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Study Shows Marijuana Use In Teens Correlates To Decreasing IQ 626

retroworks writes "The BBC reports on a paper published in the U.S.'s Proceedings of the National Academy of Sciences showing a correlation between persistent, regular cannabis use and risk of lower IQ. The study finds the risk particularly correlates use of cannabis by teenagers who use the drug "four times a week year after year." The more people smoked, the greater the loss in IQ. Reviewers of the study at King's College Institute of Psychiatry states that the data and methodology are exceptional, but she also cautions that there may be another explanation, such as depression, which could lower IQ while stimulating marijuana use. The study does not mention or rule out 'nocebo' effects, i.e. just feeling stupid for spending your teens hanging out with potheads."
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Study Shows Marijuana Use In Teens Correlates To Decreasing IQ

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  • Mods (Score:3, Insightful)

    by Anonymous Coward on Tuesday August 28, 2012 @09:14AM (#41147513)

    Tag news article 'Propaganda'

  • News Flash (Score:4, Insightful)

    by Lumpy ( 12016 ) on Tuesday August 28, 2012 @09:15AM (#41147521) Homepage

    Drinking Wine or Beer 4 times a day year after year will reduce your IQ. Over use of ANYTHING will cause problems.

  • Re:News Flash (Score:5, Insightful)

    by sonamchauhan ( 587356 ) <sonamc@[ ]il.com ['gma' in gap]> on Tuesday August 28, 2012 @09:19AM (#41147567) Journal

    4 times a week, not 4 times a day.

  • No surprise there (Score:0, Insightful)

    by Anonymous Coward on Tuesday August 28, 2012 @09:21AM (#41147589)

    Just listening to the incoherent babbling and giggling of stoners, this does not really come as a surprise.
    Combine this with the risk of acute psychoses really strong cannabis can cause and I think some countries should rethink their lax attitudes towards cannabis use.
    I am looking at you, Netherlands.
    Oh, and the hight tar content of weed that will cause lung cancer.

  • Re:Mods (Score:5, Insightful)

    by i kan reed ( 749298 ) on Tuesday August 28, 2012 @09:31AM (#41147711) Homepage Journal

    Propaganda by whom, and for what purpose? How do you identify it as propaganda instead of legitimate science? You have to answer these basic questions and support your answers with evidence before anybody is going to buy into your conspiracy theories.

  • Re:News Flash (Score:3, Insightful)

    by lengau ( 817416 ) on Tuesday August 28, 2012 @09:39AM (#41147843)
    I think this is a case of where "overdoing it" is. There are some things for which just about any amount is overdoing it (e.g. cyanide). On the other hand, reading has a much higher threshold. Unless your reading is actively hindering another part of your life (e.g. you read for days on end without eating, drinking or sleeping, thus causing medical problems), it's fine. [Note: As I am not familiar with the subject, I withhold commentary about where I believe that line to be regarding cannabis use.]
  • by svick ( 1158077 ) on Tuesday August 28, 2012 @09:41AM (#41147883)

    How far does that go? Can I invite all my friends into your house while you're at work? After all, why can't we use that empty house? It doesn't matter that it "belongs" to someone.

  • Re:News Flash (Score:3, Insightful)

    by NeoMorphy ( 576507 ) on Tuesday August 28, 2012 @09:44AM (#41147933)

    And cue the queue of stoners attempting to defend their addiction.

    Desperate attempts to rationalize the use of marijuana is one of the signs of addiction. They're big on pointing out some benefits, but ignore all of the mental and physical problems associated with it.

    Teenagers who are in the "I know everything" stage can be very frustrating when you try to explain the dangers.

  • Re:News Flash (Score:3, Insightful)

    by Rei ( 128717 ) on Tuesday August 28, 2012 @09:52AM (#41148025) Homepage

    Desperate attempts to rationalize the use of marijuana is one of the signs of addiction.

    So by your argument, pretty much anything I use in my daily life would become a "sign of addition" if you challenged it and I defended it. Apparently I'm addicted to my bed, underwear, forks, and washcloths, to name a few.

    Full disclosure: I don't use pot. In case your immediate assumption was to do an "attack the messenger" reply.

  • Re:Mods (Score:2, Insightful)

    by Anonymous Coward on Tuesday August 28, 2012 @10:01AM (#41148183)

    IQ statistics are almost inherently biased. Given the civil disobedient nature of recreational drug use, it's almost a no-brainer that this research is useless. Granted, drugs in general cause problems when abused and recreational use implies abuse, but when it comes down to it, kids aren't going to care about obedience when there's nothing in it for them.

