The American Academy of Pediatrics has issued new guidelines for doctors and parents to talk to teens about the risks of using marijuana, CNN reports.

The organization said changes in the legal status of marijuana may lower teens’ perceptions of the risk, and may lead to more teens trying the drug. A recent survey found there is a decrease in the percentage of teens who say they believe there is a great risk in smoking marijuana once a month or once or twice a week.

Doctors should screen preteens and teens for marijuana use, the group said. If they find a teen is using marijuana regularly or heavily, they can then decide if the teen would benefit from treatment, including counseling and medication.

Parents should tell teens marijuana can cause abnormal brain development and impact memory, concentration and executive functioning skills, the group said. They also noted, “If you use marijuana in front of your teens, they are more likely to use it themselves, regardless of whether you tell them not to.”