Watch VoirFilms. More than six years ago, Dr. Sanjay Gupta set out to investigate the science behind medical marijuana. A year later WEED, the first documentary in the award-winning series aired on CNN with an accompanying op-ed penned by Gupta: “Why I Changed my Mind on Weed.” Now, his fifth documentary WEED 5: The CBD Craze, will premiere on Sunday, September 29th at 8pm ET/PT, with Gupta returning to Colorado where he started his journey and introduced viewers for the first time to the word few could even pronounce – Cannabidiol (CBD).