NORML Responds To Latest ‘Pot Shrinks The Brain’ Fears

  • by Paul Armentano, NORML Deputy Director November 12, 2014

    NORML’s Deputy Director today on Alternet.org addressed new media claims that cannabis use can potentially shrink the brain:

    [excerpt] A new study identifying minor differences in the brain imaging of habitual marijuana consumers compared to non-users may be ideal for stimulating sensational headlines (e.g., “Regular pot smokers have shrunken brains, study says,” Los Angeles Times, November 10), but tells us little in regard to whether pot poses actual health risks.

    Specifically, an MRI scan revealed less gray matter in the orbital frontal cortex of pot-smoking subjects compared to those who had never used the drug. Researchers also identified increased connectivity between certain regions of the brain in regular marijuana users compared with non-users.

    So precisely what do these findings tell us in regard to pot use and health? Not much. Since the study design is not longitudinal, investigators cannot determine whether these differences are caused by subject’s cannabis use, whether these differences existed prior to subjects’ ever trying cannabis, or whether these differences persist when users’ cannabis consumption ceases.

    Most importantly, investigators in this study failed to determine whether any of these differences are positively associated with any measurable adverse performance outcomes, such as cognitive performance or quality of life. It may be that these cannabis users are functioning in their daily lives in a manner that is indistinguishable from controls, in which case the imaging differences may hold little if any real-world significance. (In fact, one of the paper’s authors acknowledged, “[C]hronic users appear to be doing fine.”)

    Full text of NORML’s response, “Media Leaping to Extremely Faulty Conclusions from Study on the Effects of Marijuana on the Brain,” appears online here.

    81 responses to “NORML Responds To Latest ‘Pot Shrinks The Brain’ Fears”

    1. SgtStorm says:

      Mine brain never dontt b ofected nD i smook al thime cinse a kid

    2. Juniata says:

      All the most sober literature on the effects of cannabis on the brain is coming from people who smoke! Changes in the brain can be related to just about anything; exercise, caffeine, sleep deprivation, and love probably all have their cognitive influences which are viewable by Magnetic Resonance Imaging. A picture is worth a 1000 words because it is an instance of time. Gray matter is something that probably constantly fluctuates in our systems to accommodate the constant flow of new experiences that we have. The “fact” that pot smokers had less gray matter seems irrelevant to whether or not they had healthy cognitive functioning. I’m sure that musicians, basketball players, computer geeks, and fisherman all have discernible features on MRI compared to non doers of those things, respectively.

    3. Brent says:

      what does norml have to say about the UN coming in and ruining our momentum

    4. Galileo Galilei says:

      I took 5 or 6 of those intelligence tests you used to see on the Internet.

      I took an average and the mean, mode, and median calculated to be EXACTLY the same as my score in Kndergarden.

      I can never seem to corroborate findings like this with my own life’s experience.

      I wonder why??????

    5. Voice of the Resistance says:

      They should try the brain scan thing on my brother. Images of a easy chair, a couple of cans of beer, a hot-dog covered in mustard,. a football. Wow the doctors would say, the pleasure centers in this guys brain just lit up like a Christmas tree! This is my brothers brain on football, duh.

    6. mark says:

      I think this is a bunch of bull shit.they are .just trying to start fear mongering again.. look at alcoholics brains if they have any left..what about the brains of perscription drug users,,,the reefer madness people are at it again …im 60 yrs old i have been smoking along time ..i still pass tests in the insurance world these tests are exstreamly hard ///as for the U.N..they need to take a leap off a mountain ..they need to mind there own buissness… sounds like a bunch of jealous kids im going to tell my mommy the usa is leagalizing weed ,,,keep up the good work norml/////

    7. Dave Evans says:

      Oh, you mean that feeling I have of various government agents still trying to find Osama bin Laden and Marijuana in my pants is just my brain shrinking?

      Thank God, I was starting to get worried. The government isn’t out of control, it just our brains are shrinking and we can’t tell lies from truth anymore.

      I mean, for a minute there, I almost thought that arresting million innocent people itself is a crime, but that’s just my shrunken brains trying to justify drug addiction. When you have a shrunken brain, you should let other people think for you. It is the safer option.

    8. Dave Evans says:

      Galileo of Galilei,

      That is because while there are dumb stoners; there are plenty of smart stoners too. There are just trying to get other people to look down on us. They are still just losers with nothing but bullshit ideals to support why they are better than us.

    9. Julian says:


      Thanks to the fact that marijuana increases intellectual and emotional development, thanks to our votes, letters to Congress and donations, thanks to advocates of science and well founded statistics like Mr. Armentano here, and thanks to cannabis, we are GAINING momentum.
      The truth is out.
      Prohibition can no longer be used to disproportionately incarcerate minorities, or to scapegoat our socioeconomic challenges. We ALL suffer from prohibition, especially that of marijuana, and we are poised to avalanche across the half-way mark of sensibly regulated legalization of international marijuana commodities on the way to 2016…

      Whether the U.N. and all the drug lords in the DOJ like it or not.

    10. fireweed says:

      Likewise, Galileo. I took my MRE (admissions exam to grad school) stoned and scored high enough to overcome a mediocre gpa to get accepted. Years later when being tested for ADHD, they had me take a bunch of cognitive functioning tests in areas of math facility, word recognition and others, and I scored in the “very superior” range in several areas, and only one area was even near average, all well above average. And I think I was stoned for most of those 🙂