A new study has revealed that marijuana use more than doubled in the US from 2001 to 2002 and 2012 to 2013.
Furthermore, the research team that did the study found that the increase in disorders related to marijuana use saw almost as large a growth for that period.
According to the findings, almost 3 out of 10 marijuana users experienced a disorder of abuse or dependence for the same in 2012 to 2013, affecting around 6,846,000 people in the US.
"At a time when Americans increasingly view marijuana use as harmless and favour its legalization, our findings suggest the need for caution and more public education about the potential harm that is warranted," said Deborah Hasin, researcher and professor of clinical epidemiology at Columbia University Mailman School of Public Health in the US.
For the study, the researchers compared data from two US national surveys. The first was conducted from 2001 to 2002 covering 43,093 individuals and the second covered 36,309 individuals in the survey conducted from 2012 to 2013.
The study team used similar measures and procedures in the two surveys to allow proper comparison.
The findings showed that the prevalence of using marijuana had more than doubled from 2001 to 2002 (4.1%), to 2012 to 2013 (9.5%).
Marijuana use disorders also saw a substantial increase from 1.5% of the adult population in 2001 to 2002, to 2.8% in 2012 to 2013.
The rise in marijuana use disorders was attributed to the increase in the prevalence of marijuana users.
The findings appeared online in the journal "JAMA Psychiatry".