Marijuana damages teens' brains

(Marc Galanter, M.D., from the New York University School of Medicine, specializes in psychiatry and substance abuse.)

I worry that marijuana poses more risks to teens than they, or their parents, recognize.

Marijuana use can have a marked effect on young people's mental health, as well as their overall wellbeing. Marijuana has been linked to depression, anxiety and schizophrenia.

There is also a growing body of research indicating that marijuana smoking may actually cause many of these and other mental health problems. Youth who use marijuana weekly have double the risk of depression later in life, and teens aged 12 to 17 who smoke marijuana weekly are three times more likely than non-users to have suicidal thoughts.

Can chronic marijuana use produce psychological changes to a developing brain?

While researchers still have a long way to go in understanding the complexity of brain function, we do know that illicit drug use produces psychological - if not physical - changes, impacting on a young person's developing brain, as brain development continues into the early 20s.

Unfortunately, the average age for teens trying marijuana is 14. This means that many people who smoke pot do so before their brain development is settled, leaving room for chronic drug use to influence certain centers that control emotion and reason.

The high levels of THC (the active component in marijuana) can influence the brain centers into feeling or thinking in a distorted way, which can present outwardly as depression or paranoia. Research also shows that marijuana use affects blood flow in the brain as well, which may be reflected in altered activity and function.

How can I tell if my son or daughter is having mental health problems?

It is often difficult for parents to know the difference between emerging mental health problems and typical changes in mood or attitudes in their teen.

It is normal to see temper outbursts, changes in sleeping habits and changes in hobbies. However, there are a number of ways of identifying whether your child is having psychological problems related to marijuana use.

First and foremost, it is critical that you are attentive. You can look for signs of depression, withdrawal, carelessness with grooming habits or hostility.

Other questions you can ask yourself: Is your child doing well in school, getting along with friends, taking part in sports or other activities? If there have been marked changes in your teen's activities, it's time to do some more homework. Look for evidence, such as missing prescription drugs and bottles of eye drops, which mask bloodshot eyes.

An excellent place to find help for mental health issues is to visit the U.S. Substance Abuse and Mental Health Services Administration website, mentalhealth. samhsa.gov/cmhs. If you do not have access to the internet, you can call 1- 800-662-HELP.