Some rodents are naturally calm. Others turn to cannabis to cope. Here's what a new study says Neuropsychopharmacology at least seems to suggest, after finding that higher levels of stress hormones are associated with higher levels of cannabis consumption in rats.
“We ran an extensive battery of behavioral and biological tests on rats and found that when we look at all of these different factors and all of the variables that we measured, stress level seemed to matter most when it came to cannabis use,” said Ryan McLaughlin, study author and professor of psychology at Washington State University, according to press release.
Read more: Marijuana may help reduce depression and anxiety
Cannabis use in rats?
More and more US states are lifting their regulations prohibiting recreational cannabis use, although factors influencing individual cannabis use in any form are are still less than clear. In fact, although some recreational cannabis users develop cannabis use disorderor a pattern of problematic or addictive cannabis use that ranges in severity from mild to moderate to severe, others do not develop the condition after repeated or regular use, raising questions about the traits that contribute to an individual's effects of the drug.
To learn more about these traits, McLaughlin and a team of researchers turned to a relevant animal model: rats. Assessing a range of behavioral and biological characteristics of these animals, including levels of stress and stress hormones, the researchers compiled behavioral and biological profiles for a total of 48 animals. They then gave people a daily opportunity to use the drug by allowing rats to stick their noses into a sealed vapor vent and receive three-second inhalations of cannabis vapor.
By monitoring rats who self-administered these puffs for three weeks, the researchers determined that rodents with high levels of stress hormones were much more likely to prefer consuming cannabis, choosing to snort port wine more often.
“If you really want to boil it down, there are baseline levels of stress hormones that can predict levels of self-administered cannabis use, and I think that only makes sense given that the most common reason people typically use cannabis is to cope with stress,” McLaughlin said in a press release.
Read more: Why does marijuana cause panic attacks in some people?
High levels of stress hormone
Of course, humans have a baseline level of the stress hormone cortisol in their bodies, and rats have something similar—a baseline level of the stress hormone corticosterone—which, like cortisol in humans, varies from person to person. According to the researchers, it was this baseline level that was associated with cannabis consumption in the rats, as the increased hormone levels observed after exercise, cognitive exhaustion and exposure to stressors were not strongly associated with the number of nose pokes.
Also important for the rats' self-administration were measures of endocannabinoids, or compounds that regulate mood, metabolism and other internal processes to maintain a healthy balance in the body, as well as measures of cognitive function: Rats with lower levels of endocannabinoids and lower levels of cognitive flexibility showed higher motivation to seek out cannabis odors.
According to the researchers, the results may contribute to a better understanding of predictors cannabis use and abuse — an understanding that must continue to evolve as the legal status of cannabis changes.
“Our findings highlight potential early or pre-use markers that may one day inform screening and prevention strategies,” McLaughlin added in the press release. “I could certainly imagine a scenario in which assessing your baseline cortisol levels could provide some level of insight into whether you would be more likely to develop problematic drug use patterns later in life.”
Article sources
Our authors in discovermagazine.com use peer-reviewed research and high-quality sources for our articles, and our editors review scientific accuracy and editorial standards. Review the sources used below for this article:
