When it comes to marijuana’s medical potential, the ongoing debate is still pretty heated. Take stress and anxiety for example — studies have shown both positive and negative effects associated with consumption, and at the moment, it’s still unclear how much good it can do (despite anecdotal evidence and despite what your friends might tell you). Now, a new study found that it’s all about the quantity: lower quantities do help, but higher quantities do more harm than good. Emma Childs, one of the study authors, explains:

“We found that THC at low doses reduced stress, while higher doses had the opposite effect, underscoring the importance of dose when it comes to THC and its effects.”

A hybrid Cannabis strain (White Widow)which contains one of the highest amounts of cannabidiol. Image credits: Lenny Montana.

Tetrahydrocannabinol (THC) is the active psychoactive constituent of cannabis. Researchers from the University of Illinois at Chicago and the University of Chicago wanted to better understand the practical effects of THC in regards to stress. They recruited 42 healthy volunteers 18 to 40 years old with some cannabis consumption experience, but who were not daily users. They then divided them into three groups,:

• a low-dose group, which got 7.5 milligrams of THC,
• a high-dose group, which got 12.5 milligrams of THC,
• and a placebo group, which got empty tablets.

These are very low doses, because researchers didn’t want to subject the volunteers to the unhealthy effects of THC. The doses were administered through pills, not through smoking.

“The doses used in the study produce effects that are equivalent to only a few puffs of a cannabis cigarette,” said Childs, noting that it is difficult to compare doses of smoked cannabis to doses of ingested THC. “We didn’t want to include a much larger dose, because we wanted to avoid potential adverse effects or cardiovascular effects that can result from higher doses of THC.”

There were two study sessions, five days apart, each lasting four hours. First, after taking the THC pill, participants were told to relax and let the substance to enter the bloodstream. Then, they were asked to spend 10 minutes preparing for a mock interview. The five minute interview offered no feedback whatsoever to the participants, and during it, they were asked to carry out relatively simple but stress-inducing tasks, such as counting backwards from a five-digit number by subtracting 13. During the second session, after the two hour relaxation period, they were simply asked to talk about their favorite book or movie, and then play solitaire for five minutes.

Before, after, and throughout both tasks, key stress indicators (blood pressure, heart rate, cortisol) were measured. Self-assessment forms were also handed to the participants.

Researchers learned that participants who were on the low-dose group were significantly less stressed throughout the tasks than the placebo group, whereas the high-dose group exhibited a completely opposite trend. These latter participants were more likely to label the tasks as “challenging” and “threatening” and required more pauses during the mock interview.

“Our findings provide some support for the common claim that cannabis is used to reduce stress and relieve tension and anxiety,” Childs said. “At the same time, our finding that participants in the higher THC group reported small but significant increases in anxiety and negative mood throughout the test supports the idea that THC can also produce the opposite effect.”

High doses of THC were associated with higher stress. Image via Pixabay.

Still, the study should be taken with a grain of salt, as 42 participants is not that big of a sample size. Researchers would like to carry out similar studies with a wider range of subjects, but the problem is that cannabis studies are notoriously difficult to carry out, due to laws and regulations.

Considering that the low dose is equivalent to a slight buzz, and the high dose to a mild high, and also considering how widespread cannabis consumption is across the world, the need to study these effects becomes more and more evident. Hopefully, regulators will also understand this.

“Studies like these — examining the effects of cannabis and its pharmacological constituents under controlled conditions — are extremely important, considering the widespread use of cannabis for both medical and non-medical purposes,” she said. “Unfortunately, significant regulatory obstacles make it extremely difficult to conduct this type of research — with the result that cannabis is now widely available for medical purposes with minimal scientific foundation.”

Journal Reference: Emma Childs, Joseph A. Lutz, Harriet de Wit –: Dose-related effects of delta-9-THC on emotional responses to acute psychosocial stress. https://doi.org/10.1016/j.drugalcdep.2017.03.030