Psilocybin ( [3-(2-DIMETHYLAMINOETHYL)-1H-INDOL-4-YL] DIHYDROGEN PHOSPHATE) is better known as magic mushrooms or shrooms. It is a naturally occurring psychedelic compound found in over 180 species of mushrooms. The effect of psilocybin is due to its effects on serotonin receptors in the brain. 

Psilocybin mushrooms can be consumed in various forms, from eating the mushrooms themselves to drinking mushroom tea or consuming mushroom chocolate. Users report a sense of openness, strong emotions, and visual hallucinations. The openness to thoughts that may generally be avoided has been useful in the psychotherapeutic treatment of various conditions including anxiety, depression, and addiction.