Marijuana, Sleep, and Dreams

The indica vs. sativa debate, continued. 

[First published July 13, 2015.]

Anyone who has smoked marijuana more than a couple of times knows that cannabis can alter how you sleep. The effect of cannabis on sleep is even part of the never-ending debate over Cannabis indica vs. Cannabis sativa, the two major species of the marijuana plant. Indica smokers typically report a marijuana high that is body-intensive and often soporific, sometimes leading to the condition aptly known as “couch lock.” Whereas sativa smokers, according to marijuana lore, experience a more cerebral, energetic “head high,” with fewer somatic effects. Not surprisingly, hybrid strains incorporating the alleged characteristics of both indica and sativa strains are popular in the medical marijuana community.

Although there is no official sanction for it in the medical community, marijuana is often dispensed medically for sleep problems. One piece of common wisdom holds that the higher the THC content of marijuana, the more helpful it will be in promoting sleep and improving poor sleep. The stronger the better, in other words. Similarly, indica strains are assumed to promote sleep more than sativa strains.

In an effort to clear the air, so to speak, a group of researchers, writing in Addictive Behaviors, sought to “document naturalistic choice of particular medical cannabis types among individuals who self-report using cannabis for the treatment of sleep problems…. Little research has documented species or cannabinoid concentration preferences among individuals who use medical cannabis for particular conditions…. We also evaluated the interaction between the type of cannabis used and diagnosis of cannabis use disorder among study participants.”

The researchers recruited participants from a medical cannabis dispensary in California under procedures approved by the VA and Stanford University review boards. 163 people with a mean age of 40, who used cannabis twice a day on average, provided self-reported information on their cannabis use for the study. 81 participants reported using cannabis for the management of insomnia, and another 14 reported using cannabis to reduce nightmares. (Frequent smokers insist they dream less. THC does appear to decrease the density of REM cycles, leading to more restful, dream-free sleep, according to some studies.)

So what did they find?

—“Individuals who reported using cannabis for nightmares, compared to those who did not, preferred sativa to indica.” (Small effect.)

Indica, considered the “heavier” high, might have seemed the likely choice here.

—"Individuals who self-report using cannabis to treat symptoms of insomnia and those with greater self-reported sleep latency reported using cannabis with significantly higher concentrations of CBD.” (Large effect.)

Again, a somewhat counterintuitive finding, since it is widely believed that CBD conduces toward a more wakeful state than THC alone.

—“Individuals who used sleep medication less than once/week used cannabis with higher THC concentrations than those who used sleep medication at least once a week.” (Large effect.) “There were no differences in THC concentration as a function of self-reported sleep quality, or use for insomnia or nightmares.”

Pretty straightforward finding: THC makes you sleepy. It is not clear, however, that above a certain threshold, more THC makes you even sleepier. In fact, some researchers would consider this finding unexpected, given that high THC concentrations have been shown to have a stimulating effect.

—“Older individuals were less likely to have cannabis use disorder compared to those younger….

No surprise about the older folks, since prior studies show a decrease in the prevalence of cannabis use disorders with age.

—“Individuals who preferred sativa or primary sativa hybrid strains were less likely to have cannabis use disorder compared to those who preferred indica or primary indica hybrid strains.” (Small effect.)

If replicated, this finding could have significant implications; both in strengthening programs to reduce marijuana smoking among the very young, and it warning consumers that some evidence suggests indica strains may be more addictive than sativa strains in plants with similar THC/CBD levels and ratios.

—“Neither concentration of THC nor CBD were associated with cannabis use disorder.”

Common sense, but useful to remember. In other addictive behaviors, such as heroin and alcohol abuse, the relative strength of the drug is not the primary determinant of its addictive potential.

Caveats and design limitations: The survey relied on retrospective reports of sleep quality and pot preferences. Also lacking is an examination of additional variables such as PTSD and co-occurring substance abuse.

Who Smokes Marijuana Where?

The full article is available here: http://www.bendsource.com/

Marijuana: Where Things Stand

Results of the 2016 election.

Source: Governing.com

Cannabis sativa vs. Cannabis indica: Science or Folklore?

Golden Goat or  Sour Diesel?

The bland assurances from medical marijuana dispensaries about the physical and psychological effects of the bewildering array of hybrid plant strains on offer is mostly bunk, claim a growing number of cannabis scientists.

Ethan Russo, a neurologist and pharmacology researcher, as well as the medical director of a biotechnology company, author of numerous books about herbal medicine, and a former faculty member at the University of Washington and the University of Montana, has something to say to marijuana connoisseurs: “There are biochemically distinct strains of Cannabis, but the sativa/indica distinction as commonly applied in the lay literature is total nonsense and an exercise in futility.”

How’s that again? The much-vaunted divide between the cerebral sativa strains, and the sedating, body-oriented effects of indica, are an integral part of marijuana lore and legend. Cannabis growers and biologists endlessly debate the hybridization of new strains. Extolling the virtues of a sativa plant crossed with a plant redolent of indica is a common sales pitch.

In an interview with Dr. Daniele Piomelli for the January 2016 issue of the journal Cannabis and Cannabinoid Research, Russo detailed his disagreement with the assumption that hard evidence exists for this distinction. Dr. Piomelli notes that “sativa is often described as being uplifting and energetic, whereas indica as being relaxing and calming.” Folklore, says Russo. Of course different strains have different effects. But in recent years, says Russo, almost all marijuana has been coming from high-THC strains, with a slight increase in CBD-predominant strains:

"The differences in observed effects in Cannabis are due to their terpenoid content, which is rarely assayed, let alone reported to potential consumers. The sedation of the so-called indica strains is falsely attributed to CBD content when, in fact, CBD is stimulating in low and moderate doses. Rather, sedation in most common Cannabis strains is attributable to their myrcene content, a monoterpene with a strongly sedative couch-lock effect that resembles a narcotic."

And, as for sativa strains: “A high limonene content (common to citrus peels) will be uplifting on mood, while the presence of the relatively rare terpene in Cannabis, alpha-pinene, can effectively reduce or eliminate the short-term memory impairment classically induced by THC.”

Well. I for one do not wish to be caught in the firing line between Dr. Russo and the legions of growers who will beg to differ with his conclusions. For years, it has been accepted wisdom that cannabis comes in two different forms, essentially considered two different species even though they readily interbreed. Even Jean-Baptiste Lamarck, the legendary naturalist of the 18th Century, agreed with the indica and sativa concepts.

But Russo will have none of it: “To paraphrase and expropriate an old Yiddish expression: 12 botanical taxonomists, 25 different opinions…. One cannot in any way currently guess the biochemical content of a given Cannabis plant based on its height, branching, or leaf morphology. The degree of interbreeding/hybridization is such that only a biochemical assay tells a potential consumer or scientist what is really in the plant.”

And finally: “I would strongly encourage the scientific community, the press, and the public to abandon the sativa/indica nomenclature and rather insist that accurate biochemical assays on cannabinoid and terpenoid profiles be available for cannabis in both the medical and recreational markets. Scientific accuracy and the public health demand no less than this.”

Russo’s interview is strong evidence of a viewpoint brought to public attention a few years ago by several others, including the controversial cannabis chemist Jeffrey Raber.

Raber told the L.A. Weekly in 2013 that there was no compelling scientific evidence for the claims routinely made by cannabis dispensaries about the effects of a given colorfully named strain of marijuana. “We took a popular [strain] name, Jack Herer, and found that most didn’t even look like each other. OG whatever, Kush whatever, and the marketing that goes along with it—it’s not really medically designed.”

And the difference between sativa and indica? The cerebral, bracing “mental” high vs. the sleepy, couch-lock “body” high? Forget it, said Raber. The two sub-species are distinguished by morphology only—different structures and appearance, but no hard and fast rules about the quality of the smoking experience. They look different, but that’s no guide to the distribution of THC, CBD, and numerous terpenes that determine the actual quality of the marijuana experience. Moreover, extensive crossbreeding by growers and dealers has helped to obliterate any consistent, meaningful distinctions between sativa and indica highs. (The so-called “skunk” varieties are simply high quality female plants that are prevented from going to seed, which dramatically pushes up the THC content. Almost all of the high-quality weed sold in the U.S., Canada, and the U.K. is skunkweed, so the definition is virtually useless.)

