Chilled Out?

Cannabis users often report using the drug to combat stress. Now, new evidence suggests that regular cannabis users have a different response to stress compared with non-users – even when they aren’t under the influence (1).

Carrie Cuttler, Clinical Assistant Professor at Washington State University Department of Psychology and co-author of the study, says, “One of the most common reasons cannabis users report using cannabis is to cope with stress. In support of this, previous research has shown that acute administration of THC or cannabis dampens affective responses and subjective stress ratings. We wanted to determine whether the stress relieving properties of cannabis would extend beyond the period of intoxication.”

To find out, the group recruited approximately 40 self-identified regular cannabis users and 40 non-users (all of whom were asked to abstain on the day of the study) for a psychological study. Participants were randomly assigned to take part in a high-stress or no-stress version of the same task – the Maastricht Acute Stress Test. Those in the high-stress group had to plunge their hand into ice cold water for around a minute, before being asked to do some tricky mental math. To pile on the pressure, they were verbally corrected if they got an answer wrong, and were monitored by a camera which displayed their own image to them. Participants selected for the no-stress version had a much easier time, simply placing their hand in lukewarm water before counting from 1 to 25.

All trial subjects gave a saliva sample before and after the test, so that researchers could measure their levels of stress hormone cortisol. “The most important finding was the discovery of a blunted stress response in chronic cannabis users. More specifically, we found that levels of cortisol were much higher in non-users subjected to an acute stressor relative to non-users who were not subjected to a stressor. In contrast, the cortisol levels of cannabis users who were subjected to an acute stressor were comparable to the levels found in cannabis users who were not subjected to the stressor,” says Cuttler.

The fact that cannabis users showed little change in cortisol after a stressful task suggests that the drug has an impact on physiological responses to stress beyond the immediate period of intoxication.

So what’s next? “We plan to corroborate these findings in animals,” says Cuttler. “One of the limitations of our research is that because we did not manipulate cannabis use we cannot conclude that cannabis caused the muted stress response. It is possible that there is something else that differs between cannabis users and non-users that is driving this effect (e.g., personality differences). However, we can manipulate cannabis use in animals and then examine their stress response.”

Assuming the results are borne out in animal studies, it’s an intriguing finding, but further work will be needed to determine whether this blunted response to stress has a positive or negative effect on cannabis users’ health.

Reference

1. C Cuttler et al., “Blunted stress reactivity in chronic cannabis users”, Psychopharmacology, 234, 15 (2017).