Twins Study Finds No Evidence That Marijuana Lowers IQ In Teens (sciencemag.org) 307
sciencehabit writes: Roughly half of Americans use marijuana at some point in their lives, and many start as teenagers. Although some studies suggest the drug could harm the maturing adolescent brain, the true risk is controversial. Now, in the first study of its kind (abstract), scientists have analyzed long-term marijuana use in teens, comparing IQ changes in twin siblings who either used or abstained from marijuana for 10 years. After taking environmental factors into account, the scientists found no measurable link between marijuana use and lower IQ.
who cares? (Score:2)
Teen-agers should not be smoking cannabis. Legalize and regulate it like alcohol... 21+
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When looking at the big picture, and taking its overall negative impact on a person's health over a person's entire lifetime, quite possibly.... in terms of the immediate effects on one's motor skills, not so much.
Re:who cares? (Score:5, Interesting)
I live in the Netherlands, and we've had easy access to cannabis for a long time now. When I studied, a lot of roommates smoked it sometimes, and the heavy users had a few plants in their room. About a quarter of the teenagers have used it incidentally, the rest doesn't really bother with it.
With the experience we have locally we have also seen some issues. The issues are mainly psychological issues - IQ drops haven't been seen but motivation does tend to suffer from long term use. There is a very real link with schizophrenic disorders but it's unknown if people who have the genetic predisposition smoke cannabis because of that, or vice versa - in any case, if you have schizophrenic disorders in the family it is very unwise to smoke cannabis long term, although short term and incidental use may be safe.
Also, an acute psychosis brought on by too much cannabis is a well-known issue and cause of death for young tourists in Amsterdam as well. Usually we have a few casualties each summer because people in a psychosis sometimes think they can fly.
For the majority of incidental users, cannabis is MUCH safer than alcohol. However, there is a minority with genetic vulnerability to cannabis that should not use it at all, and long term use of cannabis (2+ years) is probably unhealthy for a much larger group - and I'm ignoring the wider and well-known effects of smoking here, since you could also drink it (as thee) or eat it (in cake).
I'm not against recreative drug use. It should be decriminalized asap. But it's not as harmless as some people make it out to be, even if it doesn't do nearly as much damage as alcohol or cigarettes.
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Also, an acute psychosis brought on by too much cannabis is a well-known issue and cause of death for young tourists in Amsterdam as well. Usually we have a few casualties each summer because people in a psychosis sometimes think they can fly.
The jumpers are mostly mushroom users.
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Odd, because as I've mentioned elsewhere in this thread, I live in Colorado. Mushrooms aren't legal here. We have the jumper issue as well. Also, when the blood work comes back, all they had in their system was THC. In fact, the GPs post almost perfectly sums up the issues we've been seeing since legalization.
Rebuttal?
You mean the single jumper? To claim this you have to show that it was in fact the cause and they weren't insane or suicidal anyhow. Also if you want to compare it to alachol related fatalities which are likely thousands to tens of thousands of times higher.
Re:who cares? (Score:4, Funny)
I understand your point, but as long as alcohol is legal, all the discussion about cannabis being "not as safe as some people make it out to be" are meaningless.
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It's a million times safer than alcohol.
We've told you a million times: Stop exaggerating.
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Heh.
Seriously though, he's off by a few orders of magnitude. He should have said something more like 5,000 times safer, if we broadly go by number of cannabis cigarettes versus alcoholic drinks.
Or if we go by weight, like 1500 pounds of cannabis versus less than 2 pounds of alcohol?
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why not 16?
So that means... (Score:2)
... my kid was always stupid, then? Well, shit. :(
On the other hand (Score:5, Funny)
The people in Flint, Michigan are about to gain a first hand appreciation of what lead does to cognitive abilities.
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The people in Flint, Michigan are about to gain a first hand appreciation of what lead does to cognitive abilities.
Not to mention disposition to criminal behavior:
http://www.chicagotribune.com/... [chicagotribune.com]
According to studies, the effects will become most apparent when the children exposed to lead reach their twenties.
