Stressed out? Smoking this much weed can calm you down

Lizette Borreli

We all deal with some form of stress, whether it's during a job interview, or a public speaking task.

There are several coping techniques, such as humor, meditation, or physical activity, that can help manage our stress, but science suggests smoking weed can also calm our nerves. Researchers at the University of Illinois at Chicago and the University of Chicago found low doses of tetrahydrocannabinol (THC) — the mind-altering ingredient in weed — can relieve stress in certain situations.

In the study, published in the journal Drug and Alcohol Dependence, participants in the low-dose group, who received a capsule containing 7.5 milligrams of THC, reported fewer stressful feelings about doing a series of tasks. Meanwhile, the moderate-dose group (12.5 milligrams of THC) experienced greater negative moods before and throughout the tasks, and were more likely to rate psychosocial tasks as "challenging" and "threatening" beforehand. The placebo group did not show any significant changes in initial stress levels.

Previous research supports weed's stress-reducing effects on the brain. In a 2013 study, an international team of researchers found the drug acts on the endocannabinoid system in the brain. This system is believed to naturally regulate anxiety and stress level via the release of chemicals that belong to the same class of chemicals found in marijuana —  (endo)cannabinoids. THC bears a striking resemblance to one of the first endocannabinoids found in humans, known as anandamide — a neurotransmitter, creating a happy, relaxed feeling, as well as sleepiness. Therefore, since they act on the same pathways of the brain, they seem to possess stress- and anxiety-reducing properties.

Childs and her colleagues are aware many with stress and anxiety issues self medicate with marijuana, but  “very few published studies have looked into the effects of THC on stress, or at the effects of different levels of THC on stress,” said Emma Childs, corresponding study author and an associate professor of psychiatry in the UIC College of Medicine, in a statement.

A total of 42 healthy volunteers 18 to 40 years old, with a history of marijuana use, but not daily use, were randomly divided into three groups: the low-dose group, the moderate-dose group, and a placebo group to determine the influence of various THC levels in stressful scenarios. The doses were meant to produce effects that are the equivalent to only a few puffs of a cannabis cigarette. The researchers note it's difficult to compare doses of smoked marijuana to doses of ingested THC.

The participants had to attend two four-hour sessions at the University of Chicago, five days apart. During each session, they took a capsule, and relaxed for two hours to allow THC to be absorbed in the bloodstream. The blood absorbs ingested marijuana through the stomach, where it then carries it to the liver, and the rest of the body. The stomach absorbs THC more slowly than the lungs, which means THC levels in the body are lower, but the effects last longer.

In one session, participants had to spend 10 minutes preparing for a mock job interview, followed by a five-minute interview with lab assistants who did not offer any feedback, verbally or through body language, although participants could see their performance via video display. They were then asked to count backwards from a five-digit number by subtracting 13, for five minutes. Childs believed this was "very reliably stress-inducing."

Similarly, in their second session, participants were asked to talk to lab assistants about a favorite book or movie for five minutes, and then play solitaire for another five minutes. Before, during, and after each of the two activities, the participants rated their stress levels and feelings about the tasks.

The researchers measured blood pressure, heart rate, and the stress hormone cortisol, at intervals.

Childs and her colleagues found the low-dose group had less stress after the psychosocial test than the placebo group, and stress levels quickly decreased after the test. Meanwhile, the moderate-dose group fared worse with stress management, and had more pauses during the mock interview compared to those in the placebo group. The researchers saw no significant differences in participants' blood pressure, heart rate or cortisol levels — before, during or after the doses or the tasks.

“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," said Childs.

Although weed was found to reduce stress and alleviate tension and anxiety, high doses can provoke anxiety. Other studies have found people who have a history of panic disorders are more likely to experience worse anxiety when smoking weed. The effects of marijuana on stress, anxiety, and other mental health conditions are on a case-by-case basis.

This is why studies that examine the effects of weed and its pharmacological constituents are important since marijuana use for both medical and recreational purposes is rising in the U.S.
Our understanding of THC's health risks is changing, and future research will investigate whether its benefits outweigh those risks.