Psilocybin in Alcohol Use Disorder With Comorbid Depression

Inclusion Criteria: * Patient with a confirmed DSM-5 diagnosis of severe alcohol use disorder. * BDI II (Beck Depression Inventory) score ≥ 14. * Last alcohol consumption must have occurred between 60 and 14 days prior to study inclusion. The patient must have had at least one heavy drinking day during the last period of alcohol consumption. NB: The last period of alcohol consumption prior to inclusion is defined as the last 4 weeks counted from the last drink. * Patient with free and informed consent. * The patient must be a member or beneficiary of a health insurance plan Exclusion Criteria: * The subject is participating in an interventional study involving a drug or in a clinical trial according to the REC. * The subject is in a period of exclusion determined by a previous study * The subject unable to express consent * It is impossible to give the subject informed information * The patient is under safeguard of justice or state guardianship * Schizophrenic disorder, or any history of psychotic disorder according to the clinician's judgment. * Past or current manic or hypomanic episode. * Need for antipsychotic treatment that may interfere with psilocybin. * Need for treatment with monoamine oxidase inhibitors (MAOIs) which may interfere with psilocybin. * Current scripted suicidal ideation (according to clinician judgment) corresponding to a "high risk" score on the Columbia-Suicide Severity Rating Scale (C-SSRS). * First-degree family member diagnosed with psychotic disorder or bipolar disorder type 1. * High risk of negative emotional or behavioral response based on the investigator's clinical judgment (e.g., signs of serious personality disorders, antisocial behavior, severe current stressors, lack of meaningful social support) * Patient with dementia or severe cognitive impairment (as judged by the clinician). * CIWA-R score ≥ 8. * Medical conditions that would prevent safe participation in the trial; for example: seizure disorders, significant impairment of liver function, coronary heart disease, history of arrhythmia, heart failure, uncontrolled hypertension (greater than 165/95 mmHg at screening), history of stroke, severe asthma, hyperthyroidism, narrow-angle glaucoma, stenotic peptic ulcer, pyloroduodenal obstruction, symptomatic enlarged prostate or bladder neck obstruction), Uncontrolled type I or type II diabetes or history of ketoacidosis, hyperglycemic coma or severe hypoglycemia with loss of conscience * History of hallucinogen use disorder, any use in the past year or \>25 lifetime uses. * Dependence on cocaine, psychostimulants, opioids or cannabis (last 12 months). * Current non-medical use of cocaine, psychostimulants or opioids (past 30 days). * Serious ECG abnormalities (e.g., signs of ischemia, myocardial infarction, QTc prolongation (QTc \> 0.45 seconds for men, QTc \> 0.47 seconds for women). * Hypersensitivity to the active ingredient or excipients * No access to email. * Insufficient understanding of French to complete the questionnaires. * Patient for whom it is impossible to provide informed information. * Pregnant or breastfeeding patient. * Patient planning a pregnancy