More Americans are seeking treatment for cannabis-related health problems, according to a UN agency report that is likely to intensify the US debate on marijuana legalization.
Washington and Colorado became the first US states to legalize recreational marijuana after voters backed the move in 2012.
Citing statistics from before the legalization took effect, the number of people in the United States age 12 or older that had used cannabis at least once in the previous year rose to 12.1% in 2012 from 10.3% in 2008, according to the United Nations Office on Drugs and Crime (UNODC).
In the US between 2006 and 2010, there was a 59% increase in cannabis-related hospital emergency room visits and a 14% increase in cannabis-related treatment admissions, the report said.
Additionally, the report found that there were increased levels of tetrahydrocannabinol (THC) in seized cannabis crops in the U.S, with levels rising to 11.9% in 2011 from 8.7% in 2007. THC is the main mind-altering chemical found in the cannabis plant.
Increased cannabis use by Americans is partly fueled by a misperception of the health risks, the UNODC report said. It cautioned that although the public may perceive cannabis to be the least harmful of illicit drugs, there has been a noticeable increase in the number of people seeking treatment for cannabis-use disorders over the past decade.