Sativa plants are characteristically tall and rangy, with long branches and long, thin leaves. They evolved, scientists believe, in humid jungle climates. Indica plants are shorter, more compact, and stubbier-looking, with shorter branches and fatter leaves designed for a hot, desert-like climate. It has been assumed that sativas originally came from India, and indicas from Afghanistan. However, indica is the term meant to indicate a plant from India, so right away we find that the situation is all muddled up: the plant from Afghanistan is known by the name of the plant from India. Blame this one on esteemed plant drug investigator Richard Evans Schultes, who apparently mislabeled the plants grown in Afghanistan as C. indica when he drew up the first cannabis taxonomy in the 1970s.

It gets worse. In 2014, at a meeting of the International Cannabis Research Society, research John McPartland with GW Pharmaceuticals announced  the results of his study of genetic markers on the three subspecies of cannabis: C. sativa, C. indica, and a third wild variety, known as C. ruderalis, with very little THC. Any of the three subspecies can be bred as hemp or marijuana, said McPartland. Cannabis sativa should really be known as Cannabis indica, being the Indian variety, while the formerly misnamed indica subspecies should now be called Cannabis afghanica. The name of C. sativa, the high-end connoisseur favorite, would now go to the lowly C. ruderalis, otherwise known as ditch weed, under his new classification scheme.

Quite a lot of changes to a decades-old nomenclature, but it means we are finally getting some serious genetic information about one of the most popular drugs in the world. As Jeremy Daw of The Leaf Online writes: “Starbucks, for example, sources coffee beans from farmers spread across four continents…. In an astonishing feat of global supply chain logistics, Starbucks can now claim to have the ability to trace 94% of its coffee beans all the way back to the exact farm where they were produced.” The cannabis industry, he concludes, still has “a lot of growing up to do.”

Krymon deCesare, chief research director at Steep Hill Halent Lab in Oakland, California, a company developing more sophisticated tests for identifying the various compounds found in marijuana, told AlterNet  that “sativa and indica are only really valid for describing the physical characteristics of the cannabis strain in a given environment. They are not nearly as reliable as terms for making assumptions about energy versus couch lock.” To the extent that there is a grain of truth in the basic division between the mind high of sativa and the body high of indica, as traditionally classified, deCesare believes the culprit is myrcene. Based on the analysis of more than 100,000 samples, deCesare says that his team found “consistently elevated levels of the terpenoid myrcene in C. indica as compared to C. sativa. Myrcene is the major ingredient responsible for ‘flipping’ the normal energetic effect of THC….”

Ethan Russo invokes his notion of the “entourage effect,” in which the distinctive highs normally associated with indica and sativa are in fact the result of a complex combination of many different cannabinoids and terpenes working in harmony. Teasing that apart in the lab is not a cheap or easy affair. If you don’t know your terpene levels, says Russo, than you can’t compute your relative chances of full couch-lock. And even if terpene levels are known, the same pot plant, when smoked, can still cause one person to become energized and talkative, while another person may just fall asleep. Same chemicals, different metabolisms. One person’s happy, giggly high is another person’s paranoid bad trip.

The result of this recent research is to bolster the general suspicion about medical marijuana dispensaries: The names of various marijuana varieties are not only stupid and immature, but also completely misleading and unhelpful. Coherent labeling will require much more than listing relative THC percentages. We’ve only just begun.

A Roundtable Discussion on Cannabis Use Disorder

Addressing the habit-forming aspects of marijuana.

A trio of leading marijuana scientists participated in a panel discussion moderated by Dr. Daniele Piomelli from the School of Medicine at the University of California-Irvine, and published in a recent issue of the journal Cannabis and Cannabinoid Research.

Dr. Margaret Haney is with the New York State Psychiatric Institute at Columbia University Medical Center; Dr. Alan J. Budney is affiliated with the Geisel School of Medicine at Dartmouth College; and Dr. Pier Vincenzo Piazza works at the Magendie Neurocenter in Bordeaux, France.

Excerpts from the long discussion appear below:

It seems that most specialists in the field agree that Cannabis is addictive. If you had to choose one piece of evidence, either clinical evidence or animal experiment evidence, in support of this conclusion, which one would you pick?

Dr. Margaret Haney: “One of the key features for me is demonstrating that there is a pharmacologically specific withdrawal from Cannabis use…. We can demonstrate that daily smokers go through a time-dependent and pharmacologically specific withdrawal when they abstain from Cannabis…. I think another really important feature is the clinical data showing how high relapse rates are with Cannabis. Although Cannabis may have a lower abuse liability than other drugs like cocaine or nicotine, once somebody has developed a dependence on the drug, then quitting becomes extremely difficult.

Dr. Alan J. Budney: “If I had to pick out the ‘smoking gun’ to convince the public and the scientific world that Cannabis Use Disorder (CUD) is real, then it would be the data from clinical epidemiological research…. the data on CUDs are remarkably similar to the other substance use disorders…. for a substantial number of people, Cannabis use causes similar and substantial problems that are comparable to other types of drugs that we all agree have addictive potential.”

Dr. Pier Vincenzo Piazza: “[In] Australia, Canada, the United States, and the European Union, over the last two years Cannabis represents the highest new entries for treatment in specialized centers…. Since these four countries have very different rates of referral of patients by the judicial system, these figures really mean that patients experience a discomfort high enough to spontaneously seek treatment…. In France, for example, as well as in many other European countries, referral from the judicial system is very low. Nevertheless, the demand for treatment for CUD is now the highest of all drugs, legal and illegal.”

What is curious is that we now accept the concept that Cannabis is addictive, but for many years we have been told that it was not. Why is it that, for so long, the scientific community failed to recognize the addictive properties of Cannabis?

Dr. Margaret Haney: “I have been speaking about Cannabis addiction for 20 years and was met by full-on boredom for the first 15 years because I felt that scientists, like the public at large, just viewed Cannabis as a benign compound not too different from caffeine in a way…. THC is lipophilic, and so long-lasting, withdrawal takes quite a while to manifest…. if an individual is dependent on nicotine, he or she cannot go a couple of hours without experiencing withdrawal. A heavy Cannabis user, by contrast, has to go quite a while before experiencing withdrawal, and so it was not quite as obvious to people that withdrawal existed.”

Dr. Alan J. Budney: “Moreover, many of those that have experience with using Cannabis, do not get addicted, develop problems, or experience withdrawal. Although the same is true for those who have used alcohol or even opiates, for reasons that are not completely clear, the personal experience of those who used Cannabis and did not develop problems or experience withdrawal, seems to lead to the perception that Cannabis is not a substance that others can become addicted to.”

Dr. Pier Vincenzo Piazza: “What we know now is that, since cannabidiol is an antagonist of THC, the greater the ratio between THC and cannabidiol the greater the risk for Cannabis to be addictive…. Now, we are up to a 5- to 10-fold difference in favor of THC, making Cannabis more addictive.”

How addictive is Cannabis? Is it more addictive than, say, tobacco or alcohol? Is it less addictive? Is this question even correctly asked? Is there a better way to ask it?

Dr. Alan J. Budney: [I] would like to emphasize a point so that our audience does not think we are going way overboard and engaging in reefer madness related to the severity of Cannabis addiction. All factors held constant, the pharmacology of opiates would probably produce a more severe addiction…. Access, dose, route of administration, societal acceptance, perceived risk, cost, societal consequences for use or intoxication, and multiple other factors contribute to the real-world question of how addictive a drug is compared to another.”

Dr. Margaret Haney: “My opinion is that Cannabis has a lower abuse liability than something like cocaine [but] even if Cannabis has a lower abuse liability, the sheer number of people using it will result in a large number of people with a use disorder….”

Dr. Pier Vincenzo Piazza: “If we try to express abuse liability in numbers, the abuse liability for Cannabis… is between 10% and 15%, depending on the survey you look at. However, I believe that abuse liability should also be measured by a second factor; that is, how easy it is to quit if you have developed a substance use disorder. My understanding… is that stopping Cannabis use, if you have developed CUD, is not easier than other drugs.”

The major point, all three experts agree, is that marijuana cannot be considered a completely benign drug. “Cannabis is not the worst drug,” says Dr. Haney, “but it is not a drug without consequences. Again, societal attitudes often seem to skew one way or the other; it is all good or it is all bad, when it is clearly both.”

