The Marijuana Potency Data

Nov 21 2008 Published by under Cannabis, Drug Abuse Science

You may have heard a relatively sustained drumbeat in the mainstream press reports in the past few years regarding the content of current illicit cannabis products. It has been promulgated in a PR campaign which attempts to convince baby boomers that today's marijuana is more dangerous than that of their own misbegotten youth because it is "stronger". In other words, higher in the concentration of the major psychoactive constituent, Δ9-THC. The subtext, I assume, is to alleviate the boomer parents of today's teens of any guilt related to communicating seemingly hypocritical anti-dope messages. If the pot today is more dangerous, then it is not hypocritical that Daddy and Mommy used to smoke in the seventies, right?
I have an objection to one of the fundamental concepts here* which explains my laziness in never bothering to track down the data on which the assertion rests. Happily, I stumbled across the relevant source.


ElSohly-delta9THC-graph.png
Quarterly Report Potency Monitoring Project
Report 100 December 16, 2007 thru March 15, 2008
NIDA Contract Number: N01DA-5-7746, Mahmoud A. ElSohly, Ph.D.
[ http://www.whitehousedrugpolicy.gov/pdf/FullPotencyReports.pdf ]
Browsing around the ONDCP site after yesterday's comments, I ran across an interesting document that I hadn't viewed before. It is the March 18, 2008 report from a NIDA contract that monitors the cannabinoid content of samples seized in law enforcement actions in the US.
I graphed the Δ9-THC data from Table 2 which reports the non-normalized cannabinoid averages of illicit cannabis samples by year seized. The report is methodologically light so I can't figure out why the data are "non-normalized", nor what normalizing procedures should be performed. Perhaps to account for site bias if they get more samples from one area of the country? Something like that. And who knows anything about the sensitivity of the assays for cannabinoids over time...we can assume there are comparable methods but it would be nice to see methods. (Surprisingly, I don't immediately pull any relevant publications from the contract's PI on Pubmed...) Anyway it seems likely that these are fairly raw analyses.
These are interesting trends. Reminds me of something...what was it....what was it... oh yes.
Remember this graph that I put up in a prior post on the efficacy of the War on Drugs?
2006-Fig5-4a-MJ-amp.jpgThese data report the annual prevalence for marijuana smoking in the Monitoring the Future survey. As we see in the left panel, there was an increasing trend from the mid seventies until the start of a sustained decline in the popularity of marijuana which started in the early eighties. This trend lasted until about the early nineties whereupon marijuana popularity started to increase again (I blame Snoop Dogg's release of The Chronic, myself :-)). [Update 11/24/08: Yeah yeah, commenters, it was released by Dr. Dre with significant contribution from Snoop that some would say launched his career. My bad. If you clicked through the link you would see this is made clear on Wikipedia.] Looking at the potency trends it is tempting to conclude that market forces influence the Δ9-THC content of the illicit marijuana supply, is it not?
MonkeyEgg.jpg
return to hunt
Speculation on illicit drug capitalism aside, I'm glad that I finally viewed the data on which the PR message rests. I have to admit that I'd been a bit skeptical about the basic claim over marijuana potency, just because of the generic suspicion (which many of my readers apparently share) that official anti-drug messages are sometimes a little free and easy with claims relative to the actual supporting data. I now have some framework on which to consider the assertions.
I didn't work up the graph yet, maybe I will later, but Table 1 of the report has a breakdown of the number of seized marijuana samples which are in less-than 3%, 3-4.9%, 5-8.9% and 9%+ categories. This information will require a little more work (i.e. data entry from me) to make some sense but a quick glance will show you that the lower-concentration samples are more abundant. This should be taken into account when estimating content of the typical marijuana to which teens might be exposed.
__
*My hesitation to credit the purported link between the Δ9-THC content in commonly available weed and increased risk is that smoked drugs of abuse tend to lend themselves to exquisite individual control over dosing. I'll have to drag up some references eventually but there's a whole literature in which it is shown that if you manipulate the nicotine content of cigarettes, smokers will alter their smoking topography (volume per puff, puff duration, etc) in the direction of restoring the dose obtained from their usual brand. The marijuana literature is smaller and hampered by the fact that the official NIDA-supplied (grown by El Sohly, the one who runs the analysis contract) marijuana tops out at about 3.6% Δ9-THC. Nevertheless a close reading of the available literature in controlled human laboratory studies will suggest that marijuana smokers are also quite good at titrating dose in response to the content of the smoked product.
Another way to put this is that users smoke to reach a subjective high rather than to consume a certain number of puffs of a certain amount of drug. The product and route of administration are such that the overdosing variance would seem to be quite narrow relative to cases where the drug administration is more of a one-shot ballistic event (like swallowing a purported Ecstasy pill of unknown content, IV administration of drugs of uncertain purity / weight). Consequently I tend to doubt that the concentration of the source material plays a huge role in establishing marijuana dependence.
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Update: 11/23/08: New readers (Thanks Andrew Sullivan!) may wish to read my prior posts on
Comparing Cannabis and Nicotine Withdrawal
and
"Legalize eet mon" the ongoing series: In which the "scientists" are blamed, yet again, for the failings of journalism.

