Effects of Psilocybin in Advanced-Stage Cancer Patients With Anxiety

Inclusion Criteria: * Have advanced-stage cancer and anxiety. * Be between the ages of 18 - 70. Note: The location for the two treatment sessions is Los Angeles, California. Treatment sessions are scheduled three to six weeks apart, and they include one overnight hospital stay both times. Exclusion Criteria: * Not have cancer that affects the central nervous system or brain function. * Have no history of major psychiatric disorder. * Have no kidney disease, abnormal liver functions, epilepsy, or cardiovascular disease, including untreated hypertension. * Not be taking insulin, oral hypoglycemic, anti-seizure, or cardiovascular medications (except anti-hypertensive drugs). * May take PRN benzodiazepines up to 3 days before the session. * No Prozac for the previous 5 weeks. * No medications the day of and the day after treatment sessions, except may take ongoing adjuvant chemotherapy as prescribed, prescribed or over-the-counter non-narcotic pain medication at any time, and narcotic pain medications up to eight hours before administration of psilocybin and six hours after administration. * No alcohol consumption the day before, the day of, and the day after a session. * Female subjects of childbearing potential must have a negative pregnancy test and agree to use an effective form of birth control.