The most commonly abused prescription drugs in the U.S. are painkillers, stimulants and central nervous system depressants.
Out of the nearly 2 million substance abuse treatment admissions reported to State administrative data systems in 2008, heroin and other opiates made up the largest percentage of drug-related admissions (20.0 percent).
The rise in demand for diverted prescription drugs in the U.S. has also come with an increase in crime associated with its misuse.
The cost of Ambien tends to be lower in the United States than in other parts of the world where generic brands of the drug are available, making it more available and accessible for use and abuse.