77 responses so far

  • llewelly says:

    Most of the medical dangers of marijuana come from the smoke particulates. Thus - danger is more likely proportional to amount of marijuana smoked rather than THC. If THC percentage goes up, but smokers try to maintain a given THC intake, they'll be smoking less material. And less particulates will get into their lungs.

  • DrugMonkey says:

    llewelly, the question is whether increasing the THC content increases dependence liability. which among other things would increase the lifetime exposure to particulate. but you knew that....

  • phisrow says:

    I would be inclined to suspect that law enforcement (indirectly) affects potency as well. If pressure on growers and distributors is fairly low, nonintensive cultivation of indifferent strains would be a decent strategy, since artificial selection is labor intensive, and grow lights, hydroponic widgetry, supplemental CO2 and the like are expensive. If pressure is high, the incentive to produce maximum THC per unit area that has to be hidden and per unit product that has to be transported, will be considerably higher.
    I'll be particularly interested to see if something like that is observed in response to the passage of question 2 here in MA. If being caught with 1 ounce or less is a petty civil offence($100 fine) there is a certain incentive to pack as much THC per ounce as possible so that the greatest amount of intoxication can be achieved with the lowest level of legal exposure. Of course, if this does turn out to be the case, I'm sure we'll see "Question 2 leads to Super Weed, threatens children, 'We told you so' say responsible authorities."

  • Mahakal says:

    In principle, the higher the potency the better as long as there is no risk of accidental overdose. Given the amazing safety profile of cannabis, no human fatality having been caused by cannabis overdose in history, there is really nothing to be alarmed about even with more potent forms like kief.
    As you say, people titrate their dose according to potency, and when the only harms potentially associated with cannabis consumption are related to combustion products, the less combustible material needed to gain desired effects, the better.

  • S. Rivlin says:

    What phisrow said. As to the delta-9-THC concentration in the cannabis grown today, the most reliable source would be weed users who continuously use it since the 70s (Bill Mahr?). My sources are telling me that this is the case i.e., THC concentration in today's cannabis is significantly higher than that of the 70s.
    I'll have to contact my old colleague, Refael Mechoulam, to find out what his lab results are. He used to be my "pusher" where cannabinoids are concerned, supplying me with enough material to complete my Ph.D. thesis on the effects of cannabinoids on biomembranes and other biological systems. The old geezer is still hard at work being involved in the discovery of the cannabinoid receptors and in the identification of the endogenous cannabinoid. Raffie is another example of an old geezer who continues to greatly contribute to our scientific knowldge.

  • PalMD says:

    DM, in addition to your objection to the basic argument (people will smoke till they're stoned), there is an ethical problem. My previous--hypothetical--use of an illegal substance is right or wrong independent of the dose of psychoactive chemicals in the substance. I should teach my child to act ethically independent of my past actions.

  • MitoScientist says:

    Purely in the interest of scientific accuracy, I believe it was Dr. Dre who released The Chronic, thereby setting off a renaissance of teens with the munchies.

  • When Comrade PhysioProf was in college, he was aware that people sometimes sat around smoking bong hit after bong hit for hours on end. Comrade PhysioProf is now aware that people sometimes smoke one hit of good shit and refrain from smoking more for hours.
    Comrade PhysioProf has absolutely no direct access to the subjective experiences of either the former or latter individuals.

  • leigh says:

    i have several comments. first and foremost, did they provide sd or sem for error bars? i think that would be quite telling itself.
    i have seen numbers as high as 14%, which is a number i'm sure the drug policy people just love, but i'm also sure that's the extremely rare sample.
    has comrade physioprof considered the effect of subject age in this observation?
    i have a supercool study in the works that is right up the alley of one of the topics presented here, but i will say no more because i like my pseudonymity.

  • jj says:

    Along with the idea that higher potency would most likely mean that users would use less to achieve the same thing, one other issue that I always wonder about is the lungs capacity to absorb the cannibinoids from smoke - that is, you can only hold smoke in for so long - and I would imagine at higher concentration a lower ratio of total THC:Absorbed THC would be seen. Or in other words, some of that THC probably is getting exhaled. Just a thought, though.

  • jj says:

    @Phisrow
    "I'm sure we'll see "Question 2 leads to Super Weed, threatens children, 'We told you so' say responsible authorities.""
    Believe me, if people could grow "super weed" it'd be on the market. Those kids in Humboldt county have been doing everything they can to increase potency. In fact, i'd say there already is a good deal of "super Weed" flowing around Northern California.

  • DrugMonkey says:

    Oh Sol, Mechoulam totally kicks ass, I agree. Stop with the intentional misunderstanding of the position already. Nobody's talking about age-based mandatory retirement, sheesh.
    As to the delta-9-THC concentration in the cannabis grown today, the most reliable source would be weed users who continuously use it since the 70s
    That is a complete crock and you know it. Personal anecdote is ok to give you a hint as to which hypotheses to test but puh-leez. better than longitudinal, large sample data gathered in a reasonably consistent fashion?

