The beaver is a proud and noble animal

THC, the main psychoactive ingredient in cannabis, makes rats less willing to exert cognitive effort – lazy – but, you know, that’s just, like, your opinion, man.

The new research, published on Tuesday in the Journal of Psychiatry and Neuroscience, looked at the effects of both THC and the non-psychoactive compound cannabidiol, or CBD, on the male lab rats’ willingness to exert cognitive effort.

Researchers trained 29 rats on two different challenges: rats which successfully carried out the more difficult task earned two sugar pellets; those which carried out the easier task earned just one. Rats usually preferred the harder, but more rewarding, task. But after being dosed with THC, the same rats picked the easier task.

CBD, which does not cause a high and is believed to have medicinal benefits such as relieving pain and the symptoms of epilepsy, had no impact on the rats’ cognitive behaviour. It also did not mitigate the cognitive impact of THC in the rats.

The THC did not make the rats less intelligent – just lazier, said the study’s lead author, Mason Silveira, a PhD candidate in psychology at the University of British Columbia. “What’s particularly interesting is though they were less likely to do these more difficult tasks they were still able to. There’s this distinction between THC’s ability to affect your cognition versus your willingness to actually use your cognitive abilities.”