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posted by CoolHand on Tuesday January 19 2016, @08:07PM   Printer-friendly
from the smoke-em-if-u-got-em dept.

Meta at Science News reports on a new study (DOI: 10.1073/pnas.1516648113) still paywalled at PNAS:

Marijuana is used more than any other recreational drug, with recent trends toward greater social and legal acceptance in some regions. Concerns remain, however, about a possible causal relationship suggested in scientific studies between marijuana use and decline in IQ.

A new study from two longitudinal studies of twins, examine the link between marijuana use and IQ using data from more than three thousand individuals from Southern California and Minnesota.

The study by scientists from UCLA and the University of Minnesota focused on three criteria they proposed as measures for evidence of a direct causal relationship between marijuana use and cognitive decline.

  1. If marijuana use causes IQ decline, as opposed to merely being associated, then poor cognition scores should only be evident after use begins, and not before.
  2. If a causal link exists, a dose-response relationship would be expected.– that is, higher decline with heavier marijuana use.
  3. finally, if the relationship is causal, then the association of marijuana use and IQ decline should remain, even after accounting for genetic and social factors.

In tests of abstract reasoning and problem solving associated (called "fluid intelligence") showed no significant differences between uses and non users.

[more]

The study did find decreases in ability among marijuana users compared to non-users in the ability to use previously learned knowledge. (Vocabulary and Information retrieval, or so called "crystallized intelligence".)

The authors noted, however, that the baseline IQ scores of eventual users were already significantly lower in the affected areas.

Here, marijuana use does not precede cognitive decline, and they point out prior evidence that suggests other factors such as behavioral disinhibition and conduct disorder that may predispose individuals to both lower IQ and substance use.

(So criteria 1 above was not met).

The study also found no relationship between heavier or more frequent marijuana use and the magnitude of IQ decline.

(Criteria 2 was not met).

Finally, the authors examined the effects of outside factors associated with IQ decline. They found the decrease in Vocabulary scores was reduced in one study and "completely eliminated" in the other when adjusted for participants who self-reported binge drinking and use of other drugs.

(Criteria 3 also failed).

The authors conclude that taken together, the results provide "little evidence to suggest that adolescent marijuana use has any direct effect on intellectual decline".


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  • (Score: 5, Insightful) by jdavidb on Tuesday January 19 2016, @08:44PM

    by jdavidb (5690) on Tuesday January 19 2016, @08:44PM (#291770) Homepage Journal

    It's great to see studies like this to give some evidence one way or the other.

    But for discussion among peers, I feel it's necessary to start with the premise that even if cannabis were to cause an IQ decline, that doesn't give anybody the right to stop anybody else from using it.

    When that premise is not in place, the discussion is disrespectful and controlling from the very beginning.

    --
    ⓋⒶ☮✝🕊 Secession is the right of all sentient beings
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  • (Score: 1, Touché) by Anonymous Coward on Tuesday January 19 2016, @08:50PM

    by Anonymous Coward on Tuesday January 19 2016, @08:50PM (#291774)

    What's controlling isn't a discussion, but Schedule I status.

    • (Score: 3, Insightful) by jdavidb on Tuesday January 19 2016, @09:33PM

      by jdavidb (5690) on Tuesday January 19 2016, @09:33PM (#291794) Homepage Journal
      That kind of thing will become much harder to enforce when a larger percentage of the population accept what I said above.
      --
      ⓋⒶ☮✝🕊 Secession is the right of all sentient beings
  • (Score: 2, Disagree) by Gravis on Tuesday January 19 2016, @09:39PM

    by Gravis (4596) on Tuesday January 19 2016, @09:39PM (#291799)

    I feel it's necessary to start with the premise that even if cannabis were to cause an IQ decline, that doesn't give anybody the right to stop anybody else from using it.
    When that premise is not in place, the discussion is disrespectful and controlling from the very beginning.

    then you should make that your discussion because not everybody agrees with that. the fact that you find discussions to be "disrespectful and controlling" is because you fail to acknowledge that this is not a universally agreed upon concept.

    • (Score: 2, Touché) by Anonymous Coward on Tuesday January 19 2016, @09:58PM

      by Anonymous Coward on Tuesday January 19 2016, @09:58PM (#291807)

      then you should make that your discussion because not everybody agrees with that.

