DR. WALLACE: I'm 17 and live a rather sheltered life with my younger brother and our parents. My best friend has a new boyfriend that she has been seeing for about a month. Last night, she told me that this guy admitted to her that he is a cocaine addict. She told me that she has decided to stop seeing him because her brother said that cocaine users have a very difficult time trying to stop using the drug.

Is this true, and if so, why is it difficult to overcome? What exactly is cocaine, and where does it come from? —Patty, Cleveland, Ohio.

PATTY: According to the U.S. Department of Health and Human Services, cocaine belongs to a class of drugs known as stimulants. Cocaine initially elevates mood, temporarily filling the user with a sense of exhilaration and well-being, but as the effects of the drug wear off, the user slides into edginess and depression.

Addiction is a great danger for all cocaine users. Dependency on this drug is so strong that it dominates all aspects of an addict's life. Addiction can erode physical and mental health, drain financial resources, drive away friends and loved ones and destroy careers. Addicts hurt themselves and all those around them.

In addition, using cocaine can be fatal. It can constrict the blood vessels around the heart, thus making it harder to move blood through the body. This stress may trigger chest pain or a heart attack. The drug can also interfere with the signals controlling the heart's pumping action. When this occurs, the heart beats so irregularly that it may stop — for good! Cocaine in all of its commonly used forms has been associated with sudden heart attacks in people in their 20s, some of whom were using the drug for the very first time.

As you can see, cocaine is a powerful, addictive drug that leads to a life of despair and sometimes an early death! Since it is such a powerfully addictive drug, it is difficult for the user, by himself, to free himself from it.

Tell your friend to encourage this young man to seek professional assistance to help him overcome his addiction but to avoid dating him. P.S.: Cocaine comes from the coca plant grown in South America.

THE ODD MAN IS OUT

DR. WALLACE: I am 16 and so are all the members of my group — five girls and a guy. All of us hang around together at school and go places in the evening. Many times it's really nice to have a guy along, especially after dark. But there are times we girls would rather do things by ourselves. We have encouraged him to hang around with guys once in a while, but he won't.

This guy has five sisters and no brothers, so maybe that's why he would rather be with us. He has dated several of us from time to time.

Please tell me how we can tell him to bug off once in a while without hurting his feelings. He is always around when we make our plans. —Judy, Newark, N.J.

JUDY: Make your "girls only" plans by telephone with the "odd" man out.

Dr. Robert Wallace welcomes questions from readers. Although he is unable to reply to all of them individually, he will answer as many as possible in this column. Email him at [email protected]. To find out more about Dr. Robert Wallace and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.