CHICAGO — An influential doctors’ group is beefing up warnings about marijuana’s potential harms for teens amid increasingly lax laws and attitudes on use of the drug.

Many parents use marijuana and think it’s OK for their children, but ‘‘we would rather not mess around with the developing brain,’’ said Dr. Seth Ammerman.

The advice comes in a new report from the American Academy of Pediatrics.

It says emphasizing that message is important because most states have legalized medical use for adults, and many have decriminalized adults’ recreational use.

Associated Press