Thursday, August 02, 2007

Letter to

The media coverage of the Lancet study has been deplorable. Causation and correlation have been confused. Errors of fact of been made. Context is lacking and dissenting opinion, of which there is much, is missing. However bad the MSM’s coverage though, Christopher Wanjek’s “Marijuana’s New Reality: More Potent, More Risky” is of a magnitude worse.
Wanjek follows the main stream press’s lead and begins thus. Wanjek:
“The research team, based in England, found that weed smokers have on average a 41 percent increased risk of developing psychotic disorders later in life. The heaviest users doubled their risk; yet even infrequent smokers had a modest increased risk.”
Maia Szalavitz at Stats at George Mason University pointed out why such lead in is specious.
“A 40% increase in risk sounds scary, and this was the risk linked to trying marijuana once, not to heavy use. To epidemiologists a 40% increase is not especially noteworthy-- they usually don’t find risk factors worth worrying about until the number hits at least 200% and some major journals won’t publish studies unless the risk is 300 or even 400%. The marijuana paper did find that heavy use increased risk by 200-300%, but that’s hardly as sexy as try marijuana once, increase your risk of schizophrenia by nearly half! By contrast, one study found that alcohol has been found to increase the risk of psychosis by 800% for men and 300% for women.”
Shortly thereafter Wanjek followed Britain’s Daily Mirror in making this claim.
“Zammit's group, led by Dr. Glyn Lewis of the University of Bristol, analyzed 35 published cannabis studies and controlled for confounding effects, such as personality traits that might be more of a determinant of psychosis than pot.”
As the Guardian pointed out though, this is simply wrong.
“In fact they identified 175 studies which might have been relevant, but on reading them, it turned out that there were just 11 relevant papers, describing seven actual datasets.” It should be noted that despite Wanjek’s deferential treatment of Zammit, many of the studies looked at have been heavily and rightly criticized as being beset by methodological problems and Zammit et al either did not address these concerns or could not address them. Summarizing the findings of these studies does not make these methodological shortcomings go away.
Wanjek makes other factual errors and in this respect he goes far beyond most of the main stream media. Indeed, he makes this rather startling claim.
“Today most of what's smoked in the United States is grown domestically or in Canada”.
Never mind that US domestic production dwarfs what is coming in from Canada, only around 2% of marijuana seized at US borders is from Canada. Mexico remains the largest foreign source of marijuana in the US. US DEA:
“Overall marijuana production in Mexico--the principal source of foreign-produced marijuana to U.S. drug markets appears to be increasing.”
Yet another problem Wanjek’s coverage shares with most media outlets is that no room was provided for dissenting voices. In particular, Wanjek did not address the biggest obstacle facing those claiming that marijuana can cause schizophrenia, viz., how to explain why schizophrenia levels have been stable for more than 50 years even as marijuana use levels have gone through the roof. A few news agencies did not ignore this elephant in the living room, but they were few and far between. It was mentioned in a Globe Mail article and the following quote by Oxford’s Leslie Iverson was recorded by the BBC and the Times of London “
Despite a thorough review the authors admit that there is no conclusive evidence that cannabis use causes psychotic illness. Their prediction that 14 per cent of psychotic outcomes in young adults in the UK may be due to cannabis use is not supported by the fact that the incidence of schizophrenia has not shown any significant change in the past 30 years.”
Finally with regard to the alleged schizophrenia marijuana link, Wanjek did not point out that the study was funded by the British government as part of an effort by Gordon Brown to have marijuana reclassified. Hence, it was not mentioned that neither the study nor Gordon Brown’s efforts generally have been particularly well received. To wit:
“Dr Iddon, the chairman of the all-party parliamentary group on drugs misuse, said the study did not convince him it was time to return cannabis to class B. "I don't think the causal link has been proved. I think cannabis might - possibly for genetic reasons - trigger psychosis at an earlier age." The MP, who is also a member of the science and technology select committee, said there was a danger of criminalising "hundreds of thousands of young people" if the status of the drug was changed. "If Gordon Brown changes the class of the drug, it won't be evidence-based but for political reasons," he said.
Of course, Wanjek did not limit his coverage to alleged link between schizophrenia and marijuana, he also felt compelled to pass along the Drug Czar’s latest musings about “potent pot”.
“According to NIDA, marijuana seized in drug arrests during the late 1990s was twice as potent as that seized in the late 1980s and nearly four times as potent as that seized in the 1970s. The active ingredient in pot is THC. On average, the pot on the streets 30 years ago was about 1 percent THC; today the average is about 4 percent.”
The problem with this is that no one outside the Britain’s Independent takes the Drug Czar seriously on this matter. See the following from the Guardian,,2041749,00.html and the following from Slate For starters, trying to get stoned on pot with a THC content of 1 is akin to trying to get drunk on non alcoholic beer. I suppose it is theoretically possible, but all one is likely to get out of doing so is a headache. Hemp has a THC content of 1% or below.
However suppose “potent pot” is a reality is it anything to be concerned about? Of course not. Saying that potent pot is reason for effectively criminalizing marijuana possession is akin to saying that alcohol should be banned because gin has higher alcohol content than beer. It makes no sense. The pharmacological affects of consuming 1 “chemically supercharged” joint, as various US attorneys like to say, versus x number of your “dad’s joints” would be no different if the amount of THC consumed is the same. As for consumption, just as people do not drink the same volume of gin as beer, the higher the THC level in pot the less people consume. Hence, ironically more potent pot may be a welcome development. After all, one of the most prominent health effect related to marijuana, if not the most, is that it is usually smoked. The more potent the pot, the less people have to smoke to achieve the same high. This same point was made to Wanjek a number of years back.
“Comparing marijuana strength through the years is ‘absurd,’ according to Lester Grinspoon, an emeritus professor at Harvard Medical School, who consults patients, many of them elderly, on using marijuana to relieve pain and nausea. ‘The whole issue on potency is a red herring,’ he said. ‘The more potent the pot, the less you use.’Grinspoon said that studies have shown -- and his patients' experiences confirm -- that marijuana users smoke until they feel high -- or, as he prefers to say, ‘achieve symptom relief,’ -- and then stop, whether it took two hits or an entire joint. In this regard, today's higher-potency pot is no more ‘dangerous’ than the bunk weed of yesteryear, he said.”
All that being said, if potency is the concern, then it should be legalized. The only way to regulate the potency of pot is to legalize it. Moreover, so long as the drug is illegal, producers will seek to increase potency. The higher the potency the smaller the package the smaller the package the less likely they will get caught.

No comments: