More Teenagers Use Cannabis “Problematically” After Legalization, Study Finds
Marijuana use among teenagers is on the rise in states with legal recreational access, according to a new study.
Problematic use among adolescents (aged 12 to 17) increased from 2.18 to 2.72 percent in Colorado, Washington, Alaska, and Oregon after legalization – a jump of 25 percent.
Published in JAMA Psychiatry, the observational study also found that the prevalence of cannabis use disorder (CUD) jumped from 0.9 to 1.23 percent among adults aged 26 or older but fell amid adults aged 18 to 25.
Problematic cannabis use (CUD) is recognized by the National Institute of Drug Abuse as an illness typified by cravings and withdrawal symptoms when cannabis isn’t taken. As legalization spreads across the United States there have been concerns that rates of CUD will follow and put further pressure on health services.
Recent studies reporting a decline in adolescent marijuana use following legalization have countered these fears. But the new JAMA study – which claims to be the first to test the impact of recreational cannabis legalization on both use and CUD across multiple age groups – may change the narrative.
“There are, indeed, important social benefits that legalizing marijuana can provide, particularly around issues of equity in criminal justice,” Magdalena Cerdá, an associate professor at NYU Langone Health and the study’s lead author, said in a statement.
“Our findings suggest that as more states move toward legalizing marijuana for recreational use, we also need to think about investing in substance use prevention and treatment to prevent unintended harms – particularly among adolescents.”
To get their results, Cerdá and her colleagues analyzed the data of 505,796 respondents from the National Survey on Drug Use and Health, with a specific focus Colorado, Washington, Alaska, and Oregon, the first four states to enact recreational marijuana laws.
Respondents were deemed to have CUD if they displayed an increased tolerance to cannabis, repeatedly attempted to quit, and experienced social interpersonal problems due to use.
From 2008 to 2016, rates of CUD increased among those aged 12 to 17 (by 0.54 percent) and those aged over 26 (by 0.33 percent) but fell among those aged between 18 and 25 (by 0.14 percent).
All three age groups experienced an increase in both past month and frequent marijuana use after legalization.
Reducing the risk
Although the study has its limitations – the findings were self-reported and may be affected by marijuana’s social acceptability – Cerdá and her colleagues still consider it a “major step forward in understanding the changes in marijuana use that may follow the legalization of recreational marijuana use in the United States.”
“Cannabis use disorder in adolescence is associated with long-term adverse health, economic and social consequences,” Silvia S. Martins, an associate professor at Columbia University Mailman School of Public Health and the study’s senior author, said in a statement.
“Given our findings on problematic use across age groups, legalization efforts should coincide with prevention and treatment,” she wrote. “The general public should be informed about both benefits and potential harms of marijuana products to make informed decisions.”
Ian Hamilton, a senior lecturer in addiction at the University of York, told Analytical Cannabis that the JAMA study demonstrates the need to collect information on the effects of cannabis policy on an ongoing basis.
“I don't think this study shows that access to cannabis shouldn't be permitted, but it does show that, for the small proportion of users who develop problems, support services need to be adequately funded and available – something other states and countries should factor in when thinking of changing their cannabis policies.”
Hamilton, who wasn’t involved in the JAMA study, told this publication that “even a small percentage increase in regular cannabis users can increase the risk of developing problems like cannabis dependence, which services would be unlikely to have the capacity to support.”
“It’s difficult to draw firm conclusions from observational studies like these as there are several factors which could account for the results. The researchers weren’t able to collect any data about the strength or potency of the cannabis used, so it might be that some people were using low potency cannabis frequently, which wouldn't create the same degree of risk as those using high potency cannabis regularly.”