Chronic cannabis users may be more resilient to stressful situations, new research suggests.
The team, led by Washington State University clinical assistant professor of psychology Carrie Cuttler have compared cortisol (a stress-hormone) levels in chronic cannabis users and non-users during a stress-test. They report that the former show a much dampened physiological response to stress and stressful situations.
Stressing for science
"To the best of our knowledge, this is the first study to examine the effects of acute stress on salivary cortisol levels in chronic cannabis users compared to non-users," Cuttler said.
"While we are not at a point where we are comfortable saying whether this muted stress response is a good thing or a bad thing, our work is an important first step in investigating potential therapeutic benefits of cannabis at a time when its use is spreading faster than ever before."
The participants were asked to self-report their cannabis consumption habits, which the team used to split them into two groups: chronic cannabis users (40 participants), with daily or almost-daily use for the previous year, and non-users (42 participants) who had consumed the drug 10 or fewer times during their life and none at all during the past year. All users were required to abstain from use in the day the tests were performed.
All participants provided a saliva sample upon arrival at the lab, which the team used to determine their baseline stress levels. Then, members of both groups were randomly assigned to take the high-stress or no-stress version of the Maastricht Acute Stress Test, or MAST. This is a common tool for stress-related research and combines physical, psychosocial and unpredictable types of stress.
The no-stress variation required participants to hold their hand in lukewarm water for 45 to 90 seconds, and then count from 1 to 25. For the high-stress variation, participants held their hand in ice cold water for the same period of time then count back from 2043 by 17. They were given negative verbal feedback whenever they made a mistake, and were monitored by a web camera whose video feed was played back to them to up the stress factor.
Immediately after the test, all participants gave a new saliva sample to rate their current levels of stress. Before departing, the team also took urine samples to check on the participants' self-reported cannabis use with their THC levels.
The researchers report there was no significant difference in the salivary cortisol levels for chronic users before or after the tests. For non-users, however, cortisol levels were much higher after the test than at baseline. The results add to a growing body of literature linking cannabis use to reduced adrenal and emotional reactivity.
Whether or not this is something you'd want, however, is still up for debate. On the one hand, Cuttler's team says cannabis may have some use in propping up stress resilience, particularly for people who have a heightened response to stressful situations. But they also explain that cortisol has a very important role to play. Cortisol allows our bodies to mobilize energy stores in response to dangerous situations, and as such represents a key adaptive system in dealing with threats.
"Thus, an inability to mount a proper hormonal response to stress could also have detrimental effects that could potentially be harmful to the individual," Cuttler said. "Research on cannabis is really just now ramping up because of legalization and our work going forward will play an important role in investigating both the short-term benefits and potential long-term consequences of chronic cannabis use."
The paper "Blunted stress reactivity in chronic cannabis users" has been published in the journal Psychopharmacology.