People who abuse prescription drugs often do so believing the pills are safe because they are prescribed by doctors and approved by the Food and Drug Administration, addiction experts say.

In 2005, non-medical use of painkillers contributed to more than 8,500 deaths. Overdose deaths involving prescription pain relievers increased 114 percent from 2001 to 2005, the most recent year for which nationwide data is available, according to the Office of National Drug Control Policy.

Heath Ledger and Anna Nicole Smith, two celebrities whose deaths resulted from accidental overdoses, had each taken a lethal combination of prescription drugs -- painkillers, anti-anxiety drugs and sleeping aids. The cause of Michael Jackson's death remains under investigation, pending the result of toxicology screening.

Non-medical use of prescription drugs is most prevalent among young adults between the ages of 18 and 25, according to the Office of National Drug Control Policy.

In a study of 1,000 teenagers between the ages of 13 and 18, 155 reported abusing prescription drugs. In the 2007 study, released by The Partnership for a Drug-Free America, teenagers reported obtaining the drugs through a friend or family member, or in a medicine cabinet, or at a party.

One trend is "pharming parties," where teens raid their home medicine cabinets, put various pills in a bowl and pick which one to consume. Sometimes, they take the pills with alcohol which presents dangers, said Susan Foster, vice president and director of policy research and analysis at The National Center on Addiction and Substance Abuse at Columbia University in New York.

But older adults who take medication to treat pain, can also become addicted.

"Often what happens is someone experiences discomfort, anxiety, or pain. They start being treated with medicine, and need more," said Dr. Steven Juergens, an assistant clinical professor of psychiatry at the University of Washington and a private addiction specialist in Bellevue, Washington.

They feel better when using the medication and often feel like "they need it," he said.
"They're caught in this hell of using the drugs illicitly, not seeing it as a problem," said Juergens, who first reported the abuse of Xanax in the 1980s. "It takes a while to unravel that."

People deny there is a problem and sometimes do not understand that their behavior is dangerous.