In 2014, 4.176 million people in the U.S. abused or were dependent on marijuana, just as persons can be dependent on many prescription drugs. This number is likely to increase with legalization in many states.
Long-term heavy use may result in marijuana use disorder, generally defined as continued use of marijuana despite mild to moderate impairment. Up to 30% of marijuana users may have some degree of marijuana use disorder. People who begin using marijuana before the age of 18 are about 5 times more likely to develop a marijuana use disorder.
In severe forms of marijuana use disorder, addiction involving craving and dependency on marijuana despite undesirable social and health consequences, as well as subjective complaints of withdrawal when stopping its use develop. Withdrawal in frequent users is described as complaints of mood and sleep difficulties, decreased appetite, cravings, or physical discomfort within the first week after quitting marijuana. These effects can last up to 2 weeks.
The number of people addicted to marijuana is unknown, but studies suggest that 9% of people who use marijuana will become dependent on it, and 17% of people who start using while in their teenage years.
A recently published study by Hasin and partners involved face-to-face interviews of 43,093 people in 2001 and 2001, and 36,309 people in 2012 and 2013 as part of the National Epidemiologic Survey on Alcohol and Related Conditions. In 2001-2002, about 4.1% of surveyed adults used marijuana, and this had increased to 9.5% by 2012/2013. Evidence of marijuana use disorder was only 1.5% in 2001/2002 but also about doubled to 2.9% in 2012/2013.
Withdrawal from marijuana is usually less severe than that from opioids or alcohol. However, starting to use marijuana at a younger age, or prolonged and heavy use of marijuana are risk factors for marijuana use disorder, dependence and withdrawal. Patients with marijuana use disorder appears to be increasing over the past decade.