A study published in Neuropsychopharmacology focused on cannabis-seeking behavior and found that rats with higher natural stress levels are much more likely to self-administer cannabis.
The Washington State University research team analyzed the rats’ social behaviors and traits, including sex, cognition, reward, and arousal, and then developed a behavioral profile for each rat. The team then observed the rats for one hour daily as they were given the option to inhale cannabis by inserting their noses in a vapor port that dispensed a three-second cannabis vapor. The researchers tracked the number of “nose-pokes” by each rat during the hour.
Data analysis revealed a direct correlation between the number of nose-pokes and baseline stress hormone levels. Study author and associate professor of veterinary medicine Dr. Ryan McLaughlin explained, "We ran rats through this extensive battery of behavioral and biological tests, and what we found was that when we look at all of these different factors and all the variables that we measured, stress levels seem to matter the most when it comes to cannabis use.” Measuring the rats’ stress hormone corticosterone levels (comparable to the human stress hormone cortisol in humans) indicated that rats with higher stress hormone levels were much more likely to self-administer cannabis.
The study emphasized that the association between cannabis use was between the rat’s resting baseline stress levels and cannabis self-administration, and not stress that increases and decreases in real time in response to physical or mental challenges. They also found significant relationships between rates of cannabis self-administration and measures of cognitive flexibility (adaptability to situational changes). The research team calculated stress hormone levels after exposure to a stressor and found no significant link to cannabis-seeking behavior triggered by this event.
The study highlights the importance of future research examining the association between stress and cannabis use. Identifying potential early cannabis use markers that could inform drug screening and educational awareness efforts. A significant number of research studies have highlighted how cannabis positively affects the mental and cognitive functioning of rodents, but clinical trials with human subjects are limited.
Sources: Eureka News Alert, Neuropsychopharmacology, Washington State University
