Neurofeedback for Major Depressive Disorder

Inclusion Criteria: * Meets The Diagnostic and Statistical Manual of Mental Disorders five (DSM5) criteria for Major Depressive Disorder, single or recurrent, active or in partial remission * Patient Health Questionnaire (PHQ9) greater or equal (≥)6, and approximately (\~) 50% with PHQ9≥10 * If participants are taking antidepressant medications, on stable dosage for 4 weeks * No history of active substance use disorder in the past 6 months * Absence of suicidal thoughts with plans or intentions, as assessed by Columbia Suicide Severity Rating Scale (C-SSRS) * If a woman of child-bearing age, not pregnant or trying to become pregnant * Ability to tolerate small, enclosed spaces without anxiety * No metals, implants or metallic substances within or on the body that might cause adverse effects to the subject in a strong magnetic field, or interfere with image acquisition, e. g. aneurysm clips, retained particles (for example metal workers with exposures, protocol has more details), etc. * Size compatible with scanner gantry (per protocol) * Ability and willingness to give informed consent to participate. Exclusion Criteria: * Size not compatible with scanner * Not meeting diagnostic criteria for bipolar disorder, schizophrenia, other psychosis, obsessive-compulsive disorder, active eating disorder or Post-traumatic stress disorder (PTSD) * No history of serious neurological illness (including, but not limited to, seizures/epilepsy) or current medical condition that could compromise brain function, such as liver failure * No history of closed head injury, e. g. loss of consciousness \> \~5 min, hospitalization, neurological sequela