Psilocybin mushrooms had been used for spiritual, religious or divinatory purpose for thousands of years. It is constantly found in the earliest human drawings and arts dated 9000 B.C., and its usage in mankind could be earlier than that.
There are about two hundred kinds of psilocybin mushrooms worldwide, from america and Africa to Europe and Asia, with different concentrations of psilocybin in each type of mushroom. In modern days, psilocybin has been used for different psychiatric and psychological purposes. As a hallucinogen, psilocybin containing mushrooms are tightly regulated in many countries. Legally it is illicit drug without proven safety.
In the clinical studies approved by the FDA, psilocybin has been shown to have therapeutic efficacy for personality disorders and obsessive compressive disorders. The recent breakthrough in this drug is the effective treatment for the treatment-resistant-depression. Psilocybin and other psychedelic supplements have been shown to positively affect the mental health by mechanisms that modern science understands only at the very superficial level, which is the 5-HT receptor, as shown in this recent article.
Human brain is such a profound world to know for mankind itself. Our knowledge of depressive mechanism is limited, so there are the treatment-resistant-depression. While modern science offers chemical, electroconvulsive, repetitive magnetic or surgical treatments but in cases only proven to have limited efficacy, this ancient witchy mushroom may offer some reasonable solution.