Credit: UConn
Key Points:
- Mice responded with the same effects when dosed with legal Δ8-THC, and illegal Δ9-THC.
- Researchers say the two types of THC are the same, although one is considering a Schedule I drug and the other is sold as hemp.
- The distinction is causing tensions to rise between the hemp and cannabis industries.
Tetrahydrocannabinol, or THC, is the psychoactive compound produced by cannabis plants. The federal government lists Δ9 -THC on the Schedule 1 list of drugs with no accepted medical use. But other versions of THC that differ only by the location of a double bond, such as Δ8-THC, remain legal.
In a new study, researchers at the University of Connecticut say the differences between the types of THC aren’t backed by science, they pose a danger to consumers, and are causing conflict between the hemp and cannabis industries.
For the study, published in Drug and Alcohol Dependence, researchers reproduced work done in Japan in the 1980s that showed Δ8-THC produced the same effects in mice as Δ9-THC. UConn researchers Steve Kinsey and Olivia Vanegas confirmed the results: the mice given Δ8 became lethargic, their body temperature dropped, and they became cataleptic, meaning the researchers could put the mice in unusual positions and they’d stay like that for several seconds, which is common in THC-treated mice, but not normal mice.
Taking the work further, the UConn researchers blocked the mice’s THC receptors. Blocked mice had no reaction to Δ8-THC, making it clear that Δ8 interacts with the same receptors as Δ9-THC. Then, they gave a group of mice Δ8-THC twice a day for five days. Over time, the mice became desensitized to it, and when they were then given the THC blocker, the mice acted like they were in withdrawal.
Collaborators at RTI International ran an experiment “asking” the mice how the drug felt. First, they trained the mice to go to a specific spot for a reward if they were dosed with Δ9-THC. After the training, the mice were dosed with Δ8-THC. Unsurprisingly, they went to the same reward spot as when they were dosed with Δ9.
“So, they’re telling us the same thing people buying the stuff in gas stations tell us: Δ8 feels like THC,” Kinsey says.
Legally, this is causing problems.
The distinction between Δ8- and Δ9- originally came about from the congressional Farm Bill covering hemp growing and sales. Hemp is defined as a cannabis plant that has less than 0.3% Δ9-THC by dry weight. Anything that has more concentrated Δ9-THC is considered marijuana. Additionally, the Farm Bill said anything else naturally present in the hemp plant is legal—that includes Δ8-THC.
“It’s creating a fight between marijuana and hemp growers,” says John Harloe, an attorney on Colorado’s THC taskforce. “[Products classified as marijuana] must be sold through dispensaries and pay high taxes, while hemp producers can sell essentially the same product but without the same regulations, due to the ambiguity in the Farm Bill,” said Harloe.
Harloe will present the current study to the Colorado taskforce, which is trying to create appropriate regulation that will address the different chemical variations of THC and guard public safety without crippling the hemp industry.
Information provided by UConn.