Heroin has become dangerously fashionable

ATLANTA (CNN) -- U.S. public health authorities are increasingly worried that heroin, once a hard-core "junkie" drug, is becoming dangerously fashionable.

According to a report from U.S. Department of Health and Human Services, the use and abuse of heroin has jumped 500 percent in the last 10 years.

"Mainly what it does in the brain is decreases anxiety, decreases any sense of apprehension, produces a euphoric feeling," said Dr. Surita Rao of Emory University.

Heroin can be snorted, injected intravenously or smoked. In about five to seven seconds, the drug reaches the brain and releases dopamine, the so-called "feel good" chemical.

The increased purity of heroin has become a concern

Heroin is an opiate, with a pain-relief effect similar to morphine, codeine or Demerol. But the drug also acts like a barbiturate or alcohol, slowing down bodily functions. And that's where things can go wrong -- deadly wrong if an addict stops breathing.

Authorities are concerned that much of the heroin being sold on the street today is more pure -- and potentially more addictive. And it's now often combined with other drugs, such as cocaine, that increase the threat of death.

And because heroin is so insidiously addictive, it is often hard to break addicts of their habits.

"As you use heroin on a regular basis, you need more and more of the same amount of heroin to produce the same effect, because the receptors in your brain get used to a certain amount, and then they're no longer turned on by that amount, and they want more and more," Rao said. "Then, the person becomes physiologically dependent."