  • Personal anecdote is ok to give you a hint as to which hypotheses to test but puh-leez. better than longitudinal, large sample data gathered in a reasonably consistent fashion?

    Better for the persons in the anecdotes!!

  • Myself, I appreciated the slam of Bill Mahr.

  • Becca says:

    Hey DM, I'm talking about mandatory age-based retirement! At 40.
    I think it's the only way to get the reforms in the educational/training system that I think need to occur.
    Did I mention we also need to throw out the US dept of Education?
    */random Ron-Paul-esque batshit crazytalk*

  • Sven DiMilo says:

    With regard to Comrade PhysioProf's observation in #8, I'd just like to say that I resemble that remark.

  • blader says:

    I used it in the mid 70's, when it was all Mexican giddy weed. Good times could be had doing a cigarette and then coming back inside the house to watch 30 min of Monty Python.
    After that source was paraquated to oblivion, all that was available was far more potent weeds...sensimelia, thai, etc. That stuff would just put me in a catatonic trance.
    Weaned on silly, the more potent stuff just wasn't for me, so I quit weed and did mushrooms for a while.
    But the bongers sure loved the more potent weed. Except for one, who became a college town cop, they all eventually dropped out while I went on to get a PhD in pharmacology. lulz!!!
    So yeah, I buy the data.
    Seems plausible from my own experience.

  • Martijn says:

    The Dutch government had this researched. The report is in Dutch, but there is an English abstract:

    A double-blind, randomized, placebo-controlled, cross-over study on the pharmacokinetics
    and effects of cannabis
    Systematic measurements of the concentration of the psycho-active substance (THC) in
    �netherweed� cannabis obtained from coffeeshops in the Netherlands have revealed that the
    mean THC concentrations have steadily increased from circa 8.6% in December 1999-
    January 2000 to 17.7% in December 2004-January 2005. Smoking cannabis with higher THC
    contents (external exposure: 9.75 to 23.12% THC) was associated with a dose-related
    increase of the serum concentrations of THC (internal exposure).
    Smoking cannabis with higher THC contents was also associated with a dose-related increase
    of physical effects (such as increase of heart rate, and decrease of blood pressure) and
    psychomotor effects (such as reacting more slowly, being less concentrated, making more
    mistakes during testing, having decreased functioning of motor control, and having more
    drowsiness). Results as mentioned above were derived from a clinical study with 24 cannabis
    users.

  • Martijn says:

    Oh, and The Chronic is an album by Dr. Dre, not by Snoop Dogg.

  • Karla says:

    I do know the potency of pot today is far beyond the stuff of the 70s. This post is not addressing medical marijana, which should be available to all who need it. This is about recreational drug use.
    I work in a holistic clinic near San Francisco that treats a number of disorders including various drug addictions. THE hardest addiction to overcome is pot, by far. We are seeing a higher number coming in with psychoses from daily pot smoking, including one client whose 1st joint messed with her head so much she (after 3 years) has not recovered. The THC is incorporated into the double fatty-acid layer in brain cells and requires both a lot of time and specific nutrients to detox it. Many pot smokers cannot stop and even in-house drug treatment programs have uneven results due to the amount of time (up to 1 year) needed to stop the addiction. I used to think pot was a harmless recreation way to unwind, but this new pot is almost like a completely different plant from the pot of 30-40 years ago.

  • Mahakal says:

    Karla, for those without medical need, there is no physical dependency on cannabis. If you are trying to treat people for psychological "dependence" you are trying to change personal preferences.
    It's a lot harder to quit using sugar. Many sugar users cannot stop despite trying lots of diets.
    Cannabis is harmless.

  • DrugMonkey says:

    hmmm, let's see here.
    Wrong. Wrong. Even if true, so what?Even if true, so what? Oh, and one more Wrong.
    /based on actual evidence, some referenced in prior posts-see archive.
    What do you base your assertions on?

  • Mahakal says:

    DrugMonkey, how many fatal overdoses of cannabis have occurred in human history?
    Even water is more dangerous.

  • DrugMonkey says:

    So if something fails to directly kill you it is "harmless"?
    try again. a six year old could field that one...

  • Mahakal says:

    It is not only harmless, it is beneficial to health. It can reduce the chances of age related diseases like Alzheimer's and cancer and it can treat both.

  • DrugMonkey says:

    I am all ears, waiting for the evidence in support of these amazing claims.
    but.... Why do we still have AD and cancer? I mean, MJ is pretty cheap to produce, right?

  • JohnC in PH says:

    No surprise that cannabis now has THC. Contraband always drifts toward its stronger, more concealable form. It happened when beer and wine deferred to 'ardent spirits' in the 1920s; amphetamine to meth in the 1960s-70s; and coca to cocaine, then to crack during its long run in the 20th century.

