Article by Natasha Ryz, The Ubyssey
An Alternative Explanation
After reviewing the study and previous scientific work in this area, a different interpretation may better explain the results.
It is well known that cannabis can increase appetite (read: munchies). However, higher doses of THC can actually suppress appetite and cause weight loss in rats. Particularly, very high THC doses, like the ones used in the study, have been shown to suppress appetite and reduce sugar cravings in rats.
Here’s an alternative explanation of the results: the rats aren’t “lazy” — perhaps they just aren’t hungry. This could have made the high-effort/high-reward no longer desirable and is a reasonable alternative explanation of the study’s findings that is supported by previous research.
The researchers found that when rats were treated with high doses of THC, the rats chose the harder-task/high-reward less often. At the highest dose of THC, 11 rats (eight workers and three slackers) failed to initiate any trials —they didn’t complete any games to get sugar.
Interestingly, the rats’ attention ability, impulsivity and ability to perform the tasks were not significantly affected by the THC dose. Even though the lowest dosage reported in this study (0.3 mg/kg) was about twice the recommended medical dosage for this drug in humans, no significant differences in the rat’s “cognitive effort” were observed until the synthetic THC dosage was increased to an amount several times higher than is recommended for medical use.
The researchers conclude that rats given high amounts of THC must be cognitively lazy because they no longer make an effort to get the high sugar treat and prefer a lower sugar reward or none at all. Perhaps these results can be explained by the rats having a smaller appetite or a reduced desire for sugar because of the high dose of THC.