    If you ask me, drug use is the result of bad parenting and an economy that takes advantage of youth. Civil disobedience is the logical result of denial in the larger and older community. The only kids who would disagree are ones from wealthy families who aren't going to get drafted, nailed by education loans and typically eldest sons who are going to inherit their way into management jobs anyway. Some of them do drugs anyway if they think its "cool" to engage in a Bohemian lifestyle. That's just isolated white kids who want to make their parents cry.

    Civil disobedience show high IQ if you ask me. Of course, some kids aren't going anywhere, anyway but I doubt anyone is creating pseudo-scientific reports to annoy them. In fact, their drug use provides easy rationalization by the system to control them by creating barriers to opportunity through urinalysis tests, which of course, nobody demands of the boss's son.

  • Re:News Flash (Score:5, Insightful)

    by Anonymous Coward on Tuesday August 28, 2012 @10:02AM (#41148193)

    Teenagers who are in the "I know everything" stage can be very frustrating when you try to explain the dangers.

    Probably because you're an adult in the "I know everything" stage, and think you know the dangers. Funnily enough, teenagers with internet access can easily learn more about a given subject than you know offhand, and it may surprise you that some of them actually research marijuana before smoking it. Which is often more than their parents can manage before laying down the law to them about it.

    In fact your entire attitude stinks, and teenagers can smell that a mile away. The teenager doesn't actually think he knows everything, but he has learnt that his parents don't. Yet many of them still insist on being treated as unquestioned authorities. Hence your "frustration" when you're not treated that way. It's a parenting problem, not a growing up problem.

    I'll bet $100 all you know is what you've uncritically read in the sensationalist media. For instance, you seem to think marijuana addiction exists. There is no scientific basis for this idea, as you should know if you want to engage in a serious discussion with your teenager about what you believe the risks to be. Talking about marijuana addicts just makes you look ridiculous, I'm afraid, and that is why you fail.

  • Re:News Flash (Score:5, Insightful)

    by Radres ( 776901 ) on Tuesday August 28, 2012 @10:05AM (#41148251)

    But pot use after age 18 doesn't have long-term affects on IQ, only for the time immediately after consuming the drug. This was an important point lost in the summary. So, marijuana should be illegal for young kids to smoke. If marijuana were legal and regulated like alcohol, we would see less young people abusing the drug.

  • by ultranova ( 717540 ) on Tuesday August 28, 2012 @10:13AM (#41148385)

    if you have nothing better to do in life than sit around and inhale a drug to "get high" and have psychodelic hallucinations then you're probably not destined for greatness

    So? The chances are, you are not "destined for greatness" no matter what you do. Why waste your life chasing for a winning lottery ticket rather than simply relax and enjoy what you can have? Besides that the lottery company - the 1% - have a harder time exploiting you if you don't buy into the lie, I mean.

    Most people can never be great, because great means exceptional, and most people are average by definition. You are not exceptional and will never be great. And there's no shame in that, no matter how much you're trying to evoke it.

    The stereotypical stoner mentality - "relax, take it eeeeasy" - is the antithesis of the rat race mentality, and almost impossible to exploit, so of course the people who benefit from having all the little hamsters spin their wheels fight pot. And since they are nasty people, they use nasty methods, to the point of calling their fight a War with capital W, complete with propaganda front to complement the armed forces and prison camps. And all that should really make you wonder if you should trust them to be quite honest.

  • Re:Mods (Score:2, Insightful)

    by NeoMorphy ( 576507 ) on Tuesday August 28, 2012 @10:20AM (#41148491)

    Propaganda; n. Any material which proposes to sway a reader to form a conclusion that conflicts with your own.

    Not the best definition. Ironically, it's bad enough to resemble propaganda, since propaganda usually involves "lying by omission".

    Are medical experts who warn of the dangers of tobacco use to tobacco addicts spreading propaganda or is it anti-propaganda? I'm sure there are plenty of tobacco addicts who think that medical experts are wrong. And they'll explain why with their rasping smoker's voice coming out of their wrinkly leather-like face.

    Are math teachers using propaganda when they teach?

  • Re:News Flash (Score:5, Insightful)

    by CanHasDIY ( 1672858 ) on Tuesday August 28, 2012 @10:37AM (#41148783) Homepage Journal

    Do you have any evidence to support that assertion?

