Americans' cocaine use fell by about half from 2006 to 2010, while their use of marijuana jumped by more than 30 percent, a new report concludes.
The report, by the RAND Drug Policy Research Center, estimated Americans spent $100 billion annually on cocaine, heroin, marijuana and methamphetamine between 2000 and 2010, according to HealthDay.
During the decade studied, heroin use remained fairly stable. Use of methamphetamine increased sharply during the first half of the decade, and then decreased.
In 2000, Americans spent much more on cocaine than on marijuana, but that spending pattern had reversed by 2010, the article notes.
The report does not cover the recent increases in heroin use, or the effects of laws in Colorado and Washington state that have legalized recreational use of marijuana.
"Our analysis shows that Americans likely spent more than one trillion dollars on cocaine, heroin, marijuana and methamphetamine between 2000 and 2010," lead researcher Beau Kilmer said in a news release. He noted the increase in marijuana use appears to be related to a rise in the number of people who said they use the drug every day or almost every day.
The figures for marijuana use come from the National Survey on Drug Use and Health, while estimates for use of cocaine, heroin and methamphetamine are largely based on information from the Arrestee Drug Abuse Monitoring Program (ADAM). The federal government recently stopped funding for ADAM, the researchers note. They say it will be much more difficult to track the abuse of these drugs in the future.