Precision Functional Brain Mapping in Psilocybin

Inclusion Criteria: 1. men and woman between 18 and 40 years of age; 2. Have used a psychedelic substance within the previous 5 years but not within the last 6 months 3. No active psychiatric conditions requiring treatment with psychotropic medications (may be included if psychiatric condition is stable and participant is willing to discontinue medication for 1 month prior to participation with permission from their treating provider); 4. Able to provide informed consent. Exclusion Criteria: 1. Presence of medical conditions that may confound results of imaging study or that are contraindications to psilocybin exposure (e.g. neurological, renal, hypertension, metabolic or cardiovascular disease or pregnancy); 2. No prior exposure to classic psychedelics (psilocybin, LSD, ayahuasca, mescaline); 3. Presence of psychiatric conditions that may confound interpretation of results or that are contraindications to psilocybin exposure (e.g. major mood disorder, current substance use disorder, personal or immediate family history (parents, siblings) of any schizophrenia spectrum disorders); 4. Use of psychotropic medication during the study; 5. Presence of contraindications to MRI scanning (implantable devices, bone hardware, IUD). 6. Prior adverse reactions to psychedelics, based on the Challenging Experiences Questionnaire administered during initial screening