Safety and Efficacy of Psilocybin-assisted Psychotherapy for Demoralization Syndrome in Patients Diagnosed With Advanced Stage Cancer

Inclusion Criteria: * Patients diagnosed with advanced stage cancer (stages 3 and 4) * Aged between 18 and 70 years. * Moderate-to-severe demoralization as measured by Demoralization Scale≥ 30 * English proficiency * Ability to understand and the willingness to sign a written informed consent document. * Individuals of child-bearing potential who are sexually active must agree to use an acceptable contraceptive method (hormonal or barrier method of birth control; abstinence) throughout their participation in the study. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately. Men treated or enrolled in this protocol must also agree to use adequate contraception prior to the study, for the duration of study participation, and 4 months after completion of psilocybin administration. Exclusion Criteria: * Condition impairing oral intake or digestive absorption. * Primary brain tumor. * Presence of delirium. * Significant suicide risk as defined by suicidal ideation with intent and a plan. * Current or past history of schizophrenia, psychotic disorder, bipolar disorder, delusional disorder, paranoid personality disorder, schizoaffective disorder, or borderline personality disorder, as assessed by medical history. * Patients with first-degree relatives with schizophrenia or bipolar disorder * Previous diagnosis of epilepsy, stroke or Transient Ischemic Attack (TIA), dementia, and Parkinson's disease. * History of allergic reactions attributed to compounds of similar chemical or biologic composition to psilocybin. * Other personal circumstances and behavior that would limit compliance with study requirements or that are judged by the study psychiatrist and/or principal investigator to be incompatible with establishing rapport or safe exposure to psilocybin. * Potential for adverse drug-drug interactions. Concomitant medications with significant potential to interact with study medications will be exclusionary if they cannot be tapered. These include the following: * MAO inhibitors * Patients currently on antipsychotics (e.g. first and second generation) when taken regularly (6 weeks or less prior to screening visit) * Mood stabilizers (e.g. lithium, valproic acid, lamotrigine) * Aldehyde dehydrogenase inhibitors (e.g. disulfiram) * Significant inhibitors of UGT 1A0 or UGT 1A10 * Patients who have elevated AST and ALT five times above the normal laboratory limit on their last available bloodwork performed at screening and patients with symptoms suggestive of liver failure including confusion, asterixis or jaundice. * Any other clinically significant cardiovascular, pulmonary, gastrointestinal, hepatic, renal condition or any other unstable condition that, in the opinion of the principal investigator, may interfere with the interpretation of the study results or constitute a health risk for the participant if he/she takes part in the study. This may include but is not limited to clinical symptoms or recent history of significant tachyarrhythmias; severe angina or myocardial ischemia; poorly controlled congestive heart failure; poorly controlled hypertension; poorly controlled hypo- or hyperthyroidism; uncontrolled diabetes; severe renal or liver dysfunction; acute respiratory failure; sepsis; history of cerebral aneurysms; glaucoma; increased intracranial pressure and any intracranial mass. * Women who are pregnant, nursing, or planning a pregnancy. * Use of a classic psychedelic or MDMA in the last 12 months