How to talk to your kids about pot Attitudes toward marijuana have changed over time.

 -- The public attitude toward marijuana has changed within the U.S., with more than half of states legalizing the drug for medicinal or recreational purposes.

But the changing attitudes and loosening of legal barriers raise a question for parents: What should they tell their children about marijuana use and its possible risks?

Parents appear to be less concerned with marijuana use compared to other issues. According to the Yahoo-Marist poll released today, most people are more concerned about their children having sex or smoking cigarettes than smoking marijuana. Experts say the parent-child conversation about marijuana may have to be more nuanced, especially if the parents themselves use marijuana recreationally.

“The issue is that the perceived risk of marijuana is at an all-time low,” says Dr. Merrill Herman, associate professor at Albert Einstein College of Medicine and an addiction psychiatrist at Montefiore Medical Center.

But he warns that “cannabis can cause people to lose motivation, have a cognitive impact and can affect their psychiatric status.”

Herman brings up the fact that teens who are reluctant to talk to their parents about feelings of depression or anxiety may self-medicate with marijuana, which can delay important treatment and lead to greater problems in the future. He emphasizes that the marijuana available now is much more potent than it was the 1960s and 70s, something that is especially important for parents to remember when reflecting on their own experiences.

Though he says marijuana does not cause people to use other drugs, Herman notes that “most people who use other drugs have also used marijuana.”

The American Academy of Pediatrics has released a few helpful talking points on how marijuana can affect growing teens. The academy also recommends that parents be honest but brief about their drug-use history when discussing marijuana with their children.

The points include:

-Marijuana is federally illegal, and is illegal everywhere for people under the age of 18. Being caught by police with marijuana can have legal consequences. Many schools also have no-drug policies for participation in extracurricular activities.

-Driving under the influence of marijuana is illegal, and marijuana is the most common illegal drug to be used by people involved in deadly car accidents.

-Marijuana is a psychoactive drug that impacts brain development. Research has shown that the brain is not fully formed until at least the age of 21. Using a drug that affects the brain while it is developing can permanently change it and cause it to develop abnormally.

-Teens who are susceptible to certain psychotic disorders may increase their risk of developing them with heavy marijuana use.

-Marijuana can be addictive: about 9 percent of all users develop an addiction to the drug, and up to 50 percent of teenagers who use marijuana daily become addicted to it. The myth that marijuana is not addictive is not true.

-Marijuana smoke has toxins in it that are not eliminated by vaporizers or hookahs.

Dr. Carolyn Certo Gnerre is a third-year psychiatry resident at Montefiore Medical Center in New York and resident in the ABC News Medical Unit.