Perceived availability was associated with medical marijuana laws and marijuana use among adults aged 26 years and older, suggesting that availability may influence change in marijuana use rates due to medical marijuana laws.
“A major concern with the enactment of medical marijuana laws is that this type of legislation could potentially increase marijuana use in adolescents and adult populations. A potential pathway in which this may occur involves the recognition that [medical marijuana laws] have been passed and could be increasing the availability of marijuana in the U.S.,” Silvia S. Martins, MD, PhD, of Columbia University, New York, and colleagues wrote. “Increases in availability of marijuana on its own may normalize both medical and nonmedical marijuana use and reduce harm-related risk perceptions of marijuana use, which could result in changes in marijuana use.”
To assess the relationship between medical marijuana laws and prevalence of past-month marijuana use and perceived availability of marijuana, researchers analyzed National Survey of Drug Use and Health data for 2004 to 2013.
After medical marijuana law passage, past-month prevalence of marijuana use increased from 5.87% to 7.15% among adults aged 26 years and older but did not change among participants aged 12 to 17 years or 18 to 25 years.
Perceived availability of marijuana increased among participants aged 26 years and older after passage of medical marijuana laws, but not among younger groups.
Prevalence of marijuana use and perception of easy availability was higher among all age groups in states that eventually passed medical marijuana laws by 2013, compared with states that did not.
Perceived availability was significantly associated with increased risk for past-month marijuana use among all ages.
“This study shows that, from 2004 to 2013, in the U.S. general population of the 23 states with [medical marijuana laws] by 2015, there was evidence for an increase in the prevalence of past-month marijuana use from the before to the after [medical marijuana laws] period in adults 26 and older. Perceived availability was associated with both [medical marijuana laws] and marijuana use among adults 26 and older,” the researchers wrote. “Other unexplored factors need to be examined to better understand why the prevalence of past-month marijuana use increased in adults 26 and older following [medical marijuana laws] but remained stable among younger cohorts.” – by Amanda Oldt
Disclosure: The researchers report no relevant financial disclosures.