Low-dose psilocybin in short-lasting unilateral neuralgiform headache attacks: results from an open-label phase Ib ascending dose study.

The study met with recruitment difficulties and cognition could not be assessed during the acute experience due to subjective dose intensity, likely mediated in part by expectancy effects. The clinical results provide no conclusive evidence for the use of psilocybin in SUNHA. We suggest that accounting for psychological factors in chronic SUNHA may be an important facet of treatment.