The purpose of this study is to investigate the effects of oral psilocybin in post-traumatic
headache. Subjects will be randomized to receive placebo, low dose psilocybin, or high dose
psilocybin on two separate test days approximately 14 days apart. Subjects will maintain a
headache diary prior to, during, and after the treatments in order to document headache
frequency and intensity, as well as associated symptoms. Blood samples will be drawn at
various timepoints to measure levels of inflammatory peptides.