Graphics Credit: hhttp://moodsurfing.com

The Great Gateway Theory

Smoke pot, shoot smack?

The Great Gateway Hypothesis has had a long, controversial run as a central tenet of American anti-drug campaigns. As put forth by Denise B. Kandell of Columbia University and others in 1975, and refined and redefined ever since, the gateway theory essentially posits that soft drugs like alcohol, cigarettes, and marijuana—particularly marijuana—make users more likely to graduate to hard drugs like cocaine and heroin. What is implied is that gateway drugs cause users to move to harder drugs, by some unknown mechanism. The gateway theory forms part of the backbone of the War on Drugs. By staying tough on marijuana use, policy makers believe they will have much broader impacts on hard drug use down the road.

This notion is virtually an article of faith in the drug prevention community. It just feels intuitively right: Scratch a junkie, and you’ll find a younger, embryonic pot smoker or furtive teenage drinker. Ergo, prevent teen pot smoking, and you will block the blossoming of a multitude of future hard drug addicts.

For years, the gateway hypothesis has had its share of contentious opponents. The countervailing theory is known primarily as CLA, for Common Liability to Addiction, the genetically based approach that lines up with the notion of addiction as a chronic disease entity. Most genetic association studies have failed to record risk variations for addiction that are specific to one addictive drug. Writing in 2012 in Drug and Alcohol Dependence, Michael M. Vanyukov of the University of Pittsburgh, along with a large group of prominent addiction researchers, argued that the gateway hypothesis is essentially a form of circular reasoning. “It is drug use itself that is viewed as the cause of drug use development,” they write. The staged progression from one drug to another “is defined in a circular manner: a stage is said to be reached when a certain drug is used, but this drug is supposed to be used only upon reaching this stage. In other words, the stage both is identified by the drug and identifies the drug. In effect, the drug is identical to the stage.”

The researchers reject any causal claims on behalf of the gateway hypothesis and insist there is no necessary usage of soft drugs at an earlier stage to pave the way for hardcore addiction, however watertight the idea might sound. The high correlations are “artifactual,” they argue, “because they are estimated among hard drug users, without taking into account the large population of those who try or even habitually use marijuana but never transition to harder drugs.” A common cause, such as an underlying vulnerability to all drugs of abuse, seems more to the point, they insist. There is nothing out there to suggest that “these stages are either obligatory or universal, nor that all persons must progress through each in turn… the initiation order is frequently reversed even for the licit-to-illicit sequence.” There is only one stage that universally precedes hard drug use, they argue. And that is non-use. “It is the non-use then, which should be the actual gateway condition.”

The leading theory supporting the gateway hypothesis is that some as yet undetermined mechanism of “sensitization” occurs after using a gateway drug. But there is no science supporting this notion. “If sensitization does occur,” the researchers say, “it is equivalent to an increase in individual liability at the level of neurochemical mechanisms of addiction.”

The paper in Drug and Alcohol Dependence notes that in Japan, where marijuana is used by less than 5 percent of young people, “cannabis is not used first by a staggering 83.2% of the users of other illicit drugs, thus violating the gateway sequence.” Japan also handily knocks down the idea of alcohol as a gateway drug: Whereas the prevalence of aldehyde dehydrogenase deficiency—the so-called alcohol flush reaction—keeps many Asians from drinking alcohol regularly, this does not correlate with lower rates of non-alcohol substance use in that population.

All of this would seem to put the last nail in the notion that “involvement in various classes of drugs is not opportunistic but follows definite pathways,” as Vanyukov et. al. put it. Common sense seems to be ahead of official drug policy in this regard.

For proponents of common liability to addiction models, any staged sequencing of drug use is considered opportunistic and trivial. Which, interestingly, is how many addicts tend to view the gateway theory. But the idea of marijuana or alcohol as a gateway drug just feels intuitively correct to many people. Part of the problem is chronological. “At the relatively distal time when genetic relationships are usually evaluated,” the authors maintain, “the role of this early-acting factor may be as difficult to detect as it is to find a match that started a forest fire.” Your genetic endowment is with you from birth, while your first drink or toke of marijuana does not happen for a decade or two. Individual environmental conditions, from epigenetic changes to a move to a different neighborhood, determine how it will play out down the road, but these factors are mostly invisible at the time of addiction.

All of this matters from a policy point of view, because research “may be hindered or misdirected if a concept lacking substance, validity and utility is accorded prominence.” However, even when the gateway hypothesis is taken as a given, different legal and social outcomes are still possible. The best example is found in The Netherlands. The prevailing belief there is that “the pharmacological effects of cannabis increase adolescents’ likelihood of using other drugs,” as stated  by Wayne Hall, a professor of public health policy at the University of Queensland, Australia. Writing in Addiction, Hall says that drug policy analysts in The Netherlands have argued that the fabled gateway “is a consequence of the fact that cannabis and other illicit drugs are sold in the same black market; they have advocated for the decriminalization of cannabis use and small retail sales in order to break the nexus between cannabis use and the use of other illicit drugs.”

This “Marijuana Shop” approach may have direct relevance in the U.S., in the wake of cannabis legalization in Washington and Colorado. James Anthony, a professor of epidemiology at the Bloomberg School of Public Health at Johns Hopkins, writes about the real-world ramifications of the cannabis shop in Addiction: “Do we actually achieve a near-term delay in the time to a young person’s first chance to try cocaine or heroin... [or] do we run the risk of accumulating more cases of dependence on marijuana, or other hazards attributable to non-essential marijuana use?

The true gateways to addiction appear to be behavioral. As part of their genetic endowment, budding addicts are far more likely than other people to exhibit behavioral “dysregulation” when young, in the form of disinhibition, impulsivity, and antisocial behaviors. More than half of all addicts are co-morbid, meaning they also have a psychological or behavioral disorder in addition to addiction. Further analysis of this fact would seem to be a more fruitful research avenue than simply prodding at alcohol or marijuana in an effort to uncover their chemical “secrets” for compelling future drug use.

First published April 14, 2013.

Marijuana Deconstructed

What's In Your Weed?

Australia has one of the highest rates of marijuana use in the world, but until recently, nobody could say for certain what, exactly, Australians were smoking. Researchers at the University of Sydney and the University of New South Wales recently analyzed hundreds of cannabis samples seized by Australian police, and put together comprehensive data on street-level marijuana potency across the country. They sampled police seizures and plants from crop eradication operations. The mean THC content of the samples was 14.88%, while absolute levels varied from less than 1% THC to almost 40%.  Writing in PLoS one, Wendy Swift and colleagues found that roughly ¾ of the samples contained at least 10% total THC. Half the samples contained levels of 15% or higher—“the level recommended by the Garretsen Commission as warranting classification of cannabis as a ‘hard’ drug in the Netherlands.”

In the U.S., recent studies have shown that THC levels in cannabis from 1993 averaged 3.4%, and then climbed to THC levels in 2008 of almost 9%. By 2015, marijuana with THC levels of 20% were for sale in Colorado and Washington.

CBD, or cannabidiol, another constituent of cannabis, has garnered considerable attention in the research community as well as the medical marijuana constituency due to its anti-emetic properties. Like many other cannabinoids, CBD is non-psychoactive, and acts as a muscle relaxant as well. CBD levels in the U.S. have remained consistently low over the past 20 years, at 0.3-0.4%. In the Australian study, about 90% of cannabis samples contained less than 0.1% total CBD, based on chromatographic analysis, although some of the samples had levels as high as 6%.

The Australian samples also showed relatively high amounts of CBG, another common cannabinoid. CBG, known as cannabigerol, has been investigated for its pharmacological properties by biotech labs. It is non-psychoactive but useful for inducing sleep and lowering intra-ocular pressure in cases of glaucoma.

CBC, yet another cannabinoid, also acts as a sedative, and is reported to relieve pain, while also moderating the effects of THC. The Australian investigators believe that, as with CBD, “the trend for maximizing THC production may have led to marginalization of CBC as historically, CBC has sometimes been reported to be the second or third most abundant cannabinoid.”

Is today’s potent, very high-THC marijuana a different drug entirely, compared to the marijuana consumed up until the 21st Century? And does super-grass have an adverse effect on the mental health of users? The most obvious answer is, probably not. Recent attempts to link strong pot to the emergence of psychosis have not been definitive, or even terribly convincing. (However, the evidence for adverse cognitive effects in smokers who start young is more convincing).