    The medical community has known for some time that marijuana has adverse effects.

    Lol, it never fails to amuse me when someone lambastes another for making an un-backed statement without citing any evidence... moments before they themselves make an un-backed statement without citing any evidence.

    To that end, who is this 'medical community' of which you speak, and what are these 'adverse affects' you so ambiguously refer to?

  • Re:News Flash (Score:5, Insightful)

    by mikael_j ( 106439 ) on Tuesday August 28, 2012 @10:45AM (#41148915)

    In my experience most of those in favor of cannabis legalization aren't blind to the adverse effects, it's just that they're sick to death of seeing time and time again how some study proclaims "Teenagers who are genetically predisposed to end up with severe mental illness may have slightly earlier onset of their condition if they smoke marijuana on a daily basis" and how the media and those who fervently hate cannabis turn that into "POT MAKES YOU CRAZY!".

  • Re:News Flash (Score:5, Insightful)

    by ebh ( 116526 ) <edhorch&gmail,com> on Tuesday August 28, 2012 @10:47AM (#41148963) Journal

    Short form: If you admit it, you're addicted. If you don't, you're in denial.

  • Re:News Flash (Score:3, Insightful)

    by Knuckles ( 8964 ) <knuckles@NOsPAM.dantian.org> on Tuesday August 28, 2012 @10:49AM (#41149009)

    I've been practicing Tai Chi Chuan and meditation for more than 15 years in an attempt to keep myself healthy and sane. Sometimes between work and other commitments I don't practice enough. By your argument if I decide to put in some additional effort and time, this would be a sign of addiction?

  • Re:Mods (Score:5, Insightful)

    by Immerman ( 2627577 ) on Tuesday August 28, 2012 @10:50AM (#41149017)

    recreational use implies abuse

    I assume your stance on this extends to alcohol and caffeine as well, correct? Personally I wouldn't call a couple glasses of beer/wine/etc at a party abuse, but it's most definitely recreational.

  • Re:News Flash (Score:4, Insightful)

    by slim ( 1652 ) <john@NosPam.hartnup.net> on Tuesday August 28, 2012 @11:01AM (#41149213) Homepage

    So, marijuana should be illegal for young kids to smoke

    It *is* illegal for young kids to smoke marijuana (and for anyone else).

    The problem here is that there isn't a direct link between "it's illegal" and "people cease to do it". Prohibiting drug use has demonstrably failed to stop people wanting to use drugs, and has demonstrably failed to prevent them from doing so. It's even possible that prohibition has made it *easier* for people to get hold of drugs, since production, distribution and retail is in the hands of people who aren't beholden to the usual rules.

    Make it legal, such that illicit supply is no longer profitable. Regulate and educate, so that kids (and adults) generally don't want to use, kids that want to can't find a supply, adults that want to have a trustworthy supply and a society that encourages sensible usage levels.

  • by betterunixthanunix ( 980855 ) on Tuesday August 28, 2012 @11:07AM (#41149313)
    Scientific conclusion: heavy marijuana use amongst teenagers is correlated with decreasing IQ.


    The difference is in how this is presented. A scientific presentation cannot possibly say that marijuana is a causal factor until at least all of the following are addressed:
    1. What can cause IQ to change over time? As someone else pointed out, it is entirely possible that sitting around doing nothing all day will lower IQ, and so marijuana's role may just be in discouraging teenagers from participating in activities that maintain or increase their IQ. Marijuana can increase appetite -- it is possible that eating too much junk food lowers IQ.
    2. There may be a particular trait that attracts some teenagers to smoke pot heavily, which also causes them to have lower IQs later in life.
    3. Teenagers who smoke marijuana may be participants in a subculture that involves other activities that cause lower IQ.
    4. Marijuana may be produced using fertilizers or pesticides that are also absorbed when the drug is used, and those might cause lower IQ.
    5. Marijuana smoke may contain chemicals that cause lower IQ; maybe other methods of taking the drug will not have such an effect (or maybe other methods are even worse).

    There are a lot of things that can cause the results the scientists saw -- which is good news for them, since it means they have plenty of questions to answer. Unfortunately, the media will see this, ignore the part about heavy users, spend no time discussing confounding factors, and jump right on the "marijuana is bad" bandwagon. Typical, unsurprising, propaganda-driven approach.

  • Re:News Flash (Score:5, Insightful)

    by Hatta ( 162192 ) on Tuesday August 28, 2012 @11:15AM (#41149449) Journal

    For one reason or another, the pot smoking community seems to get all defensive and denies all allegations backed by science almost as fiercely as denial of global warming or evolution.

    We don't deny that there are adverse effects. We deny that the adverse effects are sufficient enough to justify imprisioning people. Life is full of risks, and the fun parts even more so. A country that allows people to ride motorcycles [wikipedia.org] for recreation has no place telling us Cannabis is too unsafe for recreation.

  • Re:News Flash (Score:5, Insightful)

    by hazah ( 807503 ) on Tuesday August 28, 2012 @11:58AM (#41150177)
    We all trust what the government says. There couldn't possibly be any motive for the same entity that is responsible for the existance of the DEA to say anything that would support their own agenda. Couldn't be that at all. Shoving the same article into every post you make doesn't reinforce the point... especially if it's utter bullshit.
  • Re:News Flash (Score:4, Insightful)

    by Belial6 ( 794905 ) on Tuesday August 28, 2012 @12:40PM (#41150795)
    Or football.
  • Re:News Flash (Score:3, Insightful)

    by Tyndmyr ( 811713 ) on Tuesday August 28, 2012 @02:23PM (#41153053)
    Look, I've never smoked pot in my life, and have absolutely no urge too. But even a cursory investigation of the government's history on weed indicates they've gleefully made shit up to make it sound bad. A certain degree of skepticism in light of that is only rational.
  • Re:News Flash (Score:4, Insightful)

    by mcgrew ( 92797 ) * on Tuesday August 28, 2012 @02:56PM (#41153797) Homepage Journal

    http://en.wikipedia.org/wiki/Long-term_effects_of_cannabis [wikipedia.org]
    But of course, that's all lies and false propaganda right?

    The first link obviously is, that's like asking Newt Gingrich if Obama's a good president. You might as well cite High Times for an equally biased view of pot. However, you didn't read the wikipedia link, did you?

    A study of the development of 59 Jamaican children was conducted with the children being monitored from childbirth to age 5 years... The results over the entire research period showed no significant differences in development testing outcomes between using and non-using mothers. At 30 days of age, however, the children of marijuana-using mothers had higher scores on autonomic stability and reflexes
    Research has shown a substantial percentage of cannabis users develop cannabis-related problems, including dependency.

    If you do anything whatever every single day for a year, you're going to miss it if you no longer have it. Dependancy != addiction. Addiction has physical withdrawal symptoms; tobacco, alcohol, heroin, coffee are addictive. Orange juice and marijuana can introduce dependancies. Hell, there's a woman in my office who almost freaked out because the vending machine was out of little chocolate donuts and she'd been eating them every day for years. Yes, smoke pot every day for a year and you'll miss it when you can't find it... but you won't freak out or steal for it.

    Cannabis use has been assessed by several studies[23] to be correlated with the development of anxiety, psychosis, and depression

    You know about correlation and causation, of course. Marijuana eases symptoms of depression and anxiety, and probably psychosis as well. They're putting the cart before the horse here. Smoking pot doesn't make you crazy, being crazy makes you smoke pot. From your link: "A recent study has shown that cannabidiol (a major constituent of cannabis) may be as effective as atypical antipsychotics in treating schizophrenia."

    Gateway drug hypothesis

    You'll find many pot smoker to deny a link, but there is a clear link: the same people who sell pot also sell other drugs. In short, the drug laws themselves cause it to be a gateway drug.

    A 2002 longitudinal study published in the Canadian Medical Association Journal concluded that "marijuana does not have a long-term negative impact on global intelligence [in adults]
    Cannabis smoke contains thousands of organic and inorganic chemicals in the tar. This includes many of the same carcinogens as tobacco smoke.

    Odd that a two year old study wasn't mentioned here. Researchers thought that because of the facts cited above, that marijuana would cause cancer, so they did a test on very long term (>30 years) users. They had four groups: nonsmokers, pot smokers, cigarette smokers, and users of both tobacco and marijuana. They expected the users of pot to have as many or more cancers than cigarette smokers and users of both to have far more, but their research showed the opposite: those who smoked both pot and cigarettes had half the cancers of those who only smoked cigarettes, and those who smoked only pot amazingly had fewer cancers than nonsmokers, although the difference was statistically insignifigant.

    So put that in your pipe and smoke it. Gees... drugabuse.org, why not cite the partnership for a drug-free america as well? Sheesh!

Statistics are no substitute for judgement. -- Henry Clay