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Lead transfer to water from copper piping with lead based solder is negligible, even in stagnant water conditions. Lead piping on the other hand sees very little transfer only if the water is moving fairly rapidly, any stagnant water sitting in the lead pipes will pick up massive amounts of lead. All lead piping should be removed. Lead solder on the other hand is not a significant enough risk to require large capital investments to remove it, though if work is being done lead based solder should not be used
Teenagers smoke, and they seem pretty on-the-ball. (Score:2)
Is there a false assumption here? (Score:3, Insightful)
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This is your brain. This is your brain on drugs. (Score:3)
They look basically the same. It turns out that marijuana doesn't turn your brain into a fried egg [wikipedia.org]. Who knew?
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Everyone who didn't believe the bullshit they spewed.
If anything, that scaremongering campaign was detrimental to the whole drug prevention. Because kids ain't as dumb as these people. Or at the very least as dumb as these people think. The idea was "we scare the kids straight". And that backfired badly. Because kids tried weed, noticed that hey, it ain't killing me. And in turn came to the correct realization:
They're bullshitting me.
Of course this led to them ignoring the warning. And doing the same that t
Resistance to the effects of THC, + Mark Twain (Score:4, Interesting)
This just in: Having a twin provides a natural immunity to the IQ-reducing properties of marijuana.
"When I was a boy of 14, my father was so ignorant I could hardly stand to have the old man around. But when I got to be 21, I was astonished at how much the old man had learned in seven years." - Mark Twain
Twins (Score:2)
Dude, you go take the test. I'm staying home and getting baked.
Pot is tricky to study (Score:2)
It's nice to see a more statistically rigorous study, b
The War on (this) Drug is almost over. (Score:2)
Gambling used to be illegal almost everywhere in the US. Gambling was addictive, it ruined families, it caused all manner of social ills.Then governments figured out how much money there was to be made from lotteries and casinos, and now gambling is legal and casinos and lotteries are everywhere.
I think the very same thing is going to happen with cannabis. Colorado made about $125 million in tax revenue on weed last year. There are going to be a whole lot of other state governments that see that and
Yeah (Score:3)
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You don't have much experience thinking about medical issues, I take it?
Re:Great Parents!! (Score:5, Informative)
You posted an comment so vague it is meaningless. You did not provide anything agreeing with or refuting what was written.
There's nothing to agree with or refute. If you take even a cursory look at the story, you will see that this was not the kind of study that the GP assumed it was.
Teenagers were not subjected to drug use for this study. Adults who had used marijuana as teens were studied.
The first hint was right there in the summary:
If we're studying the effects of marijuana use on teens, and ten fucking years have gone by, then what exactly is the probability that these subjects are still teens at the time of the study?
Go ahead, get out your calculator and I'll wait here for your answer.
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If we're studying the effects of marijuana use on teens, and ten fucking years have gone by, then what exactly is the probability that these subjects are still teens at the time of the study?
Go ahead, get out your calculator and I'll wait here for your answer.
Sorry dude, but we're sitting around getting baked, and somone stole the fucking Doritos! Not time dude, no time, no....
Honesty? (Score:3)
Adults who had used marijuana as teens were studied.
No, adults who SAID that they had used marijuana as teens were studied. How many of them were honest about it?
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That is because anybody with minimal intelligence and education knows the answer. You obviously are lacking in those departments.
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Science cares about reality.
Your fiction of "what if" and fear of the unknown is how we ended up with prohibition in the first place. This attitude that "if it feels good it must be bad for you" is puritan, religious non-sense.
Marijuana is common place is society, and scientifically it has been shown to be rather benign.
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Except that part of the study was a meta study LOOKING AT OTHER STUDIES THAT HAD ALREADY SHOW IT TO BE BENIGN.
But I'm guessing you couldn't be arsed to read what the actual study was about.
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It's not exactly a stretch to consider that those who smoke marijuana despite being told that they're not supposed to might also not commit themselves to tests designed to show their IQ.
Re: Great Parents!! (Score:2)
Define "stoners". Most likely, it revolves around a whole lifestyle of consumption. You were also working around a bunch of THC consumers who did not call out such attention.
