A small study of 12 patients with treatment-resistant depression, which in some cases does not pass for a decade, showed that each participant experienced a reduction in symptoms within a week after receiving psilocybin strictly controlled. 8 out of 12 (67%) patients achieved a complete remission after a week of treatment and have been temporarily released from depression. 3 months after the use of psilocybin 7 patients continued to show improvement, and 5 people have completely got rid of depression. It is noted that in the course of treatment was used a high dose of psilocybin, equivalent to eat more "hallucinogenic" mushrooms.

Nevertheless, in the treatment of several observed adverse side effects. Thus, some patients have reported confusion, nausea and headaches, while 2 members affected by short-term episodes of mild paranoia.