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The Straight Story

(48,121 posts)
Mon Jul 1, 2013, 09:28 AM Jul 2013

Long-term cannabis use may blunt the brain's motivation system

Long-term cannabis users tend to produce less dopamine, a chemical in the brain linked to motivation, a study has found.

Researchers found that dopamine levels in a part of the brain called the striatum were lower in people who smoke more cannabis and those who began taking the drug at a younger age.

They suggest this finding could explain why some cannabis users appear to lack motivation to work or pursue their normal interests.

The study, by scientists at Imperial College London, UCL and King’s College London, was funded by the Medical Research Council and published in the journal Biological Psychiatry.

The researchers used PET brain imaging to look at dopamine production in the striatum of 19 regular cannabis users and 19 non-users of matching age and sex.

http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_1-7-2013-11-49-21

62 replies = new reply since forum marked as read
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Long-term cannabis use may blunt the brain's motivation system (Original Post) The Straight Story Jul 2013 OP
Minor detail: “Although we only looked at cannabis users who have had psychotic-like experiences think Jul 2013 #1
Here is the study The Straight Story Jul 2013 #4
Edited for paranoid reflexes think Jul 2013 #7
OK wait. From your above post to the study: think Jul 2013 #9
Hell if I know, I don't read the crap I post The Straight Story Jul 2013 #10
I'm just curious as that would seem to be a rather limiting control factor think Jul 2013 #13
19 subjects? those researchers lack motivation nt arely staircase Jul 2013 #19
LOL. Indeed... think Jul 2013 #22
nice XemaSab Jul 2013 #39
A rebuttal from Bill Hicks: deutsey Jul 2013 #2
Bill Hicks... trumad Jul 2013 #8
Let them get stuck in traffic, all our pizzas will be free! Initech Jul 2013 #48
Somebody on here, a while ago... CanSocDem Jul 2013 #20
Motivation in general or specific motivation? hobbit709 Jul 2013 #3
I really didn't want to respond to this post but I guess I will tularetom Jul 2013 #5
Bring on that lack of motivation BlueToTheBone Jul 2013 #6
Oh noes!!!!! We may not be as productive as the overseers demand?!? burnodo Jul 2013 #11
Certainly couldn't have seen this one coming NoPasaran Jul 2013 #12
Worker drones, don't be happy and creative, just build those widgets for the shareholders. tridim Jul 2013 #14
I was barely able to click on this thread bigtree Jul 2013 #15
First off, cannabis is a PLANT, not a "drug." Le Taz Hot Jul 2013 #16
"19 Regular Cannabis users" think Jul 2013 #21
No agenda there, no siree! Le Taz Hot Jul 2013 #23
agree with your post but how can you claim THC isn't a drug? it's a psychoactive substance. dionysus Jul 2013 #41
So is caffein and nicotine but we don't label those as drugs. Le Taz Hot Jul 2013 #44
i consider caffeine and nicotine to be drugs too, i don't think drugs are (always) bad. dionysus Jul 2013 #45
It's just all about labels Le Taz Hot Jul 2013 #46
Willie Nelson agrees with Le Taz Hot SCantiGOP Jul 2013 #62
Couldn't have made it without the pot Jessy169 Jul 2013 #42
That ain't rocket science. nt Zorra Jul 2013 #17
It's not a legitimate study, either. Le Taz Hot Jul 2013 #24
The parent company Elsevier did a fake peer review to cover Merk's ass! think Jul 2013 #29
This is one of the reasons I like DU. Le Taz Hot Jul 2013 #31
Agree! I've learned so much on DU! think Jul 2013 #34
Operative word there is May madokie Jul 2013 #18
40+ years, two careers, a PhD, dozens of projects, both personal and professional.... mike_c Jul 2013 #25
So they used indica instead of sativa? NT Trillo Jul 2013 #26
News Flash: Prohibition propagandists may be motivated to lie about effects of cannabis. Fozzledick Jul 2013 #27
Maybe they don't need as much dopamine, so their bodies make less? bemildred Jul 2013 #28
Or maybe a lack of dopamine may produce "psychotic-like experiences". Fozzledick Jul 2013 #32
And it pays well, if you do it that way. nt bemildred Jul 2013 #40
Really RobinA Jul 2013 #43
Oh dear, this will end in tears. Safetykitten Jul 2013 #30
Not for those stoners who actually read the "study"... Democracyinkind Jul 2013 #33
What would motivate them to do that? think Jul 2013 #37
That's commitment for ya burnodo Jul 2013 #35
Ah, so that explains why all the motivated Americans choose Oxycontin. nt raouldukelives Jul 2013 #36
To paraphrase your article Half-Century Man Jul 2013 #38
We're motivated, we just realize it's not worth the effort. Initech Jul 2013 #47
Maybe they lack motivation to conform to what society wants them to do? Generic Other Jul 2013 #49
Bookmarking to read later IDemo Jul 2013 #50
Carl Sagan! eom wildbilln864 Jul 2013 #51
I need to look up the definition of "blunt"... KansDem Jul 2013 #52
I just don't care d_r Jul 2013 #53
LOL! Politicalboi Jul 2013 #54
I'd like to read the article Dyedinthewoolliberal Jul 2013 #55
I call horse pucky! Faux pas Jul 2013 #56
Dont care DJ13 Jul 2013 #57
I was going to comment on this... cherokeeprogressive Jul 2013 #58
Ode to Cannabis babydollhead Jul 2013 #59
I read the headline too fast as "cannibalism"... aikoaiko Jul 2013 #60
Oh well... demwing Jul 2013 #61
 

