How marijuana really affects the brain

How Marijuana Really Affects the BrainYahoo News

Although there’s a lot of buzz about marijuana being nonaddictive, the evidence is stacking up that people can — and do — become dependent on the drug. A study released earlier this year, for example, found that 40 percent of marijuana users in an outpatient treatment program showed signs of withdrawal, a classic indicator of addiction. Now, new research in the journal PNAS sheds light on how lighting up changes the brain — and potentially primes people for withdrawal.   

It’s long been known that exposure to THC, the primary psychoactive ingredient in pot, can lead to changes in the brain. Problem is, different studies have shown different structural alterations, making it difficult to pinpoint exactly how the stuff affects people mentally. That’s why a group of researchers decided to use three different magnetic resonance imaging (MRI) techniques to examine the brains of 48 chronic marijuana users and 62 nonusers, while also assessing IQ and negative life consequences of pot smoking.

The most obvious difference: The people who regularly toked up had less volume in the orbitofrontal gyri. This brain region is part of the orbitofrontal cortex, “one of the primary areas within the reward system, which is basically a network of brain regions implicated in the addiction process,” said study author Francesca Filbey, an addiction researcher at the Center for BrainHealth at the University of Texas at Dallas. “More specifically, the orbitofrontal cortex is important for decision-making. This is the area of the brain that would learn something is good for us or bad for us.”

So why does pot cause shrinkage in this area? Simple: The orbitofrontal cortex is highly concentrated with cannabinoid receptors, the places in your brain where THC binds. As a result, it’s much more vulnerable to the effects of a chronic flood of the substance. In animal studies, “the number of those receptors decreased as a result of THC exposure as a way to regain balance in that system,” Filbey told Yahoo Health. “So too much THC basically leads to lower numbers of those receptors in the brain.”

It’s this effect that gives credence to the “pot is addictive” camp. As Filbey explained, the fewer cannabinoid receptors a marijuana user has, the more THC he requires to achieve the desired high. “This really describes tolerance,” she said. “Around 10 percent of users, on average, report changes in tolerance and also increased craving and withdrawal.” The marijuana users in this study weren’t just casual smokers — they used the drug at least four times per week.

Although this study may help illuminate the addiction process, the findings are a little hazier when it comes to how these brain changes affect people’s behavior and intelligence, if at all. The researchers did find that marijuana users scored lower on an IQ test than non-users did. But as tempting as it is to link this to the changes in their brains, the researchers weren’t able to firmly establish that connection, suggesting there’s another factor behind the users’ lower IQs. One possibility: “If these individuals were using during their adolescent years, then they may have missed a lot of the verbal knowledge that IQ is testing for,” Filbey said.

18 thoughts on “How marijuana really affects the brain

  1. because we all know TOBACCO is NOT addictive. it DOES NOT restrict the blood oxygen and cause heart troubles. that’s why it’s legal, don’t ya know?

  2. Heat is needed to create the THC.
    I have read (I don’t remember where) that many of the benefits of
    the plant may be obtained by juicing it. I hope to be looking into this after I retire.
    I do not know how long prescription pain medications will be available
    thanks to the nanny State.

  3. “The marijuana users in this study weren’t just casual smokers — they used the drug at least four times per week.”

    That’s casual.

    1. “A reminder to those of our viewers who missed our story last week on the influx of so-called Killer Dope in urban areas around the country. ‘Weekend Update’ has been analyzing the samples of marijuana sent to us anonymously all week. We are pleased to report that, so far, the only significant finding has been that if you force a baby squirrel to smoke seven-hundred cannabis joints a day, he will become disoriented, seems to take the laws of self-preservation less seriously, tending to play with his nuts rather than store them.” — Chevy Chase, SNL News, Season 1, Episode 10

  4. So the people taking the concentrates and oils must be getting extra stupid…no, they’re not, they are getting healed. Studies in the Emperor Wears No Clothes say exactly the opposite, a higher IQ for chronic marijuana smokers, those who smoke over 30-70 joints per day of those huge Jamaican joints too! I concur!

  5. Dependent on marijuana? I never met anyone who was physically dependent on it! As a kid I smoked every single day, possibly 10x a day for 5 years and one day decided I didn’t feel like smoking it anymore. Didn’t have any withdrawal whatsoever and I think that was a sufficient amount to develop an addiction with. Or maybe I hadn’t quite done enough? Reefer Madness I tell ya! Haha 😀

    1. I smoked daily for maybe twenty years and one day just stopped as I couldn’t be bothered anymore. I still have the occasional smoke(maybe two or three times per year). I have a coffee tin full of buds and have hardly touched it in the three years since it was given to me.
      On the other hand one of my mates is about to celebrate his fiftieth anniversary of IV Heroin use. He is an addict that has had the good fortune to not have to earn his money via criminal methods. He is in perfect health apart from a back injury received years ago in his job assisting a quadriplegic (it’s heavy work). He is a kind, helpful, salt of the Earth bloke and I wouldn’t trade his friendship and loyalty for anything.

