Marijuana legalization increased marijuana use and cannabis use disorder among older adults, a new study finds.
While the benefits of marijuana legalization are aplenty, it’s also important to consider the possible consequences as well. According to a new study, not only does legalization lead to increased cannabis use, it increases the rate of cannabis users who develop addictive behaviors. The study highlights the possible public health consequences to legalization, so that regulators and lawmakers can create proper policies to prevent them.
“Although occasional marijuana use is not associated with substantial problems, long-term, heavy use is linked to psychological and physical health concerns, lower educational attainment, decline in social class, unemployment, and motor vehicle crashes,” researchers wrote in the study published in JAMA Psychiatry.
For the study, lead author Magdalena Cerdá, a drug policy expert at New York University, and her team analyzed data from the National Survey on Drug Use and Health (2008-2016). The survey divided age groups between those between 12 to 17 (teenagers), 18 to 25 (young adults), and 26 years or older (older adults). The researchers then looked at how marijuana legalization affected whether participants used cannabis in the past month, and if they met the NSDUH’s definition for cannabis use disorder (their criteria include problematic use to addiction).
Where the sharpest rises in marijuana use occurred was for older adults, when comparing those in legal states vs. those in non-legal states. Among the age group, cannabis use in the past month jumped from 5.65% to 7.1%, frequent use rose from 2.13% to 2.62%, and cannabis use disorder recorded in the past year changed from 0.9% to 1.23%. However, the young adult group had no significant changes in marijuana consumption behaviors. While researchers found an increased risk of cannabis use disorder among teenagers, it was a relatively minor adjustment.
“For adolescents, I think we need to take the findings with a grain of salt,” Cerdá told Vox. “We need to really track changes among adolescents over a longer period of time and across other states that are legalizing to see if that’s really a robust finding or it’s actually due to some other third factor.”
As Vox adds, the researchers took special care in checking their findings against possible limitations. That included analyzing whether marijuana use was already increasing prior to legalization, if demographic or socioeconomic changes had any effect, or if other variables could be influencing their results.
The researchers took several steps to validate their results. They looked at both demographic and socioeconomic changes to see if they had any effect; they checked to see if marijuana use had already been on the rise in states that eventually legalized cannabis; and they conducted statistical sensitivity analyses to try to account for other variables that they may have missed. But ultimately, because the data used comes from self-reporting participants, it’s always difficult to draw definitive conclusion from the research.
What Cerdá emphasized, though, is that she and her team don’t believe their study should stop any possible marijuana legalization. Instead they want their research to influence how states develop regulations and frameworks around legalization. As she told Vox, legal drugs remain available despite their negative effects. Tobacco results in 480,000 to 540,000 deaths each year while drinking in excess is connected to 88,000 annual deaths.
For marijuana, we should “start to think about ways to legalize that prevent those unintended consequences, just like we would regulate tobacco and alcohol,” Cerdá said.
“[Because legalization] has a lot of important benefits from a criminal justice standpoint, and I think it could, if done well, have benefits from a public health standpoint,” she added. “If it’s well-regulated, we could regulate the quality of the product, we could regulate the potency of the product — in a way we couldn’t if it were illegal.”