      Indeed, tyrants do disagree with that; they aren't exactly enthusiastic about freedom in general, after all. They also support things like mass surveillance, stop-and-frisk policies, and the TSA. Ah, but if they work, stripping people of their freedoms must be justified.

      The people who don't agree should be regarded with nothing but absolute contempt, for they are advocating policies that will strip people of their freedoms. It's not just a matter of petty disagreement at that point.

    • (Score: 1, Flamebait) by jdavidb on Wednesday January 20 2016, @03:04AM

      by jdavidb (5690) on Wednesday January 20 2016, @03:04AM (#291921) Homepage Journal

      the fact that you find discussions to be "disrespectful and controlling" is because you fail to acknowledge that this is not a universally agreed upon concept.

      I still consider such people to be acting disrespectfully and to be controlling, even if they don't agree that they are. It is extremely easy to be disrespectful and controlling without even knowing it. I used to be that way all the time. Probably still am, frequently, although I hope I've made a little bit of headway in dealing with it.

      --
      ⓋⒶ☮✝🕊 Secession is the right of all sentient beings
      • (Score: 2) by Gravis on Wednesday January 20 2016, @03:35AM

        by Gravis (4596) on Wednesday January 20 2016, @03:35AM (#291938)

        the fact that you find discussions to be "disrespectful and controlling" is because you fail to acknowledge that this is not a universally agreed upon concept.

        I still consider such people to be acting disrespectfully and to be controlling, even if they don't agree that they are.

        what you have stated is that anyone that does not agree with your point of view on this issue is being disrespectful and controlling before you even meet them. there is name for that, prejudice.

        • (Score: 1, Flamebait) by jdavidb on Wednesday January 20 2016, @01:37PM

          by jdavidb (5690) on Wednesday January 20 2016, @01:37PM (#292046) Homepage Journal

          what you have stated is that anyone that does not agree with your point of view on this issue is being disrespectful and controlling before you even meet them. there is name for that, prejudice.

          Some people believe that those who want to use marijuana should be controlled and forbidden from doing so. That is the very definition of controlling. I used to be open to that sort of viewpoint but after serious consideration I have rejected it. Furthermore I see this is why political discussions cannot be respectful: one or both sides want the other to be forced to submit to their point of view.

          --
          ⓋⒶ☮✝🕊 Secession is the right of all sentient beings
          • (Score: 2) by Gravis on Wednesday January 20 2016, @05:05PM

            by Gravis (4596) on Wednesday January 20 2016, @05:05PM (#292138)

            what should be allowed and what should be prohibited is a matter of what is good for the general welfare. you have to remember that everyone is part of an interconnected society, so if what one person does infringes upon what is good for the general welfare, it's where your rights end. your particular issue is not unique but rather of a type because the same argument could easily be used by anti-vaxxers, tax dodgers, cult leaders and all sorts of people doing crazy things that are bad for the general welfare. you decided that regardless of the consequences of doing so, people should be able to use marijuana and anyone who thought otherwise was automatically controlling and disrespectful. the general welfare should always be considered when speaking of personal liberties... unless you are an anarchist.

            • (Score: 2) by jdavidb on Wednesday January 20 2016, @05:29PM

              by jdavidb (5690) on Wednesday January 20 2016, @05:29PM (#292148) Homepage Journal
              I am an anarchist.
              --
              ⓋⒶ☮✝🕊 Secession is the right of all sentient beings
              • (Score: 2) by Gravis on Thursday January 21 2016, @01:35AM

                by Gravis (4596) on Thursday January 21 2016, @01:35AM (#292349)

                well then, only thing you have accomplishes here is proving you are both a fool and a hypocrite.

                • (Score: 0) by Anonymous Coward on Thursday January 21 2016, @05:52PM

                  by Anonymous Coward on Thursday January 21 2016, @05:52PM (#292682)

                  A fool I can understand, but not "hypocrite".

            • (Score: 2) by Anal Pumpernickel on Thursday January 21 2016, @05:48PM

              by Anal Pumpernickel (776) on Thursday January 21 2016, @05:48PM (#292680)

              what should be allowed and what should be prohibited is a matter of what is good for the general welfare

              Never heard of individual liberties, then? Personally, I'm not a fan of tyranny of the majority, so I will have to disagree. If you seek to control what other people are allowed to put into their own bodies, you are nothing but a moral thug and should be treated with nothing but absolute contempt. Since I am not a coward who favors safety over liberty, such authoritarians are my enemies.