  • anandine says:

    Having used marijuana continuously since 1973, my experience is that it takes less of your average weed to get high than it used to, so I make my joints shorter. I drop a narrow, rolled up strip of 3 x 5 card at one end of my rolling machine, as a handle rather than a filter, and a bit of quarter inch dowel at the other, and the dope goes in the middle. Single-person joints are under an inch long now. I have different lengths of dowel and cut the paper strips different widths for different strengths of dope or for joints big enough to share.
    If you're going to smoke dope all the time and still have a normal life (job, family, all that), you have to be a responsible drug abuser.
    As I suspect y'all are aware, it is not the case that all weed now is better now than all weed then, although the average is much better. In the early 70s there were grades, just as now, and the best then was as good as I've ever had.

  • Splendid One says:

    Karla, I smoked marijuana from about 1975 to 1983; then I had children. I quite until they grew up and left the house. They're out of the house now, and I do drink a bit more vodka than I would like, so a couple of years ago I purchased some weed. It does seem more potent, but to your "dependency" perspective: If I run out, I run out - no stress, no panic, no worries. A few months after I started again, I decided to stop, and did. But then I found myself drinking too much, so I am now into my second month of smoking again. Not due to a desire for the weed, but due to the knowledge that it cuts down on my drinking.
    There's no doubt in my mind at all that I, personally, would be vastly better off if weed was legal.

  • Mahakal says:

    DrugMonkey, just Google "Alzheimer's" or "cancer" and "cannabis" and you'll get a lot more. Here's an excellent summary of the current research by my friend Paul Armentano:
    http://www.norml.org/index.cfm?Group_ID=7002
    As for why we still have these diseases with us that cannabis can effectively treat -- yes it's pretty cheap to produce cannabis but it's illegal in most jurisdictions. Maybe something should be done about that.

  • Physiogroupie IV says:

    lol. DM, you really ought to google this shit.

  • juniorprof says:

    Mahakal, Let's forget about cannabis abuse potential for just a second and look at your health benefit and disease treatment claims:
    1) Cannabis is not a disease treatment, it has been shown to alleviate some symptoms of certain diseases (e.g. A) cancer chemotherapy pain where it treats the pain but does nothing to the underlying neuropathy or B) AIDS wasting where it can stimulate feeding but does not reverse the pathology). A potential exception is cancer treatment where some cannabinoids have been shown to reverse cancer cell growth. The problem with cannabis, and its active compound, thc, for this is that it is a weak agonist and is especially weak at the CB2 receptor which appears to be a primary target.
    2) What would you say to cannabis derivative compounds to treat symptoms that have improved potency and do not get you high (or cause dysphoria, etc..) and carry little abuse potential? What would you say if I told you that there are hundreds of labs and dozens of pharma companies working on making these compounds a reality (with some trials going on now)? Medicinal cannabis may work for some people now but many don't like it and don't want to take drugs that have abuse potential or that cause dysphoria.
    3) The alzheimer's thc link is based on a single study where the evidence of an effect is based completely on enzyme inhibition. While this may be a promising avenue for future research it is miles and miles from showing a link to actual disease pathology. Read for yourself: http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=17140265

  • Omar says:

    Karla, it is possible your psychotic clients had underlying conditions triggered by cannabis. Note the word triggered and not created. I have introduced dozens of people to pot, many of whom dubbed it a great experience, with no one showing any negative reactions. What does this mean? Probably that persons with normal mental conditions and states should not fear using cannabis recreationally. Also, a joint messing with someone for 3 years? Absurd...

  • Denial says:

    Drugmonkey, you asked for some evidence for the harmlessness of weed:
    http://www.erowid.org/plants/cannabis/cannabis_effects.shtml
    Since it's cut into positive, neutral, and negative, let me take the 3 worse side effects of the drug:
    # panic attacks in sensitive users or with very high doses (oral use increases risk of getting too much)
    # racing heart, agitation, feeling tense
    # mild to severe anxiety
    Personally, I've had one of those panic attacks. They are terrifying, but they don't last more than 10 minutes and are rare. Worst case scenario is that you can't move the person for a bit until they calm down. As to the racing heart and agitation, I've gotten close to the worst of that as well when I found myself shivering uncontrollably after smoking a lot of a particularly potent strain (a Cannabis Cup winner no less) in a foreign environment, which considerably lowered my tolerance. These effects are rare and in neither case were they particularly dangerous.
    And as to overdosing, we can all take solace in the fact that the New England Journal of Medicine reports that you would have to smoke 1500 pounds of weed in 15 min to overdose. Seeing as it is physically impossible to smoke a single pound of weed in 15 min:
    (From http://students.washington.edu/aed/archivemidget/2.htm)
    There has been no reported case of death from marijuana overdose...The estimated ratio of effective dose to lethal dose for marijuana is between 20,000 and 40,000 to one as compared to between 4 and 10 to one for pure ethanol. This is equal to smoking about 1500 pounds of pot in fifteen minutes. This data has been extrapolated from animal models. (NEJoM, Aug.7, 1997. P. 438)

  • MsInformed says:

    Cannabis is treatment for the patient. If it alleviates symptoms, it can be valuable part of disease management. Oh, and it's not evil.

