Today the federal government released the latest results from its National Survey on Drug Use and Health, which indicate a slight uptick in marijuana use. Between 2009 and 2010, the share of respondents reporting past-month consumption rose from 6.6 percent to 6.9 percent. Among 18-to-25-year-olds, past-month use rose from 18.1 percent to 18.5 percent—leading Reuters to declare that "marijuana is increasingly becoming the drug of choice among young adults in the United States." If we are talking about illegal substances, marijuana has been "the drug of choice among young adults in the United States" ever since researchers started asking them about their drug use. Similarly, USA Today reports that "marijuana is as popular as ever," even though survey data (PDF) from the late 1970s and early '80s indicate it was more popular then.

None of this seems like cause for alarm, unless you are Gil Kerlikowske, director of the Office of National Drug Control Policy (ONDCP), who predictably blames medical marijuana laws. "People keep calling it medicine," he said at a press conference today, "and that's the wrong message for young people to hear." Because when "young people" hear "medicine," they think, "I bet that'll get you fucked up," whereas before they had no idea you could get high by smoking pot. However plausible that hypothesis may seem to you, there is little evidence to support the idea that legalizing marijuana for medical purposes increases recreational consumption by teenagers.

The new data do not bolster that case, says Morgan Fox of the Marijuana Policy Project:

We can see from this latest report that past-month marijuana use by 12-17 year olds has stayed the same for males and only increased by .1% in the past year for females. In addition, this report and other available data clearly show that in a majority of medical marijuana states, teen use rates actually decreased since the implementation of their medical marijuana programs.

In any case, Kerlikowske's argument suggests that a drug should not be recognized as a medicine if teenagers can use to alter their consciousness. But as the Drug Policy Alliance's Bill Piper observes, "In the field of medicine, whether or not a youth might abuse something doesn't determine whether or not an adult should have access to a medication and whether a doctor should prescribe it." Kerlikowske does not extend his logic to the stimulants, sedatives, tranquilizers, and opioid painkillers that can be legally obtained with a doctor's prescription. Indeed, he brags that use of black-market methamphetamine is half as common today as it was in 2006, even though the drug's legal status has not changed since then and it is still available for medical use.

The meth numbers, by the way, illustrate the perils of political explanations for drug use trends. If the Obama administration wants to take credit for the 30 percent decline in past-month meth use between 2009 and 2010, shouldn't it also take the blame for the 60 percent increase between 2008 and 2009? The upshot is that reported meth consumption was a bit higher last year than it was when Barack Obama took office. Taking a slightly longer view, the ONDCP emphasizes the drop in meth use since 2006, perhaps because that is when Congress imposed restrictions on the sale of the meth precursor (and decongestant) pseudoephedrine—regulations that Obama supported as a senator. Yet data from the Monitoring the Future Study (which covers a longer period than the National Survey on Drug Use and Health) indicate that meth use among teenagers peaked in 1999 or so.

The Republicans play similar games with drug use numbers.