Yes, Reefer Madness was a flick made way back in the 1930s more or less, which is so utterly glob-handed and over the top in its “treatment” of the subject that it became a smash hit in theaters as a parody during the weed-reeking 1970s (trust me, I was there… at least, I think I remember being there…)
“That 70s Show” did a fairly good send up of “Reefer Madness” in one episode; in fact I think they made the two-minute imaginary sequence in black-and-white … it shows the kids as hopeless dope fiends and gangsters. They got the tone, just the right balance of hilariously stilted language and stupidly exaggerated actions – all to assure, as in the original, that every last innocent moron in the audience would get the point.