Did Teen Pot Smoking Rise or Hold Steady This Year? Yes.

The latest results from the Monitoring the Future Study, which tracks drug use by teenagers, generated dueling press releases today from the Drug Policy Alliance (DPA) and the Marijuana Policy Project (MPP). DPA's take: "Monitoring the Future Survey Finds Cigarette and Alcohol Use at Historic Lows, with Marijuana Use Holding Steady." MPP's headline is notably different: "Teen Marijuana Use Continues to Rise Despite High Arrest Rates." The latter jibes better with the press release from the University of Michigan researchers who conduct the study under contract with the National Institute on Drug Abuse:

Marijuana use continues to rise among U.S. teens, while alcohol use hits historic lows

…Marijuana use among teens rose in 2011 for the fourth straight year—a sharp contrast to the considerable decline that had occurred in the preceding decade. Daily marijuana use is now at a 30-year peak level among high school seniors.

So did marijuana consumption by teenagers hold steady or go up this year? According to the researchers, we can't be sure (emphasis added):

Marijuana use continued to rise among 10th and 12th graders this year for all prevalence periods (lifetime, past year, past 30-days, and daily use in the past 30-days). No one of these changes was large enough to be statistically significant, but they all continue the pattern of a gradual rise.

The share of seniors who admitted smoking pot in the previous month, for example, rose from 21.4 percent in 2010 to 22.6 in 2011. For 10th-graders, this number rose from 16.7 percent to 17.6 percent, but among eighth-graders it fell, from 8 percent to 7.2 percent. None of these changes was statistically significant.

But looking at data for the last several years, you can see a modest upward trend in this number since 2006 among 12th-graders and since 2008 among 10th-graders. Past-month use by high school seniors has risen by 4.3 percentage points since 2006, an increase of 23 percent. But it is still a bit lower than it was in the late 1990s and substantially lower than it was in the late 1970s and early '80s. Past-month use by seniors peaked in 1978 at 37.1 percent, 64 percent higher than today's level. "Daily" use, defined as "use on 20 or more occasions in the past 30 days," also peaked in 1978, when it hit 10.7 percent. This year it is 6.6 percent, which is indeed "a 30-year peak level," meaning it is lower than it was at the beginning of the Reagan administration.

Although they describe the data somewhat differently, DPA and MPP both note continued declines in cigarette smoking and drinking by teenagers, which they see as evidence that underage consumption can be more effectively addressed in legal markets than it can under prohibition. "The decline in cigarette smoking is great news," says DPA's Jag Davies, "not just because it's the most deadly drug but also because it reveals that legal regulation and honest education are more effective than prohibition and criminalization." MPP's Rob Kampia offers a similar spin:

Political leaders have for decades refused to regulate marijuana in order to keep it out of the hands of drug dealers who aren't required to check customer ID and have no qualms about selling marijuana to young people. The continued decline in teen tobacco and alcohol use is proof that sensible regulations, coupled with honest, and science-based public education can be effective in keeping substances away from young people. It's time we acknowledge that our current marijuana laws have utterly failed to accomplish one of their primary objectives – to keep marijuana away from young people – and do the right thing by regulating marijuana, bringing its sale under the rule of law, and working to reduce the easy access to marijuana that our irrational system gives teenagers. 

The once startling fact that high school seniors are more likely to have smoked pot in the last month than tobacco (22.6 percent vs. 18.7 percent) reinforces Kampia's point. While we should not ignore the likelihood of leakage from a legal marijuana market, it is important to emphasize that the law distinguishes between adults and minors with respect to many risky decisions, that concerns about underage access hardly count in favor of maintaining a black market where such distinctions are ignored, and that the government should not treat all of us like children simply because some of us are.