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Sifo
| | Posted on Friday, August 31, 2012 - 10:32 am: | 
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Blaming pot for intelligence loss is silly. Problem is when "experiments" are "reviewed" by non-technical folks.
Certain personality types are drawn to intoxicating substances - whatever they are. This is true with certain personalities being drawn to certain activities (high risk behaviors like motorsports, racing, combat, marathon/triathlon).
There are certainly those users who don't have a genetic predisposition - but the marijuana-smoking population MAY be largely made up of CERTAIN types of folks from the get go.
There is CORRELATION and there is CAUSE.
Clearly correlation doesn't mean causation. The correlation has been well known for a long time. No new there. This study was to investigate if there was causation. They have shown the causation aspect with this study. It would be nice if we could easily see the details of the study, but sadly, as so often happens with published papers, it's hidden behind the green curtain. The abstract is freely available though... http://www.pnas.org/content/early/2012/08/22/12068 20109.abstract
(emphasis is mine)
quote:Persistent cannabis users show neuropsychological decline from childhood to midlife
Madeline H. Meiera,b,1,
Avshalom Caspia,b,c,d,e,
Antony Amblere,f,
HonaLee Harringtonb,c,d,
Renate Houtsb,c,d,
Richard S. E. Keefed,
Kay McDonaldf,
Aimee Wardf,
Richie Poultonf, and
Terrie E. Moffitta,b,c,d,e
+ Author Affiliations
aDuke Transdisciplinary Prevention Research Center, Center for Child and Family Policy,
bDepartment of Psychology and Neuroscience, and
cInstitute for Genome Sciences and Policy, Duke University, Durham, NC 27708;
dDepartment of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710;
eSocial, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King’s College London, London SE5 8AF, United Kingdom; and
fDunedin Multidisciplinary Health and Development Research Unit, Department of Preventive and Social Medicine, School of Medicine, University of Otago, Dunedin 9054, New Zealand
Edited by Michael I. Posner, University of Oregon, Eugene, OR, and approved July 30, 2012 (received for review April 23, 2012)
Abstract
Recent reports show that fewer adolescents believe that regular cannabis use is harmful to health. Concomitantly, adolescents are initiating cannabis use at younger ages, and more adolescents are using cannabis on a daily basis. The purpose of the present study was to test the association between persistent cannabis use and neuropsychological decline and determine whether decline is concentrated among adolescent-onset cannabis users. Participants were members of the Dunedin Study, a prospective study of a birth cohort of 1,037 individuals followed from birth (1972/1973) to age 38 y. Cannabis use was ascertained in interviews at ages 18, 21, 26, 32, and 38 y. Neuropsychological testing was conducted at age 13 y, before initiation of cannabis use, and again at age 38 y, after a pattern of persistent cannabis use had developed. Persistent cannabis use was associated with neuropsychological decline broadly across domains of functioning, even after controlling for years of education. Informants also reported noticing more cognitive problems for persistent cannabis users. Impairment was concentrated among adolescent-onset cannabis users, with more persistent use associated with greater decline. Further, cessation of cannabis use did not fully restore neuropsychological functioning among adolescent-onset cannabis users. Findings are suggestive of a neurotoxic effect of cannabis on the adolescent brain and highlight the importance of prevention and policy efforts targeting adolescents.
So it's not amateur interpretation of a study that is showing pot to degrade your mental faculties. That is explicitly stated by the researchers. Silly is to deny this without other conflicting scientific information.
Also the fact that they followed 1,037 people from their birth, and a certain percentage (if the study is worth the paper it's written on) would include a certain number of control patients that didn't use pot at all. This is why Boogiman's 5.2% number is meaningless. Clearly the pot users are put into multiple categories too. His math may be correct (although he still hasn't said where the 52 number came from) but it's a meaningless calculation.
There MAY BE other factors at work.
Perhaps this is why they measured IQ BEFORE they took up their stoner habits. It gives them a baseline to judge against to rule out the idea that the correlation is caused by stupid people tend to become stoners. This may or may not be true, but it wasn't being studied by this study.
These discussions were richer when Hex was still around.  |
Slaughter
| | Posted on Friday, August 31, 2012 - 04:10 pm: |
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Good link - however, the ONLY way they can make more than "tendency" statemenets is to have a controlled experiment in which a couple groups of volunteers are brought in and TOLD they are being part of an inhaled intoxicant test. Half get placebo, half get the evil weed. Measure before, measure after. The problem is that you'd STILL have people who had a predisposition to self-destructive behaviour unless you excluded smokers from the populations in the test.
We have PLENTY of 3rd and 4th year college students majoring in psych or sociology (or art history) who will be working at the fast food window when graduating anyways... |
Sifo
| | Posted on Friday, August 31, 2012 - 08:58 pm: |
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I wouldn't say that would be the ONLY way to test the effects is with that sort of experiment. It is probably the most direct way though (double blind of course), but you would have problems with giving human subjects a federally controlled substance. That creates some pretty serious ethical issues, which is why we rely on studies such as this one for this sort of matter. You do need to study more individuals to get a suitable signal to noise ratio from the data. That's why a study like this uses a large number of subjects, 1,037 in this case, instead of a few dozen that might be used for a double blind study with more tightly controlled laboratory conditions. You also can't feasibly study humans in a lab for 38 years. |
Slaughter
| | Posted on Friday, August 31, 2012 - 09:08 pm: |
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Agreed - so results are still somewhat open to interpretation.
