New study shows potent marijuana linked to brain damage, psychosis

ST. GEORGE – A new study released last week warns the highly-potent strains of marijuana available on the market today could cause brain damage or even lead to psychosis, continuing the debate on whether or not marijuana triggers long-term neurological and psychological changes in a person.

Isolated Cannabis BudsAs heated debates on the issue of whether marijuana should be legalized or whether we should continue to criminalize the drug continue, policymakers argue on scientific facts that marijuana has as many drawbacks as it has benefits for your health.

No matter where you stand on the issue, a team of scientists from King’s College London and Sapienza University of Rome warn smoking high potency ‘skunk-like’ cannabis can damage a crucial part of the brain responsible for communication between the two brain hemispheres — whether a smoker experiences psychosis or not.

Researchers have known for some time that long-term cannabis use has been linked to psychotic symptoms and multiple studies show it’s been linked to schizophrenia —  recent evidence suggests that alterations in brain function and structure may be responsible for this greater vulnerability. However, this new research, published Nov. 26 in “Psychological Medicine,” is the first to examine the effect of cannabis potency on brain structure.

‘Skunk-like’ products have higher levels of the psychoactive compound Δ9-tetrahydrocannabinol, or THC, than “regular” pot. It has become much more prevalent in recent years, as people seek out more potent versions of the drug, making research on the impact of cannabis potency particularly important.

“We found that frequent use of high potency cannabis significantly affects the structure of white matter fibres in the brain, whether you have psychosis or not,” author Paola Dazzan said in a media statement. “This reflects a sliding scale where the more cannabis you smoke and the higher the potency, the worse the damage will be.”

The researchers used Diffusion Tensor Imaging, a Magnetic Resonance Imaging technique, to scan the brains of 56 people who had sought treatment for a first episode of psychosis, and 43 healthy participants.

Male Corpus Callosum Brain Anatomy - blue conceptThe team examined the density in the brain’s corpus callosum, the vast network of white matter in the brain consisting of nerve cell projections that connect different regions of the brain and enable communication between them. Damage to the connections means less efficient communication between brain cells, which can be linked to cognitive problems.

The corpus callosum is particularly rich in cannabinoid receptors, the study said, on which the THC content of cannabis acts.

The study found that people with frequent use of high-potency cannabis had a greater likelihood of damage to their white matter than people who smoked less frequently or who smoked lower-potency version. Using high-potency cannabis was linked to white matter damage regardless of whether or not psychotic symptoms were reported.

“There is an urgent need to educate health professionals, the public and policymakers about the risks involved with cannabis use,” Dazzan said, and added:

As we have suggested previously, when assessing cannabis use it is extremely important to gather information on how often and what type of cannabis is being used. These details can help quantify the risk of mental health problems and increase awareness on the type of damage these substances can do to the brain.


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Twitter: @STGnews

Copyright St. George News, LLC, 2015, all rights reserved.


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  • ladybugavenger December 3, 2015 at 12:41 pm

    Oh bull crap!!! Pain meds lead to psychosis, you all should seen this girl I worked with on pain pills, psycho! but they are FDA approved hahaha. Of course, I’ve seen the buds, on tv, in Colorado. I know it would not be good for me. I’m going to Colorado in 10 days. What happens in Colorado stays in Colorado. Just sayin’

    • .... December 3, 2015 at 3:01 pm

      Well then your staying in Colorado to ? I’m sure they have douchebags there to. so you should feel right at home..go go gadget brain…!

      • ladybugavenger December 3, 2015 at 6:40 pm

        My twin grandchildrens 4th birthday party. I hope they don’t sell weed at chuck e cheese, that would be awkward…I love inspector gadget references…. 🙂

        • .... December 4, 2015 at 1:22 am

          Oh so you’re not staying in Colorado then ? …go go gadget vomit bag ! LOL

        • Terry December 4, 2015 at 6:45 am

          I’m with you Ladybug, I’m goin to Colorado next week ????

  • JOSH DALTON December 3, 2015 at 1:06 pm

    pssfft….and a Volkswagen is destroying our environment. What a load of malarkey.

