Although marijuana use is on the rise, with approximately 12.5 percent of adults in the United States using the drug at least once in 2013, a new study by Washington University School of Medicine researchers claims that the increase is not as big as previously believed. The team points to a previous study that claimed that use has doubled from 2002 to 2013 and reports that this is false, as well as revealing that the problems related to the drug have remained steady.
The new study reveals that instead of doubling, the increase was closer to 20 percent from 2002 to 2013, and pot-related problems, such as addiction, have either remained the same or decreased. However, despite the fact that the percentage of pot-smoking adults has doubled, the new study also reveals that the amount of people using the drug in 2013 was higher than reported in the previous study, 12.5 percent compared to the previously reported 9.5 percent.
"It's not surprising that marijuana use is on the rise - several states have legalized it for either medicinal or recreational use - but our data suggest that the use rate hasn't come close to doubling," Richard Grucza, first author of the study, said in a press release. "That doesn't mean there are no problems. The two studies agree that close to one in 10 adults uses the drug. The difference is that we believe the 2002 survey for the other study underestimated the percentage of adults using the drug."
So where does the discrepancy come from? The authors believe that it lies in the nature of each study's data-collection method - in the previous study, the team relied on face-to-face interviews, whereas the new study used data gathered from computer surveys.
"Data from face-to-face surveys previously have been demonstrated to be more sensitive to social attitudes than data collected anonymously," Grucza said. "People may say one thing to an interviewer but something else on an anonymous computer survey, particularly when the questions deal with an illegal substance."
The face-to-face study also reported an increase in marijuana-related problems, although Grucza's study found no change.
"We're certainly seeing some increases in marijuana use," Grucza said. "But our survey didn't notice any increase in marijuana-related problems. Certainly, some people are having problems so we should remain vigilant, but the sky is not falling."
The findings were published in the Feb. 10 issue JAMA Psychiatry.