  • Mahakal says:

    Juniorprof,
    1) Herbal cannabis contains a lot of other compounds than THC, several of which have demonstrated cancer fighting properties and synergistic potentiation. As you agree that cannabis treats cancer, let's move on.
    2) I would say that it is good to research isolates and synthetic cannabinoids for their properties and potential benefits, but whole plant medicine is effective. Those who find cannabis unpleasant to use may prefer alternatives.
    3) This is only one study and more research is certainly needed, but other countries have been researching this as well and in this country is has been difficult to do any study on the health benefits of cannabis because NIDA controls the supply and will not authorize anyone to do research unless the study is designed to show harm. There are a number of other obstacles, such as that the only authorized supplier is ElSohly and what he supplies is low potency, full of sticks and seeds and generally of poor medical quality.
    At any rate, the conclusion is very promising:
    We have demonstrated that THC competitively inhibits AChE, and furthermore, binds to the AChE PAS and diminishes Aβ aggregation. In contrast to previous studies aimed at utilizing cannabinoids in Alzheimer's disease therapy,8-10 our results provide a mechanism whereby the THC molecule can directly impact Alzheimer's disease pathology. We note that while THC provides an interesting Alzheimer's disease drug lead, it is a psychoactive compound with strong affinity for endogenous cannabinoid receptors. It is noteworthy that THC is a considerably more effective inhibitor of AChE-induced Aβ deposition than the approved drugs for Alzheimer's disease treatment, donepezil and tacrine, which reduced Aβ aggregation by only 22% and 7%, respectively, at twice the concentration used in our studies.7 Therefore, AChE inhibitors such as THC and its analogues may provide an improved therapeutic for Alzheimer's disease, augmenting acetylcholine levels by preventing neurotransmitter degradation and reducing Aβ aggregation, thereby simultaneously treating both the symptoms and progression of Alzheimer's disease.

  • pinus says:

    The conclusion is that AChE inhibitors may be helpful. Lets all jump on the physostigmine bandwagon...forget weed!

  • Mahakal says:

    Pinus,
    According to Wikipedia, physostigmine is used to treat myasthenia gravis, glaucoma and delayed gastric emptying.
    Unlike cannabis, overdose can cause a cholinergic syndrome.

  • I was under the impression that the measurement methodologies changed in the mid-90s. I can't find the original article that showed how it distorted the numbers, but the idea was that in pre-1995 studies more stems and seeds were weighed, and post 1995 only the THC-rich buds were measured. This, of course, would drastically change the potency numbers. This may be the unexplained 'normalization' you found in the study, but it has probably been left out.
    There have been tons of highly flawed reports on this subject over the last 30 years, so I wouldn't trust anything that doesn't list its complete methodology.
    Take a look at this slate article to see what I mean. http://www.slate.com/id/2074151

  • juniorprof says:

    to quote CPP "!!!physostigmine!!!!!!!!ELEVENTY!!!!!!!!111!!!!1!!!!1!!!!!!!!"

  • leigh says:

    i can see now why DM has challenged me on some of the more loose statements i have made. wow. people really, really want to believe stuff without sufficient evidence.

  • Michael says:

    Your argument does not make sense to me. Sure, in the short term a smoker would be very good at finding the dose they are used to - but are you really meaning to tell me that if you expose for the first time one test group marijuana with 2% and another marijuana with 7% THC, they wouldn't develop different habits over time? It's like exposing one group to tea and one to Starbucks coffee (about 4:1) or exposing one group to caffeine and another to cocaine (similar effects, much more potent.) If it is true that you can do in one bong rip what would have previously been able to do in only a half hours worth of smoking has tremendous implications for how much people are more likely to smoke..

  • Klem says:

    DM, don't be so quick to put away your skepticism of ONDCP reports. Remember that the ONDCP is explicitly an anti-drug-legalization advocacy organization, ordered by law to "take such actions as necessary to oppose any attempt to legalize the use of [Schedule I substances, as marijuana]".
    On potency data, see the Slate article cited above by Nicholas. As you note, the methodology of the cannabis potency survey is completely unclear, what is the definition of "seized cannabis", and has it changed over the years? Does it include ditchweed, wild industrial hemp, which is 98% of DEA seized cannabis plants? Were seeds and stems previously included in the total weight?
    Concentrated hash has been available for centuries. And hash is today sold openly in the Netherlands. DM, I really recommend that you visit Amsterdam, just to look around and talk with people, likely you could get a lecture invitation from a Dutch university!

  • Becca says:

    What do cancer patients in Amsterdam take?

