by Patrick Appel

A reader writes:

As someone who has worked in drug use survey research, let me put the numbers regarding (30-day) marijuana and cigarette use into a bit more perspective. Yes, marijuana use was very high in the 70s, and has dropped since, but it actually goes in waves (as does cigarette use, but we'll get to that in a moment). Using the CDC's Youth Risk Behavior Survey data (which is a fairly consistent national sample using the same questions over the past two decades and more), we can see that marijuana use in high school had a local peak in 1999 at almost 27%, about 7 percentage points higher than today, and has since declined (to about 20% in recent years, with about 2 percentage point margin of error). The real story is not marijuana use, but cigarette use, which also peaked in the late 90s at about 36% (a wave in the 1990s again), but has since shot down to about 20% as well, with the biggest drop coming between 2001 and 2003 (28.5% to 21.9%, both with about 2.5 percentage point margins of error). So it's really not about how much pot has or has not risen; in fact, marijuana has been declining. It's about how much cigarettes have fallen. And that's a big success story, because unlike marijuana, there are definite health impacts to cigarette use, particularly early cigarette use.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.