              Pretty much everything is going to have some indirect effect on others. That is no excuse to ban something.

              • (Score: 2) by Gravis on Thursday January 21 2016, @07:38PM

                by Gravis (4596) on Thursday January 21 2016, @07:38PM (#292730)

                If you seek to control what other people are allowed to put into their own bodies, you are nothing but a moral thug

                this has nothing to do with morals. if something is proven to lower your IQ or be chemically addictive then it should be banned or heavily regulated because it will have a widespread negative cumulative effect on society. if you think this is wrong, perhaps you should investigate the absurd amount of people that have and will become diabetic.

                Pretty much everything is going to have some indirect effect on others. That is no excuse to ban something.

                should we allow people to put lead in paint and gasoline? should we let everyone pollute as much as they like? indirect effects are absolutely good enough reasons to ban something.

                • (Score: 2) by Anal Pumpernickel on Thursday January 21 2016, @08:54PM

                  by Anal Pumpernickel (776) on Thursday January 21 2016, @08:54PM (#292777)

                  this has nothing to do with morals.

                  Of course it does. You're suggesting that it's alright to violate people's fundamental right to control their own bodies in the name of safety. To me, you're no better than those who say we should have mass surveillance to stop the terrorists, or other such things. Even if you don't support mass surveillance simply because you don't think it is effective, you probably would support it if they made it effective, at least judging from what you've said so far. If so, that means you cannot ever be considered to be a real ally when it comes to matters of freedom, as you will abandon everyone's freedoms when you want to increase safety.

                  if something is proven to lower your IQ or be chemically addictive then it should be banned or heavily regulated because it will have a widespread negative cumulative effect on society.

                  Science doesn't tell us what we "should" do; it doesn't deal with such questions at all. So even if such proof is found, we could still say that we prefer freedom over a deeply authoritarian society that is more safe. Well, maybe not you, since you seem to think living in padded rooms is okay.

                  if you think this is wrong, perhaps you should investigate the absurd amount of people that have and will become diabetic.

                  Freedom is more important than safety, so the number of people who have and will become diabetic is irrelevant to this conversation.

                  should we allow people to put lead in paint and gasoline? should we let everyone pollute as much as they like?

                  What I said was that the mere existence of an indirect effect on others is not enough to ban something. You require something more than that. But your thought process appears to be so authoritarian in nature that it seems likely that you would find any given reason to ban something that you don't like to be good enough, so I'm wasting my time.

                  indirect effects are absolutely good enough reasons to ban something.

                  Ice skating is unnecessary and dangerous. You could have an accident, get injured, and then the taxpayers might have to foot the bill in some way. Obviously, this is unacceptable and we must ban ice skating or other similar activities that are unnecessary and could indirectly affect others in negative ways.

                  I'd rather just pay more taxes than live in the tyrannical society you seem to desire. That's an option too.

                  • (Score: 2) by Gravis on Thursday January 21 2016, @09:44PM

                    by Gravis (4596) on Thursday January 21 2016, @09:44PM (#292798)

                    To me, you're no better than those who say we should have mass surveillance to stop the terrorists
                    ...
                    you will abandon everyone's freedoms when you want to increase safety.
                    ...
                    Well, maybe not you, since you seem to think living in padded rooms is okay.
                    ...
                    But your thought process appears to be so authoritarian in nature that it seems likely that you would find any given reason to ban something that you don't like to be good enough, so I'm wasting my time.
                    ...
                    I'd rather just pay more taxes than live in the tyrannical society you seem to desire.

                    "Splitting (also called black and white thinking or all-or-nothing thinking) is the failure in a person's thinking to bring together both positive and negative qualities of the self and others into a cohesive, realistic whole. It is a common defense mechanism used by many people.[1] The individual tends to think in extremes (i.e., an individual's actions and motivations are all good or all bad with no middle ground)."

                    you are your own problem, not me.

                    • (Score: 2) by Anal Pumpernickel on Friday January 22 2016, @12:05AM

                      by Anal Pumpernickel (776) on Friday January 22 2016, @12:05AM (#292872)

                      Nice try, but that has nothing to do with the validity of what I said.

                      • (Score: 2) by Gravis on Friday January 22 2016, @08:38AM

                        by Gravis (4596) on Friday January 22 2016, @08:38AM (#293040)

                        to be clear, i'm not participating in a flame war, so i'm done discussing the matter with you.