think

(11,641 posts)
1. Minor detail: “Although we only looked at cannabis users who have had psychotic-like experiences
Mon Jul 1, 2013, 09:31 AM
Jul 2013
while using the drug, we think the findings would apply to cannabis users in general, since we didn’t see a stronger effect in the subjects who have more psychotic-like symptoms. This needs to be tested though"

The Straight Story

(48,121 posts)
4. Here is the study
Mon Jul 1, 2013, 09:38 AM
Jul 2013
http://www.sciencedirect.com/science/article/pii/S0006322313005027

Dopaminergic Function in Cannabis Users and Its Relationship to Cannabis-Induced Psychotic Symptoms

Background

Cannabis is the most widely used illicit drug globally, and users are at increased risk of mental illnesses including psychotic disorders such as schizophrenia. Substance dependence and schizophrenia are both associated with dopaminergic dysfunction. It has been proposed, although never directly tested, that the link between cannabis use and schizophrenia is mediated by altered dopaminergic function.
Methods

We compared dopamine synthesis capacity in 19 regular cannabis users who experienced psychotic-like symptoms when they consumed cannabis with 19 nonuser sex- and age-matched control subjects. Dopamine synthesis capacity (indexed as the influx rate constant KicerKicer) was measured with positron emission tomography and 3,4-dihydroxy-6-[18F]-fluoro-l-phenylalanine ([18F]-DOPA).
Results

Cannabis users had reduced dopamine synthesis capacity in the striatum (effect size: .85; t36 = 2.54, p = .016) and its associative (effect size: .85; t36 = 2.54, p = .015) and limbic subdivisions (effect size: .74; t36 = 2.23, p = .032) compared with control subjects. The group difference in dopamine synthesis capacity in cannabis users compared with control subjects was driven by those users meeting cannabis abuse or dependence criteria. Dopamine synthesis capacity was negatively associated with higher levels of cannabis use (r = ?.77, p < .001) and positively associated with age of onset of cannabis use (r = .51, p = .027) but was not associated with cannabis-induced psychotic-like symptoms (r = .32, p = .19).
Conclusions

These findings indicate that chronic cannabis use is associated with reduced dopamine synthesis capacity and question the hypothesis that cannabis increases the risk of psychotic disorders by inducing the same dopaminergic alterations seen in schizophrenia.
 

think

(11,641 posts)
9. OK wait. From your above post to the study:
Mon Jul 1, 2013, 09:55 AM
Jul 2013

We compared dopamine synthesis capacity in 19 regular cannabis users who experienced psychotic-like symptoms when they consumed cannabis with 19 nonuser sex- and age-matched control subjects.


So the study was 19 cannabis users who experienced psychotic-like symptoms when they consumed cannabis and 19 NON USERS.

Am I reading it correct this time that the only cannabis users in the study were those who experienced pychotic like reactions?

deutsey

(20,166 posts)
2. A rebuttal from Bill Hicks:
Mon Jul 1, 2013, 09:36 AM
Jul 2013

“They lie about marijuana. Tell you pot-smoking makes you unmotivated. Lie! When you're high, you can do everything you normally do just as well — you just realize that it's not worth the fucking effort. There is a difference.”

