Even Recreational Marijuana May Be Linked To Brain Changes

[zachw]

Adding to earlier evidence that marijuana may be linked to lasting neurological changes, a new study in the Journal of Neuroscience  today finds that even casual pot smoking may have an effect on the size and structure of certain brain regions. The new research reports that for each additional joint a person smokes per week, the greater the odds of structural changes to areas involved in motivation, reward, and emotion. Though it seems like the country has embraced pot as a relatively harmless option in recent years, the authors of the study say that their findings suggest otherwise, especially for young people whose brains are still developing.

 

“This study raises a strong challenge to the idea that casual marijuana use isn’t associated with bad consequences,” said study author Hans Breiter, psychiatry and behavioral sciences professor at Northwestern University Feinberg School of Medicine and psychiatrist at Northwestern Memorial Hospital. “Some of these people only used marijuana to get high once or twice a week. People think a little recreational use shouldn’t cause a problem, if someone is doing OK with work or school. Our data directly says this is not the case.”

 

In the new study, the team looked at the brains of people 18-25 years old, some of whom smoked pot recreationally and some who did not. None of the participants showed any signs of being addicted to the drug.

Using different brain imaging techniques, the researchers were able to measure the volume, shape, and grey matter density of two key structures: the nucleus accumbens and the amygdala. The nucleus accumbens is involved in the reward circuit, including pleasure-seeking and motivation, and it’s strongly linked to addiction. The amygdala is involved in emotion, particularly in fear, anxiety, and the stress response, and in drug craving.

The team found that both brain structures varied in multiple ways, according to the number of joints per week the participants smoked – in other words, the more joints smoked, the more brain changes were evident. The nucleus accumbens was especially likely to show alterations in shape and density, and to be larger, as a function of joints per week.

 

“These are core, fundamental structures of the brain,” said study author Anne Blood, director of the Mood and Motor Control Laboratory at Massachusetts General Hospital and psychiatry professor at Harvard Medical School. “They form the basis for how you assess positive and negative features about things in the environment and make decisions about them.”

 

What’s interesting about the study is that it suggests that even sometimes-smokers show changes in the brain. What’s not clear is whether there were differences in the pot smokers’ behavior or cognitive function. But the authors suggest that the brain changes seen here may be a sort of precursor to addiction: Earlier studies in animals have shown that the active ingredient in pot, tetrahydrocannabinol (THC), may affect neural connectivity, which could be an early sign of a bourgeoning addiction.

“It may be that we’re seeing a type of drug learning in the brain,” said author Jodi Gilman, at Massachusetts General Center for Addiction Medicine. “We think when people are in the process of becoming addicted, their brains form these new connections.”

 

Although a majority of people in the country support legalization of marijuana, not everyone is so convinced. Last year, Breiter’s team showed that everyday pot smoking in teenagers was, even two years after stopping, linked to brain abnormalities and to poorer working memory. “With the findings of these two papers,” Breiter said, “I’ve developed a severe worry about whether we should be allowing anybody under age 30 to use pot unless they have a terminal illness and need it for pain.”

 

The study will no doubt attract a lot of debate, as it raises as many questions as it answers. More research is clearly needed to know just how pot affects the brain and behavior over the long term. In the meantime, you may just want to pass on the pot – or at least wait till you’re 30 and your brain is done developing before you use it as a test subject in your own experiment.

 

Original news article here.

 

Journal of Neuroscience article here.

Edited April 16, 2014 by zachw

[zachw]

BTW, here is NORML's response to the study in which they reiterate their stance that cannabis is not for kids that lack medical necessity, but challenge certain aspects of the study. Among other things, the marijuana group in this study got drunk more than 4 times as much in the last six months as the controls!

Edited April 16, 2014 by zachw

[t-pain]

the propaganda studies shall continue!

 

we'll make marijuana illegal because there are teens who use marijuana! that makes sense.

