Spread of legal marijuana outpacing awareness of risks, study suggests

New study finds that, with more permissive state laws, marijuana use is up – and so is addiction to the drug.

Support for legalizing marijuana in the United States is at its highest in nearly 50 years – and with it comes a hike in both cannabis use and dependence, a new study has found.

The findings suggest that, as laws and attitudes change toward the drug, further research is needed on the impact of changing policy on marijuana use. There's also a need for more public education on the drug’s effects.

“Given the increased permissiveness in US attitudes and laws related to marijuana … updated information is needed,” said the report, a joint project among Columbia University in New York, the National Institute on Alcohol Abuse and Alcoholism, and the New York State Psychiatric Institute.

“This study and others suggest caution and the need for public education about the potential harms in marijuana use, including the risk for addiction,” the report concludes.

Twenty-three states and the District of Columbia have now legalized the use of marijuana for medical reasons. Four states and D.C. have made recreational pot legal, as well. “Legalization advocates say that 2016 is likely to be the next big year, when Arizona, California, Maine, Massachusetts, and Nevada (at a minimum) could all vote on legalization,” wrote The Christian Science Monitor’s Amanda Paulson in February.

At the same time, public support for such legislation has soared during the past year, with nearly 60 percent of Americans today saying marijuana should be legal – up seven percentage points from 2014 and the highest point in the last 46 years, according to Gallup.

To Deborah Hasin, the new study’s lead author, the changing environment around marijuana requires a more robust approach to both scientific research and public education on the drug.

“Counteracting the perceptions that (marijuana) is harmless with a balanced message about the potential harms is important,” said Dr. Hasin, who is also a professor of clinical epidemiology at Columbia University in New York, to Reuters. “For researchers, I think it's important to find what characteristics put people at risk.”

From 2012-13, more than 9 percent of adults surveyed used marijuana, compared with just over 4 percent from 2001-02, according to the study, published Wednesday in the Journal of the American Medical Association. And while many individuals can use marijuana without becoming addicted, the study noted, addiction to or dependence on the drug has doubled from 1.5 percent to nearly 3 percent in the past decade.

“[A]s the number of US users grows, so will the number of those experiencing problems related to such use,” Hasin and her colleagues wrote. “This information is important to convey in a balanced manner to health-care professionals, policymakers, and the public.”

Over the past year, Colorado, the first state to legalize recreational pot sales, has launched at least two major initiatives to educate the public about both the potential benefits and harms of marijuana and the laws surrounding it.

The “Good to Know” campaign, which began in January, was the first “deliberate attempt to educate without alienating,” USA Today reported at the time. The initiative – a $5.7 million project funded with taxes from pot sales and designed by public health officials in collaboration with marijuana retailers and legalization skeptics – used print and broadcast media as well as the Internet to deliver a positive, informational message about the drug.

"I've always said we need to start treating marijuana like the drug it is, not the drug some fear it to be," said Colorado state Rep. Jonathan Singer, a Democrat.