Psilocybin mushrooms (aka magic mushrooms, or shrooms) is the name given to fungi that contain psilocybin, a naturally occurring psychedelic compound. Magic mushrooms are used mainly as an entheogen and recreational drug whose effects can include euphoria, altered thinking processes, open and closed-eye visuals, synesthesia, an altered sense of time and spiritual experiences and have been used in therapeutic settings to treat a wide variety of ailments and disorders including cluster headaches, obsessive-compulsive disorders, anxiety, depression, and addiction. Over 100 species are classified in the genus Psilocybe. Biological genera containing psilocybin mushrooms include Copelandia, Galerina, Gymnopilus, Inocybe, Mycena, Panaeolus, Pholiotina, Pluteus, and Psilocybe. Psilocybin mushrooms have likely been used since prehistoric times and may have been depicted in rock art and pre-Columbian historical materials in Mesoamerica. Many cultures have used these mushrooms in religious rites. In modern societies, they are used for spiritual reasons, and recreationally for their mood lifting and psychedelic effects.