The latest numbers from the government-sponsored Monitoring the Future Study, released today, indicate that marijuana use among teenagers continues a modest upward trend that began a few years ago. The share of high school seniors who reported smoking pot in the previous month, for example, rose from 20.6 percent in 2009 to 21.4 percent in 2010. That's up from a recent low of 18.3 percent in 2006 but still lower than the rates seen in the mid-to-late 1990s. Federal drug czar Gil Kerlikowske blames "mixed messages about drug legalization, particularly marijuana legalization." He told ABC News Radio:
We have been telling young people, particularly for the past couple years, that marijuana is medicine. So it shouldn't be a great surprise to us that young people are now misperceiving the dangers or the risks around marijuana.
The timing of the increase in marijuana use does not seem to fit this theory. States began legalizing the medical use of marijuana in 1996, after which past-month marijuana use among high school seniors went up and down until 2003, when it began a decline that continued until 2007. Furthermore, as the Drug Policy Alliance's Bill Piper points out, states that have liberalized their marijuana policies have not seen noticeably bigger increases in use than states that have not:
Fifteen states (plus Washington, D.C.) have legalized marijuana for medical use and 13 states have decriminalized marijuana for personal use. Decades of research have consistently demonstrated that marijuana use rates in those states go up and down at roughly the same rates as in other states.
Mason Tvert, co-author of Marijuana Is Safer (which I reviewed in the April issue of Reason), notes that the increase in marijuana use has been accompanied by a decline in drinking, which could mean a net reduction in drug-related harm.