Why is cannabis still such a contentious issue? The God Plant takes a deep dive into its history, medical benefits, and modern legal challenges.

'Stoner' stereotypes abound in modern Western culture. But the stigmatizing laws and cultural views that lead to these stereotypes are a relatively new phenomenon, by historical standards.

The cannabis plant has been cultivated as a crop for thousands of years, and used as medicine in civilizations around the world.

All of that changed in the 20th century, however, when governments criminalized its use.

Here, filmmaker John K. Webster breaks through the negative connotations, interviewing the grandmothers who've overcome cancer, the patients alleviating Parkinson's, and the mothers who've successfully treated their children's severe epilepsy using cannabis.