Does researching casual marijuana use cause brain abnormalities?

Why the Media's Fearmongering on Marijuana Effects on the Brain Is Faulty
By Paul Armentano / AlterNet April 17, 2014

A neuroimaging study of the brains of marijuana smokers caused unwarranted frenzy.


Photo Credit: Darren J. Bradley / Shutterstock.com

The mainstream media launched into a reefer mad frenzy this week after researchers from Harvard University in Boston and Northwestern University in Chicago published the results of a neuroimaging study assessing the brains of a small cohort of regular marijuana smokers and non-users. The brain scans identified various differences between the two groups in three aspects of brain morphometry: gray matter density, volume, and shape. These differences triggered dozens of high-profile media outlets to lose their collective minds. Here’s just a sample of the screaming headlines:

CNN: Casual marijuana use may damage your brain; Science Daily: More joints equal more damage; Financial Post: Study proves occasional marijuana use is mind altering; Time: Recreational pot use harmful to young people’s brains; Smoking cannabis will change you. That’s not a risk, its acertainty.

Just imagine how the media would have responded if the study in question had included more than 20 actual cases — or if the authors had actually bothered to assess its subjects for demonstrable deficits in cognitive performance. Yes, that’s right. Despite the sky-is-falling rhetoric and the shock claims of permanent brain damage, a careful review of the study and its findings reveals little, if any, cause for alarm.

So what did the study find? In truth, not a whole lot.

Using high–resolution MRI imaging, scientists identified specific changes in particular regions of the brain that they inferred were likely due to marijuana exposure. (Since researchers only performed a single MRI session, they could not say definitively whether these changes were, in fact, caused by cannabis or whether they existed prior to subjects’ use of the plant.) Notably, however, these changes did not appear to be associated with any overt adverse effects in subjects’ actual cognition or behavior. (Separate studies assessing youth use of legal intoxicants, such as nicotine and alcohol,have also been associated with documented changes in brain structure. Ditto for caffeine intake in preclinical models. These findings have received far less media attention.)

Both the cases (20 marijuana users) and controls (20 nonusers) in the study were recruited from local universities, undermining the notion that the alleged ‘brain damaged potheads’ were any more academically challenged than their non-using peers. Further, as summarized by HealthDay: “Psychiatric interviews revealed that the pot smokers did not meet criteria for drug dependence. For example, marijuana use did not interfere with their studies, work or other activities, and they had not needed to increase the amount they used to get the same high.”

In other words, case subjects and controls appeared to function similarly in their professional and academic endeavors.

That finding should hardly come as a surprise. Dozens of separate neurocognitive studies consisting of far larger sample sizes find no substantial, systematic effect of long-term, regular cannabis consumption on brain functioning once the users have abstained from the drug. As concluded in one recent meta-analysis of 33 such studies, published in the journal Experimental and Clinical Pharmacology: “As hypothesized, the meta-analysis conducted on studies evaluating users after at least 25 days of abstention found no residual effects on cognitive performance. ... These results fail to support the idea that heavy cannabis use may result in long-term, persistent effects on neuropsychological functioning.”

A separate review of nearly a dozen studies (involving a total of 623 cannabis users and 409 non- or minimal users) published in the Journal of the International Psychological Society similarly reported, “The results of our meta-analytic study failed to reveal a substantial, systematic effect of long-term, regular cannabis consumption on the neurocognitive functioning of users who were not acutely intoxicated.”

Moreover, other studies, though admittedly comprised of small sample sizes, have indicated that in some instances cannabis may actually protect the brain, particularly against the potentially damaging effects of alcohol.

This is not to say that consuming marijuana, particularly in heavy quantities, is not without potential risk to learning retention, short-term memory, and other potential cognitive skills—especially when it is consumed by young people whose brains are still developing. However, after decades of marijuana use by significant portions of the public (despite the plant’s prohibition), it is apparent that these associated potential risks are not so great as to warrant the continued arrest of some 700,000 Americans annually for possessing the plant. Nor do these potential risks justify marijuana’s present status as a schedule I controlled substance, a classification that equates the purported dangers of pot to be equal to those of heroin.