  • DrugMonkey says:

    Interestingly Amsterdam is closing a bunch of their cannabis joints over proximity to schools.
    http://news.yahoo.com/s/afp/20081121/wl_afp/netherlandsdrugscannabis
    and apparently some other Dutch cities are closing all of their to combat drug crime or some such...
    http://scaredmonkeys.com/2008/11/23/amsterdams-marijuana-selling-coffee-shops-up-in-smoke/
    As longer term readers know I don't really take public policy positions but let us be clear with our perceptions of other countries' experiences with less-restrictive policies.
    Michael @#42: I completely agree that my position is only one testable hypothesis. Yours has merit as well. It is very much the case that some animal research perspectives could be interpreted (and are) as indicating that what is most important is cumulative exposure to the active drug and that every little extra bit adds up.
    My usual point is that until we know more about that minority of users who will become dependent (For arguments sake it is in the 8-9% range, although there are denominator issues) we don't know much about route-to-dependence. Me, I suspect that those individual and (nonTHC concentration-related) situational factors that dictate who will become dependent are going to trump THC concentration every time.

  • DrugMonkey says:

    Denial @#34, sorry you got caught in the filter. But to address your point, nobody is arguing about the acute lethality of cannabis. My issues are first and foremost dependence, which is not debatable at this point. It occurs and to a clinically significant degree in some people. The essential point being that people want to quit because they judge it is screwing with their lives and they find it difficult to stop.
    Second issue is lasting health consequences of chronic cannabis exposure independent of the presence of dependence. From cognitive to lung to immune to whatever, scientists are still working on this.

  • Erik says:

    the chronic was by Dr. Dre, not Snoop Dogg.

  • Mahakal says:

    DM, physical dependence is absolutely debatable. Psychological dependence is another matter, it can be a habit as can television watching.

  • juniorprof says:

    Where exactly could psychological dependence exist except in the physical? Psychological effects are a product of brain function, yes? Can we not all agree that the brain is a mysterious, yet wholly physical thing.

  • Mahakal says:

    On the health consequences of chronic exposure, there have been no serious harms found despite every effort being made to prove harm. To the contrary, efforts to demonstrate lung cancer risk found a slight reduction in risk when samples were controlled for concomitant tobacco use. It appears also to have a beneficial role in modulating the immune system. Cognitively, one must distinguish between acute effects and long term. Acutely memory is affected as well as creativity. Long term cognitive benefits are possible due to the reduced risk or deterioration due to aging related diseases like Alzheimer's (discussed above) and possibly Parkinson's (where it provides at least symptomatic relief for some patients).

  • Mahakal says:

    Juniorprof, if you want to profess a monistic view, why not say that everything is mind and energy?

  • DrugMonkey says:

    #48:
    Here we go again.
    Start here
    http://drugmonkey.wordpress.com/2007/08/01/cannabis-research-denialism/
    then read
    http://scientopia.org/blogs/drugmonkey/2008/04/comparing-cannabis-and-nicotine-withdrawal
    including all of the comments.
    Then, Mahakal, please come on back and explain in as clear of terms as you can why the symptoms of withdrawal from cannabis/MJ are not evidence of "physical" dependence. Also, please delineate, in dualistic OR monistic terms as you like, exactly what "psychological" dependence and "habits" entail and how we distinguish those from each other and from "physical" dependence?
    #50
    a meta-analytic review was published in 2003 which concluded that reliable decrements in learning and increase forgetting were sustained by the analysis. For the interested, if you read the paper you will appreciate the incredible difficulty in trying to pull out clean data from the diversity in the long term cannabis abuser population. Admittedly it takes effort to understand what is most likely to be true in this context. It is stone simple to cherry pick examples as if they denied the validity of any of the findings.
    Another frame of reference is provided by the MDMA/cognitive literature where the major issue is trying to dissociate potential lasting effects of MDMA from the chronic cannabis use in those populations. It is very typically the case that the cannabis "control" groups in such studies are impaired versus the nondrug controls (start here)
    So there are areas in which the evidence is definitely mixed. Having poured through much of it, I conclude there is evidence of lasting harm specific to cannabis smoking - to the extent we can ever conclude anything from human studies.
    with respect to Alzheimer's, need I remind you that smoking may be protective in familial AD (remember that paper?) and that nicotine is pro-cognitive in age-related cognitive impairment? and that nicotine has anti-AD like effects in rodent models of AD? so even if THC works out to be as promising as you think with respect to the neuropathology, there are still downsides which preclude it from being a viable therapy, just as with cigarette smoking.

  • Mahakal says:

    DM, it is impossible to argue with someone who denies the existence of psychological habits and tries to claim that everything is physical. By this reasoning we must speak of the physiological basis of television viewing habits.
    You then go on to argue that there isn't a lot of good data and therefore you feel supported in your claims of cannabis negative effects.
    Clearly, you are a person whose mind is undisturbed by facts.

