The number of Americans who use marijuana increased by 10 million from 2002 to 2014

The number of Americans who use marijuana increased by 10 million from 2002 to 2014

Between 2002 and 2014, the number of adult Americans who use marijuana increased by 2.9%, according to a new study published Wednesday in the Lancet, a British medical journal. That percentage increase is tantamount to 10 million adults, the Guardian reports.

By 2014, the number of adults who disclosed using marijuana was around 32 million. In reality, that number is likely higher — the illegality of cannabis in a number of states increases the likelihood people would not be as forthcoming about their use of the drug. 

An unexpected finding was "how many people there are using marijuana in a daily or near daily basis," said Dr. Wilson M. Compton, one of the study's authors, according to the Guardian. 

In 2002, 3.9 million adults were using the drug with such regularity. By 2014, that number had jumped to 8.4 million.

The study was designed not just to garner insights into the frequency with which marijuana is used, but also how common "use disorders" are with the drug. 

Despite growing numbers of marijuana users, the proportion of those abusing the drug stayed the same over the 12-year period, hovering around 1.5% of users, the study found. The number of people who thought getting high on a weekly or biweekly basis could produce "great risk of harm" dropped from around half to a third. 

Past studies have suggested weed can negatively impact your health, but there's also ample information on its benefits. Studies have shown compounds found in cannabis can protect against Alzheimer's disease and reduce epileptic seizures.

Still, the researchers suggested the country's increasing marijuana use calls for "a need for education regarding the risk of smoking marijuana and prevention messages," according to the Guardian.