Such fear-mongering and sensationalism by the mainstream media in regards to the supposed harms of pot upon the brain are nothing new. It wasn’t long ago that the mainstream media was boldly claiming that cannabis use permanently lowered IQ, a finding that marijuana prohibitionists and anti-drug bureaucrats were happy to repeat ad nauseam.

Reported CBS News at the time, “Dr. Nora Volkow, director of the National Institute on Drug Abuse which helped fund the research, said the research was ‘the cleanest study I've ever read’ that looked long-term harm from marijuana use.”

Except it wasn’t. A separate analysis of the data, published only weeks later in the Proceedings of the National Academy of Sciences, acknowledged that the study’s authors failed to properly control for subjects’ socioeconomic status. It concluded, “A simulation of the confounding model reproduces the reported associations from the Dunedin cohort, suggesting that the causal effects estimated in Meier et al. are likely to be overestimates, and that the true effect in regards to marijuana’s potential effect on IQ) could be zero.”

Predictably, the mainstream media’s coverage of this refutation was nonexistent.

As a result, prohibitionists still continue to publically raise the disproven allegation that pot use lowers IQ as if it is fact. Most likely, those of us who advocate for saner marijuana policies will be similarly responding to these equally specious claims that cannabis causes brain damage for many years to come.

AlterNet Paul Armentano is the deputy director of NORML (National Organization for the Reform of Marijuana Laws) and the co-author of Marijuana Is Safer: So Why Are We Driving People to Drink (Chelsea Green, 2009).

Here's the Real Story Behind That 'Marijuana-Changes-Your-Brain' Study

Chances are you saw the headlines on Wednesday: "Casual marijuana use linked to brain changes," "Marijuana re-shapes brains of users, study claims" or "Casual marijuana use may damage your brain." Oh my god, marijuana is bad for my brain!

Not so fast.

"I think I saw one headline that was 'Marijuana reshapes the brain' and I groaned — that's not what we did," said Dr. Jodi Gilman, 31, author of the now-famous Harvard Medical School/Massachusetts General Hospital study on marijuana's effects, in an interview with PolicyMic.

Research is full of nuance, and nuance sometimes gets lost in the conversation. The collective freakout over this study had to do with its findings: Certain regions of the brain of people who smoke marijuana are structurally different than people who don't. That got interpreted, at least in headlines and ledes, as marijuana changes your brain.

"The conclusions were modest in the paper — we never say marijuana causes these changes," Gilman said, who's a neuroscientist with a Ph.D. from Brown University. "The media may have given that impression in headlines, but the study doesn't show causation."

It was a classic A and B study. Take group one and see how they're different from group two. That's it.

Does researching casual marijuana use cause brain abnormalities?

Neurology
Striking a Nerve: Bungling the Cannabis Story
Published: Apr 16, 2014
By John Gever, Deputy Managing Editor, MedPage Today
Correlation does not equal causation, and a single exam cannot show a trend over time. Basic stuff, right?

But judging by coverage of a study just out in the Journal of Neuroscience, these are apparently foreign concepts for many folks in the media.

Interesting, but remember that these findings only reflected differences between the marijuana users and controls at a single point in time. The researchers did not, could not, demonstrate that the differences resulted from marijuana smoking or even that the "abnormalities" relative to controls reflected changes from some earlier state.

Bad science, and really bad reporting

Jacob Sullum calling out the press
Study of Pot Smokers' Brains Shows That MRIs Cause Bad Science Reporting
This week a study of cannabis consumers published by The Journal of Neuroscience provided powerful evidence that MRI scans cause shoddy science reporting.



comments

kaptinemo April 18, 2014

On topic: it’s interesting to read the various comments at each of the articles. The reactions can be distilled into three different groups.