[trichcycler]

ah, no worries. Years ago they threw people who self medicated their depression and adhd with amphetamines into jail cells  , and now, they freely GIVE these drugs to kids of all ages. Its a brave new world.

[Restorium2]

Very interesting. When they disected Einstein's brain they found these sort of changes/enlargements too.

[trichcycler]

While chronic use of medical marijuana has increased my awareness of surroundings, it has done nothing to locate those darn keys.

[pic book]

any similar warnings for another drug---use under age 30 is not recommended except if terminal----would be reviewed by the fda, a step missing due to cannabis scheduling.

Edited April 16, 2014 by pic book

[jointedone]

Hmmm..............notice the age the the pts in the study. They should study older chronic MMJ users,because I just read an article on how MMJ can deflect the ravages of  Alzheimers Disease.

[thanks2]

Everything from video games to exercise has been shown to make lasting changes in the brain.  Processed food, especially wheat, has been shown to have a very negative effect on recall. Cholesterol lowering drugs are one of the number one cause of chronic fatigue, motivation killer, and have not been shown to prevent first time stroke or heart attack in patients.

 

What we do and consume changes us.  People have known that all of written history and probably beyond.  Fact is lack of exercise, toxic medications, and toxic chemical rich processed food is destroying the health and well being of this great nation.  Not cannabis.

 

People should have the liberty to do what works for them.  If we prohibited everything that a person or two thinks it has a negative effect on us we would have prohibited many things that turned out to be healthy.  Eggs, coconut oil, and butter would have all been replaced with chemicals and trans-fat filled margarine by law.

[jointedone]

HECK YES! I couldn't live without BACON!

[GregS]

What they don't say is that these changes may be a benefit. There is every likelihood that is the case just as is the potential for harm. They just don't know.

 

The amygdala is a primitive part of the brain. It is the source of the fight/flight response. We no longer have to determine in a fraction of a second whether to face that sabre tooth cat or run for the hills. It is argued that without true life threatening circumstances our ancestors faced, the stress caused by that response to more mundane everyday stressors is a health hazard, producing hormones through the endorine system. Those hormones, which are subsequently not adequately diminished by fight or flight remain and continue to cause stress long after a perceived but nonetheless inconsequential threat is gone. That stress is the source of many diseases. A good read regarding the topic is Daniel Goleman's Emotional Intelligence.

 

Evolution has not caught up with civilization. We don't need to overrev our engines like we used to for that quick burst of speed or violence, only to get no traction. The result is engine damage. Cannabis acts as to modulate panic and unnecessary anxiety. Is that a bad thing?

Edited April 17, 2014 by GregS

[solabeirtan]

Brought to you by our favorite slightly biased authority on all cannabis knowledge:
 
This work was supported by the National Institute on Drug Abuse (Grants 14118, 026002, 026104, and 027804 to
H.C.B. and Grant 034093 to J.M.G.),the Office of National Drug Control Policy,  
Counterdrug Technology AssessmentCenter (Grants DABK39-03-0098 and DABK39-03-C-0098)
 
 As our resident authority recently pointed out: "...only recent studies are relevant....." something like that eh ***? Anyway heres Hans Breiter in 2009 beating another related tune:
 

 

From here
 
 
****   I don't even like to search back further than around 2010 since our understanding have developed so much since then.  ****
 
To me, this thread among other things is about self empowerment. It's about not believing that we need to wait for the gatekeepers to provide us with clinically available cannabinoids. Cannabinoids are relatively safe. We know how to cultivate and manipulate cannabis to procure the chemotypes we desire. We know about other natural sources of cannabinoids. We can learn which combinations of cannabinoids, terpenes, and flavonoids might be best suited to our needs. If we can blindly target ailments, imagine what could be done with a more systematic and scientifically based approach.
 
Let's form a legion of patients and caregivers that know more about “one of the most important physiological systems involved in establishing and maintaining human health”, than most practicing physicians. Then let's educate them.
 
 
From here

...agreed, thanks in vivo...

Edited April 17, 2014 by solabeirtan