USA - Marijuana’s Impact On Brain Function “Minimal,” New Study Says

[chillinwill]

The consumption of cannabis, even long-term, has a “minimal” impact on brain function, according to a systematic literature review just published online by the journal Psychological Medicine.

An international team of investigators from the United Kingdom, Spain, Brazil, Australia, and Switzerland conducted a systematic review of the effects of cannabis on brain structure and function.

Authors wrote, “We reviewed literature reporting neuroimaging studies of chronic or acute cannabis use published up until January 2009. … Sixty-six studies were identified, of which 41 met the inclusion criteria. Thirty-three were functional (SPECT/PET/fMRI) and eight structural (volumetric/DTI) imaging studies. … Only three of the structural imaging studies found differences between users and controls.”

Investigators concluded, “Minimal evidence of major effects of cannabis on brain structure has been reported,” noting that marijuana users and controls perform similarly on cognitive tasks.

According to a 2001 study published in the journal Archives of General Psychiatry, long-term cannabis smokers who abstained from pot for one week “showed virtually no significant differences from control subjects (those who had smoked marijuana less than 50 times in their lives) on a battery of 10 neuropsychological tests.” Investigators added, “Former heavy users, who had consumed little or no cannabis in the three months before testing, [also] showed no significant differences from control subjects on any of these tests on any of the testing days.”

By: Paul Armentano
July 28, 2009
Norml Blog
http://blog.norml.org/2009/07/28/mar...ew-study-says/

[Jatelka]

For those that are interested, the full paper this story refers to is in the archive here...

http://www.drugs-forum.com/forum/loc...tid=21&id=7463

[ninjaned]

is this really surprising? i'm sure most of the members of this forum know that pot doesn't really impact how you think and feel(except when your actually high and even then...). course show this paper to some people and they'll freak out or claim its findings as false. if only governments would do studies such as this and realize the truth many of us already know, cannabis isn't something that should be prohibited.

[Nature Boy]

Thanks for posting this up. It appears to be an important study, something which many regular cannabis users have suspected for years. I would love to see this get some real publicity. By right, it should be front-page news as it asks hard questions about the US government's stance of marijuana prohibition. Studies such as this have an important role in killing many of the stupid myths about marijuana.

[Greenport]

Well, that's certainly a good thing isn't it?

SwiM once read a study or something which talked about how smoking weed every day for like 40 years results in slightly smaller brains...although it didn't say there were any effects on the actual working of the mind as a result of this shrinkage. So your brain may get smaller, that doesn't mean in any way though that pot makes you stupid or anything...

This made me smile though Nature Boy yeah perhaps it should be published in newspapers and stations around the world although that prolly won't happen unfortunately ...