Participate in Research at CU Anschutz

21 to 75 years

Inclusion: Age 21 years or older Diagnosis of Major Depressive Disorder, moderate to severe Currently under the care of a psychiatric practitioner who practices within the Department of Psychiatry at the University of Colorado English speaking Right-handed Age 21 years or older Diagnosis of Major Depressive Disorder (MDD), moderate to severe MDD meets criteria for being treatment-resistant Currently under the care of a psychiatric practitioner who practices within the Department of Psychiatry at the University of Colorado English speaking Right-handed Women of childbearing potential must agree to practice an effective means of birth control throughout the study Have an identified support person and agree to be accompanied home by the support person following dosing Ability to abstain from caffeine and nicotine for 2 hours prior to MRI scan visits Exclusion: Unstable medical conditions or serious lab abnormalities History of significant central nervous system pathology Family history of first degree relative with psychotic or serious bipolar spectrum illnesses Active substance use disorder Extensive use of hallucinogens History of hallucinogen persisting perception disorder History of severe suicide attempt in the past year Use of medications or supplements that may interfere with study procedures or study drug Failed drug screen Claustrophobia Weight over 300lbs Lack of internet access Metal in body unsafe for MRI History of valvular heart disease