Clinical Research Directory

Inclusion Criteria: * Diagnosed with Major Depressive Disorder (MDD), single or recurrent episode, and currently experiencing a Major Depressive Episode (MDE) * Failed to achieve a satisfactory clinical response to at least one adequate antidepressant trial during the current depressive episode * Currently engaged in treatment with a mental health clinician Exclusion Criteria: * Axis I psychotic disorder (e.g. schizophrenia, bipolar I, depression with psychosis) * Axis I psychotic disorder in first degree relative * Currently taking a conventional antidepressant medication * Unstable medical or neurological conditions * Significant cognitive disorders * History of intolerance to drugs known to significantly alter perception e.g., psilocybin, LSD, salvinorin A, mescaline, etc. * Pregnant, breastfeeding, lack of adequate birth control * Urine toxicology positive to drugs of abuse on experimental test days