CBS News reports.
Bill Gates, chairman and co-founder of Microsoft, hinted at once using LSD and marijuana in a <a href="http://ei.cs.vt.edu/~history/Bill.Gates.html">1994 interview with Playboy</a>. Likewise, <a href="http://www.amazon.com/Gates-Microsofts-Reinvented-Industry-Himself/dp/0671880748">biographer Stephen Manes</a> wrote that "<a href="http://www.mpp.org/outreach/top-50-marijuana-users-list.html">Gates was certainly not unusual there</a> [around drugs]. Marijuana was the pharmaceutical of choice…”
Former Ronald Reagan economic adviser and current CNBC host Larry Kudlow is reported to have both smoked marijuana and <a href="http://www.guardian.co.uk/money/2000/nov/29/workandcareers.madeleinebunting">used cocaine frequently</a> at periods in his life. After being fired from Bear Sterns in the mid-1990s, <a href="http://books.google.com/books?id=bOQCAAAAMBAJ&pg=PA38&dq=kudlow+cocaine&ei=VCR0S9XdEpG2NJDq0bsE&cd=1#v=twopage&q&f=true">Kudlow entered a rehabilitation program to deal with his cocaine addiction</a>, according to New York Magazine.
Super model Naomi Campbell <a href="http://www.nbcnews.com/id/7018893/site/todayshow/ns/today-entertainment/t/naomi-campbell-say-she-nearly-self-destructed-because-cocaine/#.USU_XVo6VOg">admitted in 2005 to abusing cocaine during her career</a>. "I have admitted using illegal drugs and some years ago I recognised that I had a problem" <a href="http://www.dailymail.co.uk/news/article-99840/Naomi-confesses-drug-abuse.html#ixzz2LTfhOeI6">she was quoted as saying in The Daily Mail.</a> "I knew that it was wrong and had damaged me and I decided to try and sort myself out."
Peter Lewis, former CEO of Progressive Insurance, has both <a href="http://www.forbes.com/sites/clareoconnor/2012/04/20/high-roller-how-billionaire-peter-lewis-is-bankrolling-marijuana-legalization/">smoked marijuana and lobbied heavily for its legalization</a>. After smoking weed recreationally in his youth, he started using it medicinally after his leg was amputated. “<a href="http://www.bostonmagazine.com/news/blog/2012/07/16/medical-marijuana-question-thank-78-year-billionaire-insurance-executive/">I was very glad I had marijuana,"</a> he told Boston Magazine. "It didn’t exactly eliminate the pain, but it made the pain tolerable — and it let me avoid those heavy-duty narcotic pain relievers that leave you incapacitated.”
Former California Governor and all around legend Arnold Schwarzenegger can be seen smoking marijuana in the 1977 documentary "Pumping Iron." He later said that he <a href="http://www.cbsnews.com/2100-207_162-529462.html">"did smoke a joint and I did inhale,"</a> CBS News reports.
In a 2009 lawsuit, it was alleged that Ponzi schemer Bernie Madoff frequently sent messengers to buy cocaine for <a href="http://www.dailymail.co.uk/news/article-1221984/Fraudster-Bernie-Madoff-cocaine-office-dubbed-North-Pole.html">"himself and the company."</a> Actually, before Madoff's $60 billion Ponzi scheme fell apart, his office was known as <a href="http://articles.cnn.com/2009-10-22/justice/madoff.lawsuit_1_bernie-madoff-kpmg-jp-morgan-chase?_s=PM:CRIME">"the North Pole"</a> because of the allegedly excessive cocaine use during work hours, according to CNN.
Essayist and author Aldous Huxley is said to have experimented with hallucinogenics, even writing an account of his use of mescaline in <a href="http://www.huffingtonpost.com/2012/04/20/10-celebrity-lsd-users_n_1440786.html">"The Doors Of Perception."</a>
Former Vice President and climate change activist Al Gore is rumored to have smoked marijuana often in college. However, Gore characterized his marijuana use as <a href="http://www.guardian.co.uk/world/2000/feb/07/uselections2000.usa">"infrequent and rare,"</a> according to The Guardian.
Best-selling author Maya Angelou reportedly <a href="http://books.google.com/books?id=uVEK3f8ojJUC&pg=PA16&lpg=PA16&dq=maya+angelou+marijuana+use&source=bl&ots=iiUM7k5Uqw&sig=BlWCUSUqUIHOokcdjr3kA2GVrjg&hl=en&sa=X&ei=BHouUbW_FYm-9QSPooHABw&ved=0CFAQ6AEwAw#v=onepage&q=maya%20angelou%20marijuana%20use&f=false">"settled into a job as a waitress and began smoking marijuana with abandon"</a> early in her life, <a href="http://www.amazon.com/Angelou-Blooms-BioCritiques-Cindy-Dyson/dp/0791061779">according to a biography by Harold Bloom and Cindy Dyson</a>.
CNN founder and Atlanta Braves owner <a href="http://coedmagazine.com/2009/02/06/the-10-most-successful-potheads-on-the-planet-cool-enough-to-admit-it/">Ted Turner is rumored</a> to have grown pot in his college dorm room, according to COED Magazine (he's reportedly also a major donor to the Kentucky Hemp Museum). After banning cigarette smoking at CNN in the early '90s, a memo emerged that claimed it <a href="http://tobaccodocuments.org/pm/2024271877.html">"was common knowledge that Turner sits in his office and smokes marijuana."</a>
Supreme Court Justice Clarence Thomas smoked marijuana <a href="http://www.nytimes.com/1991/07/11/us/thomas-smoked-marijuana-but-retains-bush-support.html">"several times"</a> in college, White House spokesman Judy Smith said back in 1991.
