Heavy marijuana use shrinks brain parts - study

because i'm lazy and have already said it on another forum (newscientist.com) this was my response to essentially the article and some denalist who was defending the statistical rigour of 31 subjects.....

And YES 31 subjects is plenty for a rigorous statistical analysis
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By your logic large scale epidemiological are a waste of money and time, if 31 subjects is sufficient to prove that heavy cannabis use shrinks brains.

I won't belittle the readers of New Scientists but there are so many variables that I hardly believe the University of Melbourne were able to overcome. However it needs to be said a massive problem in long term drugs studies is that is almost impossible to find subjects that aren't poly drug users.

I find it impossible to believe that these 15 cannabis users did not use, on a regular basis, any other drug, illicit or legal.

The other problem is that no one has published the full paper that was peer reviewed (apparently) by Archives of General Psychiatry, who by the way require payment in order to see the paper.

What has been feed, in an alarmist way, is a shallow media release, regurgitated by lazy journlists, across the entire planet.

I won't deny that there negative outcomes with heavy cannabis. However most studies show (and I can attest to this from personal experience) that these negative outcomes are relatively temporary and cease once user reduces or stops their habit.

Thirdly if the brains of heavy cannabis users were shrinking we would have see millions of these walking wounded all around the world.

Clearly this is not the case.

I also have a massive problem with the use of the word "joint". Which should be banned. Was the joint 5 inches long and 2 inches wide? Did the user smoke high THC content cannabis, or just leaf?

Can the researchers even guarantee the drugs weren't cut with other agents (cannabis in Australia can be mixed with speed for example)?

Lastly I find it laughable that the Guardian did a far superior job of researching and reporting on this story. They even found a study that:

"A New York University scanned the brains of a group of 17- to 30-year-olds who had smoked cannabis two to three times a week for at least a year. In that study, the brains of drug users looked no different from those who had never taken cannabis.

http://www.guardian.co.uk/science/2008/jun/03/drugs.drugsandalcohol

There are so many variables and its a shame New Scientist is not vigorously challenging this sort of research.

NB: I find it disgusting that many respectable publications have done nothing more then to paraphrase the media release.
 
Who the hell underwrote this study?

I could find you 15 homogenously burnt-out stoners by tomorrow. You could tailor your 'wanted for research' ads just to attract this type.

I also agree with the opinion at the end of the article that any psychoactive substance taken in large, frequent doses for years and years is going to show physiological changes in the brain.
 
BeenArrested4Pot said:
really? you love those withdrawals and cavings and pawning electronics huh?
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HAHAHA, that brings back some memories.

I used to be in a vocational electronics class, my junior year of high school. I stole about $300 worth of shit there. I still have some of it. Stole a bunch of old computer parts too.
 
IMHO - sounds like another replay like that of the Johns Hopkins bogus study on MDMA creating "holes in brain".

Ps- I still dont understand where they gained their control for a study with only 15 individuals. Government dollars are seriously paying for this crap?!
 
amor fati said:
I stopped reading after "5 marijuana cigarettes daily for 20 years"
excessive much?
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not really.. i mean sure it's a lot for the average person but its not excessive in terms of cannabis addiction imo
 
hehe.

all the pot smokers trying to discredit this study :D yet they'll happily believe anything that's positive about weed.

smoking marijuana prevents lung cancer for instance :P
 
chugs said:
because i'm lazy and have already said it on another forum (newscientist.com) this was my response to essentially the article and some denalist who was defending the statistical rigour of 31 subjects.....


What has been feed, in an alarmist way, is a shallow media release, regurgitated by lazy journlists, across the entire planet.

I won't deny that there negative outcomes with heavy cannabis. However most studies show (and I can attest to this from personal experience) that these negative outcomes are relatively temporary and cease once user reduces or stops their habit.



Clearly this is not the case.

I also have a massive problem with the use of the word "joint". Which should be banned. Was the joint 5 inches long and 2 inches wide? Did the user smoke high THC content cannabis, or just leaf?


Lastly I find it laughable that the Guardian did a far superior job of researching and reporting on this story. They even found a study that:
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I don't have a problem with smoking weed. Thought I'd say that first so you don't think I'm an anti-drug dude.


Thirdly if the brains of heavy cannabis users were shrinking we would have see millions of these walking wounded all around the world.

It's not the whole brain that shrinks...just a small area of it.

Buddhist monks have been shown to have slightly larger areas of the brain than normal. Is it so hard to believe weed could have a similar effect? The brain is also known to physically change depending on lots of things.

I smoked for 3 years heavily and my memory has never been the same since. This was before I used other drugs. Even after a year of staying off weed my memory is still not what it was. Of course being stoned for 3 years is going to have some effect on the brain...even if it's slight. It's my fault for going overboard though...I don't hold that against cannabis :)

Can the researchers even guarantee the drugs weren't cut with other agents (cannabis in Australia can be mixed with speed for example)?

I guess they can't guarantee it but weed mixed with any other expensive drug is very rare..even in Australia. It would be extremely unlikely...

Yes, the sample size isn't huge but that does not discredit their findings..


I find it impossible to believe that these 15 cannabis users did not use, on a regular basis, any other drug, illicit or legal.

Why? People that use only cannabis far outnumber other drug users.

The other problem is that no one has published the full paper that was peer reviewed (apparently) by Archives of General Psychiatry, who by the way require payment in order to see the paper.

Pretty standard stuff these days unfortunately :(


They're not saying cannabis will shrink your brain.

They are saying heavy cannabis use MAY shrink a small area of the brain.

