Causal Role of Delta-beta Coupling for Goal-directed Behavior in Anhedonic Depression

Prior treatment

• Prior brain surgery

Other illness

• Neurological disorders and conditions including, but not limited to history of epilepsy; seizures, except childhood febrile seizures; dementia; history of stroke; Parkinson's disease, multiple sclerosis, cerebral aneurysm; brain tumors
• Medical or neurological illness or treatment for a medical disorder that could interfere with study participation. For example, unstable cardiac disease, HIV/AIDS, malignancy, liver or renal impairment
• Any brain devices/implants including cochlear implants and aneurysm clips, cardiac pacemaker, or any other implanted electronic device
• History of current traumatic brain injury
• Current severe substance use disorder
• DSM-V diagnosis of present moderate or severe substance use disorder or alcohol use disorder, and past severe substance use disorder or alcohol use disorder, or psychotic disorder within the last 12 months

Other

• ADHD (currently under treatment)
• Pregnancy (for females)
• Claustrophobia
• Based on the use of MRI, additional exclusion/inclusion criteria are considered. Note that many contraindications for stimulation are common with MRI and thus are not repeated. Participants must not have metal in the body that is ferrous, will be required to remove all jewelry, must not have tattoos on the face or neck, must refrain from wearing metal in clothing (underwire) or active gear (possibility of metallic microparticle technology), must not be a metal worker or have an eye injury involving metal.
• Anything that in the opinion of the investigator would place the participant at increased risk or preclude the participant's full compliance with or completion of the study

• Between the ages of 18 and 65
• Able to provide informed consent
• Have normal to corrected vision
• Willing to comply with all study procedures and be available for the duration of the study
• Speak and understand English
• Mild suicide risk as determined by the Hamilton Depression Rating Scale (HAM-D; less than 3 for the suicidality item) and non-existent or mild risk according to the Depression Symptom Index Suicidality Subscale (DSI-SS).
• Patient Health Questionnaire (PHQ-8) greater than or equal to 8 prior to the first session
• Snaith Hamilton Pleasure Scale (SHAPS) greater than 33 at the first session
• A diagnosis of major depressive disorder on the Mini International Neuropsychiatric Interview for the DSM-V (MINI)