Research Commentary by Dr Peter Gates

One of the common misconceptions surrounding the use and study of cannabis is the expectation that one plant will be similar to the next. In fact, the effects from smoking cannabis can differ significantly between plants and also can depend on what part of the cannabis plant is used and how it is prepared. This is because different plants and different parts of the same plant will have different concentrations of "cannabinoids". These are the naturally occurring constituents of the cannabis plant and around 100 different varieties have been identified. The most commonly referred to cannabinoid is delta-9-tetrahydrocannabinol, or THC. This is because THC is the most noticeably psychoactive cannabinoid. Interestingly another commonly referred to cannabinoid, cannabidiol, or CBD, has been shown to offset the impact of THC due to its anti-psychotic properties. Thus, the effects from smoking cannabis, or its potency, are determined by a complex interaction of cannabinoids.