Patient description: A 46-year-old Asian woman with MDD complains of persistent feelings of sadness and loss of interest in daily activities. She states that her mood is still depressed most of the days. She complains of loss of energy and feelings of worthlessness nearly every day. She is on anti-depressants for the past 6 months, but the symptoms are still present. She does not drink alcohol or smoke. She used to exercise every day for at least 30 min., but she doesn't have enough energy to do so for the past 3 weeks. She also has some digestive issues recently. She is married and has 4 children. She is menopausal. Her husband was diagnosed with colon cancer a year ago and is undergoing chemotherapy. Her past medical history is unremarkable. Her family history is negative for any psychologic problems. Her HAM-D score is 20.

Clinical trial eligibility criteria: eligible ages (years): 50.0-999.0,  Major Depressive Disorder Patients meeting one of the following may be eligible to participate in this study. 1. Patients with medication-resistant MDD who have undergone rTMS or ECT and responded to it but whose benefit has lapsed, and they need repeat a rTMS or ECT course that they cannot access 2. Patients with medication-resistant MDD who have undergone rTMS or ECT and responded to it but whose benefit has lapsed, and they need repeat a rTMS or ECT course that they cannot access 3. Patients with medication-resistant MDD who are undergoing rTMS or ECT and responding, but cannot continue to get the rTMS or ECT course due to COVID-19 pandemic-related regulations or other access concerns 4. Patients with medication-resistant MDD who are referred to rTMS or ECT and are found well qualified but cannot access rTMS or ECT due to COVID-19 pandemic-related regulations or other access concerns. The benefits of this project address a present need due to the COVID-19 pandemic, but also go beyond the present situation and address a larger, pre-existing need. Across all these potential groups of participants, prospective participants will need to have a primary psychiatrist who agrees to their participation in the study and is willing to continue to follow the patient and work collaboratively with the study team need to be assessed by their primary psychiatrist to be stable enough to be able to remain at home and participate in the present study without undue risk to their safety need to be living with an adult willing and capable to provide oversight and learn to deliver the home-based tDCS have the capability to connect with the study team for daily supervision of the intervention sessions and close safety monitoring, and be willing to commit to doing so Individuals with MDD Participants will be men and women who Are aged 50 or older Able to read, write, and communicate in English Have a caregiver who is willing and able to provide the home tDCS sessions Participants must be under the care of a treating psychiatrist who approves of the study participation and believes that TMS or ECT is indicated for his/her patient but that it would not endanger the patient to participate in the present study rather than pursue such alternative, or  for participants with MDD will be Any DSM-psychotic disorder Drug or alcohol abuse or dependence in the preceding three months Concurrent benzodiazepine medication High suicide risk (Utilizing the Beck Depression Inventory and the Hamilton Depression Scale, suicide risk will be assessed at baseline by the study psychiatrist)  History of clinically defined neurological disorder or insult; Metal in the cranium or skull defects Skin lesions on the scalp at the proposed electrode sites Pregnancy Medical devices (i.e. cardiac pacemaker, deep brain stimulator, medication infusion pump, cochlear implant, vagus nerve stimulator) Previous skull surgery with resultant skull defects