Former NIDA International Program Distinguished International Scientist Octavio Campollo, M.D., M.Sci., Ph.D., Mexico, and colleagues report in Drug and Alcohol Dependence that Mexico’s 2004 controls on ephedrine and pseudoephedrine changed the U.S. methamphetamine market. Restrictions on these precursor chemicals in Mexico resulted in widespread emergence of less potent methamphetamine and declines in prevalence and availability of the most potent type of the drug, which had dominated the U.S. market since the late 1980s. The authors found that U.S. methamphetamine treatment admissions declined between 2005 and 2010 and suggest that the emergence of less potent methamphetamine may have helped limit dependence. (Cunningham JK, et al. Mexico’s precursor chemical controls: Emergence of less potent types of methamphetamine in the United States. Drug Alcohol Depend. 2013 Apr 1;129(1–2):125–36. doi: 10.1016/j.drugalcdep.2012.10.001) PubMed abstract.