Federal legalization of cannabis could provide an opportunity to enact rules that better protect public health, researchers say.
In a white paper published July 18, researchers at the Leonard D. Schaeffer Center for Health Policy & Economics outlined several possible policies that could be enacted by the federal government if it decriminalizes cannabis.
This includes setting limits on the amount of tetrahydrocannabinol (THC) – the main psychoactive compound in cannabis – that can be included in products, and limiting how many individuals can buy at one time based on the amount of THC in the product.
Other policies include taxing cannabis products based on potency rather than weight or retail price and tracking all cannabis or hemp from cultivation to sale as a product.
A July 2022 study published in The Lancet Psychiatry suggests that people who use more potent cannabis have a higher risk of developing a cannabis use disorder. They are also more likely to have a psychotic disorder, such as schizophrenia.
According to the USC white paper, other research has found that legalizing cannabis at the state level is linked to an increase in cannabis-related emergency department visits by children and teens, and an increase in cannabis-influenced driving.
“A public health approach to cannabis regulation is about empowering users in ways that maximize benefits and reduce harm,” Rosalie Liccardo Pacula, PhD, senior fellow at the USC Schaeffer Center and Elizabeth Garrett Chair in Health Policy, Economics & Law at the USC Price School of Public Policy, Healthline told me.
Pacula added that a public health approach to how cannabis products are sold and developed “is aware that higher THC levels cause more restrictions and more health risks.”
In the United States, cannabis is illegal at the federal level, although many states have passed laws permitting medical and/or recreational use of cannabis.
A bill introduced in the US Senate on July 21 would decriminalize cannabis at the federal level and allow states to enact their own cannabis laws. Other bills in the House and Senate are in the works.
While this seems like a positive development for cannabis enthusiasts, Pacula expressed concern. “If the federal government legalizes cannabis without introducing a THC limit, we will never get one,” she said. “The only states that have introduced potency limits are the ones that did this when they first legalized cannabis.”
Current state cannabis laws vary in terms of purchase quantity limits and potency limits. Vermont and Connecticut, for example, are the only states to have established THC potency limits for both cannabis flowers and concentrates, according to USC researchers.
Pacula said the limits set by these two states are “probably reasonable for the US market, although they may still be too high. But I think it’s okay to leave it that way, rather than set no limit at all. “
In addition, she and her colleagues point out that most states that restrict cannabis sales do so based on the weight and type of the product rather than the amount of THC in the product. This allows people to buy a large amount of more potent cannabis products in one go.
The policies outlined by the USC researchers in the white paper would discourage excessive cannabis use, especially the use of products with a higher THC content, such as edibles and cannabis concentrates.
“Right now, [cannabis] flour is the main product sold, but we’re seeing a huge shift to concentrate from vape oils, while edibles have stabilized in the market,” Pacula said.
While the policy outlined in the white paper focuses on the THC content of cannabis products, Liz Rogan, founder of The Cannabis Business Council of Santa Barbara County, said it misses the role that various components of cannabis can play in the intoxicating or other effects of these products.
However, Pacula stressed that the standards should be adjusted as additional scientific data is available on the risks of different doses of THC. These policy updates may also take into account new science about the effects of other components of cannabis.
“It took us decades to understand alcohol and what a standardized drink was,” Pacula said. “So we have to set these limits and wait at least 5 years before we adjust them because it will take some time for the science to come out.”
R. Lorraine Collins, PhD, professor and associate dean for research at the University at Buffalo’s School of Public Health and Health Professions, supports the white paper’s proposed policy. She said setting THC limits on cannabis products and taxing products based on THC content would be easy to implement, calling these strategies an “excellent start.”
For a THC cap to be effective, Collins said laws must limit the potency of all cannabis products, including those that come directly from the cannabis plant and products derived from hemp or cannabis.
“The cannabis industry is very smart,” she said. “One of the things they do is if you say you’re going to limit the potency of cannabis flower, they’ll increase the potency in other cannabis products. So the key is to limit THC in ‘all cannabis products’.
In addition, she said the laws should be broad enough to cover developed cannabis products in the future.
As for individual limits on cannabis purchases, Collins has expressed some reservations about this policy, as the US does not have comparable limits on other adult-use products, such as alcohol and tobacco.
Rogan agreed: “This is an adult we’re talking about. This is someone who should be able to make their own decisions,” she said. “It really goes back to personal choice — you have [the] freedom to do whatever you want; we hope you’re responsible.”
In addition, Collins said individual purchase limits may not be very effective. “What’s stopping someone from going from store to store?” she said. “You could collect a lot of cannabis that way, even if there is a limit to how much you can buy at one time.”
Rogan is also concerned about the impact a cap on THC limits and purchase limits could have on people who use cannabis to treat medical conditions.
“If you’re treating cancer or chronic pain, you often need high doses of THC,” she said. “So is it fair for that person to have to go to the [cannabis] pharmacy every day and buy more often because they can’t buy the products in a concentrated form?”
While states like Connecticut and Vermont have stricter limits on THC levels, USC researchers argue that federal regulations would ensure public health is equally protected across the country.
“You’re not going to encourage good standards for the cannabis industry if you let states vary these limits,” Pacula said. “It will be much easier to do it at the federal level.” A federal limit, she added, would only determine the maximum potency for cannabis products. States could have more restrictive laws.
In addition, there is now a precedent for the federal government to regulate the maximum THC content of cannabis products.
“The FDA, which eventually got clearance to regulate nicotine products, can do things like put a limit on the amount of nicotine in cigarettes or remove certain types of flavors from tobacco,” Collins said.
Collins noted that having different cannabis laws in each state — especially THC caps — could lead people in places with stricter laws to buy cannabis in neighboring states with milder regulations. Something similar happened before all states set 21 as the minimum drinking age, she said.
Still, Collins said many people will be drawn to the legal cannabis market for what it offers – being able to buy products that are safe and contain exactly what they should.
“You don’t have to worry about your weed being cut with fentanyl or another drug that could harm you,” she said. “You also don’t have to worry about poor cultivation leading to molds that can harm you if you smoke cannabis.”
New research makes a compelling case for regulating cannabis at the federal level. Decriminalizing cannabis could help limit the sale and use of potent cannabis products, which studies have shown pose a threat to human health.
Even with federal legalization, however, experts like Collins and Rogan say that putting limits on THC could still encourage consumers to buy more potent products in the illicit cannabis market.
“If people are concerned about young people — especially men 26 and younger — using products with high THC content, the justice system will be better,” Rogan said. “Because at least they know what they’re getting there rather than if they get a product on a street corner.”