It’s not terribly difficult to track how ditch weed evolved into sinsemilla. It is the historical result of several trends: 1) Selective breeding of cannabis strains with high THC/low CBD profiles, 2) near-universal preference for female plants (sinsemilla), 3) the rise of controlled-environment indoor cultivation, and 4) global availability of high-end hybrid seeds for commercial growing operations. And in the Australian sample, much of the marijuana came from areas like Byron Bay, Lismore, and Tweed Heads, where the concentration of specialist cultivators is similar to that of Humboldt County, California.

The investigators admit that “there is little research systematically addressing the public health impacts of use of different strengths and types of cannabis,” such as increases in cannabis addiction and mental health problems. The strongest evidence consistent with lab research is that “CBD may prevent or inhibit the psychotogenic and memory-impairing effects of THC. While the evidence for the ameliorating effects of CBD is not universal, it is thought that consumption of high THC/low CBD cannabis may predispose users towards adverse psychiatric effects….”

The THC rates in Australia are in line with or slightly higher than average values in several other countries. Can an increase in THC potency and corresponding reduction in other key cannabinoids be the reason for a concomitant increase in users seeking treatment for marijuana dependency? Not necessarily, say the investigators. Drug courts, coupled with greater treatment opportunities, might account for the rise. And schizophrenia? “Modelling research does not indicate increases in levels of schizophrenia commensurate with increases in cannabis use.”

One significant problem with surveys of this nature is the matter of determining marijuana’s effective potency—the amount of THC actually ingested by smokers. This may vary considerably, depending upon such factors as “natural variations in the cannabinoid content of plants, the part of the plant consumed, route of administration, and user titration of dose to compensate for differing levels of THC in different smoked material.”

Wendy Swift and her coworkers call for more research on cannabis users’ preferences, “which might shed light on whether cannabis containing a more balanced mix of THC and CBD would have value in the market, as well as potentially conferring reduced risks to mental wellbeing.”


Swift W., Wong A., Li K.M., Arnold J.C. & McGregor I.S. (2013). Analysis of Cannabis Seizures in NSW, Australia: Cannabis Potency and Cannabinoid Profile., PloS one, PMID: 23894589

(First published at Addiction Inbox Sept. 3 2013)

Graphics Credit: https://budgenius.com/marijuana-testing.html

The Blunt Facts About Blunts

Mixing tobacco with marijuana.

People who smoke a combination of tobacco and marijuana, a common practice overseas for years, and increasingly popular here in the form of “blunts,” may be reacting to some unidentified mechanism that links the two drugs. Researchers believe such smokers would be well advised to consider giving up both drugs at once, rather than one at a time, according to an upcoming study in the journal Addiction.

Clinical trials of adults with cannabis use disorders suggest that “approximately 50% are current tobacco smokers,” according to the report, which was published in the journal Addiction, and authored by Arpana Agrawal and Michael T. Lynskey of Washington University School of Medicine, with Alan J. Budney of the University of Arkansas for Medical Sciences.  “As many cannabis users smoke a mixture of cannabis and tobacco or chase cannabis use with tobacco, and as conditioned cues associated with smoking both substances may trigger use of either substance,” the researchers conclude, “a simultaneous cessation approach with cannabis and tobacco may be most beneficial.”

A blunt is simply a marijuana cigar, with the wrapping paper made of tobacco and the majority of loose tobacco removed and replaced with marijuana. In Europe, smokers commonly mix the two substances together and roll the combination into a single joint, the precise ratio of cannabis and nicotine varying with the desires of the user. “There is accumulating evidence that some mechanisms linking cannabis and tobacco use are distinct from those contributing to co-occurring use of drugs in general,” the investigators say. Or, as psychiatry postdoc Erica Peters of Yale put it in a press release, “There’s something about tobacco use that seems to worsen marijuana use in some way.” The researchers believe that this “something” involved may be a genetic predisposition. In addition to an overall genetic proclivity for addiction, do dual smokers inherit a specific propensity for smoked substances? We don’t know—but evidence is weak and contradictory so far.

Wouldn’t it be easier to quit just one drug, using the other as a crutch? The researchers don’t think so, and here’s why: In the few studies available, for every dually addicted participant who reported greater aggression, anger, and irritability with simultaneous cessation, “comparable numbers of participants rated withdrawal associated with dual abstinence as less severe than withdrawal from either drug alone.” So, for dual abusers, some of them may have better luck if they quit marijuana and cigarettes at the same time. The authors suggest that “absence of smoking cues when abstaining from both substances may reduce withdrawal severity in some individuals.” In other words, revisiting the route of administration, a.k.a. smoking, may trigger cravings for the drug you’re trying to quit. This form of “respiratory adaption” may work in other ways. For instance, the authors note that, “in addition to flavorants, cigarettes typically contain compounds (e.g. salicylates) that have anti-inflammatory and anesthetic effects which may facilitate cannabis inhalation.”

Studies of teens diagnosed with cannabis use disorder have shown that continued tobacco used is associated with a poor cannabis abstention rate. But there are fewer studies suggesting the reverse—that cigarette smokers fair poorly in quitting if they persist in cannabis use. No one really knows, and dual users will have to find out for themselves which categories seems to best suit them when it comes time to deal with quitting.

We will pass up the opportunity to examine the genetic research in detail. Suffice to say that while marijuana addiction probably has a genetic component like other addictions, genetic studies have not identified any gene variants as strong candidates thus far. The case is stronger for cigarettes, but to date no genetic mechanisms have been uncovered that definitively show a neurobiological pathway that directly connects the two addictions.

There are all sorts of environmental factors too, of course. Peer influences are often cited, but those influences often seem tautological: Drug-using teens are members of the drug-using teens group. Tobacco users report earlier opportunities to use cannabis, which might have an effect, if anybody knew how and why it happens.

Further complicating matters is the fact that withdrawal from nicotine and withdrawal from marijuana share a number of similarities.  The researchers state that “similar withdrawal syndromes, with many symptoms in common, may have important treatment implications.” As the authors sum it up, cannabis withdrawal consists of “anger, aggression or irritability, nervousness or anxiety, sleep difficulties, decreased appetite or weight loss, psychomotor agitation or restlessness, depressed mood, and less commonly, physical symptoms such as stomach pain and shakes/tremors.” Others complain of night sweats and temperature sensitivity.

And the symptoms of nicotine withdrawal? In essence, the same. The difference, say the authors, is that cannabis withdrawal tends to produce more irritability and decreased appetite, while tobacco withdrawal brings on an appetite increase and more immediate, sustained craving. Otherwise, the similarities far outnumber the differences.

None of this, however, has been reflected in the structure of treatment programs: “Emerging evidence suggests that dual abstinence may predict better cessation outcomes, yet empirically researched treatments tailored for co-occurring use are lacking.”

The truth is, we don’t really know for certain why many smokers prefer to consume tobacco and marijuana in combination. But we do know several reasons why it’s not a good idea. Many of the health-related harms are similar, and presumably cumulative: chronic bronchitis, wheezing, morning sputum, coughing—smokers know the drill. Another study cited by the authors found that dual smokers reported smoking as many cigarettes as those who only smoked tobacco. All of this can lead to “considerable elevation in odds of respiratory distress indicators and reduced lung functioning in those who used both.” However, there is no strong link at present between marijuana smoking and lung cancer.

Some researchers believe that receptor cross-talk allows cannabis to modify receptors for nicotine, or vice versa. Genes involved in drug metabolism might somehow predispose a subset of addicts to prefer smoking. But at present, there are no solid genetic or environmental influences consistent enough to account for a specific linkage between marijuana addiction and nicotine addiction, or a specific genetic proclivity for smoking as a means of drug administration.

Agrawal, A., Budney, A., & Lynskey, M. (2012). The Co-occurring Use and Misuse of Cannabis and Tobacco: A Review. Addiction DOI: 10.1111/j.1360-0443.2012.03837.x

Photo credit: http://www.hightimes.com/

(First published at Addiction Inbox on March 22, 2012).

Marijuana Statistics vs. Perception

Who smokes cannabis, and how much?

(First published 12/27/2013)

Most statistical surveys of marijuana focus on a single quantitative measurement: How many people are using? But there’s a problem: More marijuana use does not necessarily translate into more marijuana users. And that’s because a clear majority of the consumption, and black market dollars, come from the heaviest smokers.

