New information from the National Institute on Alcohol Abuse and Alcoholism states that marijuana use doubled from 2001 to 2013. This information is published in JAMA Psychiatry.

Researchers on the study analyzed nationally representative data on marijuana use and marijuana use disorders in the United States. The data came from both the 2001-2002 and 2012-2013 National Epidemiologic Survey on Alcohol and Related Condition.

In 2001-2002, 4.1 percent of study participants used marijuana. This number jumped to 9.1 percent in the 2012-2013 study. The study also showed the 3 out of every 10 Americans who used marijuana were diagnosed with a marijuana use disorder.

The groups that used the drug the most were those between the age of 45 and 64, were Hispanic or Black and had the lowest income levels in their area.

Researchers on this study noted the need for public education on marijuana use, specifically on the risk of addiction. This is needed due to the fact that now 23 states have medical marijuana laws, 4 of which have legalized marijuana for general use.