Re:Great Parents!! (Score:4, Insightful)
I think the big problem here is reliance on any test intended to show off levels of intelligence. Many of the cheaper, simpler to administer tests vary wildly in both consistency and accuracy.
Most US schools rely on a specific test to determine gifted/intelligence level. Its cheap and easy to do and doesn't take long. Its primary problem is that in the case of very gifted kids, the test results reverse themselves and may even indicate that a very introverted, very intelligent kid is well below average in intelligence. Then you give the same kid that same test a month later when they're focused and interested in the test and you get a completely different result.
So if you want to show in a study that average scores are lower, use the cheap test. If you want to show higher average scores, use the expensive long tests that capture all of the kids with IQ's over 125 instead of showing them at 80-90.
As far as the original story, I was a regular 'user' in my 20's and dabbled with it infrequently for 30 years. I don't think it reduced my intelligence but it sure does cut into motivation and aggression. One interesting metric I've seen was getting my social security statement a few years ago which showed my annual income since I was a teen. It goes up smoothly and sharply until about the time I started smoking pot. Then it flies level for about five years until I gave it up at which point the income numbers resume the same sharp upward line.
It'd seem to me that the last thing a teenager needs is less motivation and less interest in doing things.
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Seeing how the middle class is all but gone and most of those teens are destined for minimum wage jobs for the rest of their lives, anything that helps make that more bearable helps both them and the society at large.
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I had assumed that was "pot doesn't make you stupid, but stupid people are more likely to smoke pot", but maybe I misunderstand.
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If it was settled and indisputable, there would have been no need for the test.
You seem to be very confused about how science works.
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Re:Great Parents!! (Score:5, Informative)
That isn't how twin studies usually work. In this case, one twin decided to smoke marijuana, while the other did not. They weren't assigned roles in an experiment by researchers. Their parents either didn't have a problem with the drug, or they weren't involved in the decision.
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That means that there is a clear bias. The teen who is smart enough to figure out that they have been sold a load of hyperbole and smoke a bowl is clearly smarter than the one who, proudly no doubt, abstains from consumption.
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If the kids are 16+ then the parents' opinion isn't too important, is it?
And the reason for doing it? Well, in the US, billions upon billions of dollars has been spent on detecting, prosecuting and jailing the users, growers and importers of this more or less (for the vast majority of users) harmless plant. And if drugs policy is to be based on facts then this sort of fact is just one more reason to give it up already and let adults decide what plants they'd like to benefit from.
Re:Great Parents!! (Score:5, Insightful)
And if drugs policy is to be based on facts then this sort of fact is just one more reason to give it up already and let adults decide what plants they'd like to benefit from.
Indeed. There is a real problem when the biggest detriment that people can identify for using an illegal drug is the very fact that it's illlegal. When the primary concern isn't that the drug will kill you, put you in the hospital, give you organ damage, make you crazy, or make you dependent upon it, but is instead that you'll be fined or tossed into jail, something has gone horribly wrong.
When you have people taking 'bath salts' instead of cocaine, which has a much higher chance of, I don't know, chewing somebody's face off, because the latter is illegal as well as the former, but the 'bath salts' are more accessable for those that would use drugs, we have a problem.
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Unlike cocaine where you just chew your own face off.
Re: Great Parents!! (Score:2)
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Probably because regardless of the law, by 16 most kids will do what they like regardless of their parents opinion. It's not like people magically become self-guiding adults at 18.
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According to the law, they do.
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Except in regards to alcohol. Not that it's enforcible anyway.
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Age of consent is sometimes 16 in the US. That's probably more relevant to situations where things are put in your body.
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Maybe because teens about and above that age are fairly independent and good about keeping things from their parents?
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The age of majority in the USA is 18. Yes, it is. I don't know where you got your 16 from.
The subjects of the test had already been smoking pot for at least 10 years. So they are likely in their mid to late 20s. They are full adults, and can make their own decisions about what studies to participate in.