Big difference between those two :\
 
Christ! said:

I find it impossible to believe that these 15 cannabis users did not use, on a regular basis, any other drug, illicit or legal.

Why? People that use only cannabis far outnumber other drug users.
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Worldwide this is.... a fallacy. :p
 
Christ! said:
They are saying heavy cannabis use MAY shrink a small area of the brain.
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ya and eating pie MAY cause it too, I BET ALL THOSE FIFTEEN (fifteen whole people!) HAD ALSO EATEN PIE.

I BET THAT WAS IT



=P
 
I don't see why people find it so hard to believe that such excessive use of a drug could cause changes in the brain.

A glass of wine a day will help reduce the chance of heart disease. Getting wasted every night for 20 years will destroy your liver and damage your brain. It's all about moderation.
 
did they slice these peoples brains in half and compare them to a "normal" person's brain?

in other words how did they know that the parts shrunk?
 
I smoked for 3 years heavily and my memory has never been the same since. This was before I used other drugs. Even after a year of staying off weed my memory is still not what it was. Of course being stoned for 3 years is going to have some effect on the brain...even if it's slight. It's my fault for going overboard though...I don't hold that against cannabis
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i had the same experience. i used to smoke weed all day every day and it effected my memory and other aspects of cognition and despite the stoner mantra that it will all go back to normal when you stop, for me it never did. and so then people try to say it was because i don't exercise my brain. well i was in college, taking classes and exercising my brain even more than i do now.

i also didn't use any other drugs to any significant extent when i was a stoner, i so i don't see why it's hard to believe that these 15 stoners didn't use other drugs regularly.
 
I find it impossible to believe that these 15 cannabis users did not use, on a regular basis, any other drug, illicit or legal.

Why? People that use only cannabis far outnumber other drug users.
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The most commonly used recreational drug in Australia is alcohol. Which makes me wonder if the study controlled for alcohol use.

How much is "five joints"? There's a huge difference between a joint packed with bud and a weak spliff. Hopefully they had some more objective measurement than that.

In any case this isn't a surprising result. I know pot smokers well under 40 who have completely rooted their brains already. These people were smoking huge amounts of pot for a long time. Heavy drinking is associated with increased dementia and alzheimer's but moderate drinking might actually decrease the risk of dementia. So this study doesn't really say anything about health risks to people who smoke more reasonable amounts.
 
Christ! said:
hehe.

all the pot smokers trying to discredit this study :D yet they'll happily believe anything that's positive about weed.
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The study has a crap sample, I do not lap up positive pot studies either if they have small samples as well.

smoking marijuana prevents lung cancer for instance :P
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No one believes that smoking marijuana prevents lung cancer. Although smoking marijuana, even heavily is not positively linked to an increase in the risk for lung cancer when tobacco use is controlled. This study was performed by Dr. Donald Tashkin, with 2,200 subjects (1,212 cases and 1,040 controls). Also cannaboids show great promise in cancer and tumoral treatment, type it in a google search to find out more.
 
not special said:
How much is "five joints"? There's a huge difference between a joint packed with bud and a weak spliff. Hopefully they had some more objective measurement than that.
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Thank you!

This irks me very much, whenever I see it. I could almost crack a smile whenever I see 'joints' or 'marijuana cigarettes' as a unit of measurement in a serious scientific paper, so ridiculous and arbitrary it is. Except for the wholly unfunny implications: a measurement this vague is a statistic stretcher's and spin doctor's dream come true!

Joints vary so much in size and potency to begin with. Pile on another stone when you realize that the technique used to both construct it AND smoke it will have a large effect on the amounts of chemicals absorbed from it. For a comparison, factory-made cigarettes, which seem far more uniform to the naked eye than joints, vary appreciably in mass of tobacco used, quality of tobacco used, additives, filter density, etc. Every brand and variety varies in the amount of tar and nicotine per cigarette, but the variation of active chemicals in these factory-made products is orders of magnitude less than that in homemade joints. Still, you find 30something cigarette smokers having heart attacks, and 90somethings who are as fit as ever, still puffing away.

Marijuana studies will really only be scientific when they can speak in terms of an objective mass of THC and other cannabinoids consumed. There really ought to be a test kit, as available for ecstasy pills, where one can crumble up exactly 100mg of plant matter, add several drops of reagent, and tell from a color change approximately what percent cannabinoids the raw plant matter contains.

After this is established through several averaged samples, the mass of plant matter that goes into one joint needs to be kept uniform too, as does rolling technique (machine!).

This is essentially a roundabout argument for decriminalization and legalization, because only when the production and study of cannabis become easy enough to be widely standardized, will we have enough factors controlled for to guarantee a meaningful study.

I smoke most days. I use a 2 inch long one-hitter with about 50mg of high-quality plant matter, that I touch a flame to for a few fractions of a second. I do not stop inhaling until the burning cherry goes out (as seen in a reflection on the metallic part of the lighter), and then hold for seven seconds before exhaling. I get quite. Blazed.
I'd be willing to bet that I consume a greater volume of cannabinoids over time than at least one of the subjects in this study.
 
What has been feed, in an alarmist way, is a shallow media release, regurgitated by lazy journlists, across the entire planet.
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agreed; these "reports of serious side effects of mariijuaanna use" seems to be popping up coincidentally just as states in america are telling the federal gov to shut the fuck up and leave state with their funky ass prohibition ways.. For anyone saying marijuana is satan, do some research.
 
For anyone saying marijuana is satan, do some research.
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and for anyone saying it's harmless, do some research :) even as the article quotes someone at the end, the effects aren't nearly as bad as legal drugs, but there are negative effects.
 
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