As U.S. policies have become more tolerant of marijuana, and have received more media attention, the proportion of adults using and abusing the substance at least doubled between 2001 and 2013, according to a new study released by Reuters.
Although marijuana dependence and abuse was found to be increasing, it is is largely due to the overall increase in new users, researchers note, while existing marijuana users experienced a 15 percent decline in pot-related disorders.
Almost 4 percent of adults between 2001 and 2002 reported having used marijuana in the past year, compared to about 10 percent between 2012 and 2013. Similarly, 1.5 percent had abuse or dependence problems – marijuana use disorder – at the start of the 21st Century, compared to about 3 percent from 2012 to 2013.
23 U.S. states legalize medical marijuana use, and four also allow recreational use, and that number is likely to increase in the future the researchers write in JAMA Psychiatry. More Americans also favor marijuana legalization than before, and fewer see the substance as harmful.
For the new study, they compared data in-person interviews with over 43,000 U.S. adults between 2001 and 2002 to data from over 36,000 people collected between 2012 and 2013.They found that reports of having used marijuana in the past year more than doubled between the two time periods with especially large increases among women, blacks, Hispanics, southerners and middle-aged and older people.
Between the two generations, the researchers found that such disorders were about twice as common during the 2012 and 2013 interviews. About three of every 10 marijuana users – about 7 million Americans – were diagnosed with a marijuana use disorder in the latter survey.
Past studies have tied marijuana use to mental health issues, poor quality of life, use of other drugs and withdrawal after heavy use.
The researchers write that if the amount of U.S. adults using marijuana increases, so will the number of those with marijuana use disorders undoubtedly.
“People should consider this information when they’re making choices about using marijuana, and the public should consider the information as they consider legalization,” Hasin said.