Talk to your grandparents about marijuana — before somebody else does.

The latest release of a massive federal drug use survey shows monthly marijuana use has skyrocketed among older Americans. The past decade, in fact, has seen a sea change in the demographics of marijuana use: As recently as the early 2000s, teens were more than four times more likely to use marijuana than 50- and 60-somethings. But as of 2017, Americans ages 55 to 64 are now slightly more likely to smoke pot on a monthly basis than teens ages 12 to 17. That difference is within the survey’s margin of error.

The oldest age group — seniors age 65 and older — has seen steep increases in marijuana use, as well. In the mid-2000s, monthly marijuana use among this group was effectively at zero percent. As of last year, 2.4 percent of seniors used marijuana monthly, and nearly 4 percent were using on at least an annual basis.

Federal data showed that marijuana use among middle-aged Americans surpassed teen use several years ago, which underscores a point that often gets lost in contemporary debate about marijuana legalization: While debates about marijuana use tend to focus on the drug’s effects on young people, marijuana use is becoming more concentrated among older Americans. The effects of long-term marijuana use among that cohort are less understood.

There are a number of factors driving these trends. Nine states plus the District have legalized marijuana for adult recreational use since 2012. [Read More @ Washington Post]