  • DrugMonkey says:

    You have not even tried to "argue" since you have not described the nature of "psychological habits" and how they differ from physical or physiological dependence. If you bothered to read the prior discussions, you would see that. I.e., simple assertions aren't moving the discussion anywhere. Do you believe that there is a "mind" that exists independently from the functioning of the brain? If so, how does that work? If not, then I repeat, what is the difference between psychological and physical dependence? Do remember that essential physiological functions such as heart rate and respiration are maintained by the brain.
    You then go on to argue that there isn't a lot of good data and therefore you feel supported in your claims of cannabis negative effects.
    Acknowledging that the available evidence for one type of question are weaker, more scant or more complicated than that for another question does not mean that we cannot draw conclusions. We just have to be more nuanced about it and, likely, more informed. It is an absolutely classic science denialist position to claim that the absence of un-muddled, or uncomplicated data that is easy for an uninformed person to understand is strong evidence for the null. It is not.
    To answer your last point, no facts do not disturb me in the least. Clearly they disturb your worldview that all is a-ok with cannabis consumption.

  • n00b says:

    ...your worldview that all is a-ok with cannabis consumption.
    Special brownies anyone?

  • Mahakal says:

    I'm waiting for the physiological basis of television viewing habits to be explained.
    Thanks for the brownie, n00b.

  • DrugMonkey says:

    Nice attempt to distract from the fact that you haven't managed to respond to any of my points.
    May we assume that in fact you have never so much as considered why you parrot meaningless tropes about "psychological" addiction? Or is it that you know full well that chronic cannabis exposure is a direct cause of brain alterations that manifest themselves in some users as dependence but are otherwise invested in pretending this is not the case?

  • juniorprof says:

    And if I can pile on just for a moment, to say something that DM has likely said before: the term "psychological dependence" or "psychological addiction" adds a level of stigma to people suffering from very real physical addiction that hinders their recovery. The label of "psychological" has a long and dirty history that is best thrown in the rubbish bin. Addiction is a disorder of the brain and other target organs that, when approached constructively, can be managed (albeit not perfectly) and can give patients hope for liberation from drug abuse.

  • Zan says:

    Correct me if I'm wrong, but couldn't a purely psychological addiction/dependence arise from continuous positive reinforcement like the sort that comes from smoking weed?
    ^^; I don't actually have too much relevant knowledge (well, aside from being a pot smoker myself), so, uh, sorry if this is a dumb question..

  • DrugMonkey says:

    couldn't a purely psychological addiction/dependence arise from continuous positive reinforcement like the sort that comes from smoking weed?
    What I try to point out is that if there is an increase in the frequency of smoking weed that arises because of a prior history of smoking weed, this is most assuredly related to brain changes.
    There simply is no evidence for mental or psychological phenomena that exist apart from the structure and function of the brain. Do we know the exact mechanism of every individual human phenomenological minutia? no. We do, however, have good evidence for a lot of very complex, covert and "psychological" phenomena being brain based. Take the Wilder Penfield experiments in which local electrical stimulation of the cortex produced such covert experiences in brain surgery patients. Take the cases in which selective brain damage (traumatic or surgical) resulted in dramatic changes in subjective experience and behavior in very complex domains. Including the famous study in which insular cortical damage apparently disrupted nicotine craving (which is one of the phenomena I assume people mean when they talk about "psychological" dependence).

  • jj says:

    This is a bunch Of SHIT! I smoked Weed In 75 that was good as anything today and im still smokin!Yes I love it! why would anyone else care ? the US goverment still has a Brainfuck on the population at hand;;;; when will everybody realize its ok to be a cannabis lover instead of a beer lover, whiskey lover or even worse tobacc lover. Grow Up Pinheads!

  • juniorprof says:

    Um, jj, we're talking about drug abuse. You won't get any argument from me that tobacco is at the top of the list of the absolute worst, in all respects.

  • Parker says:

    If you would like a excellent and humorously written account of how these more potent strains came to be check out Micheal Pollan's Botany of Desire(third section after apples and tulips). I think that many people judge there dosages but not all. There is a period of late adolescence or early adulthood when there seems to be a more is better attitude among some, when binge drinking is common. I remember observing at parties that the women who where smoking tended to smoke a little and go off in the party and circulate whereas the guys would be more likely to sit around off to themselves and smoke continuously. So whether people, especially young men, limit their dose based on how strong it is depends on the social situation.

  • Zan says:

    Ah, thanks for the clarification!

  • Mahakal says:

    DM, your naive materialism is contradicted by twentieth century physics, as I mentioned in passing to Juniorprof before. Without an observer there is nothing to observe; consciousness is fundamental to existence. Moreover, everything material is made up of standing waves of energy, all of this is what the Indian philosophers call Maya.
    That being said,
    "There simply is no evidence for mental or psychological phenomena that exist apart from the structure and function of the brain," is absolutely wrong and disproven by science.

  • pinus says:

    The distinction between so called physical dependence and psychological dependence boils down mostly to opiates and alcohol. When you consume enough of these over long periods of time, your get a shift of homeostatic mechanisms such that you need the drug to not shit yourself and/or seize. Mechanistically, the processes that govern 'psychological dependence' or craving or most likely similar, but occur different regions of the brain. When you get down to it, they are both based on changes in firing patterns in key regions of the brain. To say that they are distinct entities is to really miss the point. Any drug you take for a long time alters neuronal function.
    We get it, legalize weed...yay cheer, pat yourself on the back. But don't deny that there are issues associated with long term drug use. That is nonsense. And legalizing it doesn't change that, for reference, please see THE HUGE PROBLEM WE HAVE WITH ALCOHOL AND NICOTINE.