 

CanSocDem

(3,286 posts)
20. Somebody on here, a while ago...
Mon Jul 1, 2013, 10:20 AM
Jul 2013


...had a great line along those lines. It was something like ' I smoke pot to do the jobs I like and enjoy the ones I don't like.'

This doesn't sound right but the point was that 'working' while 'high' was infinitely more enjoyable than being 'straight'.

.

hobbit709

(41,694 posts)
3. Motivation in general or specific motivation?
Mon Jul 1, 2013, 09:37 AM
Jul 2013

This sounds like another study to give them the results they wanted to hear.

BlueToTheBone

(3,747 posts)
6. Bring on that lack of motivation
Mon Jul 1, 2013, 09:43 AM
Jul 2013

I work way too hard and am way to motivated to stay above the water line! I could use some rest.

tridim

(45,358 posts)
14. Worker drones, don't be happy and creative, just build those widgets for the shareholders.
Mon Jul 1, 2013, 10:12 AM
Jul 2013

Obviously everyone knows that "units shipped" is the only measure of productivity and motivation.

Le Taz Hot

(22,271 posts)
16. First off, cannabis is a PLANT, not a "drug."
Mon Jul 1, 2013, 10:17 AM
Jul 2013

Second, different strains of cannabis affect people in different ways. I managed to get 2 college degrees, working my way through via 3 jobs and graduated with a 4.0. All while ingesting the ganja. Personally, I find exactly the opposite -- that it's a great motivator. I can get into what I call hyper-focus while under the influence whereas it's much more difficult to get into that state naturally (although I can do it).

I call bullshit. Oh, and only 38 subjects?

 

think

(11,641 posts)
21. "19 Regular Cannabis users"
Mon Jul 1, 2013, 10:21 AM
Jul 2013
who experienced psychotic-like symptoms when they consumed cannabis with 19 nonuser sex- and age-matched control subjects


Le Taz Hot

(22,271 posts)
44. So is caffein and nicotine but we don't label those as drugs.
Mon Jul 1, 2013, 12:34 PM
Jul 2013

Personally, I consider it medication for it's affects on my arthritis and occasional anxiety issues but that's for another thread. I'm not a biochemist and I'm certainly not going to attempt to debate on that level but I do know that a sampling of 38 people does not a legitimate study make.

dionysus

(26,467 posts)
45. i consider caffeine and nicotine to be drugs too, i don't think drugs are (always) bad.
Mon Jul 1, 2013, 12:35 PM
Jul 2013

and the study in the OP is bullshit, I agree...

SCantiGOP

(13,862 posts)
62. Willie Nelson agrees with Le Taz Hot
Mon Jul 1, 2013, 02:36 PM
Jul 2013

I think it was when Willie was turning 75 they asked him what he could no longer do because of his age. He said, "Well, I've had to give up drugs." The interviewers were stunned, and one stammered "You mean you don't smoke pot anymore?" Willie's reply: "Hell, pot ain't a drug, it's an herb."

Jessy169

(602 posts)
42. Couldn't have made it without the pot
Mon Jul 1, 2013, 12:08 PM
Jul 2013

Same here, Le Taz Hot. I got out of the US Navy and had to work full time while I inched my way slowly but surely on a part-time basis toward my two college degrees and 3.7-or-so GPA. A little of the magic weed definitely greased the wheels on that long, arduous and sometimes monotonous journey. I've been a software engineer for a long, long time and still find that a little bud -- definitely not too much, but just enough -- can facilitate amazing creativity and out-of-the-box thinking.

 

think

(11,641 posts)
29. The parent company Elsevier did a fake peer review to cover Merk's ass!
Mon Jul 1, 2013, 11:05 AM
Jul 2013
Merck published fake journal

Merck paid an undisclosed sum to Elsevier to produce several volumes of a publication that had the look of a peer-reviewed medical journal, but contained only reprinted or summarized articles--most of which presented data favorable to Merck products--that appeared to act solely as marketing tools with no disclosure of company sponsorship. Image: flicker/linkurl:meviola;http://www.flickr.com/photos/69659670@N00/ "I've seen no shortage of creativity emanating from the marketing departments of

By Bob Grant | April 30, 2009

of drug companies," Peter Lurie, deputy director of the public health research group at the consumer advocacy nonprofit Public Citizen, said, after reviewing two issues of the publication obtained by __The Scientist__. "But even for someone as jaded as me, this is a new wrinkle." The __Australasian Journal of Bone and Joint Medicine__, which was published by Exerpta Medica, a division of scientific publishing juggernaut Elsevier, is not indexed in the MEDLINE database, and has no website (not even a defunct one)...

