Posted on 11/23/2012 7:07:00 AM PST by lbryce
Scientists have confirmed the long-held suspicion that frequent heavy marijuana use damages the brain's memory and learning capacity.
"Our results suggest that long-term cannabis use is hazardous to white matter in the developing brain. This was especially true for those who had started in adolescence, as we know the brain is still developing during this time," Lead researcher Dr. Marc Seal, from Melbourne’s Murdoch Children's Research Institute said in a university release.
Scientists from MCRI, Melbourne University and Wollongong University compared MRI scans of the brain for 59 people who had been using marijuana for an average of 15 years to 33 healthy people who had never used the drug.
After measuring changes to the volume, strength and integrity of white matter in the brains of all participants, researchers found that long-term heavy cannabis users had disruptions in their white matter fibers.
The brain's white matter is responsible for information passed between different areas of grey matter within the nervous system, and unlike grey matter, which are the brain's thinking areas that peaks at age eight, white matter continues to develop as people age.
Seal and his team found that there was more than 80 percent reduction of white matter in the brains of users.
Additionally, researchers found that the average age of participants in the study started using cannabis when they were 16 years old, participants who started using the drug at a younger age like 10 or 11 had even more severe brain damage.
"This is the first study to demonstrate the age at which regular cannabis use begins is a key factor in determining the severity of the brain damage," Seal said, according to AAP.
He explained that marijuana interferes with naturally occurring cannabinoid receptors in the brain and by introducing external cannabinoids into a person's system it stops their white matter from maturing.
Researchers linked the significant changes in the white matter in the brain's hippocampus and commissural fibers, suggesting that long-term marijuana use may lead to memory impairment and deficits in learning and concentration ability.
"These people can have trouble learning new things and they are going to have trouble remembering things," Seal said.
"We don't know if the changes are irreversible but we do know that these changes are quite significant," he added.
Researchers said that the findings could not be explained by recreational drug and alcohol use. Researchers will monitor participants for the next two years to detect any further changes.
The latest findings add to results from previous smaller studies that showed that the brain's memory center, the hippocampus, shrunk in heavy marijuana users.
I’m sure there are conservatives who smoke dope, but the only people who’ve admitted to me that they were heavy dopers when they were young are all strong libs. So it’s a chicken or the egg thing: does smoking dope lead to liberalism or does liberalism lead to smoking dope? Nevertheless, the facts are pretty much indisputable: smoking dope causes brain damage. Most brain damaged people i.e. current or ex-heavy dopers vote for Dems. You make the call.
The Libertarians and Dems are fighting over these chumps. The recent election, many states just made medical marijuana legal, a real joke the way this has turned out in California so look for more of the same. I see this medical marijuana dude (notice his derby and pigtail hair) on TV a lot
We already knew this. Go to any Ron Paul gathering.
Are you saying that psychotherapy is ineffective only against those actively using MJ, but works fine in cases of practicing alcoholics or others actively using licit or illicit drugs?
The truth is that being addicted to any drug arrests emotional development and this effect is not limited to just MJ.
What’s funny is how potheads always claim that pot has no affect on them and claim they are normal but it is almost always obvious they smoke the ganja.
They’ll know how to do sex even if they can’t spell it. Ain’t that just wonderful.
Well I don’t use any drugs, BUT heavy long term use of any drug will cause brain damage.
See the effect of a couple of six packs a day will do to the brain of a user after 20 years.
Unfortunately, this gives some credence to the number of people who are now on social security due to mental issues.
The cost of pot use to this country is enormous. We need public service campaigns to dispel the myth that pot is not dangerous.
mark
Frankly, I’m wondering these days why we treat pot and alcohol differently if they have similar destructive effects with high-dose, long term use. I never thought I would actually say that, as it goes against everything I’ve ever believed about marijuana legalization. I guess the question is whether both should be illegal (yeah, how’d that work for us in the 20s?) or both should be legal (MJ smoke can invade the space of people who don’t want to use it, but the theory of the “second-hand high” has been pretty thoroughly disproved).
Anybody got an observation here? I’m truly looking for a rational, justifiable position on this.
I have a friend who has been smoking marijuana and has been an occasional user of other drugs since she was 18. She admits that it has made her “dumber”, but she doesn’t care. Now, the drugs have made a mess of her family and caused her husband to divorce her.
She started smoking marijuana more heavily after suffering a back injury a couple of years ago, and started growing her own. She couldn’t resist sharing her stash, though. She shared with a young college student who had been a friend of her son’s and after leaving her house, the young man struck and killed a guy on a bicycle. He ended up spending three and half years in prison upon graduating from college.
Her son is a heroin addict. He blames his addiction on her because she always made drugs sound so cool. She was one of those mothers who used to claim that they would rather see their kids high on marijuana than drunk on beer. Of course she allowed her son and his friends to drink beer in her home when they were teen agers. She never objected to a little marijuana use, either.
Her husband travelled for work and said that every time he came home she was worse, more irresponsible. He finally had enough and filed for divorce. He should have done something a long time ago. My friend is 62 years old and still a doper.
I don't know your friend, but you've shared enough to amateurishly analyze the situation.
She admits she's dumber and continues to dumb down ... there's obviously a benefit to being dumb that supercedes losing everything that resembles normalcy up to and including real, live human beings that at one time loved her.
Real. live human beings that trusted her, whom she cast aside (de facto)
Real, live human beings that make one's life a joy.
What could that desireable benefit be?
I'm not sure I have an answer, because I realized I couldn't remember anything, and as some things in my life became more and more important, and try as I might I couldn't retain the data to argue or support my thoughts, I became scared and stopped.
To this day, I struggle to memorize the scripture that I dearly love and desire to have at the forefront of my thought processes.
I can't remember quick enough the data that has been so intelligently and profusely presented here in FR since Clinton to argue and/or refute (intelligently) the lies and oblique efforts to destroy America.
I haven’t smoked in quite a while. I keep thinking somebody may find me employable and want me to pi** in a cup first. Can somebody tell me why would the brain have “naturally occurring cannabinoid receptors” other than to “recept” some cannabis?
*snort* My sister is a former police officer, now running an Alternative Sentencing program for Drug Offenders. She deals mostly with Meth addicts, since that seems to be the drug of choice, nowadays. But she says she can usually tell at which age someone started smoking pot heavily, because their mental development seems to have been arrested at that point. They think, and act, like perpetual teenagers.
Here we see psuedo-freepers buying U.N. ‘science.’
What a herd of sheep!
If the U.N. says so it is ‘confirmed.’
Yes, as always, it’s “for the children.”
Oh wowl..
Autism is 100% caused by vaccinations given to infants.
Politically incorrect, of course, so disregard the evidence...
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