Psilocybin for Hospitalized Patients with Treatment-resistant Depression

This study is testing whether psilocybin (an active compound found in certain mushrooms) can help treat severe, treatment-resistant depression in people who are currently hospitalized and have not responded to multiple antidepressant medications. **You may be eligible if...** - You are 18 or older - You have a diagnosis of moderate-to-severe major depressive disorder (without psychotic features), confirmed using DSM-5 criteria - You have tried at least 2 antidepressants at adequate doses for at least 6 weeks each, without improvement - You are not currently using alcohol (verified by breathalyzer) and provide a negative drug screen on the dosing day - You are not pregnant (verified by test on dosing day) **You may NOT be eligible if...** - You have psychotic features with your depression - You have a personal or family history of psychosis or schizophrenia - You are unable to abstain from alcohol before your dosing session - You have medical conditions that make psilocybin unsafe Talk to your doctor to see if this trial is right for you.