Psilocybin-Assisted Psychotherapy for the Treatment of Severe Alcohol Use Disorder

To be eligible, individuals must be: * English speaking adults between ages 18 and 65 * Diagnosis of DSM5 AUD, severe * Completion of inpatient withdrawal management (i.e. "detox") for AUD within 90 days of enrollment * Amenable to attending all psychotherapy and study visits at BWH CCI * Able to identify an individual who can act as points of contact during the trial * Have a friend or family member who can bring the participant home after the psilocybin sessions and stay overnight Individuals with any of the following will be excluded: * Any personal history of a psychotic disorder (schizophrenia, schizoaffective disorder, brief psychotic disorder, delusional disorder, schizophreniform disorder, substance-induced psychotic disorder or major depression with psychotic features) or any bipolar-spectrum disorder * Participants with a family history of first-degree relatives with psychotic disorder or bipolar-spectrum disorder * Participants who have a significant suicide risk as defined by current suicidal ideation (Columbia-Suicide Severity Rating Scale (C-SSRS) score 2 to 5) and/or recent (within the past 6 months) active suicidal ideation (C-SSRS score 4 or 5) * Participants who have a history of significant or serious adverse reaction to classic psychedelics * Homicidality within the last six months * History of DSM5 hallucinogen use disorder * Positive blood alcohol level at screening * Need for inpatient withdrawal management for alcohol at the time of screening * Curr…