Long-term marijuana users show dampened stress response

New research reveals that long-term users of marijuana have a blunted stress response when compared with non-users. This study is the first to show this effect by measuring salivary levels of the stress hormone cortisol.

Researchers from Washington State University in Pullman report their study findings in the journal Psychopharmacology.

First author Carrie Cuttler, a clinical assistant professor of psychology, says, "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."

One of the common reasons given for long-term use of marijuana, or cannabis, is that it helps people to cope with stress.

The researchers note that this is supported by evidence that long-term marijuana users have reduced emotional arousal and a blunted stress response when exposed to negative images.

For their study, the team recruited 40 chronic marijuana users and 42 non-users and randomly assigned them to complete either a high-stress version or a no-stress version of a recognized stress test.

This generated four groups: marijuana users and non-users who underwent the high-stress test, and marijuana users and non-users who underwent the no-stress test.

Chronic marijuana use was defined as having used marijuana every day or nearly every day during the past 12 months. Non-use was defined as not having used marijuana more than 10 times ever, or not having used it at all in the past 12 months. All participants were asked to abstain from using marijuana on the day of the stress test.

Stress test

The stress test, called the Maastricht Acute Stress Test, creates two stress conditions: one physiological and the other psychosocial.

Under the physiological stress condition, participants placed a hand in ice-cold water for up to 90 seconds. In the no-stress condition, the participants put their hand in lukewarm water.

Under the psychosocial stress condition, participants performed mental arithmetic by counting backwards from 2,043 in steps of 17. Throughout the task, they could see themselves on a screen using a video link and also received negative verbal feedback if they made any mistakes. The no-stress groups were just asked to count from 1 to 25.

Source: Medical News Today