"In the United States, the first report on synthetic cannabinoids from the Drug Abuse Warning Network revealed that an estimated 11,406 visits of the approximately 2,300,000 emergency department visits that involved drug use in 2010 were specifically linked to synthetic cannabinoids. Three quarters of these emergency department visits involved patients aged 12 to 29 (75 percent or 8,557 visits), of which 78 percent were male, and in the majority (59 percent) of these cases, no other substances were involved. The average patient age for synthetic cannabinoids-related visits was 24 years, while it was 30 years for cannabis. Overall, synthetic cannabinoid-related visits were concentrated in the younger age groups: 75 percent of the visits involved patients aged 12 to 29, with 33 percent of the patients aged 12 to 17. In comparison, 58 percent of cannabis-related visits involved patients aged 12 to 29, with 12 percent in the 12 to 17 age group.173"

Source

UN Office on Drugs and Crime, "The Challenge of New Psychoactive Substances: A Report from the Global SMART Programme" (Vienna, Austria: UNODC Laboratory and Scientific Section, March 2013), p. 38.
http://www.unodc.org/document…