A mericans, descendants of rebels and explorers, often push themselves to the edge in search for the ultimate challenge or reward. But in the never ending quest to experience it all, some have pushed too far. Those who have chosen to try narcotics for thrills have hitched their lives to the most addicting group of drugs in the world.

An addiction is a complex condition that results in an emotional and physical inability to avoid drug use. Eventually, an addict is compelled to continue taking the drug, even when met head-on with harmful consequences. Addiction affects a person's body as well as his or her mind.

Narcotics' chemical effects on the brain make them so addicting.

Sections of the brain and spinal cord contain cells loaded with opiate receptors, structures that normally bind to the body's own painkilling chemicals. When...