MRI-Guided High-Definition Transcranial Direct Current Stimulation (tDCS) for Depression

Prior treatment

• 4\. Change in antidepressant medication within 6 weeks of study start
• 6\. MRI contraindications: metal or other implants that are not MR-safe, claustrophobia, pregnancy or suspected pregnancy
• 7\. tES contraindications: skin conditions or injuries on the scalp hair extensions, wigs, braids, etc. that cannot be removed prior to the study, metal implants or pacemakers (also contraindicated for MRI)
• 10\. Current medication use potentially affecting brain function, including decongestants, antihistamines, benzodiazepines or other anticonvulsants, anti-psychotics.

Other illness

• 5\. Diagnosis of any medical condition potentially affecting brain function: neuropsychiatric or mental disorders, other mood disorders (bipolar disorder, primary anxiety disorder, PTSD), psychotic states or disorders, developmental disorders, neurological disorders, including mild cognitive impairment, significant head injury, significant history of alcohol/substance abuse or dependence within past 12 months, chronic pain (current, or for more than one year within the past one year), other major medical conditions (e.g., cancer, stroke).

Age

• 1\. Ages below 18 (neurobiology is quite different in children vs. adults)
• 2\. Ages above 65 (cortical excitability changes with age)

Other

• 3\. Active suicidal thoughts, ideation, or behavior with plan within the past month (HDRS-17 item 3 score 3-4)
• 8\. Non-English speakers (due to written consent and questionnaires administered)
• 9\. Neurostimulation or neuromodulation treatment for any reason within the past 3 months
• 11\. Prisoners will not participate in this study.

• 1\. Ages between 18 and 65
• 2\. Race/ethnicity: all races and ethnic groups
• 3\. Sex/Gender: all
• 4\. Capacity to provide informed consent
• 5\. Diagnosis of Major Depressive Disorder made by volunteer's physician at least one year prior (confirmed by patient self-report)
• 6\. Currently under the care of a clinician for depression (psychiatrist, psychologist, or other clinician)
• 7\. Currently experiencing symptoms of depression (Patient Health Questionnaire 9, PHQ9 \>4 at screening; Hamilton Depression Rating Scale 17-item, HDRS-17, score \>8 at Visit 1)
• 8\. Stable or no pharmacological antidepressant regimen (SSRI, SNRI, MOAI, or tricyclic/TCA) with no change in treatment 6 weeks prior to study start