Drug policy researchers at the RAND corporation decided that frequency of use and amount of consumption were valuable parameters gone missing in most policy discussions. So they put the focus not just on use, but also on “use-days,” and pulled a number of buried tidbits from a very big data pile. If you zero in on consumption, and not just consumers, they insist, you will find a wholly different set of inferences.

For example: “Although daily/near-daily users represented less than one-quarter of past-month cannabis users in 2002 and roughly one-third of past-month users in 2011, they account for the vast majority of use-days and are thus presumably responsible for the majority of consumption,” write Rachel M. Burns and her RAND colleagues in Frontiers of Psychiatry. As with alcohol, the majority of cannabis consumption can be accounted for by a minority of users. The heaviest users, the upper 20 percent, consume 88 percent of the U.S. marijuana supply, say the RAND researchers. “Furthermore, if over time there were no change in the number of cannabis users, but the ratio of light vs. heavy users switched from 80/20 to 20/80, then consumption would increase by 250% even though there was no change whatsoever in the number of users.”

The RAND group used two data sets on cannabis consumption—the National Survey on Drug Use and Health (NSDUH) in the U.S., and the EU Drugs Markets II (EUMII) in Europe. Data included figures for past-year and past-month use, past-month use days, and past-month purchases.

Other intriguing figures come to light when you study cannabis use, as opposed to cannabis users. The researchers declared that “only 14% of past-year cannabis users [primarily males] meet the criteria for cannabis abuse or dependence, but they account for 26% of past-month days of use and 37% of past-month purchases.”

Happen to smoke blunts? That turns out to be very telling, according to the RAND study. “Perhaps the most striking contrast concerns blunts. Only 27% of past-year cannabis users report using a blunt within the last month, but those individuals account for 73% of cannabis purchases.” Casual users, it seems, don’t do blunts.

Clearly, it takes a lot of casual users to smoke as much marijuana as one heavy user. But exactly how many? The RAND researchers ran the numbers and concluded that, in terms of grams consumed per month, it would take more than 40 casual smokers to equal the intake of a single heavy user. The share of the market represented by daily/near-daily users is clearly the motive force in their analysis.

The study in Frontiers in Psychiatry also found patterns of interest on the buy side. General use took an upswing beginning in 2007. While the probability of arrest per marijuana smoking episode hovers somewhere in the neighborhood of 1 in 3,000, everything changes if you are purchasing cannabis. RAND reported that young people collectively make more purchases per day of reported use than do older users. Therefore, “statistics indicating that the burden of arrest falls disproportionately on youth relative to their share of all users may not be prima facie evidence of discrimination if making more purchases per day of use increases the risk of arrests per year of use.” Once again, those aging Baby Boomer potheads get the best deal. They have more money with which to buy bigger amounts less often, thereby greatly lessening their chances of arrest and prosecution.

This also applies to minority arrests for marijuana offenses. “Non-Hispanic blacks represent 13% of past-year cannabis users vs. 23% of drug arrests reported by those users, but they report making 24% of the buys. Thus, some of their higher arrest rate may be a consequence of purchase patterns… African-Americans may not only make more buys but also make riskier buys (e.g., more likely to buy outdoors).”

The researchers were able to draw some conclusions about the growth in marijuana usage from 2002 through 2011, based on the NSDUH data. Their main conclusion, after exploring the demographics of this 10-year record of use, is that “consumption grew primarily because of an increase in the average frequency of use, not just because of an increase in the overall number of users.”  The driver of consumption turns out to be… greater consumption. And that increased consumption is coming from… older adults. Those older adults, it turns out, are smoking more weed.

The shift is dramatic: “In 2002, there were more than three times as many youth as older adults using cannabis on a daily/near-daily basis; in 2011 there were 2.5 times more older adults than youth using on a daily/near-daily basis.” The record of alcohol and cigarette use over the same period showed no such inversion of use patterns.  And the tweeners? “In 2002, 12-17-year-olds represented 13% of daily/near-daily users; in 2011, that had dwindled to 7%.” These trends are not just the obvious result of an increase in the proportion of older adults in the population at large. Increases in the proportion of older heavy cannabis users were much greater than the general population drift.

Among the questions raised by the RAND analysis:

— Are older marijuana smokers primarily recreational, or medicinal?

—Do increased use days among older, college-educated marijuana smokers indicate greater social acceptance, or something else?

—Are younger people replacing traditional cannabis use with other substances?

—Why did Hispanic use increase more over the study period than other ethnic groups?

Burns R.M., Caulkins J.P., Everingham S.S. & Kilmer B. (2013). Statistics on Cannabis Users Skew Perceptions of Cannabis Use, Frontiers in Psychiatry, 4   DOI: 10.3389/fpsyt.2013.00138

The Chemistry of Modern Marijuana

Is low-grade pot better for you than sinsemilla?

First published September 3, 2013.

Australia has one of the highest rates of marijuana use in the world, but until recently, nobody could say for certain what, exactly, Australians were smoking. Researchers at the University of Sydney and the University of New South Wales  analyzed hundreds of cannabis samples seized by Australian police, and put together comprehensive data on street-level marijuana potency across the country. They sampled police seizures and plants from crop eradication operations. The mean THC content of the samples was 14.88%, while absolute levels varied from less than 1% THC to almost 40%.  Writing in PLoS ONE, Wendy Swift and colleagues found that roughly ¾ of the samples contained at least 10% total THC. Half the samples contained levels of 15% or higher—“the level recommended by the Garretsen Commission as warranting classification of cannabis as a ‘hard’ drug in the Netherlands.”

In the U.S., recent studies have shown that THC levels in cannabis from 1993 averaged 3.4%, and then soared to THC levels in 2008 of almost 9%. THC loads more than doubled in 15 years, but that is still a far cry from news reports erroneously referring to organic THC increases of 10 times or more.

CBD, or cannabidiol, another constituent of cannabis, has garnered considerable attention in the research community as well as the medical marijuana constituency due to its anti-emetic properties. Like many other cannabinoids, CBD is non-psychoactive, and acts as a muscle relaxant as well. CBD levels in the U.S. have remained consistently low over the past 20 years, at 0.3-0.4%. In the Australian study, about 90% of cannabis samples contained less than 0.1% total CBD, based on chromatographic analysis, although some of the samples had levels as high as 6%.

The Australian samples also showed relatively high amounts of CBG, another common cannabinoid. CBG, known as cannabigerol, has been investigated for its pharmacological properties by biotech labs. It is non-psychoactive but useful for inducing sleep and lowering intra-ocular pressure in cases of glaucoma.

CBC, yet another cannabinoid, also acts as a sedative, and is reported to relieve pain, while also moderating the effects of THC. The Australian investigators believe that, as with CBD, “the trend for maximizing THC production may have led to marginalization of CBC as historically, CBC has sometimes been reported to be the second or third most abundant cannabinoid.”

Is today’s potent, very high-THC marijuana a different drug entirely, compared to the marijuana consumed up until the 21st Century? And does super-grass have an adverse effect on the mental health of users? The most obvious answer is, probably not. Recent attempts to link strong pot to the emergence of psychosis have not been definitive, or even terribly convincing. (However, the evidence for adverse cognitive effects in smokers who start young is more convincing).

It’s not terribly difficult to track how ordinary marijuana evolved into sinsemilla. Think Luther Burbank and global chemistry geeks. It is the historical result of several trends: 1) Selective breeding of cannabis strains with high THC/low CBD profiles, 2) near-universal preference for female plants (sinsemilla), 3) the rise of controlled-environment indoor cultivation, and 4) global availability of high-end hybrid seeds for commercial growing operations. And in the Australian sample, much of the marijuana came from areas like Byron Bay, Lismore, and Tweed Heads, where the concentration of specialist cultivators is similar to that of Humboldt County, California.

The investigators admit that “there is little research systematically addressing the public health impacts of use of different strengths and types of cannabis,” such as increases in cannabis addiction and mental health problems. The strongest evidence consistent with lab research is that “CBD may prevent or inhibit the psychotogenic and memory-impairing effects of THC. While the evidence for the ameliorating effects of CBD is not universal, it is thought that consumption of high THC/low CBD cannabis may predispose users towards adverse psychiatric effects….”

