Psilocybin to Treat Depression in Spinal Cord Injury

The main goal of this study is to determine if psilocybin is safe for use in people with SCI. The study will measure how people with SCI respond to three psilocybin doses: low (5mg), medium (10mg), and high (25mg). The main question the study aims to answer is: does psilocybin increase the number and severity of adverse (bad) events reported by people with SCI? These may include pain, muscle spasms, symptoms of depression, and symptoms of low or high blood pressure. The investigators will also measure how well people with SCI tolerate the psychedelic experience, and compare responses between the low (5mg), medium (10mg), and high (25mg) doses. Participants will: * Agree to be enrolled in the study for up to 13 months. * Agree to complete the seven (7) visits that are included in the psilocybin-assisted therapy. * Agree to complete follow-up study visits, including in-person visits to the James J Peters VA Medical Center, located in the Bronx, New York and remote visits. * Agree to keep a log of how they are feeling and any change in the frequency or severity of adverse events.