Pot Potency Peril

It also trots out warnings about reefer madness reminiscent of anti-drug propaganda from the 1930s, conflating correlation (between heavy pot smoking and depression, for example) with causation. Nora Volkow, director of the National Institute on Drug Abuse, worries that stronger pot might be more addictive, although she concedes that "more research is needed to establish this link between higher THC potency and higher addiction risk."

By contrast, the Australian scientists who wrote the Addiction article say "more research is needed to determine whether increased potency translates to harm for users." Unlike our government, they are open to the possibility that the link Volkow seeks to establish does not in fact exist.

To bolster the idea that marijuana is more addictive today, the ONDCP notes that "16.1 percent of drug treatment admissions [in 2006] were for marijuana as the primary drug of abuse," compared to "6 percent in 1992." But referrals from the criminal justice system account for three-fifths of these treatment admissions, and marijuana arrests have increased by more than 150 percent since 1990.

By arresting people for marijuana possession and forcing them into treatment, the government shows why it has to arrest people for marijuana possession. That's our self-justifying drug policy in a nutshell.