Deveras me Atrapaste (1983)

Teen angst in Mexico City is made all the worse by a young provincial woman's infatuation for a ghost, in this effective drama about disturbed youth. Aida arrives in Mexico City and is immediately introduced into the world of drugs and sex by the friends she meets. Before long, she is having visions of the ghostly "El Humo" ("Smoke") and after she meets him at a party, they both are struck by Cupid's arrow. After some back-and-forth stepping around the nature of their relationship, El Humo disappears for five days, and Aida is distraught -- she locks herself up in her dark room, smokes some weed, takes a few hallucinogenic mushrooms, and then has a vision that clears up the mystery surrounding El Humo.