Re:Great Parents!! (Score:5, Insightful)
It was likely survey based. I.e. they found identical twins and asked them if one used and one didn't, and if so, they evaluated them afterwards.
Anyways I'm kind of disappointed that they only looked at IQ, as to me it's a meaningless figure whose only purpose is for "I am more smug than thou art" clubs like Mensa. I'm more curious about other functional measurements both physiologically and sociologically (i.e. how did they vary in terms of career success.) There's some evidence that marijuana can improve both, as well as evidence that it can harm both.
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So you want the arbitrary metrics they used to be a different kind of arbitrary?
That is not what he said. He said they should report things like income in addition to IQ. My dope head friends don't really seem to be particularly stupid, but they sure seem to be apathetic and lacking in ambition. So it would be interesting if that was measured and quantified along with IQ.
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My dope head friends don't really seem to be particularly stupid, but they sure seem to be apathetic and lacking in ambition.
I'm extremely lazy and exhibit all the signs of a pothead, but I don't smoke. I wonder if I did get on it, would my natural lack of ambition be blamed on the weed?
Maybe your couch bound friends were like me already that way inclined, and figured smoking pot makes the couch an even more enjoyable place to be?
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Re:Great Parents!! (Score:5, Insightful)
The "safety" argument relative to drug legalization is huge red herring designed to drag legalization proponents down the path of needing to claim that marijuana is safer than tap water, or worse, into wild and unproven claims of its medical benefits.
The results of marijuana's relative safety have been in for years -- you can't really overdose on it and decades of mass use have failed to show any significant signs of problems in the general population. This is more than we can say about alcohol, acetaminophen, anti-depressants and whole long laundry list of substances that are legal and easy to get.
The REAL argument is that the public policy of marijuana criminalization has been an abject failure. We've spent trillions of dollars on prohibition on it and all we have to show for it is a complete dismantling of our constitutional rights, corruption of a law enforcement system that has produced an epidemic of civil rights abuses quite often enabled by the elusive pursuit of marijuana users (you didn't think they wanted to stop you for a traffic offense, did you?), an erosion in public respect for laws, almost certainly a disregard for the graver risks posed by other illegal drugs, and a criminal justice system that has ruined thousands of lives and built massive criminal enterprises
What we don't have to show for it is any reduction in marijuana use or availability. As a matter of public policy it has failed in its goals and produced a plague of horrific side effects.
This is the argument that needs to be made. The safety issue is a total and complete distraction.
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Tell it to any of the 7 kids who had between 7-36 seizures a day consistently which dropped to 0-4 a year from the first moment of treatment with CBD heavy extracts I provided in NM. Claims aren't wild and unproven, there is quite a bit of research coming out of California and other states. Enough research that many state legislatures have found it compelling enough to legalize the medicinal use.
We have an entire body subsystem that responds t
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I firmly believe that a great number of people get some kind of relief from what ails them from marijuana.
That being said, there are a lot of pro-legalization people who respond to challenges made as to its safety with a litany of medical claims that sound little different than the claims made by all manner of herbalists and charlatans.
It's a weak tactic that's not well validated scientifically and ultimately ends up making legalization advocates just sound like hippies down at the co-op.
But like I said, I
Re: Great Parents!! (Score:2)
The REAL argument is that the public policy of marijuana criminalization has been an abject failure.
Maybe if we repeat that enough, it'll actually become true. The reality, however, is that the Drug War has been achieving exactly what it was intended to achieve; most of us are just too stupid to realize it.
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You are talking about something that has an inconsistent deliver method, is difficult to measure, is only used to treat symptoms, when there are more easily measured/delivered alternatives. Although for recreation it can grow in fairly diverse conditions, would be hard to control and tax, would probably end up getting mixed with other more dangerous things like it already is, and would be problematic testing to see if someone is currently under the influence when they operate heavy machinery and cause an ac
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Since the kids weren't tested, you have a valid point that is unfortunately unrelated to the article and topic in question.
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You are kidding, right?
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All the study did was administer standard IQ tests and ask the teens about pot use confidentially.
It's not like they were handing out joints.
