Acute Effects of 2C-B Compared With MDMA and Psilocybin in Healthy Subjects

Inclusion Criteria: * Age between 25 and 65 years. * Sufficient understanding of the German language. * Understanding the procedures and the risks that are associated with the study. * Participants must be willing to adhere to the protocol and sign the consent form. * Participants must be willing to refrain from taking illicit psychoactive substances during the study. * Participants must be willing to drink only alcohol-free liquids and no coffee, black or green tea, or energy drink after midnight of the evening before the study session, as well as during the study day. * Participants must be willing not to drive a traffic vehicle or to operate machines within 48 h after substance administration. * Women of childbearing potential must have a negative pregnancy test at the beginning of the study. Pregnancy tests are repeated before each study session. * Women of childbearing potential must be willing to use double-barrier birth control. * Body mass index between 18-29kg/m2 Exclusion Criteria: * Chronic or acute medical condition, including a history of seizures. * Current or previous major psychiatric disorder (e.g. psychotic disorders, mania / hypomania, anxiety disorders). * Psychotic or bipolar disorder in first-degree relatives, not including psychotic disorders secondary to an apparent medical reason, e.g. brain injury, dementia, or lesions of the brain. * Hypertension (SBP\>140/90 mmHg) or hypotension (SBP\<85 mmHg) * Ilicit substance use (with the exception of cannabis) more than 20 times or any time within the previous two months * Pregnant or nursing women. * Participation in another clinical trial (currently or within the last 30 days). * Use of medications that may interfere with the effects of the study medications (any psychiatric medications and any medication with known to interact with the study substances). * Tobacco smoking (\>10 cigarettes/day). * Consumption of alcoholic drinks (\>20 drinks / week). * Body weigt \< 45 kg.