In a press release, Mason Silveira, the study’s lead author and a PhD candidate in UBC’s department of psychology said, “Perhaps unsurprisingly, we found that when we gave THC to these rats, they basically became cognitively lazy. What’s interesting, however, is that their ability to do the difficult challenge was unaffected by THC. The rats could still do the task— they just didn’t want to.”
Researchers trained 29 lab rats for a task that involved having to chose whether they wanted to do an easier task or a more difficult task in order to earn a treat. The harder task would pay out two treats, and the easier would only spit out one treat after completion. It was the motivation to get larger amounts of a reward that was affected in the study. Rats who have not been fed any chemicals or drugs will always choose a hard challenge in order to earn a bigger treat. The animals learn very quickly to seek the larger reward and don’t normally mind that it’s more work. But when the rats were given THC, the animals switched to the easier option, despite earning a smaller reward.
The results were not the same with the rats who had ingested CBD. CBD does not have the psychogenic properties that THC has and isn’t responsible for the high that happens after using marijuana. Researchers found that thischemical did not have any effect on the decision-making or attention of the animals. While CBD has been studied extensively as a treatment for chronic pain, epilepsy and cancer, it doesn’t produce a high and it doesn’t negate the high from THC. Researchers were hopeful that the CBD could knock out some of the less desirable effects of THC, but that was not the case.
The research will hopefully allow scientists to better understand the impact THC has on the brain. Patients with chronic conditions often use marijuana, but THC can have negative effects, such as paranoia, fear and, as was seen in this study, a listlessness and lower desire to participate fully in one’s environment. This study was the first to note the impact on decision-making as it relates to motivation. Take a look at the video below to learn more.
Sources: UBC, Forbes, Journal of Psychiatry and Neuroscience