  6. Same here Martist..Major smoke for many years..all day actually. I was in the low voltage engineering field at the time too. I got raises, I even changed the entire state in regards to how they plan check low voltage systems..Dave Coffee was Portland fire marshall at the time and he and I worked together to upgrade plan checks throughout the state…I decided to quit temporarily for personal reasons, and all that happened to me is it was kinda hard to fall asleep at night for a couple days. last year I went cold turkey on quitting my brewskies, and felt like I was gonna die for weeks.

  7. lol chris 🙂 well its legal in Oregon now, hah….funny, marijuana is legal to grow now, but it is still illegal to grow hemp…I am surely living in a matrix..
    Its fun to smoke a bowl and eat a bunch of gmo food too..Gotta go tho, I have to get my vaccine shot 🙂

  8. You know I was kidding NWO….funny story, about a year ago, my 28 year old son pulled that on me…He told me he was going to get a vaccine shot. I wrote him back and said…wtf???? he got me good. Even my kids know..Are they still kids when they are 26? I think so..I will always be a dad. Vaccines, and gmo food are to kill our God given DNA.. Noah time was to kill their DNA, so keep strong and know the blood of Jesus Christ is most important..Remember in Genesis when God asked Cain where is your brother? Cain said “am i my brothers keeper? but God said ” His blood is crying out”…the blood is mentioned almost 500 times in the new testament.
    I love you all, but without Christ, we are nothing… I am very interested in the testimonies from the Hagmann and Hagmann report..If you all dont like this stuff, its ok, but I share it with love..

    1. I was just kidding too, hweinhard, but I’ve been playing it straight a lot lately.

      Must be something I smoked.

      Heh, heh, heh…

  9. 😀 To all you fellas! You all know what’s up and nary a word is disputable. Proof that is far from the danger tptb are selling it as. Quite the contrary, it is what is God has made for us to cure many of our afflictions. It is difficult to regulate and justify any reasonable proposal for doing so therefore tptb have stalled for as long as they could and made as much money as they could through criminalizing something so natural, beneficial and benign. Their time is up. I mean that in EVERY way!!!!

  10. Classical use of dishonest rhetoric. Conflate terms to confuse and change the debate.
    Addiction and dependency are different, addiction is chemical and dependency is emotional. Both can/do cause changes in physiology.
    Tolerance and addiction are different, tolerance changes from person to person and from time to time, nothing to do with addiction.
    In the past there was an excuse for being ignorant, try going into a library (or bookstore) and asking for a book on how to manufacture PETN. Now with the internet, the only reason that people remain ignorant is that they do not bother to get the facts or do not know how to use the brains that they do have.
    “We are all born ignorant, but one must work hard to remain stupid.” — Benjamin Franklin

  11. “A study released earlier this year, for example, found that 40 percent of marijuana users in an outpatient treatment program showed signs of withdrawal, a classic indicator of addiction.”

    This “study” is bullsh!t. Even if you diet, your body will show signs of withdrawal. With the stresses of life today, everyone needs a release from reality. Some people sleep, exercise, have some form of gratifying sex, eat high-carb snack food, drink alcohol, smoke right or left handed cigarettes (or all of the above).

    However, if you deprive yourself of any type of mental release, you shall shows signs of withdrawal and become at best, cranky or, at worst, violent. Does this mean that you are addicted, or does this mean that you have a propensity to escape a sh!tty reality once a day?

    I have had dogs and cats that loved getting high on pot. Is this considered cruelty to animals, or a humane treatment for pets who are bored silly and wanting to take a pleasing trip without wandering away from the back porch? Farm livestock and deer also prefer eating marijuana instead of hay or GMO cracked corn.

    Perhaps there should be a study to compare people who take daily prescribed SSRI antidepressants, with people who smoke pot on a daily basis. I nor anyone I know have ever had violent thoughts or tendencies when we’re stoned, and the feelings of shared euphoria are greater in numbers. When there is a dry spell and no pot can be found we just bitch. If a person taking prescription SSRI antidepressants runs out of meds… there are mass murders and/or suicides.

    Perhaps this is what TPTB fear the most, a return to the 1960s pot counterculture-era: “Turn on, tune in, drop out” (without ANY need for pharmaceutical drugs).

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