The first appear to be actual scientists – who also appear to have little or no association with or enjoy the support of prohibitionists. Their reactions are almost uniform condemnation of the study. Some may be trying to be diplomatic, but even those denounce it.

The second group is much more obvious: prohibs, both ‘lettereds’ and not. The former, trailing alphabet soup after their surnames, have been silent on their fiscal sources, but their criticisms are invariably the sort made by those profiting from the ‘treatment’ industry. The greater number of that subgroup appear to be less educated, low information citizens who also do not make their fiscal sources transparent, but appear to be the usual ‘water carriers’: police, bureaucrats, ‘concerned citizens’, etc. who also benefit from prohibition.

The last group are mainly folks like those residing on the Couch. Cannabis-knowledgeable citizens. Enough said.

It’s a pattern easily discernible once you make it, and on doing so, you also realize how incredibly thin the prohib support is. For, don’t you think that if the prohibs had as much intellectual integrity as they do blind, deliberately ignorant fervor, they’d be massing in vast numbers on the usual Websites? They’re hardly making an appearance. And when they do, they are almost outnumbered a hundred to one. ..as the comments show.

Must be hard, being a prohib, nowadays…

Servetus April 18, 2014
Human genome studies indicate the mutation for lactose tolerance occurred roughly 10,000 years ago in Turkey, and then spread quickly. Marijuana consumption likely extends at least that far back. It wouldn’t surprise me to learn that we all enjoy a biological, symbiotic relationship with cannabinoids and other marijuana compounds.

"The Prefrontal Cortex"

MARIJUANA AND THE HUMAN BRAIN
by Jon Gettman, High Times, March 1995
Until the 1980s, technological limitations obstructed scientific understanding of the neuropharmacology of THC, of how the active ingredient in marijuana actually affects brain functions. Observations and conclusions about this subject, though based on some biological studies, were largely influenced by observations of behavior. This has allowed cultural prejudice to sustain the faith that marijuana is somehow related to heroin, and that research will eventually prove this hypothesis. Actually, the discovery of the THC receptor site and the subsequent research and observations it has inspired conclusively refute the hypothesis that marijuana is dope.

According to the congressional Office of Technology Assessment, research over the last 10 years has proved that marijuana has no effect on dopamine-related brain systems

Ganja mothers, ganja babies
Marijuana during pregnancy
The 30-day test showed that children of ganja-using mothers were superior to children of non-ganja mothers in two ways: the children had better organization and modulation of sleeping and waking, and they were less prone to stress-related anxiety.

So, there’s this study… (it being a NIDA-sponsored study) ding ding ding

Dr. Aggarwal posted this yesterday: “Some responses from our community of researchers to the fmri brain study published in the Journal of Neuroscience that has the media and some involved researchers on their usual 15 mins of hyperbole:

*these functional imaging techniques are a static representation of a dynamic process subject to interpretation.

*important for people to understand the importance of conflicts of interest in research, and to remember that they need to keep ideas of cannabis use in a context of its relative effect in comparison to other substances.

*it’s interesting that “social play” in rats increases anandamide levels in those two brain regions

*it’s not clear in any of these types of studies if you are actually measuring the effects of cananbis or the effects of stigma, threat, and stress related to its use.

*there isn’t any information in the actual brain scans to suppose that this is a “disruption” of function. That’s an interpretation that reveals a bias built into the study.

Here’s another. Maia Szalavitz, in a piece called No, Weed Won’t Rot Your Brain, tackles the ignorance of the media (and prohibs) when it comes to proper and rational interpretations of scientific research:

“Can casual marijuana use damage the brains of young adults? A new study says yes—but its participants suggest otherwise.”

…as we consider policy changes like legalization, we need a far more skeptical and intelligent press. Marijuana itself may or may not impair cognition— but discussions of marijuana policy clearly do so, in a way that is detrimental to our political health.

