Inclusion Criteria:  Major Depressive Disorder Age >=18 Currently experiencing a major depressive episode of at least four weeks' duration MADRS score at least 20 at trial entry. Taking at least one approved antidepressant medication (except bupropion). Has a healthcare provider, and a companion who can help administer study treatments; and be able to connect frequently with study staff Access to wireless internet (wifi) connection  Exclusion Criteria:  Any psychotic disorder. Concurrent benzodiazepine medication. High suicide risk History of significant neurological disorder. Skin lesions on the scalp at the proposed electrode sites. Pregnancy. Any antidepressant medications will be permitted (except bupropion) provided the medication dose has been unchanged for 4 weeks prior to trial entry. Any cranial metal implants (excluding ≤1 mm thick epicranial titanium skull plates and dental fillings) or Medical devices (i.e. cardiac pacemaker, deep brain stimulator, medication infusion pump, cochlear implant, vagus nerve stimulator); Previous surgeries opening the skull leaving skull defects capable of allowing the insertion of a cylinder with a radius greater or equal to 5 mm. Substance use disorder (including alcohol) within the past year.