  • Klem says:

    DM, that Amsterdam is restricting cannabis "coffee shops" around schools is an example of open market regulation. If you visited, you could talk about cannabis with police, cannabis-smokers, non-cannabis users, other scientists, in an open manner.
    juniorprof, saying that "psychological addiction" is a stigmatizing term is a bit over the top given that 800,000 people were arrested in the US last year for cannabis-crimes, that is actual stigmatization.
    Remember that quite a few of your colleagues and fellow citizens are living in fear from the police because they occasionally enjoy cannabis. It is recklessly unethical to ignore this. BTW, here is an audio tape from 2004 of US police torturing and electrocuting a suspected drug dealer in his own home for refusing to consent to a search.
    As Mahakal points out, it is not at all clear that cannabis use induces a special biochemical brain change that encounages further cannabis use. Rather, using cannabis should be looked at in the wider range of behaviors which can in some people become obsessive or problematic to stop such as watching TV, going on the internet, gambling, washing the hands etc. Clearly all experience causes brain changes (in part mediated through release of the neurotoxin glutamate!), but the above behaviors are generally considered "psychological" and not assumed to be due to stimuli-specific biochemical processes.

  • Becca says:

    "There simply is no evidence for mental or psychological phenomena that exist apart from the structure and function of the brain," is absolutely wrong and disproven by science.

    Plato, meet Aristotle. Pot, kettle.
    Face it, neither the dualists nor the monists have "science" exclusively on their side.
    In any event, entertainment aside, excessive metaphysics doesn't matter here("Maya"? That's so far out of left field one could almost wonder if you've given up any semblance of a nice rational discussion) Can't we all just settle down and argue over some juicy, delicious, data?
    Other than that +1 to pretty much everything pinus said.
    The physical dependency "your body will collapse without this" can be visually identified, and therefore distinguished, from the psychological "must get drug" urge. But for treatment purposes, or in analyzing harm, it's not a very important distinction.
    Klem- first, consider: a' criminal can clean up their act, but crazy is forever'.
    Let's not start a round of "which stigma sucks more!", ok?
    Second, wtf mate? I don't deal well with this 'glutamate as a neurotoxin' without some explaination. Personally, I think of things like "botulinum" when I hear "neurotoxin". Glutamate is filed under "neurotransmiter that makes learning possible".

  • Stephanie Z says:

    Mahakal, you'll look less silly if you read up on the reality behind quantum woo before spouting it. The observer effect actually refers to the fact that we don't interact with anything except on a physical basis and that the physical interaction required to observe something also has an effect on the thing being observed. For example, we don't see light until it hits our eye, at which point, that energy is no longer light but a chemical impulse. Still purely material, though.
    And note that "observation" may entail nothing more than a change in a piece of instrumentation. In that case, it's the instrument that's the observer. No humans, no minds, required.

  • Mahakal says:

    Really, Stephanie Z, you have no idea what you are talking about. It is purely consciousness which creates, and if you would familiarize yourself with the quantum eraser experiment you would understand why you are 100% wrong.

  • Mahakal says:

    Becca, we aren't having a discussion about monism versus dualism, but what DrugMonkey and Juniorprof seem to be advocating is materialist monism (with consciousness as perhaps an illusion?)

  • DrugMonkey says:

    I don't deal well with this 'glutamate as a neurotoxin' without some explaination.
    http://en.wikipedia.org/wiki/Excitotoxicity

  • Stephanie Z says:

    Mahakal, I am familiar with that experiment. Did you want to explain to me how a physical experiment using physical equipment and measuring physical phenomena--none of which requires a human being to produce the results--has anything to do with consciousness, aside from the fact that you want it to? Or are you telling me that the slits and polarizers are conscious?

  • Mahakal says:

    Stephanie, none of those instruments determine the presence or absence of interference patterns, which are necessarily observed by conscious humans before or after the path information the instruments may have gathered is destroyed.

  • Stephanie Z says:

    Mahakal, I almost wish this were one of those stressful holidays, so that I needed that laugh. I will admit, the detection screen used in the experiment doesn't open it's mouth to announce whether it's showing an interference pattern or not, but the information on it doesn't change based on whether someone is looking at it.
    Perhaps next time you want to know something about physics, you should ask a physicist (or a high school student who's done a double-slit experiment) instead of listening to someone who wants to sell you their stunning insight into the mysteries of the world. Sales pitches are not notoriously high in informational content.

  • Mahakal says:

    Stephanie, if you are aware of the quantum eraser experiment you should know that even a delayed choice to destroy path information changes the observed result. It is a very profound experiment which is scoffed at only by the very ignorant. Have a good day.

  • chron1k says:

    Snoop started Dre's career... RIGHT... You being wrong about this clearly shows that you are totally oblivious to what is really going on.
    Shows you havent lived the life/culture.
    You dont know what its like.
    Fuck off.

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