Toke-A-Day May Keep Old Memory Functioning

☛ The more research they do, the more evidence Ohio State University scientists find that specific elements of marijuana can be good for the aging brain by reducing inflammation there and possibly even stimulating the formation of new brain cells.
Scientists are High on Idea that Marijuana Reduces Memory Impairment

☛ A study by University of Saskatchewan researchers suggests beneficial aspects of smoking marijuana at least among rats, who appear to have sprouted new brain cells and besides benefiting from reduced depression and anxiety.
Marijuana May Live Up To Be The Elixir of Life

☛ “Why would we evolve a chemical that would make us forget, that would affect our short-term memory?” That seems maladaptive. His answer was one of the great “a-ha!” moments I had when I was working on this book. He said, “Well, do you really want to remember all the faces you saw in the subway this morning, all the faces in the supermarket?” And I realized at that moment, well, of course, forgetting is not a defect of a mental operation, although it can certainly be that; forgetting is a mental operation. It’s almost as important as remembering. He believes that there is another see-saw there. There is a chemical that helps us lock in memory, and anandamide works on the other side to make us get rid of memory. This also relates to memory loss with regard to trauma. We need cannab-inoids to forget horrible things that have happened.
Michael Pollan: "Cannabis, The Importance of Forgetting

Republican State Senator blocks PTSD study

Pot Joins The Fight Against Alzheimer's, Memory Loss

New Study Shows Cannabinoids Improve Efficiency Of Mitochondria And Remove Damaged Brain Cells
A recent study conducted by Andras Biokei-Gorzo at the Institute of Molecular Psychiatry at the University of Bonn in Germany is suggesting that marijuana (or the activation of the brain’s cannabinoid system) triggers the release of antioxidants, which act as a cleansing mechanism.

A molecular link between the active component of marijuana and Alzheimer's disease pathology.
Alzheimer's disease is the leading cause of dementia among the elderly, and with the ever-increasing size of this population, cases of Alzheimer's disease are expected to triple over the next 50 years. Consequently, the development of treatments that slow or halt the disease progression have become imperative to both improve the quality of life for patients and reduce the health care costs attributable to Alzheimer's disease. Here, we demonstrate that the active component of marijuana, Delta9-tetrahydrocannabinol (THC), competitively inhibits the enzyme acetylcholinesterase (AChE) as well as prevents AChE-induced amyloid beta-peptide (Abeta) aggregation, the key pathological marker of Alzheimer's disease. Computational modeling of the THC-AChE interaction revealed that THC binds in the peripheral anionic site of AChE, the critical region involved in amyloidgenesis. Compared to currently approved drugs prescribed for the treatment of Alzheimer's disease, THC is a considerably superior inhibitor of Abeta aggregation, and this study provides a previously unrecognized molecular mechanism through which cannabinoid molecules may directly impact the progression of this debilitating disease.

High Times for Alzheimers
'A younger sibling of mine accidentally let grandma eat the wrong brownies... You could tell she had AD --Alzheimer's disease -- but nothing so prominent. It was like it took her back 3-4 years." Postings such as this one on the Alzforum website intrigued Dr Nathaniel Milton, a biochemist at London's Royal Free and University College medical school.

Pot joins the fight against Alzheimer's, memory loss Scientific American
Scientists from Ohio State University report that marijuana, contrary to the conventional wisdom, may help ward off Alzheimer's and keep recall sharp. Their findings, released today at the Society for Neuroscience meeting in Washington D.C.: chemical components of marijuana reduce inflammation and stimulate the production of new brain cells, thereby enhancing memory.



further study of marijuana effects

No matter how unscrupulous the lab rats are conducting these science fiction papers for the faux news to spread the gossip. They always end with more research is needed.

More funding for more research is needed. Doesn't matter which headline they pick to exploit it always ends with more research.

20,000 research papers filed. 1937 until now and they still need more research just in case the past hobgoblins they hurled that never panned out can have a chance to materialize into real harm. But not without research.

The government banned medicinal research in 1974 for its potential threat to Big Pharma and Drug Worrier research funding. Such despicable disgusting vermin should be rotting behind dungeon walls away from the children they pervert.