~Snip~

http://www.the-scientist.com/?articles.view/articleNo/27376/title/Merck-published-fake-journal/



And Elsevier has ties to the weapons industry and has been accused of shilling it's publications on Amazon:

Elsevier
From Wikipedia, the free encyclopedia

Elsevier B.V. (Dutch pronunciation: [ˈɛlzəvir]) is a publishing company which publishes medical and scientific literature. It is a part of the Reed Elsevier group. Based in Amsterdam, the company has operations in the United Kingdom, USA, and elsewhere.

~snip~


Parent organisation links to weapons industry


An editorial in the medical journal The Lancet in September 2005 sharply criticized the journal's owner and publisher, Reed Elsevier, for its participation in the international arms trade.[24] Specifically, Reed Exhibitions organized the Defence Systems and Equipment International Exhibition (DSEi), a large arms fair in the U.K. The authors, appealing to the Hippocratic oath, called for the publisher to "divest itself of all business interests that threaten human, and especially civilian, health and well-being."[25]

In the 24 March 2007 issue of the The Lancet, leading medical centers including the UK Royal College of Physicians[26] urged Reed Elsevier to sever weapons ties. Doctors spoke out against Reed's role in the involvement of the organizing of exhibitions for the arms trade.[27] Reed Elsevier’s chief executive responded in June 2007 with a written statement agreeing to do so,[28] welcomed by authors of the petition[clarification needed],[29] announcing that it would sell the part of the company which handled military trade shows. The sale was completed in May 2008.[30]

~Snip~

Sponsored journals

At a 2009 court case in Australia where Merck & Co. was being sued by a user of Vioxx, the plaintiff alleged that Merck had paid Elsevier to publish the Australasian Journal of Bone and Joint Medicine, which had the appearance of being a peer-reviewed academic journal but in fact contained only articles favourable to Merck drugs.[39][40][41][42] Merck has described the journal as a "complimentary publication", denied claims that articles within it were ghost written by Merck, and stated that the articles were all reprinted from peer-reviewed medical journals.[43] In May 2009, Elsevier Health Sciences CEO Hansen released a statement regarding Australia-based sponsored journals, conceding that these were "sponsored article compilation publications, on behalf of pharmaceutical clients, that were made to look like journals and lacked the proper disclosures." The statement acknowledged that this "was an unacceptable practice."[44] The Scientist reported that, according to an Elsevier spokesperson, six sponsored publications "were put out by their Australia office and bore the Excerpta Medica imprint from 2000 to 2005", namely the Australasian Journal of Bone and Joint Medicine (Australas. J. Bone Joint Med.), the Australasian Journal of General Practice (Australas. J. Gen. Pract.), the Australasian Journal of Neurology (Australas. J. Neurol.), the Australasian Journal of Cardiology (Australas. J. Cardiol.), the Australasian Journal of Clinical Pharmacy (Australas. J. Clin. Pharm.), and the Australasian Journal of Cardiovascular Medicine (Australas. J. Cardiovasc. Med.).[45] Excerpta Medica was a "strategic medical communications agency" run by Elsevier, according to the imprint's web page.[46] On October 7, 2010, Excerpta Medica was acquired by Adelphi Worldwide.[47]

Shill review offer

According to the BBC "The firm [Elsevier] offered a $25 Amazon voucher to academics who contributed to the textbook Clinical Psychology if they would go on Amazon.com and Barnes & Noble (a large US books retailer) and give it five stars." Elsevier said that "encouraging interested parties to post book reviews isn't outside the norm in scholarly publishing, nor is it wrong to offer to nominally compensate people for their time. But in all instances the request should be unbiased, with no incentives for a positive review, and that's where this particular e-mail went too far", and that it was a mistake by a marketing employee.[48]

~Snip~

Full Wikipedia entry:

https://en.wikipedia.org/wiki/Elsevier


The Wikipedia entry does have some typographical discrepancies but the bulk of factual content appear to be backed by well documented links to main stream sources.

