Aside from endocannabinoids, several other cannabinoids including delta-9-tetrahydrocannabinol, cannabichromene, and cannabidiol, also found in marijuana are known to affect brain function. Studies show that these chemicals might be the reason why marijuana has a beneficial effect on mice behavior[7].

The role of marijuana in mice behavior is well established. In one study, Bruijnzeel et al. investigated the effects of marijuana smoke on the behavior of rats in the small and large open field test and the elevated plus maze test[8]. The small open field test is commonly used to assess the stimulant-like effects of a drug, whereas the large open field and elevated plus maze test measure locomotor activity as well as anxiety-like behavior in rats. Researchers observed that marijuana smoke exposure induced a brief increase in locomotor activity followed by a prolonged decrease in anxiety-like behaviors.

In another study, Cutler et al. investigated the effects of marijuana on social behavior of mice[9]. At 12-14 weeks, subjects were transferred from stock boxes (each containing 25-30 males) to observation boxes where they were caged in pairs. After 4-7 days, one animal of each pair was injected with marijuana suspension and was placed in an unfamiliar cage to assess anxiety-like behavior and social behavior. Researchers observed that mice treated with marijuana suspension displayed less non-social activity.

The antidepressant action of marijuana has been investigated by El-Alfy et al. using the automated mouse forced swim test (FST) and tail suspension test (TST)[7]. FST involves placing a rat or mouse inside a