    • .... December 4, 2015 at 1:19 am

      Well the important thing is that the near extinct Spotted Owl survives . They can always sit around and get stoned and come up with Volkswagen jokes . while they wait for the owner of the Washington Redskins to change the teams name !

      • JOSH DALTON December 5, 2015 at 8:22 am

        First of all…GO FALCONS! Second, GO Braves! “You people”need to give us our Tomahawk Chop back!! Third, Das Auto! Most importantly Saint George, Utah has nothing to do with the Confederacy or the South, so why call it Dixie. “You People” are the same folks who voted that Bruce Jenner should be Woman of The Year. How is that even possible? Here is an idea, log out of Facebook and Twitter and open your eyes. Or society has lost sight of the big picture! GO FALCONS!

        • ladybugavenger December 5, 2015 at 9:35 pm

          Go Raiders!

          • .... December 6, 2015 at 9:31 am

            Go Smurfs !

        • .... December 6, 2015 at 9:29 am

          Josh Dalton is nothing but another mesaman. it’s all blah blah blah and more blah blah blah. do yourself a favor and get off of Facebook and Twitter and go outside and get a life.!

  • BIG GUY December 3, 2015 at 5:30 pm

    “The science is settled.” Interesting how most of those who believe climate change science is settled are the same ones who dispute this and similar studies while having no expertise in either area.

    • .... December 4, 2015 at 1:29 am

      Well I don’t believe in climate change. But I do believe in environmental pattern shift . LOL ! Just trying to remain politically correct.

    • mesaman December 4, 2015 at 11:51 am

      An interesting conclusion. It seems to be logically correct and clearly defined. Now how to tell the pot heads, if they can stay focused long enough to accept the possibility, that they have entered into a risk that may not prove to be one of their better choices.

      • .... December 5, 2015 at 3:15 pm

        And once again Nolan shows just how STUPID he really is ! BITE ME !

        • Jim December 29, 2015 at 5:09 pm

          Someone who isn’t me (swim) recieved a 3.95 this semester with 18 credits… So if pot makes you”stupid”, how stupid are the people not using it and still getting less done than swim??? (Swim has only used the medicine in a legal setting, dab, wax, shatter, the most potent stuff out there)
          Swim has been through an opiate addiction, Marijuana saved swim’s life. Swim thanks god for growing such a great medicine and doesn’t understand the logic of anti-legalization.

  • SSTEED December 3, 2015 at 6:58 pm

    So the Queen and the Vatican hired someone named “Paola?” to tell you that weed is bad and you should know exactly what it is, and what is in it. In the meantime, Monsanto is telling you that that you don’t need to know if your food is genetically modified; and frankly, its none of your business what is in your food. Just buy drugs that we know can kill you if you don’t follow the prescription… whatever you do, DONT SMOKE THE GOOD STUFF (which has never killed anyone). Send it to me and I’ll “dispose” of it properly.

  • Green December 3, 2015 at 11:11 pm

    PARANOID POT PROPAGANDA at its finest. Regulation of cannabis has public safety and welfare written all over it. Applaud the citizens, States, and countries that have advanced the movement to end cannabis prohibition.

    Basis of study is 56 people who experience first episode of psychosis?…compared to 43 “healthy people”?
    This study shows what we know, some people are wired different then others. This study does NOT represent a “healthy brain” before cannabis use and “healthy brain” after cannabis use. If so study would probably show what we know…cannabis use can promote brain function in adults and inhibit partial development in minors.


  • .... December 4, 2015 at 1:08 am


    • Terry December 4, 2015 at 6:56 pm

      Cannabis a plant , a God Given Natural medicinal plant, It works. Nuff Said

    • ladybugavenger December 5, 2015 at 9:34 pm

      Ok Nancy

  • Terry December 4, 2015 at 6:42 am

    Yep BS on this one, write an article on Pain Meds and What that Addictive shit does to a Body. Or Alcohol or Cigarettes, Cannabis is a Natural Medicine used for 1000s of years, legalize it now?

  • sagemoon December 4, 2015 at 9:43 am

    This was a rather small study, I’ll reserve judgement until I see further research. In the meantime, I will say “of course skunk weed makes you stupid!” Stick with the good quality stuff like Northern Lights or Kush. Sheesh.

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