Marijuana use
has doubled among adults in the past decade, a new study indicates.
CHICAGO — Marijuana use among U.S. adults doubled over a decade, rising to almost 10 percent or more than 22 million mostly recreational users, government surveys show.
The trend reflects increasingly permissive views about the drug, the researchers say, noting that other studies have shown increasing numbers of adults think marijuana should be legalized. Recreational use is now permitted in four states — Alaska, Colorado, Oregon and Washington and the District of Columbia.
Almost 1 in 3 users had signs of marijuana dependence or abuse, a slight decline from a decade ago.
The results come from a comparison of health surveys from 2001-2002 and 2012-2013 sponsored by the National Institute on Alcohol Abuse and Alcoholism. Almost 80,000 adults 18 and older participated in faceto-face interviews about various health-related behaviors.
The results were published Wednesday in the journal JAMA Psychiatry.
Participants were asked if they had used marijuana in the past year and about signs of problematic use. Those include trying but being unable to reduce heavy use and continued use despite knowing it may be damaging to health or causing depression or anxiety — problems affecting about 6.8 million adults, the latest survey suggests.
Use increased among all ages but was most common in adults 18 to 29.
Because most states didn’t have medical marijuana laws during the survey years, the results likely reflect mostly recreational use, said Deborah Hasin, a Columbia University professor, substance abuse researcher and the study’s lead author.
The results “show people can use marijuana without harms, but there are risks,” she said, adding that more research is needed.