Nobel Prize-winning chemist <a href="http://www.wired.com/science/discoveries/news/2006/01/70015?currentPage=all">Kary Mullis credited much of his success to his use of LSD</a>, according to Wired.
Next: Celebrities Who Have Used Drugs
"I have done just about every drug possible: cocaine, ecstasy, LSD and, my favorite, heroin." [The Mirror, 1996]
"I didn't live my life in the right way for politics, you know. I fucked too many chicks and did too many drugs, and that's the truth. That's gonna be my campaign slogan: 'I drank the bong water.'" [Newsweek, 2011]
<em>On smoking a joint to calm herself before winning her 1991 Oscar for "Ghost":</em> "Smoking cigarettes and pot every now and then are my habits. And so I thought, 'I've got to relax.' So I smoked this wonderful joint that was the last of my homegrown. And honey, when [Denzel Washington] said my name and I popped up, I thought, 'Oh, fuck.'"
"I mean, I still love a waterfall or the odd hallucinogenic drug. I liked mushrooms, which were legal until a year or so ago. If I had a drug of choice, it would be magic mushrooms." [The Guardian, 2007]
"I’ve done drugs, and that’s how I know I don’t like them. Cocaine is back with a vengeance. Everyone in every club is doing drugs. A lot of people are on prescription drugs. Celebrities aren’t trying to hide it, except where people have camera phones. ... I wanted to try several things and make an informed decision, but I didn’t enjoy anything other than marijuana. I don’t even think of it as a drug -- it should be legalized. I know about five people who aren’t on drugs today, and I’m one of them." [Maxim, 2007]
“Without cigarettes, I would be doing heroin, probably, on a daily basis.” [Blender, 2007]
<em>On doing cocaine with her boyfriend in the '70s while working as an anchorwoman in Nashville:</em> "I did your drug. This is probably one of the hardest things I have ever said. ... I had a perfect, round, little Afro, I went to church on Sunday and I went to Wednesday prayer meetings when I could ... and I did drugs." ["The Oprah Winfrey Show," 1995]
"I spent most of my life looking for the quick fix and the deep kick. I shot drugs under freeway off-ramps with Mexican gangbangers and in thousand-dollar-a-day hotel suites. Now I sip vitamin-infused water and seek out wild, as opposed to farm-raised, salmon." ["Scar Tissue," published 2005]
"When I was 10 ½, I was sitting in a room with a group of young adults who were smoking pot. I wanted to try some, and they said, 'Sure. Isn't it cute, a little girl getting stoned?' Eventually that got boring, and my addict mind told me, 'Well, if smoking pot is cute, it'll also be cute to get the heavier stuff like cocaine.' It was gradual. What I did kept getting worse and worse, and I didn't care what anybody else thought." [People, 1989]
"I kind of took matters into my own hands and was creating drama in a very dangerous way. I think I was just bored, and I had seen everything. Especially when you're young, you just want more. ... At 18 I had just been doing a lot of cocaine." [People, 2007]
"[Marijuana] keeps me sane and happy. I could write without it if I was sane and happy. ... This is the only kind of drug I ever thought worth taking." [ITV's "South Bank Show," 2008]
"Never give up the ganja." [The Guardian, 2003]
"I've never been a major smoker, but I think America's view on weed is ridiculous. I mean, are you kidding me? If everyone smoked weed, the world would be a better place." [The Daily Mail, 2007]
"I was consumed by cocaine, booze and who knows what else. I apparently never got the memo that the Me generation had ended." ["Love Is the Cure: On Life, Loss and the End of AIDS," published 2012]
“I’m a recreational pot-smoker. ... There has never been enough of a distinction between marijuana and other drugs. In the classic, weird hygiene movies from high school, everything led to depravity -- marijuana, sex, coffee! There was no distinction made between the effects of one thing. So it’s always been lumped in with drugs in general. It’s a human rights issue, a censorship issue and a choice issue." [High Times, 2003]
“Cocaine was even in the budgets of movies, thinly disguised. It was petty cash, you know? It was supplied, basically, on movie sets because everyone was doing it. People would make deals. Instead of having a cocktail, you’d have a line." [Newsweek, 2011]
"I had a bag of mushrooms in my refrigerator. My cat used to sneak into the refrigerator and eat them. ... He ate them voraciously; it was like catnip to him. So I thought, 'What the heck, I better do it with him.' I remember lying on my bed for hours and Lewis was on the desk across my bed for hours, and we just stared at each other -- not moving, just staring at each other, and I had no doubt that he was my brother. But having said that, I don't do that anymore. And you know what? Later in life, when I was completely not doing any of that, I know he said 'Hi' to me." ["Late Show With David Letterman," 2010]
"I don't trust anyone who hasn't been self-destructive in some way. Who hasn't gone through some sort of bout of self-loathing. You've got to bang yourself around a bit to know yourself." [GQ, 2011]
"hi guys, i smoke pot. ok guys, bye." [Twitter, 2013]