MRI Studies of Emotion in Depression

Inclusion Criteria: * Male or female participants, 18-70 years of age; * Participants must be free of any psychiatric condition (for the healthy volunteer group) or meet DSM-IV criteria for major depressive disorder, without psychotic features, based on the Structured Clinical Interview for DSM-IV TR Axis I Disorders (SCID); * Participants have demonstrated inadequate response to a minimum of 1 adequate antidepressant treatment trial in current episode (e.g. TRD); * Participants must be willing to undergo washout of psychotropic medications that he or she is taking; * Participants must have a level of understanding of the English language sufficient to agree to all tests and examinations required by the study and must be able to participate fully in the informed consent process. Exclusion Criteria: * Lifetime diagnosis of schizophrenia or any psychotic disorder, bipolar disorder, pervasive developmental disorders or mental retardation; * Current diagnosis of obsessive-compulsive disorder (OCD), but not other anxiety disorders; * Diagnosis of a substance use disorder within the past six months; all participants must have a negative urine toxicology test on the day of the fMRI, prior to the scan; * Female participants who are pregnant, nursing, for may become pregnant; * Any unstable medical illnesses including hepatic, renal, gastroenterologic, respiratory, cardiovascular (including ischemic heart disease); endocrinologic, neurologic (including history of severe head injury), immunologic, or hematologic disease; * Clinically significant abnormalities of laboratories, physical examination, or ECG; * Participants judged to be at serious suicidal risk by the PI or another study-affiliated psychiatrist; * Any contraindications to MRI, including pacemakers or metallic objects in the body.