Read up on Feynman and some of his opinions on the "Science" of psychology.
(and that was my major before switching to engineering after a decade working for a living) |
Sifo
| | Posted on Friday, August 31, 2012 - 09:25 pm: |
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Agreed - so results are still somewhat open to interpretation.
We don't seem to be in agreement. I'm saying that the large sample size used in this study goes a long way to make the data clear. When they take the segment of the sample who were regular users, and the average IQ drop is 8 points, where other groups, such as occasional users, or those who abstained as teens and quit as adults didn't show an IQ drop, you have some VERY solid data. It takes little "interpretation" to see what is going on with the stoners. |
Sifo
| | Posted on Friday, August 31, 2012 - 09:28 pm: |
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Read up on Feynman and some of his opinions on the "Science" of psychology.
And we are talking physiology here, not psychology. |
Slaughter
| | Posted on Saturday, September 01, 2012 - 07:37 am: |
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I don't entirely separate psychology from physiology. People who do are skating on thin ice.
As folks do more research into neurological functioning, they are finding WAY MORE of a connection between psychological traits and basic brain function. New advances in high-resolution CAT scanning and MRI have shown very specific regions of the brain affected by and affecting behaviors.
Much of this is now being found to be genetic in nature but ALSO the "re-wiring" of the brain by other factors such as chemical and environmental - or LEARNING - seem to show that much of what we perceive to be "just" psychology is BOTH mental AND biological.
(I mean duuuuhhhh - we are a biological machine... so the arguments about "soul" start taking place about now)
(Message edited by slaughter on September 01, 2012) |
Sifo
| | Posted on Saturday, September 01, 2012 - 08:15 am: |
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Sure, there's little doubt that physiology and psychology are connected. One can certainly affect the other. In the case at hand however, they are simply studying a physiological response to a chemical. If there are psychological factors at work from that physiological response, they aren't being studied here. So while nothing operates in a vacuum, certain aspects can be isolated and studied.
BTW, the effects of pot on intelligence and reasoning has been studied in the lab with animals. I'm sure you knew that even as you point to the weaknesses of this sort of study. I'm also sure that you understood the ethical problems with doing the same sort of experiments on humans where the likely result, based on the animal experiments, is going to be permanent damage to brain function. No reputable researcher is going to do that study and no reputable university is going to provide any funding or support for such an experiment.
So bottom line, this is about as definitive type of study as will ever be done on humans (until we have some serious deterioration in ethical standards at least) and the results are consistent with lab experiments on animals. I really start to question those who can look at that sort of scientific evidence and claim that the results aren't pretty conclusive. |
Slaughter
| | Posted on Saturday, September 01, 2012 - 10:23 am: |
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Sifo - I have only one response:
Duuuude! |
86129squids
| | Posted on Saturday, September 01, 2012 - 12:45 pm: |
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Sifo abides... |
Etennuly
| | Posted on Saturday, September 01, 2012 - 01:04 pm: |
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It is all about brain cells.
Booze kills brain cells. (It did not make Bud wiser) 
Pot puts brain cells into a neutral gear, they are not necessarily dead, but useless all the same.
BUT.....if you were to drink clear mountain spring water out of a mason jar.....with a whiff of Ben-gay.....you may, or may not, have found a super charger to maximizing intoxication by minimizing toxic intake .
Me, I know nothing of the sort .
What was the question? |
86129squids
| | Posted on Saturday, September 01, 2012 - 01:57 pm: |
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...and, Vern imbibes... |
Aesquire
| | Posted on Saturday, September 01, 2012 - 09:06 pm: |
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Sifo, the repeated disproving of the Anthropomorphic global warming hypothesis makes me question a lot of people too.
Most interesting result in this study is that childhood onset intoxication abuse makes you possibly permanently dumber, adult onset abuse may let you recover some smarts, and that fits right along with common sense in a scary way.
Now I have to ask, since the Male brain is not fully developed until you are 25 or so... would raising the legal intoxication limits be a logical thing? Or just more of the old fogies want their bars back thing? ( the real reason for the 21 drinking age, IMHO. )
Don't forget to be aware of when the bars close and the Drunks are "forced" to drive.... |
Aesquire
| | Posted on Saturday, September 01, 2012 - 09:14 pm: |
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The problem with all such studies is that the subjects tend to be self selecting. If you never drank, you are pretty useless in a booze study.
Doesn't invalidate the results, but does make you have to be aware of all the "buts" "ifs" and "among certain groups".
For example, Many Japanese have a genetic condition that keeps them from "properly" processing alcohol. In short, cheap dates. They get drunk faster, harder, and take more time to recover.
You have to factor all this stuff into studies like this to keep them valid.
Psychology has a long history of bad studies. Real bad studies. But then... I tend to the Skinner view on some of this stuff. ( and am aware, vividly, that Skinner isn't always right, or applicable... ) Take my opinion with a pile of salt, I got a "D" in Psych 212 for telling the teacher "Freud was a coke head with a mama hangup".......  |
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