BTW. In case you are wondering how I found the parent company you can find a link at the very bottom of the study page's site to find the information for the site owner Elsevier:

http://www.sciencedirect.com/

Le Taz Hot

(22,271 posts)
31. This is one of the reasons I like DU.
Mon Jul 1, 2013, 11:09 AM
Jul 2013

Virtual instant exchange of information. Thanks for posting.

madokie

(51,076 posts)
18. Operative word there is May
Mon Jul 1, 2013, 10:19 AM
Jul 2013

old used to be pot head here. You can ask anyone who knows me if I ever exhibited any notion of a lack of motivation.
If my health would allow it I'd still be a toker
I'll do more in one day than a lot of people will do in a week

mike_c

(36,260 posts)
25. 40+ years, two careers, a PhD, dozens of projects, both personal and professional....
Mon Jul 1, 2013, 10:56 AM
Jul 2013

Yeah, I'm a pot smoking slacker.

Fozzledick

(3,860 posts)
27. News Flash: Prohibition propagandists may be motivated to lie about effects of cannabis.
Mon Jul 1, 2013, 11:01 AM
Jul 2013

Government funding policies create political bias and financial conflict of interests antithetical to legitimate scientific research.

bemildred

(90,061 posts)
28. Maybe they don't need as much dopamine, so their bodies make less?
Mon Jul 1, 2013, 11:03 AM
Jul 2013

Does this effect evaporate if they stop using?

Fozzledick

(3,860 posts)
32. Or maybe a lack of dopamine may produce "psychotic-like experiences".
Mon Jul 1, 2013, 11:11 AM
Jul 2013

Anti-cannabis propaganda masquerading as scientific research is consistently marked by the deliberate inclusion of uncontrolled variables capable of causing the exact effect it attempts to attribute to cannabis.

RobinA

(9,884 posts)
43. Really
Mon Jul 1, 2013, 12:17 PM
Jul 2013

Schizophrenia, whereby people experience "psychotic-like experiences" (what's "psychotic-like" anyway) as a matter of definition, is well known to involve the dopamine system.

 

burnodo

(2,017 posts)
35. That's commitment for ya
Mon Jul 1, 2013, 11:17 AM
Jul 2013
They suggest this finding could explain why some cannabis users appear to lack motivation


Half-Century Man

(5,279 posts)
38. To paraphrase your article
Mon Jul 1, 2013, 11:30 AM
Jul 2013

Marijuana makes you mellow........




Dopamine is linked to motivation?....so are carbohydrates, sugars, bowel movements and whats on TV.

Generic Other

(28,979 posts)
49. Maybe they lack motivation to conform to what society wants them to do?
Mon Jul 1, 2013, 01:20 PM
Jul 2013

Like join the military, take jobs that require pee tests, buy into the established order of things, do things by other's time clocks, obey rules without question?

Maybe their lack of motivation is an act of defiance.

 

Politicalboi

(15,189 posts)
54. LOL!
Mon Jul 1, 2013, 01:33 PM
Jul 2013

"They suggest this finding could explain why some cannabis users appear to lack motivation to work or pursue their normal interests".

It's called a piss test assholes. I was and may still be a fast worker. I love to have a challenge at work and I smoke pot ALL the fucking time. To each his own. These studies prove NOTHING. These studies are false because if you smoke weed you're already an outcast for most. If pot were legal all these years, these studies wouldn't even exist.

Faux pas

(14,636 posts)
56. I call horse pucky!
Mon Jul 1, 2013, 01:35 PM
Jul 2013

I smoked the whole time I worked and had five promotions during that time. I think it depends on each person's brain chemistry, environment, etc. etc. Can't fit everyone into the same box scientists, sorry.

babydollhead

(2,231 posts)
59. Ode to Cannabis
Mon Jul 1, 2013, 02:15 PM
Jul 2013

It reminds me to open my heart.
It reminds me to be in the moment.
It reminds me to enjoy the ride.
It reminds me that I am alive.


 

demwing

(16,916 posts)
61. Oh well...
Mon Jul 1, 2013, 02:31 PM
Jul 2013

what are ya gonna do?



I was gonna clean my room until I got high...
I was gonna get up and find the broom but then I got high...
My room is still messed up and I know why...
(Why man?)
Because I got high, because I got high, because I got high



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