Highly unusual

How high can you really get? A new study by researchers at CU Boulder has found out that huge levels of THC don’t necessarily translate into a huge buzz.

Traveling in Sprinter vans dubbed “cannavans,” researchers studied 121 regular users before, during and after inbibing marijuana. Surprisingly, they found cannabis concentrates increased blood THC levels twice as much as smoking flower but did not necessarily increase intoxication levels.

“We found that potency did not track with intoxication levels,” lead author Cinnamon Bidwell, assistant professor in the Institute of Cognitive Science, said. “While we saw striking differences in blood levels between the two groups, they were similarly impaired.”

The landmark study was published June 10 in JAMA Psychiatry and is the first to assess the acute impact of cannabis among real-world users. Such studies are difficult to perform because although 33 states have legalized marijuana in some form, it remains illegal at the federal level. As such, researchers are prohibited from handling or administering marijuana. Some studies have used strains supplied by the government, but those strains contain far less THC than real-world products.

Researchers believe the study could help inform decisions on everything from roadside sobriety tests to personal recreational or medicinal use.

To conduct the study, researchers drove the vans to the residences of study subjects who used cannabis they purchased on their own, inside their homes. “We cannot bring legal market cannabis into a university lab, but we can bring the mobile lab to the people,” Bidwell said.

Half used concentrates (oils, extracts, waxes) containing either 70 percent or 90 percent THC while the other half smoked flower containing 16 percent or 24 percent THC. Researchers then drew subjects’ blood, measured their mood and intoxication level, and assessed cognitive function and balance before, directly after and one hour after use.

Those who used concentrates had much higher THC levels at all three points, with levels spiking in the first few minutes to more than two times higher than flower users. However, self-reports of intoxication were remarkably similar, as were measures of balance and cognitive impairment. The study also found that, among all users, balance was about 11 percent worse immediately after using cannabis, and memory also was compromised. But within about an hour, that impairment faded.

“(The study) raises a lot of questions about how quickly the body builds up tolerance to cannabis and whether people might be able to achieve desired results at lower doses,” said Bidwell.

Researchers aren’t sure how the concentrate group could have such high THC levels without greater intoxication, but suspect a few things are at play, including tolerance and genetic or biological differences. And it may be that once cannabinoids compounds fill receptors in the brain, additional cannabinoids have little impact.

The authors caution that the study examined regular users who have learned to meter their use and does not apply to inexperienced users.

No word on how to sign up to be a subject in the test or take a ride in the cannavan.