Montana PBS's new documentary, Clearing the Smoke, reveals how cannabis acts on the brain and in the body to treat nausea, pain, epilepsy and potentially even cancer.

Extensive interviews with patients, doctors, researchers and skeptics detail the promises and the limitations of medicinal cannabis. Even though the video has an American perspective, marijuana use is illegal throughout many countries of the world for reasons that are not clear.

This video is important because it mainly investigates the scientific basis underlying the medical benefits of marijuana use instead of focusing on the social, political and legal hysteria that have been attached to it.