Has Medical Marijuana Increased Usage?

Marijuana use and abuse is not necessarily higher in states with medical marijuana

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) Does easier access to marijuana mean higher rates of use and abuse? Or does a community’s attitude have more to do with people smoking weed?

A recent study looked at marijuana use and abuse rates from two major national surveys.

Marijuana use is higher in states with legalized medical marijuana, but rates of abuse cannot be directly tied to easier access.

"Seek professional help if you are abusing marijuana."

Magdalena Cerda, PhD, MPH, assistant professor of epidemiology at the Mailman School of Public Health at Columbia University, led a team of researchers to look into the use and abuse of marijuana in relation to state-level legalizations of marijuana.

Stated in the abstract background for the study, “Marijuana is the most frequently used illicit substance in the United States.” 

“Little is known of the role that macro-level factors, including community norms and laws related to substance use, play in determining marijuana use, abuse and dependence.” Numbers and data taken from individuals don't necessarily paint the whole picture. 

Researchers used two national surveys: the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) providing 34,653 adults over the age of 18, and the National Survey on Drug Use and Health (NSDUH) providing approximately 68,000 people aged 12 and older.

Marijuana use, abuse and dependence were gauged based on responses found in each survey about each person’s marijuana use in the last year.

Study authors stated possible reasons behind certain data surrounding marijuana usage, “First, individual perceptions of societal norms may not always be accurate." Meaning that an individual's view does not always truly reflect how the rest of the entire community feels about marijuana use.

"Second, societal norms may influence behavior independently of individual beliefs. That is, other things being equal, a given individual may be more likely to use marijuana in an accepting than in a non-accepting society."

"Third, policy and program interventions focused on societal norms may have a wider impact than interventions focused on individuals.” Suggesting that people are, on average, more likely to stay within the bounds of socially acceptable behavior.  If marijuana is rejected by their community, individuals are more likely to reject marijuana as well.

"Therefore, studying the influence of societal-level norms is increasingly important, especially during times such as the present when marijuana use, abuse and dependence are increasing."   

Data collected from the surveys showed that people living in states with medical marijuana used more marijuana than people in states where it was still illegal. Marijuana use in medical marijuana states was 7.13 percent and non-medical states were 3.57 percent.

This does not prove that marijuana use is higher because it was made legal through a prescription. If medical marijuana states are also states where using marijuana is more socially acceptable that could be reason behind the higher usage more than the prescription availability.

Authors concluded, “Future research needs to examine whether the association is casual, or is due to an underlying common cause, such as community norms supportive of the legalization of medical marijuana and of marijuana use.”

As far as abuse of marijuana, authors were unable to prove that medical marijuana legalization directly increased the odds of people developing marijuana abuse disorders.

This study was published in the journal Drug and Alcohol Dependence, January 2012.  Funding for this study was supported by the New York State Psychiatric Institute, no conflicts of interest were reported. 

Reviewed by: 
Review Date: 
June 24, 2012
Last Updated:
November 20, 2012