@democracynow We Need a Law Against “False or Misleading News” Researching casual marijuana causes brain abnormalities!
This week a study of cannabis consumers published by The Journal of Neuroscience provided powerful evidence that MRI scans cause shoddy science reporting.
​

☛☛☛☛☛Possibly the most-studied substance on the planet☚☚☚☚☚

Should it be legalized?
"soon we will know"
Part of a larger issue on Marijuana
in Life magazine Oct 31, 1969. 25-35

Why I changed my mind on weed
By Dr. Sanjay Gupta, CNN Chief Medical Correspondent

On August 14, 1970, the Assistant Secretary of Health, Dr. Roger O. Egeberg wrote a letter recommending the plant, marijuana, be classified as a schedule 1 substance, and it has remained that way for nearly 45 years. My research started with a careful reading of that decades old letter. What I found was unsettling. Egeberg had carefully chosen his words:

"Since there is still a considerable void in our knowledge of the plant and effects of the active drug contained in it, our recommendation is that marijuana be retained within schedule 1 at least until the completion of certain studies now underway to resolve the issue."

Not because of sound science, but because of its absence, marijuana was classified as a schedule 1 substance. Again, the year was 1970. Egeberg mentions studies that are underway, but many were never completed. As my investigation continued, however, I realized Egeberg did in fact have important research already available to him, some of it from more than 25 years earlier.

The 'Virtues' of Ganja
The Politics of Pot

The Media Should Stop Pretending Marijuana’s Risks Are a Mystery
— The Science is Clear

Speaking recently with the Los Angeles Times, UCLA professor and former Washington state “pot czar” Mark Kleiman implied that we as a society are largely ignorant when it comes to the subject of weed. Speaking with Times columnist Patt Morrison, Kleiman stated, “I keep saying we don’t know nearly as much about cannabis as Pillsbury knows about brownie mix.”

Kleiman’s allegation—that the marijuana plant and its effects on society still remains largely a mystery—is a fairly common refrain. But it is far from accurate.

Despite the US government’s nearly century-long prohibition of the plant, cannabis is nonetheless one of the most investigated therapeutically active substances in history. To date, there are over 20,000 published studies or reviews in the scientific literature referencing the cannabis plant and its cannabinoids, nearly half of which were published within the last five years according to a keyword search on PubMed Central, the US government repository for peer-reviewed scientific research. Over 1,450 peer-reviewed papers were published in 2013 alone.

We know plenty about cannabis. We know more about cannabis than most (if not all) FDA-approved drugs, despite their vaunted exclusive process (which often has as much to do with politics and money as science).

The ‘we don’t know enough’ argument is used to delay or dilute legalization efforts (I would place Kleiman’s comments in the “dilute” category, formerly “delay”), and, in some cases, it is merely short for “I won’t be satisfied with any amount or type of studies until we find one that proves cannabis is bad.” (Sabet would probably be an example of that.)

Jack Herer’s “The Emperor Wears No Clothes” * electricemperor

Top 10 Cannabis Studies the Government Wished it Had Never Funded

The Tribunal of US Drug War Crimes

The Drug Worriers Should Be Busted by the (HUAC)
House Committee on Un-American Activities

Obama Needs to Slap Down His Rogue DEA Chief
The two-tiered justice:
Urine King Kin Gets Probation for Raping His 3 Year Old Daughter

 

thank you for taking the time to post this

 

Would they bitch if the possible changes were positive?

 

Thanks for posting this. I found the headlines regarding this study rather alarming myself. I've noticed a definite rise in fear mongering since marijuana was legalized in two states.

 

"Too Much Did Not Read" Would Be The Understatement

Of The Decade....



Cheers Glen.

 

Then just fuck off and don't post, Glen.

I noticed a few of these headlines, and then noticed some of the same issues when I looked into it more. Thanks for posting this!

 

Thanks for posting this Glen. It is surely a solid indication that apathy is not only or the most apparent in marijuana consumers :2thumbsup: