Psychedelic therapy aims to break the relapse cycle in alcoholism and depression

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Confirmed DSM-5 diagnosis of severe AUD. * Scale BDI-II ((Beck Depression Inventory) ≥14 * The last drink must have been consumed between day(D) -60 and D -10 at the inclusion visit. The patient must have had at least 1 HDD during the last drinking period NB: The last drinking period before inclusion is defined by the last 4 weeks counted from the last drink. * The patient must have given their free and informed consent and signed the consent form * The patient must be a member or beneficiary of a health insurance plan Exclusion Criteria: * The subject is participating in an interventional study, a clinical trial, or a clinical investigation or is in a period of exclusion determined by a previous study * The subject refuses to sign the consent * It is impossible to give the subject informed information * The patient is under safeguard of justice or state guardianship * Patient unable to give informed consent. * Participants planning to donate sperm within three months of psilocybin administration * Positive pregnancy test at inclusion for participants of childbearing age. * Patient who is pregnant, breastfeeding, or wishing to become pregnant during participation in the study. * Any use of classical psychedelic in the last year * Other current substance use disorder (except tobacco) * Diagnosed schizophrenic or bipolar disorder * High emotional lability (clinician-judged) * On antipsychotics treatment that may interfere with psilocybin. * Need for monoamine oxidase inhibitor (MAOI) treatment, which may interfere with psilocybin. * Severe suicidal ideation (high risk on the Columbia scale) * 1st degree family member with a diagnosed psychotic disorder * Severe cognitive impairment (clinician-judged) * CIWA-AR \> 8 * Medical conditions that would preclude safe participation in the trial, for example: seizure disorders; significant impairment of hepatic function; coronary artery disease; history of arrhythmia; Abnormal QT interval prolongation (QTc \> 470 ms for women and \>450 ms for men); heart failure; uncontrolled hypertension (greater than 165/95 mmHg at screening); history of stroke; severe asthma; hyperthyroidism; narrow-angle glaucoma; stenosing gastroduodenal ulcer; pyloroduodenal obstruction; symptomatic prostatic hypertrophy or bladder neck obstruction; uncontrolled type I or type II diabetes, or a history of ketoacidosis, hyperglycemic coma, or severe hypoglycemia with loss of consciousness.