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What kind of demented comment is that? These kinds of studies are very, very obviously done after the fact, i.e. adults are asked whether they used the respective drug as a teen and then they look for effects.
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And what if the psychoactive part helps with the anti-seizure part?
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Cannabidiol (CBD) and tetrahydrocannabinol (THC) are different thngs. THC is psychoactive, CBD is not.
Re:Great Parents!! (Score:5, Insightful)
It's a sad comment on our society where we are so worried that there might be some natural substance that makes people feel good that before an effective drug can be approved the feel-good properties have to be removed.
Re:Great Parents!! (Score:4, Insightful)
It's the same society that flipped it's shit when someone invented a vaccine against a virus that causes cancer, for much the same reasons.
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Good grief this melodrama was appropriate before you could just move to Colorado. Denver Tech Center needs YOU!
THC is not CBD (Score:2)
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It is generally prudent when putting forth nonsensical "arguments" to post AC, kudos for your cowardice/prudence!
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Rigorously testing a Sched 1 drug, which no matter your opinion on the stuffs efficacy should NEVER have been put in that classification, is both expensive and time consuming. Combine that with the fact that marijuana is common as dirt and anyone can grow it and there is VERY little financial incentive to perform such tests.
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> For *every* other drug out there, in the US, we have this thing called "USDA clinical trials" where the drug is rigorously tested
And we did that for alcohol, right?
Oh wait, we didn't.
Gee, what's the LD50 [rocklinusd.org] for cannabis again?
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lol.
Of course tasks like this while high are going to be challenging. Tests are not administered while under the influence. Were you the spliff smoking kid? It sounds like something hilarious to have seen, I bet you and your buddies laughed about it for days.
Re:It's not just about IQ (Score:5, Interesting)
I knew many very smart people who did marijuana. I would have thought most of them would have done more with their smarts but I see them now and they're mostly just getting by. They are happy for the most part though. Thinking about it I'm not sure if it's such a bad thing.
Re:It's not just about IQ (Score:5, Insightful)
Very smart people are not always very motivated people. And vice versa.
Take politics as an example.
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I knew many very smart people who did marijuana. I would have thought most of them would have done more with their smarts but I see them now and they're mostly just getting by. They are happy for the most part though. Thinking about it I'm not sure if it's such a bad thing.
The correlation with motivation appears much stronger than any perceived or real correlation with intelligence.
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I think almost anything in moderation is all right. A couple of beers, a little pot, no big deal. It's the ones who are real pot heads that seem to never go anywhere. They just stay in a fog. I work with a guy who drinks beer all the time. The only time he doesn't have a beer in his hand is when he's at work. I'm talking a case of bud lite every day. Nice guy, just always has a constant low level buzz. He's 50 now so it's only a matter of a few more years until it really starts to cost him. I can s
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And, did this ten-year study make use of the contemporary high-test dope, or the sort of stuff that was more commonly used ten years ago?
Yes, this dope was fully tested over the last 10 years. Obviously I can't blame it for this post now.
Seriously though unless you are talking about extracts, the drug content was around 6-12% ten years ago, already extremely high. I'm not sure what you are reefering too, but I'm sure it was within a stones throw of the highest possible naturally.
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How did they measure motivation, or paranoia, or the other things that anyone who's ever been around dedicated long-term stoners can plainly observe without needing any sort of formal study?
That's something I'd really like to see some actual studies on. I've had a few internet friends who I knew all during highschool who were absolutely brilliant at math/physics/programming. Then they got into smoking weed and, in a massive waste of talent, just sort of quit caring. Most other stoners I've known had an annoying habit of believing all sorts of stupid conspiracy theories and having a false sense of being more perceptive than everyone else. I'd be really curious to know if the smoking was a symp
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I always thought, that being a teen lowers your IQ. Some of the kids I grew up with, seemed to go bat shit crazy in puberty. Some of them, at some point, stopped being teens, and went on to do something with their lives.
Some of them seemed to stay being teens . . . and are probably still doing nothing today.
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Stoners become stoners because of lack of motivation, not the other way around.
