Fewer than 40 percent of youth believe marijuana is harmful, according to a massive survey by the National Institutes of Health. The survey, which polled more than 41,000 eighth, 10th and 12th players, also found that use of the drug is on the rise. About 6.5 percent of high school seniors admit to smoking marijuana every day, up from 2.4 percent in 1993.

Nearly a quarter of seniors say they’ve smoked pot in the past month. About 12 percent of eighth graders also say they use marijuana at least monthly.

That’s potentially dangerous. Because while teens may think pot is harmless, it isn’t—particularly for users with developing brains. Exposure to THC, the active ingredient in marijuana, has been linked to memory loss and other changes in the brain, and the levels of THC in the standard joint have gone up from 3.75 percent in 1995 to 15 percent now. (Time)

Paul Asay has covered religion for The Washington Post, Christianity Today, Beliefnet.com and The (Colorado Springs) Gazette. He writes about culture for Plugged In and wrote the Batman book God on the Streets of Gotham (Tyndale). He lives in Colorado Springs with wife Wendy and his two children. Follow him on Twitter.