In the past several years, 24 states have legalized marijuana in some manner. Most often, states have decriminalized possession or allowed for the purchase of medicinal marijuana, but two states—Washington and Colorado—have legalized pot outright. Marijuana users often say the substance is less dangerous than alcohol.

However, that’s not necessarily true—especially when it comes to teens. A new study, published in the journal Neuropsychopharmacology, finds that pot can significantly and permanently impair teens’ brains.

“(In) the past 20 years, there has been a major controversy about the long-term effects of marijuana, with some evidence that use in adolescence could be damaging,” senior author Asaf Keller said in a press statement. “Previous research has shown that children who started using marijuana before the age of 16 are at greater risk of permanent cognitive deficits, and have a significantly higher incidence of psychiatric disorders such as schizophrenia.” (The Star-Ledger)

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.