The global increase in manufacturing amphetamine-type substances (ATS) observed during the '90s might have leveled off, according to the U.S. State Department's Bureau for International Narcotics and Law Enforcement Affairs.

U.S. meth production has declined significantly since 2004, said the bureau's 2008 International Narcotics Control Strategy Report. But drug markets in Mexico and Asia are taking up the slack in U.S. production -- keeping usage numbers static. The report said central and northern Europe, and Southeast Asia, still have worrisome numbers. The report suggests ATS remain popular due to their low manufacturing cost and high profit margin.

There's good news, however. Despite increased meth production in Mexico, the Mexican government announced that by 2009 all meth precursors and products containing ephedrine or pseudoephedrine will become illegal. The passage of the Combat Methamphetamine Epidemic Act of 2005 has largely outlawed the sale and possession of ephedrine in the U.S.