The THC rates in Australia are in line with or slightly higher than average values in several other countries. Can an increase in THC potency and corresponding reduction in other key cannabinoids be the reason for a concomitant increase in users seeking treatment for marijuana dependency? Not necessarily, say the investigators. Drug courts, coupled with greater treatment opportunities, might account for the rise. And schizophrenia? “Modelling research does not indicate increases in levels of schizophrenia commensurate with increases in cannabis use.”

One significant problem with surveys of this nature is the matter of determining marijuana’s effective potency—the amount of THC actually ingested by smokers. This may vary considerably, depending upon such factors as “natural variations in the cannabinoid content of plants, the part of the plant consumed, route of administration, and user titration of dose to compensate for differing levels of THC in different smoked material.”

Wendy Swift and her coworkers call for more research on cannabis users’ preferences, “which might shed light on whether cannabis containing a more balanced mix of THC and CBD would have value in the market, as well as potentially conferring reduced risks to mental wellbeing.”

Graphics Credit: http://www.ironlabsllc.co/view/learn.php

Swift W., Wong A., Li K.M., Arnold J.C. & McGregor I.S. (2013). Analysis of Cannabis Seizures in NSW, Australia: Cannabis Potency and Cannabinoid Profile., PloS one, PMID: 23894589

Hunting For the Marijuana-Dopamine Connection

Why do heavy pot smokers show a blunted reaction to stimulants?

Most drugs of abuse increase dopamine transmission in the brain, and indeed, this is thought to be the basic neural mechanism underlying the rewarding effects of addictive drugs. But in the case of marijuana, the dopamine connection is not so clear-cut. Evidence has been found both for and against the notion of increases in dopamine signaling during marijuana intoxication.

Marijuana has always been the odd duck in the pond, research-wise. Partly this is due to longstanding federal intransigence toward cannabis research, and partly it is because cannabis, chemically speaking, is damnably complicated. The question of marijuana’s effect on dopamine transmission came under strong scrutiny a few years ago, when UK researchers began beating the drums for a theory that chronic consumption of strong cannabis can not only trigger episodes of psychosis, but can be viewed as the actual cause of schizophrenia in some cases.

It sounded like a new version of the old reefer madness, but this time around, the researchers raising their eyebrows had a new fact at hand: Modern marijuana is several times stronger than marijuana in use decades ago. Selective breeding for high THC content has produced some truly formidable strains of pot, even if cooler heads have slowly prevailed on the schizophrenia issue.

One of the reports helping to bank the fires on this notion appeared recently in the Proceedings of the National Academy of Sciences (PNAS). Joanna S. Fowler of the Biosciences Department at Brookhaven National Laboratory, Director Nora Volkow of the National Institute on Drug Abuse (NIDA), and other researchers compared brain dopamine reactivity in healthy controls and heavy marijuana users, using PET scans. For measuring dopamine reactivity, the researchers chose methylphenidate, better known as Ritalin, the psychostimulant frequently prescribed for attention-deficit hyperactivity disorder (ADHD). Ritalin basically functions as a dopamine reuptake inhibitor, meaning that the use of Ritalin leads to increased concentrations of synaptic dopamine.

In the study, heavy marijuana users showed a blunted reaction to the stimulant Ritalin due to reductions in brain dopamine release, according to the research. “The potency of methylphenidate (MP) was also reported to be stronger by the controls than by the marijuana abusers." And in marijuana abusers, Ritalin caused an increase in craving for marijuana and cigarettes.

 “We found that marijuana abusers display attenuated dopamine responses to MP including reduced decreases in striatal distribution volumes,” according to the study’s conclusion. “The significantly attenuated behavioral and striatal distribution volumes response to MP in marijuana abusers compared to controls, indicates reduced brain reactivity to dopamine stimulation that in the ventral striatum might contribute to negative emotionality and drug craving.”

Down-regulation from extended abuse is another complicated aspect of this: “Although, to our knowledge, this is the first clinical report of an attenuation of the effects of MP in marijuana abusers, a preclinical study had reported that rats treated chronically with THC exhibited attenuated locomotor responses to amphetamine. Such blunted responses to MP could reflect neuroadaptations from repeated marijuana abuse, such as downregulation of DA transporters.”

 Animal studies have suggested that these dopamine alterations are reversible over time.

Another recent study came to essentially the same conclusions. Writing in Biological Psychiatry, a group of British researchers led by Michael A.P. Bloomfield and Oliver D. Howes analyzed dope smokers who experienced psychotic symptoms when they were intoxicated. They looked for evidence of a link between cannabis use and psychosis and concluded: “These findings indicate that chronic cannabis use is associated with reduced dopamine synthesis capacity and question the hypothesis that cannabis increases the risk of psychotic disorders by inducing the same dopaminergic alterations seen in schizophrenia.” And again, the higher the level of current cannabis use, the lower the level of striatal dopamine synthesis capacity.  As for mechanisms, the investigators ran up against similar causation problems: “One explanation for our findings is that chronic cannabis use is associated with dopaminergic down-regulation. This might underlie amotivation and reduced reward sensitivity in chronic cannabis users. Alternatively, preclinical evidence suggests that low dopamine neurotransmission may predispose an individual to substance use.”

The findings of diminished responses to Ritalin in heavy marijuana users may have clinical implications, suggesting that marijuana abusers with ADHD may experience reduced benefits from stimulant medications.

Photo Credit: http://www.biologicalpsychiatryjournal.com/

NIDA’s Dark View of Teen Marijuana Use

Federal study also discusses medical marijuana.

Considering the impasse on marijuana policy between state and federal governments in the U.S., the primary government agency in charge of drug research—NIDA, the National Institute on Drug Abuse—would seem to be caught between a rock and a hard place. Neuroscientists and other marijuana investigators who do research under NIDA grants have a fine line to walk in their efforts to disseminate research findings on cannabis.

From a public health point of view, NIDA is expected to keep up the pressure against drug legalization, or at least keep out of the fight, while also researching the medical pros and cons of cannabis. So it was with some interest that drug policy officials took in a recent article in the New England Journal of Medicine by NIDA director Nora Volkow titled “Adverse Health Effects of Marijuana Use.”

While the press has understandably centered on the risk of marijuana use among teens, which is the focus of the study, the report also contains some surprising admissions about marijuana’s health benefits as well as its addictive potential.

The teen risk emphasis comes from recent studies on two fronts—impaired driving and impaired brain function. The first is seriously confounded by dual use with alcohol, and the second is based, at least in part, on a controversial long-term study showing that marijuana use in the early years demonstrably lowers adult IQs.

No one would suggest that heavy marijuana smoking is good for developing teen brains, and there is sufficient evidence to worry about impairment to memory and to certain so-called “executive” cognitive functions. It is not clear how lasting these effects can be, but lead author Volkow is confident enough to say in a prepared statement that “Physicians in particular can play a role in conveying to families that early marijuana use can interfere with crucial social and developmental milestones and can impair cognitive development.” 

That these negative effects can be the outcome of heavy pot smoking in the teen years seems established beyond reasonable doubt. The extent and duration of these negative outcomes remain the topic of vociferous debate—although it is increasingly clear that the body’s endogenous cannabinoid system plays a key role in synapse formation during early brain development.

Meanwhile, the report re-emphasized the fact that marijuana is an addictive drug for some users—a fact that should not need re-emphasizing, but, lamentably, does. As Volkow and her co-authors write: “The evidence clearly indicates that long-term marijuana use can lead to addiction. Indeed, approximately 9% of those who experiment with marijuana will become addicted.”

Moreover, as regular readers of Addiction Inbox already know, “there is also recognition of a bona fide cannabis withdrawal syndrome (with symptoms that include irritability, sleeping difficulties, dysphoria, craving, and anxiety), which makes cessation difficult and contributes to relapse.” And, in line with the report’s overall theme, “those who begin in adolescence are approximately 2 to 4 times as likely to have symptoms of cannabis dependence within 2 years after first use.”

To their credit, the investigators decline to endorse the claim that marijuana use exacerbates or initiates episodes of illness in patients with schizophrenia and other psychoses, noting that “it is inherently difficult to establish causality in these types of studies because factors other than marijuana use may be directly associated with the risk of mental illness.” Furthermore, while early marijuana use is associated with an increased risk of dropping out of school, “reports of shared environmental factors that influence the risks of using cannabis at a young age and dropping out of school suggest that the relationship may be more complex…. The relationship between cannabis use by young people and psychosocial harm is likely to be multifaceted, which may explain the inconsistencies among studies.”

Indeed. The report also declares that the effects of long-term pot smoking on the risk of lung cancer are “unclear,” and that “the smoking of cigarettes containing both marijuana and tobacco products is a potential confounding factor with a prevalence that varies dramatically among countries.”

In conclusion, the strict demands of causality mean that the long-term effect of chronic marijuana exposure is not known with any certainty. It is possible, even likely, that these effects can vary dramatically from one smoker to another. But the equally persuasive demands of common sense dictate that inhaling dried, super-heated vegetable matter on a regular basis is likely to degrade your health, the more so if you are young and healthy to begin with.

As for other health issues: “The authoritative report by the Institute of Medicine, Marijuana and Medicine, acknowledges the potential benefits of smoking marijuana in stimulating appetite, particularly in patients with the acquired immunodeficiency syndrome (AIDS) and the related wasting syndrome, and in combating chemotherapy-induced nausea and vomiting, severe pain, and some forms of spasticity. The report also indicates that there is some evidence for the benefit of using marijuana to decrease intraocular pressure in the treatment of glaucoma.”

A detailed section titled “Clinical Conditions with Symptoms That May Be Relieved by Treatment with Marijuana or other Cannabinoids” brought additional research to light:

—Glaucoma: “More research is needed to establish whether molecules that modulate the endocannabinoid system may not only reduce intraocular pressure but also provide a neuroprotective benefit in patients with glaucoma.”

—Nausea: “THC is an effective antiemetic agent in patients undergoing chemotherapy, but patients often state that marijuana is more effective in suppressing nausea…. Paradoxically, increased vomiting (hyperemesis) has been reported with repeated marijuana use. [See various blog posts by Drugmonkey and me, starting with this and this.]

—AIDS-associated conditions: “Smoked or ingested cannabis improves appetite and leads to weight gain and improved mood and quality of life among patients with AIDS.”

—Chronic pain: “Studies have shown that cannabinoids acting through central CB1 receptors, and possibly peripheral CB1 and CB2 receptors, play important roles in… various models of pain. These findings are consistent with reports that marijuana may be effective in ameliorating neuropathic pain, even at very low levels of THC.”

—Inflammation: “Cannabinoids (e.g., THC and cannabidiol) have substantial anti-inflammatory effects…. Animal models have shown that cannabidiol is a promising candidate for the treatment of rheumatoid arthritis and for inflammatory diseases of the gastrointestinal tract (e.g., ulcerative colitis and Crohn’s disease).”

—Multiple sclerosis: “Nabiximols (Sativex, GW Pharmaceuticals), an oromucosal spray that delivers a mix of THC and cannabidiol, appears to be an effective treatment for neuropathic pain, disturbed sleep, and spasticity in patients with multiple sclerosis. Sativex… is currently being reviewed in phase 3 trials in the United States in order to gain approval from the Food and Drug Administration.”

—Epilepsy: In a recent small survey of parents who use marijuana with a high cannabidiol content to treat epileptic seizures in their children, 11% reported completed freedom from seizures…. Although such reports are promising, insufficient safety and efficacy data are available on the use of cannabis botanical for the treatment of epilepsy. However, there is increasing evidence of the role of cannabidiol as an antiepileptic agent in animal models.”

Volkow N.D., Baler R.D., Compton W.M. & Weiss S.R.B.  Adverse health effects of marijuana use., The New England journal of medicine,    PMID: 24897085

Does Strong Marijuana Cause Addiction?

Strong pot matters, but maybe not the way we think.

Colorado, Washington, and some 20 additional states have now made various provisions for legal transactions involving marijuana. And since time immemorial, there has been an illegal market for marijuana. But try getting your hands on some marijuana straightforwardly, through appropriate channels, for purposes of medical research, and, well, most researchers have just said forget it.

Because in the U.S., a bizarre system of drug classification has led to the ludicrous situation of a virtual government monopoly on cannabis for experimental purposes. Can’t researchers just walk around this roadblock and procure pot in some manner that is legal in their state? No, they cannot—not if they want any serious research grants, or publication in refereed journals. Without the federal government imprimatur, marijuana research isn’t kosher, and could put researchers at legal risk. Researchers who go through channels report frequent and unpredictable delays, and this has been true for decades. Yet millions of recreational marijuana users can secure a supply of the drug, often accompanied by specific genetic information, often with relatively little effort.

The Drug Enforcement Administration (DEA) has refused to budge on its opposition to petitions for reclassification of cannabis. A recent Washington Post article  attributed the problem to “stigma associated with the drug, lack of funding and legal issues…. Scientists say they are frustrated that the federal government has not made any efforts to speed the process of research.”

However, as almost everyone knows, things are different in The Netherlands. It isn’t a big problem for researchers at the University of Amsterdam and elsewhere in that country to engage in behavioral studies of actual marijuana smokers. Participants in a recent study, the results of which appear in Addiction, were even allowed to use their own weed. (Thanks to Ivan Oransky for bringing this study to my attention.) The thesis being tested by Peggy van der Pol and colleagues is a familiar one: Do marijuana smokers “titrate” very strong pot—that is, do they modify their smoking/dosing behavior accordingly, in order to reduce overall THC exposure? If so, just because a cannabis user is ingesting high-THC plant material doesn’t mean that his or her THC blood levels are that much higher than smokers of less potent weed. But if this is NOT true—if smokers of strong pot are boosting their THC exposure significantly, the results could conceivably include impaired driving and greater rates of marijuana addiction.

Most studies that attempt to estimate the risk of cannabis dependence in pot smokers rely on a familiar yardstick—the number of days a smoker smokes per month. Dosing behavior, and other behavioral aspects of marijuana smoking that affect THC exposure, are usually ignored. The Dutch researchers found that, in a group of 600 frequent cannabis users, some smokers did in fact show “shorter puff duration and inhaled lower smoke volumes when joints with a higher THC concentration were used.” So, yes, users did engage in partial titration when they smoked stronger marijuana. However, this did not translate into the expected results. In a final sample of 98 participants, the scientists discovered that “users of stronger cannabis generally used larger amounts of cannabis to prepare their regular joint.” (The study participants smoked marijuana European-style, mixing their marijuana with tobacco.) And even though subjects smoking joints with higher THC levels did inhale at slightly lower volumes and at a slower pace, the average user of pot with THC levels of 12% or higher definitely inhaled more liters of smoked THC per month than users of less potent pot. But just to confound matters, total THC exposure over a month’s time turned out to be “a weak predictor of dependence severity, and did not remain significant after adjustment for baseline dependence severity.”

Nonetheless, even with some degree of titration, “a positive association between total puff volume and withdrawal/craving was found, indicating that a larger inhaled volume may increase the THC exposure sufficiently to result in significant effects on clinical outcomes.” (Here is the UK National Health Service take on the research.) 

It is always difficult to say for certain in a prospective, cross-sectional study of behavior whether participants are acting the way they would act in “real life,” although efforts were made to allow smoking at home, or in Dutch coffee shops, as well as the laboratory. Interestingly, the one behavior that seemed to predict dependence in post-hoc analyses was a simple one. Smokers were allowed to mix a joint however they wished, and smoke however much of it they wanted to. Smokers who finished their joints, rather than leaving a portion of it for later, were the smokers more likely to be associated with dependence in the follow-up studies. In fact, “percentage of the joint smoked may be a simple proxy for risky smoking behavior.”

In addition, certain withdrawal symptoms correlated with dependence: “Increased somatic withdrawal symptoms are predictive of relapse, and…. increased physical tension is a significant predictor of relapse.”

As with alcohol, it seems that it is not necessarily how much you smoke or drink. It is how you smoke or drink. Strong marijuana doesn't cause addiction. The way certain people use strong pot can result in addiction, however.

Earlier research has shown that higher levels of cannabis dependence are associated with greater functional impairment, and that "the average level of impairment caused by cannabis, while mild for most users, can rise to the level of tobacco withdrawal which is of well established clinical significance.”

