This is the drug scare film Stoned, starring Scott Baio, reproduced in its entirety. Baio's character is a friendless high school nerd who can't get girls. Upon his discovered of the devil's weed however, he attains charisma and class clownhood, as well as a neon wardrobe and 80's skateboard. Of course, his life slowly begins to unravel, until eventually...well, you'll just have to watch. This film has been left behind in the dustbin of film history, and exists mostly via bootlegs and as a truncated set of 9 parts here on youtube...well, just watch this whole one in one go. Without the film being here, it would have no life. There is no demand for anti-drug schoolroom propaganda such as this anymore. But none the less:

Stoned, copyright 1980 Highgate Pictures, a division of Learning Corporation of America.  producer, Boyce Harman ; written & directed by John Herzfeld.