Exactly contrary to my observations. Stoners become stoners mostly for social reasons - it's a social activity. For many, it alters them - bright, motivated, active people can become listless lumps. I've seen it in young teens, people in their twenties, less so in older adults who start.
They're paranoid because they engage in an illegal lifestyle and the law is literally out to get them.
Most of them aren't the least bit worried about the cops unless they're distributing. And the paranoia tends to be about many things, if not most things they deal with. It's seen in personal interactions (straining friendl
Re:It's not just about IQ (Score:5, Insightful)
No, most of us aren't familiar with your anecdotes.
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I've seen plenty of people who don't smoke weed become listless lumps, especially teens and young adults. I've also seen plenty of stoners become excellent writers, artists, and musicians, as well as teachers, programmers, etc..
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Stoners become stoners because of lack of motivation, not the other way around. They're paranoid because they engage in an illegal lifestyle and the law is literally out to get them.
The illegality of it wouldn't explain my roommate hiding under the coffee table for three hours. We were living in Berkeley, CA (which at the time time, made possession of a little bit of marijuana a misdemeanor explicitly not enforced by the police by decision of the city council).
This is not to say everyone reacts this way. Most people don't. Also, I've only witnessed this effect to only be short-term. I wouldn't know if some people are affected longterm (except for speech, which seems to change and slow
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You're just wishing it away. The average kid scoring some weed today is winding up with, and smoking, far more "ditch weed with meth" than their previous generational counterparts were.
Fixed that for you.
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The biggest difference today is the vastly reduced likelyhood of smoking some nasty preservative or other admixture in pot. If you read some of the experimental results form the 60s when active scientific testing of a variety of recreational drugs was going on, you'll see a theme of pot causing hallucinations, and being looked at as a hallucinogen. We know of course that pot doesn't do that, but all sorts of ill-advised stuff could be found in "campus weed" back then, at least on campuses that were net im
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- smoking weed killer should not be confused with smoking killer weed.
Great line. I'll note that the Oregon (which legalized recreational use last year) recently published a list of allowable agricultural chemicals to use on legal weed and requirements for testing before bud or other products are sold to the general public or medical users.
Re:Forgot to mention: (Score:5, Informative)
You are correct
From the study
Standardized measures of intelligence were administered at ages 9–12 y, before marijuana involvement, and again at ages 17–20 y. Marijuana use was self-reported at the time of each cognitive assessment as well as during the intervening period. Marijuana users had lower test scores relative to nonusers and showed a significant decline in crystallized intelligence between preadolescence and late adolescence. However, there was no evidence of a dose–response relationship between frequency of use and intelligence quotient (IQ) change.
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Hmm, so similar IQ but lower crystallized intelligence, does that imply that they had higher fluid intelligence? Because somehow, despite their lower crystallized intelligence, they ended up at a similar IQ.
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Question: Research candidate using Cannabis sees drop in IQ and motivation. Is the cannabis use the cause?
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No no no, some Americans spawn as teenagers, the rest are born as babies.
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From the abstract:
Because of the infeasibility of studying this phenomenon experimentally, it is unclear whether the association can be causally attributed to marijuana use itself or is instead the result of confounding factors. We approach this issue quasiexperimentally using longitudinal samples of adolescent twins.
Wonder if there are any twin studies that detail the life outcomes of stoner/non-stoner twins? That would be more useful I think.
We used a quasiexperimental approach to adjust for participants’ family background characteristics and genetic propensities, helping us to assess the causal nature of any potential associations. Standardized measures of intelligence were administered at ages 9–12 y, before marijuana involvement, and again at ages 17–20 y. Marijuana use was self-reported at the time of each cognitive assessment as well as during the intervening period. (no drug test to confirm usage or non-usage?) Marijuana users had lower test scores relative to nonusers and showed a significant decline in crystallized intelligence between preadolescence and late adolescence.
Why did you stop there?
In other words, it is likely other factors in a person's life (like the home environment) that is causing the IQ decline noted in some studies. The people with a crappy home life are also more likely to smoke marijuana so the IQ decline was sh