Back in 1998, when the federal government unveiled a new batch of anti-drug ads, I noted that widespread experience with marijuana had made the anti-pot propagandist's job more difficult: People tend to be skeptical of tall tales about psychoactive substances when they themselves have tried those substances or know others who have without suffering any noticeable harm. That phenomenon, I suggested, "helps explain why government officials continue to insist that marijuana is either more dangerous than it used to be or more dangerous than we used to think."
Bill Bennett, who when I wrote that column was already a former drug czar and has now held that position for 24 years, is still pushing both prongs of this argument, trying to make a familiar drug seem newly exotic and threatening. In a Wall Street Journal op-ed piece co-authored by Robert A. White, a former federal prosecutor, Bennett argues that "legal pot is a public health menace" because today's cannabis is stronger than the stuff that Journal readers smoked in college and because recent research shows that it damages teenagers' brains.
There is no denying that marijuana nowadays is typically stronger—i.e. better—than it used to be, although I am not sure what Bennett means when he says "it is often at least five times stronger." In any case, why does Bennett insist that better marijuana is worse? "With increased THC levels come increased health risks," he says, citing the Colorado man who killed his wife after eating marijuana-infused candy and the visiting college student who jumped off a hotel balcony in Denver after eating a pot cookie. The fact that prohibitionists endlessly recycle these two "marijuana-related deaths" suggests that things in Colorado, where recreational use has been legal since the end of 2012, must be going pretty well. How many alcohol-related deaths has the state seen during the same period?
Another problem with Bennett's evidence: He seems to have forgotten that he was supposed to be explaining why stronger pot is more hazardous to your health (a somewhat counterintuitive claim, since higher potency tends to reduce the amount of smoke inhaled). Instead he ends up arguing that marijuana edibles are especially dangerous. But edibles are made with concentrates, so their strength does not depend on the potency of the original plant matter. In fact, Colorado concentrates are often made with low-potency leaves that in the old days would have been discarded.
Getting even farther from the claim he is trying to substantiate, Bennett mentions "more intoxicated driving," which presumably is a reference to a recent study finding that the percentage of fatally injured Colorado drivers who tested positive for marijuana metabolites rose between 1994 and 2011 (i.e., prior to the policy Bennett is criticizing). For reasons I explain here, those drivers were not necessarily intoxicated when they died, and their crashes may have had nothing to do with marijuana.
Finally, Bennett makes what sounds like a health-related claim. "Since Colorado legalized recreational use earlier this year," he says, there have been "more emergency hospital admissions due to marijuana exposure and overdose." He does not cite a source or specify any numbers, but let's assume that's true. How would that trend illustrate his contention that "increased THC levels" bring "increased health risks"? Have THC levels increased since January? It's not even clear how many of the "emergency hospital admissions" to which he refers involved smoked marijuana. In cases involving edibles, the potency of the plant would be irrelevant.
If Bennett's argument that increased potency makes cannabis fundamentally different is less than persuasive, what about his claim that we need prohibition to save the children and their delicate brains? I address that marijuana menace at some length in my most recent Forbes column, which you can read if you're interested. I'll wait.
For those who do not feel like following the link, here is a quick summary: Even Nora Volkow, director of the National Institute on Drug Abuse and no fan of marijuana, concedes that research on the impact of adolescent pot smoking is inconclusive. "Although multiple studies have reported detrimental effects," Volkow and three co-authors write in a recent New England Journal of Medicine article, "others have not, and the question of whether marijuana is harmful remains the subject of heated debate." There are three major reasons for that debate: 1) The evidence is mainly correlational, meaning it does not establish cause and effect, 2) observed differences between pot smokers and abstainers do not necessarily have practical significance, and 3) results based on studies of heavy users do not necessarily apply to people who consume cannabis occasionally or moderately.
Bennett and White do not seem to have delved into this research very deeply. If they had actually read the studies they cite, they probably would not have written this:
The APA [American Psychological Association] noted that young people who become addicted to marijuana lose an average of six IQ points by adulthood. A long line of studies have found similar results—in 2012, a decades-long study of more than 1,000 New Zealanders who frequently smoked pot in adolescence pegged the IQ loss at eight points.
Actually, both of those results come from the same study, which found that subjects identified as "cannabis dependent" in three or more follow-up interviews lost an average of about six IQ points, which rose to eight points for the subjects in that group who were diagnosed as dependent before age 18.
Whatever the practical significance of such findings, how do the potential hazards of marijuana to adolescents justify treating adults who grow, sell, or use cannabis like criminals? Bennett, despite his Ph.D. in philosophy and frequent pontificating on moral issues, has never found that question interesting, and he ignores it once again in his latest prohibitionist plea.
For a review of Bennett's last co-authored collection of tired prohibitionist arguments, go here.