        • (Score: 2) by rondon on Wednesday January 20 2016, @02:06PM

          by rondon (5167) on Wednesday January 20 2016, @02:06PM (#292053)

          Please explain to me, Gravis, how prejudice is always a bad thing (I feel that is what your statement implied; if not, please feel free to disregard my request and instead educate me on your actual intent). Is it bad to be prejudiced against murder, for example? I feel like jdavid is simply expressing that he has an extreme prejudice against people who believe they should infringe on the freedoms of others.

  • (Score: 3, Insightful) by joekiser on Tuesday January 19 2016, @11:43PM

    by joekiser (1837) on Tuesday January 19 2016, @11:43PM (#291855)

    But for discussion among peers, I feel it's necessary to start with the premise that even if cannabis were to cause an IQ decline, that doesn't give anybody the right to stop anybody else from using it.

    Agreed. Moreover, it is hypocritical that public opinion is trending against the use of tobacco and carbonated beverages, while moving towards the recreational use of marijuana.

    --
    Debt is the currency of slaves.
    • (Score: 3, Touché) by takyon on Tuesday January 19 2016, @11:48PM

      by takyon (881) <takyonNO@SPAMsoylentnews.org> on Tuesday January 19 2016, @11:48PM (#291858) Journal

      I think we will reach a point where we realize that drinking soda and other sugary beverages (including Gatorade and fruit juice) is far more damaging to health than vaping cannabis.

      Guess which one can be found in school vending machines?

      --
      [SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
  • (Score: 5, Insightful) by NotSanguine on Wednesday January 20 2016, @02:48AM

    by NotSanguine (285) <NotSanguineNO@SPAMSoylentNews.Org> on Wednesday January 20 2016, @02:48AM (#291913) Homepage Journal

    In any attempt to create a free society, I feel it's necessary to start with the premise that no one has the right to tell anyone else what (e.g., marijuana, alcohol, airplane glue, fetuses, information, etc.) they should or shouldn't put in (or take out) of their bodies.

    There. FTFY.

    --
    No, no, you're not thinking; you're just being logical. --Niels Bohr
    • (Score: 2) by tangomargarine on Wednesday January 20 2016, @02:57PM

      by tangomargarine (667) on Wednesday January 20 2016, @02:57PM (#292074)

      they should or shouldn't put in (or take out) of their bodies.

      Well...other than e.g. a bomb. But the "my right extends as far as..." was probably implied, right? :)

      --
      "Is that really true?" "I just spent the last hour telling you to think for yourself! Didn't you hear anything I said?"
      • (Score: 0) by Anonymous Coward on Wednesday January 20 2016, @10:48PM

        by Anonymous Coward on Wednesday January 20 2016, @10:48PM (#292305)

        they should or shouldn't put in (or take out) of their bodies.

        Well...other than e.g. a bomb. But the "my right extends as far as..." was probably implied, right? :)

        No! Bombs are freedom. Freedom to enforce the laws of Jesus. He died for your sins, but that doesn't mean you shouldn't as well.

        All of you lib'rul elites think you're so damn smart. Well, country don't mean dumb.

        You need to accept Jesus as your personal savior. Or I will kill you dead. But don't worry, if you've asked your Lord for forgiveness, you will sit at his hand in heaven forever.

        But if not, or you're a godless commie pinko atheist, you will burn in hell for eternity!

        The lord God is my savior, but nothing can save you from my wrath!

    • (Score: 2) by tangomargarine on Thursday January 21 2016, @05:41PM

      by tangomargarine (667) on Thursday January 21 2016, @05:41PM (#292674)

      any

      no one

      anyone

      There's this thing called "context" [reference.com] of which you apparently aren't aware. The statement:

      Those damn pedants, trying to demonstrate that absolutes are only rarely useful...

      --
      "Is that really true?" "I just spent the last hour telling you to think for yourself! Didn't you hear anything I said?"
      • (Score: 2) by NotSanguine on Thursday January 21 2016, @05:48PM

        by NotSanguine (285) <NotSanguineNO@SPAMSoylentNews.Org> on Thursday January 21 2016, @05:48PM (#292678) Homepage Journal

        Why post that here? Most likely no one but me will see it.

        Why not post that drivel in the GCHQ discussion? That way other folks can see it too.

        Have a lovely day, darling!

        --
        No, no, you're not thinking; you're just being logical. --Niels Bohr