Why don't the hacks who cover the illicit-drug beat just turn their keyboards over to the drug-abuse industrial complex and let them write the stories?
This week, Reuters moved a story based on a government press release about marijuana potency issued by the Office of National Drug Control Policy—the office of "drug czar" John P. Walters. The press release and the Reuters story state that marijuana potency has reached its highest level since the government started monitoring it in the late 1970s. The average levels of THC in marijuana now stand at 8.5 percent. (THC is the primary active ingredient in marijuana.) This compares to a little less than the 4 percent measured in 1983.
Headlined "U.S. Marijuana Even Stronger Than Before: Report" on Reuters' Web site, the piece quotes nobody outside of government as it channels drug warrior hysteria.
As this drug-czar chart shows, the average percentage of THC in cannabis samples analyzed by the ongoing Marijuana Potency Monitoring Project at the University of Mississippi has increased over the years. Assuming for just a moment that these findings accurately reflect marijuana potency, I've got a question: So what?
What matters isn't how strong the material is, but how intoxicated the users get. And there's lots of evidence that marijuana users tend to have a target level of intoxication and learn how to titrate dosage to reach that level. Studies that ask marijuana users to roll a joint have found that the average size has halved, from about half a gram to about a quarter of a gram, and there's anecdotal evidence that sharing a single joint has become more common.
So much for the inherent dangers of superpotent weed.
But how accurate are the government's measurements of average THC? Writer Brian C. Bennett notes that the number of drug samples tested in the government study has varied widely, making meaningful comparisons of increased (or decreased) potency difficult. The collection of samples doesn't appear to be as scientific as it does anecdotal. The czar's press release asserts that two-thirds of the samples analyzed in the most recent study came from law enforcement seizures and purchases, and the rest from domestic eradications.
Bennett writes that the kinds of marijuana seized and tested vary from year to year, also. In 2000, sinsemilla, the extra-potent flowering tops of the marijuana plant, constituted 3.66 percent of the tested samples. In 2004, 18.39 percent of the samples were sinsemilla. Guess which year produced a higher average measure of THC? In 2000, the figure was about 5 percent. In 2004, about 7 percent.
The Reuters article also conveys the views of a National Institute on Drug Abuse official in reporting that "60 percent of teens receiving treatment for drug abuse or dependence report marijuana as their primary drug of abuse." Kleiman's blog puts the treatment numbers in perspective by pointing to the University of Maryland's Center for Substance Abuse Research, which reports (PDF) that the increase in marijuana treatment admission is driven by the increase in criminal justice referrals. Marijuana arrests "have roughly doubled over the past fifteen years," Kleiman writes in his blog, "with the vast bulk of those arrests … for simple possession. Other studies show that for juveniles, most non-criminal-justice referrals reflect parental pressure."
None of this is to champion the use of marijuana. I just want journalists to stop regurgitating whatever the drug warriors tell them. Bennett catalogs some of the most ridiculous claims about marijuana potency made by officials and published in the press during the last 40 years. If you take these statements at face value, a single joint rolled from today's marijuana should carry a bigger punch than several tons of yesteryear's Mexican grass.
Addendum, April 29: Via e-mail, I asked Mark Kleiman if his views on potency and potency reports had changed since he wrote his blog item. After I filed my piece, he responded:
In the real world, THC content seems to be continuing to drift up, though I wouldn't take the Mississippi pot farm's unsupported word for it.
In our knowledge, the idea that THC content is the be-all and end-all of cannabis potency now seems to be discredited. The work by GW Pharmaceuticals suggests that the ratios of THC to cannabidiol matters, with high-ratio stuff more likely to generate problematic levels of anxiety. (Cannabidiol seems to be anxiolytic.)
Users can titrate (though of course not perfectly) to avoid getting "too stoned" from more potent pot. But if there's less cannabidiol per milligram of THC, it's more likely that the amount of pot they have to smoke to get as high as they want to get will produce a panic reaction.
My understanding is that hashish, which generally has a higher concentration of THC than unprocessed cannabis, also has lots of CBD and thus a low THC/CBD ratio. Therefore the "Indica" cannabis that increasingly dominates the market is actually more likely to generate bad reactions than is hashish.
It seems to me that the bad faith of the anti-cannabis forces is showing. If the illicit market is creating dangerously potent (or, I would say, high THC/CBD ratio) cannabis, that's an argument for creating a legal market where the potency and the ratio can be known to the user and regulated by the government. There's no particular reason either buyers or sellers in a licit cannabis market should favor especially potent pot, any more than 150-proof rum has a big share of the alcohol market.
I've never smoked marijuana and I don't advocate its use. For compelling health reasons, kids should avoid it, and many seem to do just that. According to a Monitoring the Future study, the number of high-school pot smokers remains flat or down over the last decade. (E-mail may be quoted by name unless the writer stipulates otherwise. Permanent disclosure: Slate is owned by the Washington Post Co.)