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

Graphics Credit: http://420tribune.com

Strong Pot: What Do Schizophrenics Think?

Small study asks patients for their opinions.

The theory, fiercely debated in the research community, that strong cannabis can actually cause schizophrenia—or is associated with relapse in schizophrenics who smoke it—is the subject of a small study from Switzerland on outpatient schizophrenics, some of whom were pot smokers.

 A study of this kind, with only 10 subjects, verges on the anecdotal. Nonetheless, it is worth a look, just to see if any verification of the theory lurks therein.

In their paper for the open access Harm Reduction Journal—“Do patients think cannabis causes schizophrenia? A qualitative study on the causal beliefs of cannabis using patients with schizophrenia”—psychiatric workers with the Research Group on Substance Use Disorders interviewed patients who attended an outpatient clinic at the Psychiatric University Hospital in Zurich. The researchers did it because, as the paper states, “patients’ beliefs on the role of cannabis in the pathogenesis of schizophrenia have—to our knowledge—not been studied so far…”

“None of the patients described a causal link between the use of cannabis and their schizophrenia,” the researchers determined. However, several of the schizophrenics did have their own version of a disease model to account for their illness. Five of the patients attributed their schizophrenia to “upbringing under difficult circumstances,” and three placed the blame on “substances other than cannabis (e.g. hallucinogens).” The remaining two patients gave “other reasons.”

Interestingly, four of the patients “considered cannabis a therapeutic aid and reported that positive effects (reduction of anxiety and tension) prevailed over its possible disadvantages (exacerbation of positive symptoms).” The authors conclude that excluding schizophrenic patients from treatment settings because of marijuana use “may cause additional harm to this already heavily burdened patient group.”

Graphics Credit: http://www.salem-news.com

The Drug Myth That Will Not Die

Brits still pushing marijuana/schizophrenia connection.

If at first you don’t succeed....

The UK Telegraph reports that scientists at the Institute of Psychiatry in King's College London injected (yes, injected) 22 healthy men with high potency THC (not marijuana), and recorded the results. According to the leader of the study team, Dr. Paul Morrison, "These findings confirm that THC can induce a transient acute psychological reaction in psychiatrically well individuals."

The Telegraph article said the researchers found that the "extent of psychotic reaction" was not related to "the degree of anxiety or cognitive impairment" in the men.

Mary Brett, vice president of Europe Against Drugs, said: "This shows that anyone who is healthy can become psychotic by smoking cannabis. They don't already have to have a mental illness. Healthy people can become psychotic."

Well, no. Observant readers will no doubt find all of this familiar: More than a year ago, a national hysteria over “skunk” cannabis was sparked in Great Britain when the University College of London produced a study purporting to show that strong pot was literally driving people crazy. The lunacy peaked with Prime Minister Brown’s description of new strains of cannabis as 'lethal.' At the time, the London Guardian reported that "Whitehall's own panel of experts has concluded that increased marijuana use has not been matched by a corresponding rise in mental illness."

Against the advice of her own drug advisers, then-Home Secretary Jacqui Smith restored cannabis from class C to the “harder” class B status because of mental health concerns. British health authorities maintained that "skunk" cannabis was linked to the onset of schizophrenia. Since no one knows what, exactly, causes schizophrenia, and since recent findings continue to point toward genetic causes, this was a triply astonishing claim.

Colin Blakemore, a prominent professor of neuroscience at the Universities of Oxford and Warwick, tackled the issue of “pot so strong it can make you psychotic” in an article for the Guardian:

“And what of the alarming stories of horrifying powerful "skunk"? Some newspapers have told us that the level of THC, the active ingredient, in street cannabis today is 20 or 30 times higher than 10 years ago. That would be rather surprising, given that THC content was 7 per cent on average in 1995. In reality, two studies, due to be published later this year, concluded that the average THC content has doubled.”

With the latest report, King’s College has once again proven that if you inject someone with massive doses of THC, he or she will find the experience dramatically unpleasant. So do monkeys. Years ago, when researchers injected test monkeys with synthetic THC approximately one hundred times more powerful than the naturally occurring substance, the monkeys fell down and didn’t move. This was dramatic proof of... nothing in particular. But it was sensational and it made headlines.

Meanwhile, the solid fact that a minority of marijuana users experience strong withdrawal symptoms when they abstain—an important and verifiable scientific finding—remains largely unknown to the general public.


Photo Credit: http: www.healthjockey.com

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