 Physical distress, a “somatic” variable, often matters more, in terms of relapse, than the amount of marijuana smoked, or any other symptom on the roster of functional impairments—including mood and other negative affect variables.  In an earlier study published in PLOS ONE,  investigators found that “cannabis withdrawal is clinically significant because it is associated with elevated functional impairment to normal daily activities, and the more severe the withdrawal is, the more severe the functional impairment is. Elevated functional impairment from a cluster of cannabis withdrawal symptoms is associated with relapse in more severely dependent users.”

van der Pol P., Liebregts N., Brunt T., van Amsterdam J., de Graaf R., Korf D.J., van den Brink W. & van Laar M. (2014). Cross-sectional and prospective relation of cannabis potency, dosing and smoking behaviour with cannabis dependence: an ecological study, Addiction,   n/a-n/a. DOI: 10.1111/add.12508

State Marijuana Legalization: The Opposing Voices

Repeating Our Alcohol Mistakes?

A recent article in the always insightful Alcoholism and Drug Abuse Weekly, edited by Alison Knopf, concerns itself with the voices speaking out against Attorney General Holder’s announcement that federal authorities would not interfere with state efforts to legalize marijuana. It’s no secret that we here at Addiction Inbox have been longtime advocates for decriminalization along Dutch lines. So it’s high time we heard from some prominent dissenters on this issue.

Kevin A. Sabet, Ph.D., director of Project SAM (Smart Approaches to Marijuana) and former White House advisor on marijuana policy: “It’s the same thing with alcohol:  The marijuana industry is giving lip service, saying that they don’t want kids to use.”

Sue Thau, public policy consultant for Community Anti-Drug Coalitions of America (CADCA): “This is the start of Big Marijuana the way we have Big Alcohol and Big Tobacco…. Anyone who cares about addiction has to care about this.”

Rafael Lemaitre, spokesman for the Office of National Drug Control Policy: “We know that marijuana use, particularly long-term, chronic use that began at a young age, can lead to dependence and addiction. Marijuana is not a benign drug, and we continue to oppose marijuana legalization because it runs counter to a public health approach to drug policy.”

Gen. Arthur T. Dean, CEO of Community Anti-Drug Coalitions of America (CADCA): "This decision sends a message to our citizens, youth, communities, states, and the international community at large that the enforcement of federal law related to marijuana is not a priority."

The article is entitled “Advocates dismayed as legalization moves forward.”

Here are a few I have come across recently from other sources:

Citizens Against Legalizing Marijuana (CALM): "After decades of study the FDA continues to reaffirm that there is no medical benefit provided by the use of smoked marijuana and that, in fact, considerable harm can be caused by such use. We affirm the 2006 FDA finding and vast scientific evidence that marijuana causes harm. The normalization, expanded use, and increased availability of marijuana in our communities are detrimental to our youth, to public health, and to the safety of our society."

Office of National Drug Control Policy: "The Office of National Drug Control Policy is working to reduce the use of marijuana and other illicit drugs through development of strategies that fully integrate the principles of prevention, treatment, recovery, and effective supply reduction efforts. Proposals such as legalization that would promote marijuana use are inconsistent with this public health and safety approach.... Marijuana use is associated with dependence, respiratory and mental illness, poor motor performance, and impaired cognitive and immune system functioning, among other negative effects."

CNBC: "Contrary to the beliefs of those who advocate the legalization of marijuana, the current balanced, restrictive, and bipartisan drug policies of the United States are working reasonably well and they have contributed to reductions in the rate of marijuana use in our nation.... The rate of current, past 30-day use of marijuana by Americans aged 12 and older in 1979 was 13.2 percent. In 2008 that figure stood at 6.1 percent. This 54-percent reduction in marijuana use over that 29-year period is a major public health triumph, not a failure."


Photo Credit: LARRY MAYER/Billings Gazette Staff

A Chemical Peek at Modern Marijuana

Researchers ponder whether ditch weed is better for you than sinsemilla.

Australia has one of the highest rates of marijuana use in the world, but until recently, nobody could say for certain what, exactly, Australians were smoking. Researchers at the University of Sydney and the University of New South Wales recently analyzed hundreds of cannabis samples seized by Australian police, and put together comprehensive data on street-level marijuana potency across the country. They sampled police seizures and plants from crop eradication operations. The mean THC content of the samples was 14.88%, while absolute levels varied from less than 1% THC to almost 40%.  Writing in PLoS one, Wendy Swift and colleagues found that roughly ¾ of the samples contained at least 10% total THC. Half the samples contained levels of 15% or higher—“the level recommended by the Garretsen Commission as warranting classification of cannabis as a ‘hard’ drug in the Netherlands.”

In the U.S., recent studies have shown that THC levels in cannabis from 1993 averaged 3.4%, and then soared to THC levels in 2008 of almost 9%. THC loads more than doubled in 15 years, but that is still a far cry from news reports erroneously referring to organic THC increases of 10 times or more.

CBD, or cannabidiol, another constituent of cannabis, has garnered considerable attention in the research community as well as the medical marijuana constituency due to its anti-emetic properties. Like many other cannabinoids, CBD is non-psychoactive, and acts as a muscle relaxant as well. CBD levels in the U.S. have remained consistently low over the past 20 years, at 0.3-0.4%. In the Australian study, about 90% of cannabis samples contained less than 0.1% total CBD, based on chromatographic analysis, although some of the samples had levels as high as 6%.

The Australian samples also showed relatively high amounts of CBG, another common cannabinoid. CBG, known as cannabigerol, has been investigated for its pharmacological properties by biotech labs. It is non-psychoactive but useful for inducing sleep and lowering intra-ocular pressure in cases of glaucoma.

CBC, yet another cannabinoid, also acts as a sedative, and is reported to relieve pain, while also moderating the effects of THC. The Australian investigators believe that, as with CBD, “the trend for maximizing THC production may have led to marginalization of CBC as historically, CBC has sometimes been reported to be the second or third most abundant cannabinoid.”

Is today’s potent, very high-THC marijuana a different drug entirely, compared to the marijuana consumed up until the 21st Century? And does super-grass have an adverse effect on the mental health of users? The most obvious answer is, probably not. Recent attempts to link strong pot to the emergence of psychosis have not been definitive, or even terribly convincing. (However, the evidence for adverse cognitive effects in smokers who start young is more convincing).

It’s not terribly difficult to track how ditch weed evolved into sinsemilla. It is the historical result of several trends: 1) Selective breeding of cannabis strains with high THC/low CBD profiles, 2) near-universal preference for female plants (sinsemilla), 3) the rise of controlled-environment indoor cultivation, and 4) global availability of high-end hybrid seeds for commercial growing operations. And in the Australian sample, much of the marijuana came from areas like Byron Bay, Lismore, and Tweed Heads, where the concentration of specialist cultivators is similar to that of Humboldt County, California.

The investigators admit that “there is little research systematically addressing the public health impacts of use of different strengths and types of cannabis,” such as increases in cannabis addiction and mental health problems. The strongest evidence consistent with lab research is that “CBD may prevent or inhibit the psychotogenic and memory-impairing effects of THC. While the evidence for the ameliorating effects of CBD is not universal, it is thought that consumption of high THC/low CBD cannabis may predispose users towards adverse psychiatric effects….”

The THC rates in Australia are in line with or slightly higher than average values in several other countries. Can an increase in THC potency and corresponding reduction in other key cannabinoids be the reason for a concomitant increase in users seeking treatment for marijuana dependency? Not necessarily, say the investigators. Drug courts, coupled with greater treatment opportunities, might account for the rise. And schizophrenia? “Modelling research does not indicate increases in levels of schizophrenia commensurate with increases in cannabis use.”

One significant problem with surveys of this nature is the matter of determining marijuana’s effective potency—the amount of THC actually ingested by smokers. This may vary considerably, depending upon such factors as “natural variations in the cannabinoid content of plants, the part of the plant consumed, route of administration, and user titration of dose to compensate for differing levels of THC in different smoked material.”

Wendy Swift and her coworkers call for more research on cannabis users’ preferences, “which might shed light on whether cannabis containing a more balanced mix of THC and CBD would have value in the market, as well as potentially conferring reduced risks to mental wellbeing.”

Swift W., Wong A., Li K.M., Arnold J.C. & McGregor I.S. (2013). Analysis of Cannabis Seizures in NSW, Australia: Cannabis Potency and Cannabinoid Profile., PloS one, PMID: 23894589

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