Psilocybin with psychological support for treatment-resistant depression: an open-label feasibility study
In this open-label feasibility trial, 12 patients (six men, six women) with moderate-to-severe, unipolar, treatment-resistant major depression received two oral doses of psilocybin (10 mg and 25 mg, 7 days apart) in a supportive setting.
This study provides preliminary support for the safety and efficacy of psilocybin for treatment-resistant depression and motivates further trials, with more rigorous designs, to better examine the therapeutic potential of this approach.

http://www.thelancet.com/journals/lanpsy/article/PIIS2215-0366(16)30065-7/abstract