Can cannabidiol protect against undesirable cognitive effects caused by THC?

According to the US National library of medicine, "Studies examining the protective effects of CBD have shown that CBD can counteract the negative effects of THC". This raises many questions about how combining the two can improve the cognitive function of a recreational cannabis user.

They go on to say "CBD weakly binds to CB-Rs but is capable of antagonizing the effects of THC, even when the former is present in low doses. By inhibiting the degradation of the endogenous cannabinoid anandamide, CBD intensifies, and prolongs its effect (17). The (extended) presence of anandamide prevents THC from interacting with CB-Rs. CBD also interacts with several other recently discovered CB-Rs, and it is an agonist for the 5-HT_1A receptor (18, 19), which may explain some of the antipsychotic and anxiolytic effects of CBD (20). Through its effect on intracellular calcium concentrations, CBD might protect neurons against the possible neurotoxic effects of THC (21). CBD itself has almost no effect on normal physiological processes. Only when a stimulus (such as pain or a shock reaction) or another cannabinoid (such as THC) upsets the normal “tone” of the endocannabinoid system is the effect of CBD expressed."

The last quote shows that we are only just beginning to understand how cannabidiol can protect our cognitive function. It will be interesting to find out how CBD protects the brain regardless of the presence of THC.

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3797438/